1
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Franzese C, Fogliata A, Loi M, Badalamenti M, Franceschini D, Comito T, Cozzi L, Reggiori G, Tomatis S, Scorsetti M. Dosimetric impact of volumetric modulated arc therapy for nasopharyngeal cancer treatment. ACTA ACUST UNITED AC 2021; 26:101-110. [PMID: 34046220 DOI: 10.5603/rpor.a2021.0017] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 12/21/2020] [Indexed: 11/25/2022]
Abstract
Background The purpose of the study was to evaluate the toxicity and outcome of nasopharyngeal carcinoma patients treated using 3-dimensional conformal radiotherapy (3DCRT) or volumetric modulated arc therapy (VMAT) technique. Materials and methods 68 patients treated between 2006 and 2018 were retrospectively analysed. Since 2009 patients received 3DCRT with 50/70 Gy to the elective/boost volumes in 35 fractions; from then, VMAT with simultaneous integrated boost (SIB) with 54.45/69.96 Gy in 33, or 54/66 Gy in 30 fractions. Induction chemotherapy was administered in 74% of the patients, concomitant cisplatinum in 87%. Acute and late toxicity data, progression-free survival PSF and overall survival OS, and toxicity correlations with dose metrics were reported. Results With a median follow-up of 64 months, complete remission at the last evaluation was in 68% of the patients, while 28% and 9% had locoregional relapse and distant disease, respectively. The 5- and 10-year progression free survival (PFS) rates were 62.7 ± 6.5% and 53.2 ± 8.7%, respectively. The 5- and 10-year OS rates were 78.9 ± 5.5% and 61.4 ± 9.2%, respectively. At the multivariate Cox analysis TNM stage (p = 0.02) and concomitant chemotherapy (p = 0.01) resulted significant for PFS, concomitant chemotherapy (p = 0.04) for OS.Improvements in acute toxicity were presented for VMAT patients due to its ability to spare OARs. Odds ratio (OR) for acute salivary toxicity, between VMAT and 3DCRT, was 4.67 (p = 0.02). Dosimetrically, salivary toxicity correlated with mean parotid dose (p = 0.05), dysphagia with laryngeal (p = 0.04) and mean oral cavity (p = 0.06) doses, when dose-volume histograms (DVHs) are corrected for fractionation. Conclusion This study is a proof of a significant benefit of the VMAT technique compared with 3DCRT in terms of side effects in nasopharynx patients, and adds dosimetric correlations.
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Affiliation(s)
- Ciro Franzese
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy.,Humanitas University, Biomedical Science Dept, Milan-Rozzano, Italy
| | - Antonella Fogliata
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Mauro Loi
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Marco Badalamenti
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Davide Franceschini
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Tiziana Comito
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Luca Cozzi
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy.,Humanitas University, Biomedical Science Dept, Milan-Rozzano, Italy
| | - Giacomo Reggiori
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Stefano Tomatis
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy
| | - Marta Scorsetti
- Humanitas Clinical and Research Hospital IRCCS, Radiotherapy Dept, Milan-Rozzano, Italy.,Humanitas University, Biomedical Science Dept, Milan-Rozzano, Italy
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2
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Chevalier F, Hamdi DH, Lepleux C, Temelie M, Nicol A, Austry JB, Lesueur P, Vares G, Savu D, Nakajima T, Saintigny Y. High LET Radiation Overcomes In Vitro Resistance to X-Rays of Chondrosarcoma Cell Lines. Technol Cancer Res Treat 2020; 18:1533033819871309. [PMID: 31495269 PMCID: PMC6732854 DOI: 10.1177/1533033819871309] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Chondrosarcomas are malignant tumors of the cartilage that are chemoresistant and
radioresistant to X-rays. This restricts the treatment options essential to surgery. In
this study, we investigated the sensitivity of chondrosarcoma to X-rays and C-ions
in vitro. The sensitivity of 4 chondrosarcoma cell lines (SW1353,
CH2879, OUMS27, and L835) was determined by clonogenic survival assays and cell cycle
progression. In addition, biomarkers of DNA damage responses were analyzed in the SW1353
cell line. Chondrosarcoma cells showed a heterogeneous sensitivity toward irradiation.
Chondrosarcoma cell lines were more sensitive to C-ions exposure compared to X-rays. Using
D10 values, the relative biological effectiveness of C-ions was higher (relative
biological effectiveness = 5.5) with cells resistant to X-rays (CH2879) and lower
(relative biological effectiveness = 3.7) with sensitive cells (L835). C-ions induced more
G2 phase blockage and micronuclei in SW1353 cells as compared to X-rays with the same
doses. Persistent unrepaired DNA damage was also higher following C-ions irradiation.
These results indicate that chondrosarcoma cell lines displayed a heterogeneous response
to conventional radiation treatment; however, treatment with C-ions irradiation was more
efficient in killing chondrosarcoma cells, compared to X-rays.
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Affiliation(s)
- Francois Chevalier
- 1 CEA GANIL, Caen, France.,2 Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
| | - Dounia Houria Hamdi
- 1 CEA GANIL, Caen, France.,2 Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
| | - Charlotte Lepleux
- 1 CEA GANIL, Caen, France.,2 Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
| | - Mihaela Temelie
- 1 CEA GANIL, Caen, France.,2 Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania.,3 Centre Paul Strauss, Strasbourg, Alsace, France
| | - Anaïs Nicol
- 3 Centre Paul Strauss, Strasbourg, Alsace, France
| | | | - Paul Lesueur
- 4 Centre Francois Baclesse Centre de Lutte Contre le Cancer, Caen, France
| | - Guillaume Vares
- 5 Okinawa Institute of Science and Technology, Kunigami-gun, Okinawa, Japan
| | - Diana Savu
- 2 Horia Hulubei National Institute of Physics and Nuclear Engineering, Bucharest, Romania
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3
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Panda S, Swamidas J, Chopra S, Mangaj A, Fogliata A, Kupelian P, Agarwal JP, Cozzi L. Treatment planning comparison of volumetric modulated arc therapy employing a dual-layer stacked multi-leaf collimator and helical tomotherapy for cervix uteri. Radiat Oncol 2020; 15:22. [PMID: 32000832 PMCID: PMC6990476 DOI: 10.1186/s13014-020-1473-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 01/19/2020] [Indexed: 12/26/2022] Open
Abstract
Purpose To ascertain the dosimetric performance of a new delivery system (the Halcyon system, H) equipped with dual-layer stacked multi-leaf collimator (MLC) for risk-adapted targets in cervix uteri cancer patients compared to another ring-based system in clinical operation (Helical Tomotherapy, HT). Methods Twenty patients were retrospectively included in a treatment planning study (10 with positive lymph nodes and 10 without). The dose prescription (45Gy to the primary tumour volume and a simultaneously integrated boost up to 55Gy for the positive patients) and the clinical planning objectives were defined consistently as recommended by an ongoing multicentric clinical trial. Halcyon plans were optimised for the volumetric modulated arc therapy. The plan comparison was performed employing the quantitative analysis of the dose-volume histograms. Results The coverage of the primary and nodal target volumes was comparable for both techniques and both subsets of patients. The primary planning target volume (PTV) receiving at least 95% of the prescription isodose ranged from 97.2 ± 1.1% (node-negative) to 99.1 ± 1.2% (node-positive) for H and from 96.5 ± 1.9% (node-negative) to 98.3 ± 0.9% (node-positive) for HT. The uncertainty is expressed at one standard deviation from the cohort of patient per each group. For the nodal clinical target volumes, the dose received by 98% of the planning target volume ranged 55.5 ± 0.1 to 56.0 ± 0.8Gy for H and HT, respectively. The only significant and potentially relevant differences were observed for the bowels. In this case, V40Gy resulted 226.3 ± 35.9 and 186.9 ± 115.9 cm3 for the node-positive and node-negative patients respectively for Halcyon. The corresponding findings for HT were: 258.9 ± 60.5 and 224.9 ± 102.2 cm3. On the contrary, V15Gy resulted 1279.7 ± 296.5 and 1557.2 ± 359.9 cm3 for HT and H respectively for node-positive and 1010.8 ± 320.9 versus 1203.8 ± 332.8 cm3 for node-negative. Conclusion This retrospective treatment planning study, based on the dose constraints derived from the Embrace II study protocol, suggested the essential equivalence between Halcyon based and Helical Tomotherapy based plans for the intensity-modulated rotational treatment of cervix uteri cancer. Different levels of sparing were observed for the bowels with H better protecting in the high-dose region and HT in the mid-low dose regions. The clinical impact of these differences should be further addressed.
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Affiliation(s)
- S Panda
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Tata Memorial Centre, Homi Bhabha National Institute, Kharghar, Navi Mumbai, Maharashtra, India
| | - J Swamidas
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Tata Memorial Centre, Homi Bhabha National Institute, Kharghar, Navi Mumbai, Maharashtra, India
| | - S Chopra
- Department of Radiation Oncology, Advanced Centre for Treatment Research and Education in Cancer, Tata Memorial Centre, Homi Bhabha National Institute, Kharghar, Navi Mumbai, Maharashtra, India
| | - A Mangaj
- Department of Radiation Oncology and Medical Physics, Tata Memorial Hospital, Tata Memorial Centre, Homi Bhabha National Institute, Parel, Mumbai, Maharashtra, India
| | - A Fogliata
- Humanitas Research Hospital, Radiotherapy and Cancer Center Radiosurgery Dept, Via Manzoni 56, 20089, Milan-Rozzano, Italy
| | - P Kupelian
- Varian Medical Systems, Palo Alto, CA, USA.,Radiation Oncology Dept., University of California, Los Angeles, USA
| | - J P Agarwal
- Department of Radiation Oncology and Medical Physics, Tata Memorial Hospital, Tata Memorial Centre, Homi Bhabha National Institute, Parel, Mumbai, Maharashtra, India
| | - L Cozzi
- Humanitas Research Hospital, Radiotherapy and Cancer Center Radiosurgery Dept, Via Manzoni 56, 20089, Milan-Rozzano, Italy. .,Dept. of Biomedical Sciences, Humanitas University, Milan-Rozzano, Italy.
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4
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Feasibility of real-time motion management with helical tomotherapy. Med Phys 2018; 45:1329-1337. [DOI: 10.1002/mp.12791] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 12/21/2017] [Accepted: 01/11/2018] [Indexed: 11/07/2022] Open
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5
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Franco P, Catuzzo P, Cante D, La Porta MR, Sciacero P, Girelli G, Borca VC, Pasquino M, Numico G, Tofani S, Meloni T, Ricardi U, Ozzello F. TomoDirect: An efficient means to deliver radiation at static angles with tomotherapy. TUMORI JOURNAL 2018; 97:498-502. [DOI: 10.1177/030089161109700414] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Aims and background The TomoTherapy Hi-Art II system is able to deliver dynamic intensity-modulated radiation therapy within a helical geometry providing robust conformality and modulation, abrupt dose falloff, and reliable accuracy. A new upgrade named TomoDirect was introduced recently, allowing delivery of radiation at discrete angles with a fixed gantry. We present our preliminary clinical experience with TomoDirect. Methods Three specific clinical contexts were chosen for the implementation of TomoDirect, namely palliation of bone metastasis pain (BP), whole brain radiation therapy for intracranial secondary lesions (WBRT), and adjuvant whole breast radiation therapy after conservative surgery for early stage breast cancer (AWBRT). After appropriate positioning, planning CT, contouring, and plan generation, all patients were treated with the TomoDirect upgrade of the TomoTherapy Hi-Art II system with different doses and fractionation according to clinical decision-making. Results Between May and December 2010, 41 patients were treated with TomoDirect. Eighteen patients were treated for BP (mainly vertebral metastases) with a predominant posterior field arrangement. Seven patients were treated for WBRT (multiple brain lesions) with a parallel-opposed latero-lateral approach and 16 patients were treated for conventionally fractionated AWBRT mainly with a 2-field tangential approach. Radiation treatments were generally well tolerated and the acute toxicity was mild. Conclusions While helical tomotherapy allows the delivery of very sophisticated treatment plans, in certain anatomical sites and clinical contexts where the number of beam directions is constrained and supposed not to affect plan quality, TomoDirect might be an efficient means to deliver radiation at static angles with consistent dosimetric and clinical results.
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Affiliation(s)
- Pierfrancesco Franco
- Radiation Oncology Department, Tomotherapy Unit, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
| | - Paola Catuzzo
- Medical Physics Department, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
| | - Domenico Cante
- Radiation Oncology Department, Tomotherapy Unit, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Radiotherapy Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Maria Rosa La Porta
- Radiation Oncology Department, Tomotherapy Unit, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Radiotherapy Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Piera Sciacero
- Radiation Oncology Department, Tomotherapy Unit, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Radiotherapy Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Giuseppe Girelli
- Radiation Oncology Department, Tomotherapy Unit, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Radiotherapy Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Valeria Casanova Borca
- Medical Physics Department, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Medical Physics Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Massimo Pasquino
- Medical Physics Department, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Medical Physics Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Gianmauro Numico
- Medical Oncology Department, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
| | - Santi Tofani
- Medical Physics Department, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Medical Physics Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
| | - Teodoro Meloni
- Diagnostic and Interventional Radiology Department, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
| | - Umberto Ricardi
- Department of Medical and Surgical Sciences, Radiation Oncology Unit, University of Turin, Ospedale San Giovanni Battista, Turin, Italy
| | - Franca Ozzello
- Radiation Oncology Department, Tomotherapy Unit, Ospedale Regionale “U. Parini”, AUSL Valle d'Aosta, Aosta
- Radiotherapy Department, ASL TO4, Ospedale Civile di Ivrea, Ivrea, Italy
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6
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Ricchetti F, Barra S, Agostinelli S, Vagge S, Marcenaro M, Corvò R. Feasibility of helical tomotherapy for radical dose retreatment in pelvic area: A report of 4 cases. TUMORI JOURNAL 2018; 97:492-7. [DOI: 10.1177/030089161109700413] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Aims and background To retrospectively determine acute toxicity and local control in patients with recurrence after definitive radiotherapy for prostate, bladder and rectal carcinoma. Methods Between September 2009 and March 2010, 4 patients with a prior history of pelvic radiotherapy were treated with helical tomotherapy. The prior course of radiotherapy was given for prostate cancer in 2 patients, bladder carcinoma in 1 patient and rectal carcinoma in 1 patient. The median prescribed dose of the prior course of radiotherapy was 6320 cGy (range, 5000–7600), and the median elapsed time between the first and second course was 17 months (range, 4–73). The total prescribed dose for tomotherapy retreatment was 60 Gy in 3 patients and 50 Gy in 1 patient. Hormone therapy was administered to 2 patients before and during radiation. No patient underwent surgical resection. Results The cumulative mean dose to the rectum ranged from 3813 to 6058 cGy; cumulative rectal maximum dose to 1 cc ranged from 6475 to 8780 cGy. Regarding the bladder, the cumulative mean dose was between 4384 and 7612 cGy; cumulative maximum dose to 1 cc ranged from 7560 to 9790 cGy. All patients completed the re-irradiation course. Acute genitourinary toxicity (RTOG scale) was grade 0 in 3 patients and grade 1 in 1 patient; acute gastrointestinal toxicity was grade 0 in 3 patients and grade 1 in 1 patient. With a median follow-up of 9 months (range, 7–12), late toxicity was G0 in all patients. Three patients showed partial response with computed tomography or magnetic resonance imaging, and 1 had a PSA decrease. Conclusions Re-irradiation with helical tomotherapy was well tolerated, with low rates of acute and late toxicity. It can be therefore considered a useful tool to improve local control in patients previously treated with radiotherapy. However, a larger number of patients and a longer follow-up are required to assess retreatment safety.
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Affiliation(s)
- Francesco Ricchetti
- Department of Radiation Oncology, National Institute for Cancer Research, Genoa
| | - Salvina Barra
- Department of Radiation Oncology, National Institute for Cancer Research, Genoa
| | - Stefano Agostinelli
- Department of Medical Physics, National Institute for Cancer Research, Genoa
| | - Stefano Vagge
- Department of Radiation Oncology, National Institute for Cancer Research, Genoa
| | - Michela Marcenaro
- Department of Radiation Oncology, National Institute for Cancer Research, Genoa
| | - Renzo Corvò
- Department of Radiation Oncology, National Institute for Cancer Research, Genoa
- University of Genoa, Genoa, Italy
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7
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Rajan Radha R, Chandrasekharan G. Pulmonary injury associated with radiation therapy - Assessment, complications and therapeutic targets. Biomed Pharmacother 2017; 89:1092-1104. [PMID: 28298070 DOI: 10.1016/j.biopha.2017.02.106] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2017] [Revised: 02/27/2017] [Accepted: 02/28/2017] [Indexed: 12/20/2022] Open
Abstract
Pulmonary injury is more common in patients undergoing radiation therapy for lungs and other thoracic malignancies. Recently with the use of most-advanced technologies powerful doses of radiation can be delivered directly to tumor site with exquisite precision. The awareness of technical and clinical parameters that influence the chance of radiation induced lung injury is important to guide patient selection and toxicity minimization strategies. At the cellular level, radiation activates free radical production, leading to DNA damage, apoptosis, cell cycle changes, and reduced cell survival. Preclinical research shows the potential for therapies targeting transforming growth factor-β (TGF-B), Toll like receptor (TLRs), Tumour necrosis factor-alpha (TNF-alpha), Interferon gamma (IFN-γ) and so on that may restore lung function. At present Amifostine (WR-2721) is the only approved broad spectrum radioprotector in use for patients undergoing radiation therapy. Newer techniques also offer the opportunity to identify new biomarkers and new targets for interventions to prevent or ameliorate these late effects of lung damage.
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Affiliation(s)
- Rasmi Rajan Radha
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Trivandrum 695 011, Kerala, India
| | - Guruvayoorappan Chandrasekharan
- Laboratory of Immunopharmacology and Experimental Therapeutics, Division of Cancer Research, Regional Cancer Centre, Trivandrum 695 011, Kerala, India.
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8
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Zhu Y, Li M, Kong L, Yu J. Postoperative radiation in esophageal squamous cell carcinoma and target volume delineation. Onco Targets Ther 2016; 9:4187-96. [PMID: 27471393 PMCID: PMC4948697 DOI: 10.2147/ott.s104221] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Esophageal cancer is the sixth leading cause of cancer death worldwide, and patients who are treated with surgery alone, without neoadjuvant therapies, experience frequent relapses. Whether postoperative therapies could reduce the recurrence or improve overall survival is still controversial for these patients. The purpose of our review is to figure out the value of postoperative adjuvant therapy and address the disputes about target volume delineation according to published data. Based on the evidence of increased morbidity and disadvantages on patient survival caused by postoperative chemotherapy or radiotherapy (RT) alone provided by studies in the early 1990s, the use of postoperative adjuvant therapies in cases of esophageal squamous cell carcinoma has diminished substantially and has been replaced gradually by neoadjuvant chemoradiation. With advances in surgery and RT, accumulating evidence has recently rekindled interest in the delivery of postoperative RT or chemoradiotherapy in patients with stage T3/T4 or N1 (lymph node positive) carcinomas after radical surgery. However, due to complications with the standard radiation field, a nonconforming modified field has been adopted in most studies. Therefore, we analyze different field applications and provide suggestions on the optimization of the radiation field based on the major sites of relapse and the surgical non-clearance area. For upper and middle thoracic esophageal carcinomas, the bilateral supraclavicular and superior mediastinal areas remain common sites of recurrence and should be encompassed within the clinical target volume. In contrast, a consensus has yet to be reached regarding lower thoracic esophageal carcinomas; the “standard” clinical target volume is still recommended. Further studies of larger sample sizes should focus on different recurrence patterns, categorized by tumor locations, refined classifications, and differing molecular biology, to provide more information on the delineation of target volumes.
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Affiliation(s)
- Yingming Zhu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong, People's Republic of China
| | - Minghuan Li
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong, People's Republic of China
| | - Li Kong
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong, People's Republic of China
| | - Jinming Yu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong University, Jinan, Shandong, People's Republic of China
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9
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Albandar MH, Cho MS, Bae SU, Kim NK. Surgical management of extra-regional lymph node metastasis in colorectal cancer. Expert Rev Anticancer Ther 2016; 16:503-13. [DOI: 10.1586/14737140.2016.1162718] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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10
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Brualla-González L, Gómez F, Pombar M, Pardo-Montero J. Dose rate dependence of the PTW 60019 microDiamond detector in high dose-per-pulse pulsed beams. Phys Med Biol 2015; 61:N11-9. [PMID: 26625177 DOI: 10.1088/0031-9155/61/1/n11] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Recombination effects can affect the detectors used for the dosimetry of radiotherapy fields. They are important when using ionization chambers, especially in liquid-filled ionization chambers, and should be corrected for. The introduction of flattening-filter-free accelerators increases the typical dose-per-pulse used in radiotherapy beams, which leads to more important recombination effects. Diamond detectors provide a good solution for the dosimetry and quality assurance of small radiotherapy fields, due to their low energy dependence and small volume. The group of Università di Roma Tor Vergata has developed a synthetic diamond detector, which is commercialized by PTW as microDiamond detector type 60019. In this work we present an experimental characterization of the collection efficiency of the microDiamond detector, focusing on high dose-per-pulse FFF beams. The collection efficiency decreases with dose-per-pulse, down to 0.978 at 2.2 mGy/pulse, following a Fowler-Attix-like curve. On the other hand, we have found no significant dependence of the collection efficiency on the pulse repetition frequency (or pulse period).
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Affiliation(s)
- Luis Brualla-González
- Servicio de Radiofísica, ERESA, Hospital General Universitario de Valencia, 46014 València, Spain
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11
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Zhu Z, Fu X. The radiation techniques of tomotherapy & intensity-modulated radiation therapy applied to lung cancer. Transl Lung Cancer Res 2015. [PMID: 26207214 DOI: 10.3978/j.issn.2218-6751.2015.01.07] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Radiotherapy (RT) plays an important role in the management of lung cancer. Development of radiation techniques is a possible way to improve the effect of RT by reducing toxicities through better sparing the surrounding normal tissues. This article will review the application of two forms of intensity-modulated radiation therapy (IMRT), fixed-field IMRT and helical tomotherapy (HT) in lung cancer, including dosimetric and clinical studies. The advantages and potential disadvantages of these two techniques are also discussed.
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Affiliation(s)
- Zhengfei Zhu
- 1 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 2 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200433, China ; 3 Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
| | - Xiaolong Fu
- 1 Department of Radiation Oncology, Fudan University Shanghai Cancer Center, Shanghai 200032, China ; 2 Department of Oncology, Shanghai Medical College, Fudan University, Shanghai 200433, China ; 3 Department of Radiation Oncology, Shanghai Chest Hospital, Shanghai Jiao Tong University, Shanghai 200030, China
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12
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Wu Q, Li G, Xu F. Resected gastric cancer with D2 dissection: advances in adjuvant chemoradiotherapy and radiotherapy techniques. Expert Rev Anticancer Ther 2015; 15:703-13. [PMID: 26004039 DOI: 10.1586/14737140.2015.1042863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Surgery is the main treatment option for locally advanced gastric cancer. D2 dissection has been recommended worldwide as standard lymphadenectomy for resectable gastric cancer. Furthermore, the role of peri- or postoperative chemotherapy for D2-dissected gastric cancer has been established in both Western and European countries. It has been disputed whether adding radiotherapy to chemotherapy could further benefit those patients. Until recently, studies from Korea and China may have made it clear. In North America, however, the INT-0116 trial does not rule out that chemoradiotherapy is effective in patients with D2 dissection, but the ongoing CRITICS trial will, hopefully, clarify this. In addition, literature published in the past decade supports the theory that improved radiotherapy techniques are likely to accurately deliver radiation dose and significantly reduce radiation toxicity. Finally, the status of E2F-1 and HER-2 may be associated with efficacy of radiotherapy based on retrospective studies.
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Affiliation(s)
- Qiang Wu
- Cancer Center, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, PR China
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13
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Vacchelli E, Vitale I, Tartour E, Eggermont A, Sautès-Fridman C, Galon J, Zitvogel L, Kroemer G, Galluzzi L. Trial Watch: Anticancer radioimmunotherapy. Oncoimmunology 2013; 2:e25595. [PMID: 24319634 PMCID: PMC3850274 DOI: 10.4161/onci.25595] [Citation(s) in RCA: 79] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 06/28/2013] [Indexed: 12/18/2022] Open
Abstract
Radiotherapy has extensively been employed as a curative or palliative intervention against cancer throughout the last century, with a varying degree of success. For a long time, the antineoplastic activity of X- and γ-rays was entirely ascribed to their capacity of damaging macromolecules, in particular DNA, and hence triggering the (apoptotic) demise of malignant cells. However, accumulating evidence indicates that (at least part of) the clinical potential of radiotherapy stems from cancer cell-extrinsic mechanisms, including the normalization of tumor vasculature as well as short- and long-range bystander effects. Local bystander effects involve either the direct transmission of lethal signals between cells connected by gap junctions or the production of diffusible cytotoxic mediators, including reactive oxygen species, nitric oxide and cytokines. Conversely, long-range bystander effects, also known as out-of-field or abscopal effects, presumably reflect the elicitation of tumor-specific adaptive immune responses. Ionizing rays have indeed been shown to promote the immunogenic demise of malignant cells, a process that relies on the spatiotemporally defined emanation of specific damage-associated molecular patterns (DAMPs). Thus, irradiation reportedly improves the clinical efficacy of other treatment modalities such as surgery (both in neo-adjuvant and adjuvant settings) or chemotherapy. Moreover, at least under some circumstances, radiotherapy may potentiate anticancer immune responses as elicited by various immunotherapeutic agents, including (but presumably not limited to) immunomodulatory monoclonal antibodies, cancer-specific vaccines, dendritic cell-based interventions and Toll-like receptor agonists. Here, we review the rationale of using radiotherapy, alone or combined with immunomodulatory agents, as a means to elicit or boost anticancer immune responses, and present recent clinical trials investigating the therapeutic potential of this approach in cancer patients.
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Affiliation(s)
- Erika Vacchelli
- Gustave Roussy; Villejuif, France
- Université Paris-Sud/Paris XI; Le Kremlin-Bicêtre, France
- INSERM, U848; Villejuif, France
| | - Ilio Vitale
- Regina Elena National Cancer Institute; Rome, Italy
- National Institute of Health; Rome, Italy
| | - Eric Tartour
- INSERM, U970; Paris, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Pôle de Biologie; Hôpital Européen Georges Pompidou; Assistance Publique-Hôpitaux de Paris; Paris, France
| | | | - Catherine Sautès-Fridman
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Pôle de Biologie; Hôpital Européen Georges Pompidou; Assistance Publique-Hôpitaux de Paris; Paris, France
- Equipe 13, Centre de Recherche des Cordeliers; Paris, France
| | - Jérôme Galon
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Equipe 15, Centre de Recherche des Cordeliers; Paris, France
- INSERM, U872; Paris, France
- Université Pierre et Marie Curie/Paris VI; Paris, France
| | - Laurence Zitvogel
- Université Paris-Sud/Paris XI; Le Kremlin-Bicêtre, France
- INSERM, U1015; Villejuif, France
| | - Guido Kroemer
- INSERM, U848; Villejuif, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Pôle de Biologie; Hôpital Européen Georges Pompidou; Assistance Publique-Hôpitaux de Paris; Paris, France
- Equipe 11 labelisée par la Ligue Nationale contre le Cancer; Centre de Recherche des Cordeliers; Paris, France
- Metabolomics and Cell Biology Platforms; Institut Gustave Roussy; Villejuif, France
| | - Lorenzo Galluzzi
- Gustave Roussy; Villejuif, France
- Université Paris Descartes/Paris V; Sorbonne Paris Cité; Paris, France
- Equipe 11 labelisée par la Ligue Nationale contre le Cancer; Centre de Recherche des Cordeliers; Paris, France
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Chi A, Ma P, Fu G, Hobbs G, Welsh JS, Nguyen NP, Jang SY, Dai J, Jin J, Komaki R. Critical structure sparing in stereotactic ablative radiotherapy for central lung lesions: helical tomotherapy vs. volumetric modulated arc therapy. PLoS One 2013; 8:e59729. [PMID: 23577071 PMCID: PMC3618449 DOI: 10.1371/journal.pone.0059729] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Accepted: 02/21/2013] [Indexed: 12/25/2022] Open
Abstract
Background Helical tomotherapy (HT) and volumetric modulated arc therapy (VMAT) are both advanced techniques of delivering intensity-modulated radiotherapy (IMRT). Here, we conduct a study to compare HT and partial-arc VMAT in their ability to spare organs at risk (OARs) when stereotactic ablative radiotherapy (SABR) is delivered to treat centrally located early stage non-small-cell lung cancer or lung metastases. Methods 12 patients with centrally located lung lesions were randomly chosen. HT, 2 & 8 arc (Smart Arc, Pinnacle v9.0) plans were generated to deliver 70 Gy in 10 fractions to the planning target volume (PTV). Target and OAR dose parameters were compared. Each technique’s ability to meet dose constraints was further investigated. Results HT and VMAT plans generated essentially equivalent PTV coverage and dose conformality indices, while a trend for improved dose homogeneity by increasing from 2 to 8 arcs was observed with VMAT. Increasing the number of arcs with VMAT also led to some improvement in OAR sparing. After normalizing to OAR dose constraints, HT was found to be superior to 2 or 8-arc VMAT for optimal OAR sparing (meeting all the dose constraints) (p = 0.0004). All dose constraints were met in HT plans. Increasing from 2 to 8 arcs could not help achieve optimal OAR sparing for 4 patients. 2/4 of them had 3 immediately adjacent structures. Conclusion HT appears to be superior to VMAT in OAR sparing mainly in cases which require conformal dose avoidance of multiple immediately adjacent OARs. For such cases, increasing the number of arcs in VMAT cannot significantly improve OAR sparing.
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Affiliation(s)
- Alexander Chi
- Department of Radiation Oncology, West Virginia University, Morgantown, West Virginia, USA.
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15
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Pardo-Montero J, Fenwick JD. Tomotherapy-like versus VMAT-like treatments: a multicriteria comparison for a prostate geometry. Med Phys 2013; 39:7418-29. [PMID: 23231292 DOI: 10.1118/1.4768159] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To perform a methodological comparison of volumetric modulated arc therapy (VMAT)-like and tomotherapy-like techniques for a prostate geometry, exploring the dependence on machine, delivery, and optimization parameters of cost function values optimized for each technique. METHODS A gradient-descent algorithm is used to optimize tomotherapy-like treatments, while VMAT-like optimization is carried out using a direct-aperture simulated annealing algorithm with 180 control points equispaced at 2° angles. Dose distributions are linked to fluences via a three-dimensional double-gaussian pencil beam model. Plans are optimized for a prostate geometry, outlined according to the CHHiP protocol. The cost function used for optimization contains ten simple functions, each of which describes a single planning objective. These functions are split into three structure groups according to whether they are used to control PTV, rectal or bladder dose levels. Different optimizations have been performed by varying the relative weights of each of these structure groups, exploring in this way a three-dimensional Pareto front. Plan quality is studied according to the value of the optimized cost function and the relative Euclidean distance between the components of the cost function and those of the nearest plan lying on a reference Pareto front obtained for tomotherapy-like plans generated using a 1 cm fan-beam width and 1/3 pitch. RESULTS The quality of tomotherapy-like optimization depends on the fan-beam width, s, and rotation pitch, p, used to deliver the treatment. These values together define the effective longitudinal resolution with which fluence can be modulated, and lower cost function values are obtained for treatments optimized with tighter pitches and narrower fan-beam widths (higher modulation resolution). On the other hand, the cost function values of VMAT-like optimizations depends on the optimization running time, leaf displacement constraints, and number of arcs employed, as well as on the size of the beamlets used in the optimization (a change in leaf width from 5 to 10 mm clearly worsens the value of the objective function, but only a marginal improvement is observed when the leaf movement discretization step is reduced from 5 to 5/3 mm). However, for no combination of these parameter values did VMAT-like optimizations match the cost function values of optimized tomo-like plans obtained for s = 1 cm and p = 1∕3 (or 1/2). This is the case all across the Pareto front. On the other hand, cost function values of VMAT-like plans are generally lower than those of optimized tomotherapy-like plans obtained for s = 2.5 cm. CONCLUSIONS Tomotherapy-like plans created for the prostate geometry using a 1 cm fan-beam width and pitches of 1/3 or 1/2 have lower cost function values than VMAT-like plans, although the associated dosimetric improvements are quite small, both techniques generating very good dose distributions. When a 2.5 cm wide fan-beam is used for tomotherapy-like treatments the pattern is reversed, the tomotherapy-like plans having higher cost functions than the VMAT-like ones.
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Affiliation(s)
- Juan Pardo-Montero
- Departamento de Física de Partículas, Universidade de Santiago de Compostela, Santiago de Compostela, Spain.
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16
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Jastaniyah N, Murtha A, Pervez N, Le D, Roa W, Patel S, Mackenzie M, Fulton D, Field C, Ghosh S, Fallone G, Abdulkarim B. Phase I study of hypofractionated intensity modulated radiation therapy with concurrent and adjuvant temozolomide in patients with glioblastoma multiforme. Radiat Oncol 2013; 8:38. [PMID: 23425509 PMCID: PMC3599873 DOI: 10.1186/1748-717x-8-38] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 02/03/2013] [Indexed: 11/25/2022] Open
Abstract
Purpose To determine the safety and efficacy of hypofractionated intensity modulated radiation therapy (Hypo-IMRT) using helical tomotherapy (HT) with concurrent low dose temozolomide (TMZ) followed by adjuvant TMZ in patients with glioblastoma multiforme (GBM). Methods and materials Adult patients with GBM and KPS > 70 were prospectively enrolled between 2005 and 2007 in this phase I study. The Fibonacci dose escalation protocol was implemented to establish a safe radiation fractionation regimen. The protocol defined radiation therapy (RT) dose level I as 54.4 Gy in 20 fractions over 4 weeks and dose level II as 60 Gy in 22 fractions over 4.5 weeks. Concurrent TMZ followed by adjuvant TMZ was given according to the Stupp regimen. The primary endpoints were feasibility and safety of Hypo-IMRT with concurrent TMZ. Secondary endpoints included progression free survival (PFS), pattern of failure, overall survival (OS) and incidence of pseudoprogression. The latter was defined as clinical or radiological suggestion of tumour progression within three months of radiation completion followed by spontaneous recovery of the patient. Results A total of 25 patients were prospectively enrolled with a median follow-up of 12.4 months. The median age at diagnosis was 53 years. Based on recursive partitioning analysis (RPA) criteria, 16%, 52% and 32% of the patients were RPA class III, class IV and class V, respectively. All patients completed concurrent RT and TMZ, and 19 patients (76.0%) received adjuvant TMZ. The median OS was 15.67 months (95% CI 11.56 - 20.04) and the median PFS was 6.7 months (95% CI 4.0 – 14.0). The median time between surgery and start of RT was 44 days (range of 28 to 77 days). Delaying radiation therapy by more than 6 weeks after surgery was an independent prognostic factor associated with a worse OS (4.0 vs. 16.1 months, P = 0.027). All recurrences occurred within 2 cm of the original gross tumour volume (GTV). No cases of pseudoprogression were identified in our cohort of patients. Three patients tolerated dose level I with no dose limiting toxicity and hence the remainder of the patients were treated with dose level II according to the dose escalation protocol. Grade 3–4 hematological toxicity was limited to two patients and one patient developed Grade 4 Pneumocystis jiroveci pneumonia. Conclusion Hypo-IMRT using HT given with concurrent TMZ is feasible and safe. The median OS and PFS are comparable to those observed with conventional fractionation. Hypofractionated radiation therapy offers the advantage of a shorter treatment period which is imperative in this group of patients with limited life expectancy.
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Affiliation(s)
- Noha Jastaniyah
- Division of Radiation Oncology, Cross Cancer Institute and University of Alberta, 11560, University Avenue, Edmonton, AB, T6G 1Z2, Canada
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17
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Fischer-Valuck BW, Durci M, Katz SR, Wu HT, Syh J, Syh J, Patel B, Rosen LR. Influence of patient characteristics on survival following treatment with helical stereotactic body radiotherapy (SBRT) in stage I non-small-cell lung cancer. Thorac Cancer 2013; 4:27-34. [DOI: 10.1111/j.1759-7714.2012.00137.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
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18
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Thariat J, Hannoun-Levi JM, Sun Myint A, Vuong T, Gérard JP. Past, present, and future of radiotherapy for the benefit of patients. Nat Rev Clin Oncol 2012. [PMID: 23183635 DOI: 10.1038/nrclinonc.2012.203] [Citation(s) in RCA: 228] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Radiotherapy has been driven by constant technological advances since the discovery of X-rays in 1895. Radiotherapy aims to sculpt the optimal isodose on the tumour volume while sparing normal tissues. The benefits are threefold: patient cure, organ preservation and cost-efficiency. The efficacy and tolerance of radiotherapy were demonstrated by randomized trials in many different types of cancer (including breast, prostate and rectum) with a high level of scientific evidence. Such achievements, of major importance for the quality of life of patients, have been fostered during the past decade by linear accelerators with computer-assisted technology. More recently, these developments were augmented by proton and particle beam radiotherapy, usually combined with surgery and medical treatment in a multidisciplinary and personalized strategy against cancer. This article reviews the timeline of 100 years of radiotherapy with a focus on breakthroughs in the physics of radiotherapy and technology during the past two decades, and the associated clinical benefits.
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Affiliation(s)
- Juliette Thariat
- Department of Radiation Oncology, Centre Antoine Lacassagne--University Nice Sophia Antipolis, 33 Avenue Valombrose, 06189 Nice, France
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Performance of independent dose calculation in helical tomotherapy: implementation of the MCSIM code. AUSTRALASIAN PHYSICAL & ENGINEERING SCIENCES IN MEDICINE 2012; 35:423-38. [PMID: 23143880 DOI: 10.1007/s13246-012-0165-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2012] [Accepted: 10/31/2012] [Indexed: 10/27/2022]
Abstract
Currently, a software-based second check dose calculation for helical tomotherapy (HT) is not available. The goal of this study is to evaluate the dose calculation accuracy of the in-house software using EGS4/MCSIM Monte Carlo environment against the treatment planning system calculations. In-house software was used to convert HT treatment plan information into a non-helical format. The MCSIM dose calculation code was evaluated by comparing point dose calculations and dose profiles against those from the HT treatment plan. Fifteen patients, representing five treatment sites, were used in this comparison. Point dose calculations between the HT treatment planning system and the EGS4/MCSIM Monte Carlo environment had percent difference values below 5 % for the majority of this study. Vertical and horizontal planar profiles also had percent difference values below 5 % for the majority of this study. Down sampling was seen to improve speed without much loss of accuracy. EGS4/MCSIM Monte Carlo environment showed good agreement with point dose measurements, compared to the HT treatment plans. Vertical and horizontal profiles also showed good agreement. Significant time saving may be obtained by down-sampling beam projections. The dose calculation accuracy of the in-house software using the MCSIM code against the treatment planning system calculations was evaluated. By comparing point doses and dose profiles, the EGS4/MCSIM Monte Carlo environment was seen to provide an accurate independent dose calculation.
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20
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Bert C, Engenhart-Cabillic R, Durante M. Particle therapy for noncancer diseases. Med Phys 2012; 39:1716-27. [PMID: 22482597 DOI: 10.1118/1.3691903] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Radiation therapy using high-energy charged particles is generally acknowledged as a powerful new technique in cancer treatment. However, particle therapy in oncology is still controversial, specifically because it is unclear whether the putative clinical advantages justify the high additional costs. However, particle therapy can find important applications in the management of noncancer diseases, especially in radiosurgery. Extension to other diseases and targets (both cranial and extracranial) may widen the applications of the technique and decrease the cost/benefit ratio of the accelerator facilities. Future challenges in this field include the use of different particles and energies, motion management in particle body radiotherapy and extension to new targets currently treated by catheter ablation (atrial fibrillation and renal denervation) or stereotactic radiation therapy (trigeminal neuralgia, epilepsy, and macular degeneration). Particle body radiosurgery could be a future key application of accelerator-based particle therapy facilities in 10 years from today.
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Affiliation(s)
- Christoph Bert
- GSI Helmholtzzentrum für Schwerionenforschung, Biophysics Department, Planckstraße 1, 64291 Darmstadt, Germany
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21
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Piotrowski T, Ryczkowski A, Kazmierska J. B-Spline Registration Based on New Concept of an Intelligent Masking Procedure and GPU Computations for the Head and Neck Adaptive Tomotherapy. Technol Cancer Res Treat 2012; 11:257-66. [DOI: 10.7785/tcrt.2012.500294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The deformable image registration (DIR) procedure has been optimized for helical tomotherapy. The data on registration shifts obtained on matching planning image with pre-treatment megavoltage CT are used in our software for acceleration of the first step (rigid registration) of the DIR procedure and for implementation of the B-Spline algorithm with intelligent masking. Priorities of the masks were automatically calculated based on disagreement detected during rigid registration. Evaluation tasks included: (a) comparison of accuracy and rate for schemes of pre-registered and non-registered images; (b) qualification of the effectiveness of the intelligent masking process, and (c) determination of acceleration of achievable with GPU computing. A specially designed head and neck phantom used for evaluation included structures with controlled changes of position, volume, density, and shape. Re-contouring procedures were performed with an Adaptive Planning software (Tomotherapy Inc.). No statistical difference was observed in accuracy of DIR based on structure position match on the tomotherapy unit and non pre-registered images (p > 0.7). Using pre-registered data reduces the total time required for execution of the elastic registration procedure by 5%. These data are also necessary for intelligent masking procedure during B-Spine registration. Intelligent masking procedure increases accuracy of the registration for a masked structure (p < 0.04) without decreasing the accuracy in non-masked tissues and additionally reduces the total time by 13%. GPU computations speed up procedure 30 times. GPU computing of the DIR in current status of our investigation could be realized in a relatively short time after pre-treatment imaging. The proposed approach can be used in the routine assessment of anatomic changes occurring in healthy tissue during the course of radiotherapy. Further developments will be concentrated on the full integration of DIR computations in the imaging and treatment process of helical tomotherapy.
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Affiliation(s)
- T. Piotrowski
- Department of Medical Physics, Greater Poland Cancer Center, Garbary 15 st, 61-866, Poznan, Poland
- Department of Electroradiology, University of Medical Sciences, Poznan, Garbary 15 st, 61-866, Poznan, Poland
| | - A. Ryczkowski
- Department of Medical Physics, Greater Poland Cancer Center, Garbary 15 st, 61-866, Poznan, Poland
| | - J. Kazmierska
- II Radiotherapy Department, Greater Poland Cancer Center, Garbary 15 st, 61-866, Poznan, Poland
- Department of Electroradiology, University of Medical Sciences, Poznan, Garbary 15 st, 61-866, Poznan, Poland
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Chi A, Liao Z, Nguyen NP, Xu J, Welsh JS, Jang SY, Howe C, Komaki R. Dosimetric selection for helical tomotherapy based stereotactic ablative radiotherapy for early-stage non-small cell lung cancer or lung metastases. PLoS One 2012; 7:e35809. [PMID: 22558228 PMCID: PMC3338464 DOI: 10.1371/journal.pone.0035809] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2012] [Accepted: 03/22/2012] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND No selection criteria for helical tomotherapy (HT) based stereotactic ablative radiotherapy (SABR) to treat early stage non-small cell lung cancer (NSCLC) or solitary lung metastases has been established. In this study, we investigate the dosimetric selection criteria for HT based SABR delivering 70 Gy in 10 fractions to avoid severe toxicity in the treatment of centrally located lesions when adequate target dose coverage is desired. MATERIALS AND METHODS 78 HT-SABR plans for solitary lung lesions were created to prescribe 70 Gy in 10 fractions to the planning target volume (PTV). The PTV was set to have ≥95% PTV receiving 70 Gy in each case. The cases for which dose constraints for ≥1 OAR could not be met without compromising the target dose coverage were compared with cases for which all target and OAR dose constraints were met. RESULTS There were 23 central lesions for which OAR dose constraints could not be met without compromising PTV dose coverage. Comparing to cases for which optimal HT-based SABR plans were generated, they were associated with larger tumor size (5.72±1.96 cm vs. 3.74±1.49 cm, p<0.0001), higher lung dose, increased number of immediately adjacent OARs ( 3.45±1.34 vs. 1.66±0.81, p<0.0001), and shorter distance to the closest OARs (GTV: 0.26±0.22 cm vs. 0.88±0.54 cm, p<0.0001; PTV 0.19±0.18 cm vs. 0.48±0.36 cm, p = 0.0001). CONCLUSION Delivery of 70 Gy in 10 fractions with HT to meet all the given OAR and PTV dose constraints are most likely when the following parameters are met: lung lesions ≤3.78 cm (11.98 cc), ≤2 immediately adjacent OARs which are ≥0.45 cm from the gross lesion and ≥0.21 cm from the PTV.
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Affiliation(s)
- Alexander Chi
- Department of Radiation Oncology, West Virginia University, Morgantown, West Virginia, United States of America.
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Gupta T, Wadasadawala T, Master Z, Phurailatpam R, Pai-Shetty R, Jalali R. Encouraging Early Clinical Outcomes With Helical Tomotherapy–Based Image-Guided Intensity-Modulated Radiation Therapy for Residual, Recurrent, and/or Progressive Benign/Low-Grade Intracranial Tumors: A Comprehensive Evaluation. Int J Radiat Oncol Biol Phys 2012; 82:756-64. [DOI: 10.1016/j.ijrobp.2010.12.044] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2010] [Revised: 12/24/2010] [Accepted: 12/29/2010] [Indexed: 12/25/2022]
Affiliation(s)
- Tejpal Gupta
- Department of Radiation Oncology, ACTREC/TMH, Tata Memorial Centre, Kharghar, Navi Mumbai, India.
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Teoh M, Clark CH, Wood K, Whitaker S, Nisbet A. Volumetric modulated arc therapy: a review of current literature and clinical use in practice. Br J Radiol 2011; 84:967-96. [PMID: 22011829 DOI: 10.1259/bjr/22373346] [Citation(s) in RCA: 431] [Impact Index Per Article: 33.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Volumetric modulated arc therapy (VMAT) is a novel radiation technique, which can achieve highly conformal dose distributions with improved target volume coverage and sparing of normal tissues compared with conventional radiotherapy techniques. VMAT also has the potential to offer additional advantages, such as reduced treatment delivery time compared with conventional static field intensity modulated radiotherapy (IMRT). The clinical worldwide use of VMAT is increasing significantly. Currently the majority of published data on VMAT are limited to planning and feasibility studies, although there is emerging clinical outcome data in several tumour sites. This article aims to discuss the current use of VMAT techniques in practice and review the available data from planning and clinical outcome studies in various tumour sites including prostate, pelvis (lower gastrointestinal, gynaecological), head and neck, thoracic, central nervous system, breast and other tumour sites.
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Affiliation(s)
- M Teoh
- Department of Oncology, St Luke's Cancer Centre, Royal Surrey County Hospital, Guildford, Surrey, UK.
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25
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Intensity-modulated radiotherapy after extrapleural pneumonectomy in the combined-modality treatment of malignant pleural mesothelioma. J Thorac Oncol 2011; 6:1132-41. [PMID: 21532502 DOI: 10.1097/jto.0b013e3182199819] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
INTRODUCTION Local therapy is becoming increasingly important as a part of the definitive treatment for malignant pleural mesothelioma after extrapleural pneumonectomy (EPP) because of the emergence of trimodality therapy consisted of chemotherapy, EPP, and adjuvant radiotherapy. Herein, we explore the current evidence and indications for adjuvant intensity-modulated radiotherapy (IMRT), as well as how to further improve this technique and adapt new technology in the delivering adjuvant radiotherapy in the setting of trimodality therapy. METHODS A systematic review of relevant studies identified through PubMed, ISI Web of Knowledge (Web of Science), the Cochrane Library, and the National Guideline Clearinghouse search engines was performed. RESULTS Local control remains poor despite the inclusion of conventional adjuvant radiation therapy in trimodality therapy. This can be improved by the delivery of adjuvant IMRT. However, IMRT can be associated with severe pulmonary toxicity if the radiation dose to the remaining lung is not kept to a very low level. This is especially true when patients are receiving chemotherapy. New advances in technology can allow for lower doses to the contralateral lung, decreased treatment delivery time, and improved target dose coverage. CONCLUSION Excellent local control can be achieved through adjuvant IMRT after EPP for malignant pleural mesothelioma. Severe pulmonary toxicity may be avoided by setting stringent dose constraints for the contralateral lung. This can be aided by the advances in technology. Post-treatment surveillance may be reliably conducted by periodical [18F]-fluorodeoxyglucose-positron emission tomography imaging.
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Fenwick JD, Pardo-Montero J. Numbers of beam angles required for near-optimal IMRT: theoretical limits and numerical studies. Med Phys 2011; 38:4518-30. [PMID: 21928622 DOI: 10.1118/1.3606457] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To derive limits on the numbers of beams needed to deliver near-optimal IMRT, and to assess the accuracy of the limits. METHODS The authors four different limits have been derived. One, K(A), has been obtained by coupling Fourier techniques with a proof used to obtain Bortfeld's limit, K, that if all the cross-profiles of a many-field plan can be represented as polynomials of order (K-1) over the range [-R, + R], then within the radius R circle an identical dose-distribution can be created using just K fields. Two further limits, K(H) and K(N), have been obtained using sampling theory, the K(N) limit describing fields spaced at the Nyquist frequency. K(N) can be generalized to K(N,Fbeamlet), a limit that accounts for the finite size of the beamlets from which modulated fields are constructed. Using Bortfeld's theoretical framework, the accuracy of the limits has been explored by testing how well the cross-profiles of an 8 MV double-Gaussian pencil beam and of 1 and 4 cm wide fields can be approximated by polynomials of orders equal to the different limits minus one. The dependence of optimized cost function values of IMRT plans, generated for a simple geometry and for a head-and-neck (oropharynx) case, on the numbers of beams used to construct the plans has also been studied. RESULTS The limits are all multiples of R/W (W being the 20%-80% penumbra-width of a broad field) and work out at K = 27, K(A) = 43, K(H) = 34, and K(N) = 68 fields for R = 10 cm and W = 5.3 mm. All and none of the cross-profiles are approximated well by polynomials of order K(N)-1 and K-1, respectively, suggesting some inaccuracy in the assumptions used to derive the limit K. Order K(A)-1 polynomials cannot accurately describe the pencil beam profile, but do approximate the 1- and 4-cm profiles reasonably well because higher spatial frequencies are attenuated in these wider fields. All the profiles are represented well by polynomials of order K(N,Fbeamlet(-1)), which decreases from K(N) as beamlet width increases. Cost functions generated in the IMRT planning study fall as greater numbers of fields are used, before plateauing out around K(N,Fbeamlet) fields. CONCLUSIONS Numerical calculations suggest that the minimum number of fields required for near-optimal IMRT lies around the generalized Nyquist limit K(N,Fbeamlet). For a clinically realistic 20%-80% penumbra-width of 5.3 mm and a radius of interest of 10 cm, K(N,Fbeamlet) falls from 68 to 47 fields as the beamlet width rises from 0 to 1 cm.
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Affiliation(s)
- John D Fenwick
- School of Cancer Studies, University of Liverpool, Liverpool L69 3GA, United Kingdom.
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Rong Y, Welsh JS. Dosimetric and clinical review of helical tomotherapy. Expert Rev Anticancer Ther 2011; 11:309-20. [PMID: 21342048 DOI: 10.1586/era.10.175] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
As a modality for delivering rotational therapy, helical tomotherapy offers dosimetric advantages by combining a continuously rotating gantry with a binary multileaf collimator. Helical tomotherapy, embodied in the TomoTherapy(®) Hi-Art II(®) system, delivers intensity-modulated fan beams in a helical pattern using binary multileaf collimator leaves while the couch is translated through the gantry. Helical tomotherapy offers the possibility of treating a variety of cases--from simple to complex--with improved target conformality and sensitive structure sparing compared with 3D or conventional static field IMRT plans, thereby allowing biologically effective dose escalation. For precise irradiation and possible treatment adaptation, the fully integrated on-board image-guidance system provides online volumetric images of patient anatomy using 3.5-MV x-ray beams and the xenon computed tomography detector. Several review articles were published before the year 2007 but emphasized the technical aspects of helical tomotherapy. In this article, we review very recent papers and focus on the dosimetric and clinical aspects of helical tomotherapy.
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Affiliation(s)
- Yi Rong
- Department of Human Oncology, School of Medicine and Public Health, University of Wisconsin-Madison, 600 Highland Avenue, Madison, WI, USA.
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Mesbah L, Matute R, Usychkin S, Marrone I, Puebla F, Mínguez C, García R, García G, Beltrán C, Marsiglia H. Helical tomotherapy in the treatment of pediatric malignancies: a preliminary report of feasibility and acute toxicity. Radiat Oncol 2011; 6:102. [PMID: 21871078 PMCID: PMC3224656 DOI: 10.1186/1748-717x-6-102] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2011] [Accepted: 08/26/2011] [Indexed: 01/08/2023] Open
Abstract
Background Radiation therapy plays a central role in the management of many childhood malignancies and Helical Tomotherapy (HT) provides potential to decrease toxicity by limiting the radiation dose to normal structures. The aim of this article was to report preliminary results of our clinical experience with HT in pediatric malignancies. Methods In this study 66 consecutive patients younger than 14 years old, treated with HT at our center between January 2006 and April 2010, have been included. We performed statistical analyses to assess the relationship between acute toxicity, graded according to the RTOG criteria, and several clinical and treatment characteristics such as a dose and irradiation volume. Results The median age of patients was 5 years. The most common tumor sites were: central nervous system (57%), abdomen (17%) and thorax (6%). The most prevalent histological types were: medulloblastoma (16 patients), neuroblastoma (9 patients) and rhabdomyosarcoma (7 patients). A total of 52 patients were treated for primary disease and 14 patients were treated for recurrent tumors. The majority of the patients (72%) were previously treated with chemotherapy. The median prescribed dose was 51 Gy (range 10-70 Gy). In 81% of cases grade 1 or 2 acute toxicity was observed. There were 11 cases (16,6%) of grade 3 hematological toxicity, two cases of grade 3 skin toxicity and one case of grade 3 emesis. Nine patients (13,6%) had grade 4 hematological toxicity. There were no cases of grade 4 non-hematological toxicities. On the univariate analysis, total dose and craniospinal irradiation (24 cases) were significantly associated with severe toxicity (grade 3 or more), whereas age and chemotherapy were not. On the multivariate analysis, craniospinal irradiation was the only significant independent risk factor for grade 3-4 toxicity. Conclusion HT in pediatric population is feasible and safe treatment modality. It is characterized by an acceptable level of acute toxicity that we have seen in this highly selected pediatric patient cohort with clinical features of poor prognosis and/or aggressive therapy needed. Despite of a dosimetrical advantage of HT technique, an exhaustive analysis of long-term follow-up data is needed to assess late toxicity, especially in this potentially sensitive to radiation population.
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Affiliation(s)
- Latifa Mesbah
- Radiotherapy Department, Instituto Madrileño de Oncología (Grupo IMO), Madrid, Spain
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Tomatis S, Carrara M, Massafra E, Naldi G, Palazzi M, Orlandi E, Marchesini R. Geometry of volumes in radiotherapy planning. A new method for a quantitative assessment. TUMORI JOURNAL 2011; 97:503-9. [DOI: 10.1177/030089161109700415] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Aims and background The purpose of the study was to develop a general method able to quantify the mutual disposition in the 3D space of critical organs with respect to the target when these structures are designed for a radiotherapy treatment plan. To that end, we introduce the “expansion intersection histogram”, a function defined as the intersection between an organ at risk and the target volume, while the target is expanded in 3D. Methods and study design A software was developed to calculate the expansion intersection histogram of anatomical structures exported in a DICOM format from a commercial treatment planning system. A virtual phantom with spherical and cylindrical objects arranged in different dispositions in the 3D space was created for testing the software under known conditions. Results and conclusions Expansion intersection histogram computation was tested against reference data derived analytically for spherical volumes, with a resulting maximum error of 0.5%. Specific geometric features derived from the expansion intersection histogram, such as the distance between a selected target and each different ideal volume included in the virtual phantom, well matched the corresponding theoretical expected values. The expansion intersection histogram was evaluated also for the anatomical structures of a real patient. Data show this method as a tool to effectively take into account the mutual disposition of each critical organ with respect to the target, summarized in characteristics of distance, shape and orientation. The expansion intersection histogram method integrates and extends other preexisting modalities for evaluating the geometrical relationships among radiotherapy volumes and could be used to improve planning optimization.
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Affiliation(s)
- Stefano Tomatis
- Medical Physics Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan
| | - Mauro Carrara
- Medical Physics Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan
| | | | | | - Mauro Palazzi
- Radiotherapy Unit, Azienda Ospedaliera Ospedale Niguarda Ca' Granda, Milan
| | - Ester Orlandi
- Radiotherapy Unit, Fondazione IRCCS Istituto Nazionale Tumori, Milan
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SmartArc-Based Volumetric Modulated Arc Therapy for Oropharyngeal Cancer: A Dosimetric Comparison With Both Intensity-Modulated Radiation Therapy and Helical Tomotherapy. Int J Radiat Oncol Biol Phys 2011; 80:1248-55. [DOI: 10.1016/j.ijrobp.2010.08.007] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2009] [Revised: 07/03/2010] [Accepted: 08/17/2010] [Indexed: 11/18/2022]
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Yin Y, Ma C, Gao M, Chen J, Ma Y, Liu T, Lu J, Yu J. Dosimetric comparison of RapidArc with fixed gantry intensity-modulated radiotherapy treatment for multiple liver metastases radiotherapy. Med Dosim 2011; 36:448-54. [PMID: 21474299 DOI: 10.1016/j.meddos.2010.12.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2010] [Revised: 11/01/2010] [Accepted: 12/02/2010] [Indexed: 10/18/2022]
Abstract
We wanted to compare the dosimetric difference and treatment efficiency of RapidArc and fixed gantry intensity-modulated radiotherapy treatment (IMRT) for multiple liver metastases. Computed tomography datasets of 10 patients were studied retrospectively. IMRT plans were generated using 5 fields and RapidArc using either 1 or 2 arcs. The dose distribution of planning target volume (PTV), organs at risk (OARs), and the normal tissue were compared. Monitor units and treatment time were scored to measure expected treatment efficiency. Both RapidArc and IMRT plans resulted in equivalent target coverage. There was no statistically significant difference for the maximum and the minimum dose of PTV. RapidArc plans achieved an improved conformity index compared with IMRT (RA1 = 1.68 ± 0.27, RA2 = 1.61 ± 0.25, IMRT = 1.80 ± 0.37). For OARs, all techniques respected planning objectives. RapidArc plans had a lower dose in V(40) of small bowel than IMRT, but were higher in mean dose of kidneys. Concerning the V(5), V(10), and V(15) of healthy tissue, RapidArc plans were higher than IMRT. However, the V(20), V(25), and V(30) of healthy tissue in RapidArc plans were lower than IMRT. Monitor units per fraction of RapidArc plans were about 40% or 46% of IMRT. Compared with IMRT plans, treatment time of RapidArc plans were reduced by 60% or 70%. All techniques respected planning objectives. RapidArc showed statistical improvements in conformity index and healthy tissue sparing with uncompromised target coverage. This, in combination with fewer monitor units and short delivery time, can lead to clinically significant advances for the treatment of multiple liver metastases.
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Affiliation(s)
- Yong Yin
- School of Information Science and Engineering of Shandong University, Shandong Province, China
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Elith C, Dempsey SE, Findlay N, Warren-Forward HM. An Introduction to the Intensity-modulated Radiation Therapy (IMRT) Techniques, Tomotherapy, and VMAT. J Med Imaging Radiat Sci 2011; 42:37-43. [DOI: 10.1016/j.jmir.2010.11.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Accepted: 11/10/2010] [Indexed: 12/31/2022]
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Chi A, Jang SY, Welsh JS, Nguyen NP, Ong E, Gobar L, Komaki R. Feasibility of helical tomotherapy in stereotactic body radiation therapy for centrally located early stage non‒small-cell lung cancer or lung metastases. Int J Radiat Oncol Biol Phys 2011; 81:856-62. [PMID: 21255942 DOI: 10.1016/j.ijrobp.2010.11.051] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2010] [Revised: 11/16/2010] [Accepted: 11/25/2010] [Indexed: 12/25/2022]
Abstract
PURPOSE To investigate the ability of helical tomotherapy (HT) to spare critical organs immediately adjacent to the tumor target in stereotactic body radiation therapy (SBRT) for centrally located lung lesions. METHODS AND MATERIALS HT SBRT plans for 10 patients with centrally located lesions or lesions immediately adjacent to a critical structure were generated. A total of 70 Gy in 10 fractions was prescribed to the planning target volume (PTV) to satisfy a target volume coverage of ≥95% PTV receiving 70 Gy and an established set of dose constraints for the organs at risk (OARs). Quality assurance (QA) of the HT plans was performed with both ion chamber and film measurements. RESULTS The PTV coverage criteria was met with 95% of the PTV receiving 70.68 ± 0.33 Gy for all cases even though the OARs immediately adjacent to the PTV ranged from 0.38 to 0.85 cm away. The mean lung dose (MLD), and V(20) were 7.15 ± 1.44 Gy, and 11.93 ± 3.24 % for the total lung, respectively. The dose parameters of MLD, V(5), V(10), and V(20) for the contralateral lung were significantly lower than those for the ipsilateral lung (p < 0.05). An average dose fall off from the PTV periphery to the edge of the immediately adjacent OAR was 47.6% over an average distance of 4.87 mm. Comparison of calculated and measured doses with the ion chamber showed an average of 1.85% point dose error, whereas an average mean gamma and the area with a gamma larger than 1 of 0.20 and 0.94% were observed, respectively. CONCLUSION HT allows the sparing of critical structures immediately adjacent to the tumor target, thus making SBRT for these centrally located lesions feasible.
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Affiliation(s)
- Alexander Chi
- Department of Radiation Oncology, the University of Arizona, Tucson, AZ 85724-5081, USA.
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Pardo-Montero J, Fenwick JD. An approach to multiobjective optimization of rotational therapy. II. Pareto optimal surfaces and linear combinations of modulated blocked arcs for a prostate geometry. Med Phys 2010; 37:2606-16. [PMID: 20632572 DOI: 10.1118/1.3427410] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The purpose of this work is twofold: To further develop an approach to multiobjective optimization of rotational therapy treatments recently introduced by the authors [J. Pardo-Montero and J. D. Fenwick, "An approach to multiobjective optimization of rotational therapy," Med. Phys. 36, 3292-3303 (2009)], especially regarding its application to realistic geometries, and to study the quality (Pareto optimality) of plans obtained using such an approach by comparing them with Pareto optimal plans obtained through inverse planning. METHODS In the previous work of the authors, a methodology is proposed for constructing a large number of plans, with different compromises between the objectives involved, from a small number of geometrically based arcs, each arc prioritizing different objectives. Here, this method has been further developed and studied. Two different techniques for constructing these arcs are investigated, one based on image-reconstruction algorithms and the other based on more common gradient-descent algorithms. The difficulty of dealing with organs abutting the target, briefly reported in previous work of the authors, has been investigated using partial OAR unblocking. Optimality of the solutions has been investigated by comparison with a Pareto front obtained from inverse planning. A relative Euclidean distance has been used to measure the distance of these plans to the Pareto front, and dose volume histogram comparisons have been used to gauge the clinical impact of these distances. A prostate geometry has been used for the study. RESULTS For geometries where a blocked OAR abuts the target, moderate OAR unblocking can substantially improve target dose distribution and minimize hot spots while not overly compromising dose sparing of the organ. Image-reconstruction type and gradient-descent blocked-arc computations generate similar results. The Pareto front for the prostate geometry, reconstructed using a large number of inverse plans, presents a hockey-stick shape comprising two regions: One where the dose to the target is close to prescription and trade-offs can be made between doses to the organs at risk and (small) changes in target dose, and one where very substantial rectal sparing is achieved at the cost of large target underdosage. Plans computed following the approach using a conformal arc and four blocked arcs generally lie close to the Pareto front, although distances of some plans from high gradient regions of the Pareto front can be greater. Only around 12% of plans lie a relative Euclidean distance of 0.15 or greater from the Pareto front. Using the alternative distance measure of Craft ["Calculating and controlling the error of discrete representations of Pareto surfaces in convex multi-criteria optimization," Phys. Medica (to be published)], around 2/5 of plans lie more than 0.05 from the front. Computation of blocked arcs is quite fast, the algorithms requiring 35%-80% of the running time per iteration needed for conventional inverse plan computation. CONCLUSIONS The geometry-based arc approach to multicriteria optimization of rotational therapy allows solutions to be obtained that lie close to the Pareto front. Both the image-reconstruction type and gradient-descent algorithms produce similar modulated arcs, the latter one perhaps being preferred because it is more easily implementable in standard treatment planning systems. Moderate unblocking provides a good way of dealing with OARs which abut the PTV. Optimization of geometry-based arcs is faster than usual inverse optimization of treatment plans, making this approach more rapid than an inverse-based Pareto front reconstruction.
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Affiliation(s)
- Juan Pardo-Montero
- Department of Physics, Clatterbridge Centre for Oncology, Clatterbridge Road, Bebington CH63 4JY, United Kingdom.
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Zaidi H, El Naqa I. PET-guided delineation of radiation therapy treatment volumes: a survey of image segmentation techniques. Eur J Nucl Med Mol Imaging 2010; 37:2165-87. [PMID: 20336455 DOI: 10.1007/s00259-010-1423-3] [Citation(s) in RCA: 205] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2009] [Accepted: 02/20/2010] [Indexed: 12/23/2022]
Abstract
Historically, anatomical CT and MR images were used to delineate the gross tumour volumes (GTVs) for radiotherapy treatment planning. The capabilities offered by modern radiation therapy units and the widespread availability of combined PET/CT scanners stimulated the development of biological PET imaging-guided radiation therapy treatment planning with the aim to produce highly conformal radiation dose distribution to the tumour. One of the most difficult issues facing PET-based treatment planning is the accurate delineation of target regions from typical blurred and noisy functional images. The major problems encountered are image segmentation and imperfect system response function. Image segmentation is defined as the process of classifying the voxels of an image into a set of distinct classes. The difficulty in PET image segmentation is compounded by the low spatial resolution and high noise characteristics of PET images. Despite the difficulties and known limitations, several image segmentation approaches have been proposed and used in the clinical setting including thresholding, edge detection, region growing, clustering, stochastic models, deformable models, classifiers and several other approaches. A detailed description of the various approaches proposed in the literature is reviewed. Moreover, we also briefly discuss some important considerations and limitations of the widely used techniques to guide practitioners in the field of radiation oncology. The strategies followed for validation and comparative assessment of various PET segmentation approaches are described. Future opportunities and the current challenges facing the adoption of PET-guided delineation of target volumes and its role in basic and clinical research are also addressed.
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Affiliation(s)
- Habib Zaidi
- Geneva University Hospital, Geneva 4, Switzerland.
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Palma DA, Verbakel WFAR, Otto K, Senan S. New developments in arc radiation therapy: a review. Cancer Treat Rev 2010; 36:393-9. [PMID: 20181430 DOI: 10.1016/j.ctrv.2010.01.004] [Citation(s) in RCA: 96] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2009] [Revised: 01/14/2010] [Accepted: 01/24/2010] [Indexed: 12/01/2022]
Abstract
Arc therapies have gained widespread clinical interest in radiation oncology over the past decade. Arc therapies have several potential advantages over standard techniques such as intensity-modulated radiation therapy, with implications for patients, administrators, and oncologists. This review focuses on the rationale for arc therapy, descriptions of the modern arc techniques that are currently clinically available, and highlights some distinguishing features of arc therapies, such as dose distributions, treatment times, and imaging capabilities. Arc therapies are exciting examples of progress in radiotherapy through technological innovation, aimed at ultimately improving the therapeutic ratio for patients receiving radiation.
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Affiliation(s)
- David A Palma
- Department of Radiation Oncology, VU University Medical Center, Amsterdam, The Netherlands.
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Oliver M, Ansbacher W, Beckham WA. Comparing planning time, delivery time and plan quality for IMRT, RapidArc and Tomotherapy. J Appl Clin Med Phys 2009; 10:117-131. [PMID: 19918236 PMCID: PMC5720582 DOI: 10.1120/jacmp.v10i4.3068] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 07/14/2009] [Accepted: 07/17/2009] [Indexed: 11/23/2022] Open
Abstract
The purpose of this study is to examine plan quality, treatment planning time, and estimated treatment delivery time for 5- and 9-field sliding window IMRT, single and dual arc RapidArc, and tomotherapy. For four phantoms, 5- and 9-field IMRT, single and dual arc RapidArc and tomotherapy plans were created. Plans were evaluated based on the ability to meet dose-volume constraints, dose homogeneity index, radiation conformity index, planning time, estimated delivery time, integral dose, and volume receiving more than 2 and 5 Gy. For all of the phantoms, tomotherapy was able to meet the most optimization criteria during planning (50% for P1, 67% for P2, 0% for P3, and 50% for P4). RapidArc met less of the optimization criteria (25% for P1, 17% for P2, 0% for P3, and 0% for P4), while IMRT was never able to meet any of the constraints. In addition, tomotherapy plans were able to produce the most homogeneous dose. Tomotherapy plans had longer planning time, longer estimated treatment times, lower conformity index, and higher integral dose. Tomotherapy plans can produce plans of higher quality and have the capability to conform dose distributions better than IMRT or RapidArc in the axial plane, but exhibit increased dose superior and inferior to the target volume. RapidArc, however, is capable of producing better plans than IMRT for the test cases examined in this study.
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Affiliation(s)
- Mike Oliver
- Department of Medical Physics, British Columbia Cancer Agency, Victoria, British Columbia, Canada
| | - Will Ansbacher
- Department of Medical Physics, British Columbia Cancer Agency, Victoria, British Columbia, Canada
| | - Wayne A Beckham
- Department of Medical Physics, British Columbia Cancer Agency, Victoria, British Columbia, Canada
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Jhaveri PM, Teh BS, Paulino AC, Smiedala MJ, Fahy B, Grant W, McGary J, Butler EB. Helical Tomotherapy Significantly Reduces Dose to Normal Tissues When Compared to 3D-CRT for Locally Advanced Rectal Cancer. Technol Cancer Res Treat 2009; 8:379-85. [DOI: 10.1177/153303460900800508] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Combined modality treatment (neoadjuvant chemoradiotherapy followed by surgery) for locally advanced rectal cancer requires special attention to various organs at risk (OAR). As a result, the use of conformal dose delivery methods has become more common in this disease setting. Helical tomotherapy is an image-guided intensity modulated delivery system that delivers dose in a fan-beam manner at 7 degree intervals around the patient and can potentially limit normal tissue from high dose radiation while adequately treating targets. In this study we dosimetrically compare helical tomotherapy to 3D-CRT for stage T3 rectal cancer. The helical tomotherapy plans were optimized in the TomoPlan system to achieve an equivalent uniform dose of 45 Gy for 10 patients with T3N0M0 disease that was at least 5cm from the anal verge. The GTV included the rectal thickening and mass evident on colonoscopy and CT scan as well as with the help of a colorectal surgeon. The CTV included the internal iliac, obturator, and pre-sacral lymphatic chains. The OAR that were outlined included the small bowel, pelvic bone marrow, femoral heads, and bladder. Anatom-e system was used to assist in delineating GTV, CTV and OAR. These 10 plans were then duplicated and optimized into 3-field 3D-CRT plans within the Pinnacle planning system. The V[45], V[40], V[30], V[20], V[10], and mean dose to the OAR were compared between the helical tomotherapy and 3D-CRT plans. Statistically significant differences were achieved in the doses to all OAR, including all volumes and means except for V[10] for the small bowel and the femoral heads. Adequate dosimetric coverage of targets were achieved with both helical tomotherapy and 3D-CRT. Helical tomotherapy reduces the volume of normal tissue receiving high-dose RT when compared to 3D-CRT treatment. Both modalities adequately dose the tumor. Clinical studies addressing the dosimetric benefits are on-going.
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Affiliation(s)
- Pavan M. Jhaveri
- Baylor College of Medicine Department of Radiology, Section of Radiation Oncology One Baylor Plaza, Houston TX, 77030, USA
| | - Bin S. Teh
- The Methodist Hospital Department of Radiation Oncology,
- The Methodist Hospital Research Institute, 6565 Fannin, Houston, TX, 77030, USA
| | - Arnold C. Paulino
- The Methodist Hospital Department of Radiation Oncology,
- The Methodist Hospital Research Institute, 6565 Fannin, Houston, TX, 77030, USA
| | | | - Bridget Fahy
- The Methodist Hospital, Department of Surgery 6550 Fannin, Smith #1661 Houston, TX, 77030, USA
| | - Walter Grant
- Baylor College of Medicine Department of Radiology, Section of Radiation Oncology One Baylor Plaza, Houston TX, 77030, USA
| | - John McGary
- Baylor College of Medicine Department of Radiology, Section of Radiation Oncology One Baylor Plaza, Houston TX, 77030, USA
| | - E. Brian Butler
- The Methodist Hospital Department of Radiation Oncology,
- The Methodist Hospital Research Institute, 6565 Fannin, Houston, TX, 77030, USA
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Pardo-Montero J, Fenwick JD. An approach to multiobjective optimization of rotational therapy. Med Phys 2009; 36:3292-303. [PMID: 19673225 DOI: 10.1118/1.3151806] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Multiobjective optimization is used in radiotherapy, especially IMRT, to generate treatment plans which meet different objectives to varying extents. Trade-off surfaces can be constructed representing the gains and losses of different objectives when switching from one plan to another, and the planner can interactively explore different treatment possibilities without the need for reoptimization. In this work a method for the multiobjective optimization of rotational therapy is introduced. The proposed method is applied slice per slice and uses the geometry of the slice directly to construct several arcs, each conformally irradiating the tumor and blocking a number (0,1,2,...) of different organs at risk present in the treatment. The blocked arc dose distributions so obtained are quite inhomogeneous in the target. An algorithm, based on the iterative reconstruction of images from projections, has been developed to compensate for this inhomogeneity, leading to compensated blocked arcs which deliver more uniform target doses but still block critical structures. Different treatments can be obtained as linear combinations of these arcs, each involving different trade-offs among the objectives involved. The compensatory algorithm substantially improves the target dose uniformity of blocked arcs at the cost of slightly increasing the dose to the rest of the body, allowing delivery of good uniform dose distributions to the target without significantly irradiating the blocked organ(s). Trade-off surfaces are presented for slices containing a target and one or two critical structures. The method is directly implementable using axial or helical tomotherapy. Implementation for conventional linear accelerators will be more difficult because the number of arcs needed to deliver such treatments can be large, an issue to be explored in future work.
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Affiliation(s)
- Juan Pardo-Montero
- School of Cancer Studies, University of Liverpool, Liverpool L69 7ZE, United Kingdom.
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Zaidi H, Vees H, Wissmeyer M. Molecular PET/CT imaging-guided radiation therapy treatment planning. Acad Radiol 2009; 16:1108-33. [PMID: 19427800 DOI: 10.1016/j.acra.2009.02.014] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2008] [Revised: 02/11/2009] [Accepted: 02/19/2009] [Indexed: 01/01/2023]
Abstract
The role of positron emission tomography (PET) during the past decade has evolved rapidly from that of a pure research tool to a methodology of enormous clinical potential. (18)F-fluorodeoxyglucose (FDG)-PET is currently the most widely used probe in the diagnosis, staging, assessment of tumor response to treatment, and radiation therapy planning because metabolic changes generally precede the more conventionally measured parameter of change in tumor size. Data accumulated rapidly during the last decade, thus validating the efficacy of FDG imaging and many other tracers in a wide variety of malignant tumors with sensitivities and specificities often in the high 90 percentile range. As a result, PET/computed tomography (CT) had a significant impact on the management of patients because it obviated the need for further evaluation, guided further diagnostic procedures, and assisted in planning therapy for a considerable number of patients. On the other hand, the progress in radiation therapy technology has been enormous during the last two decades, now offering the possibility to plan highly conformal radiation dose distributions through the use of sophisticated beam targeting techniques such as intensity-modulated radiation therapy (IMRT) using tomotherapy, volumetric modulated arc therapy, and many other promising technologies for sculpted three-dimensional (3D) dose distribution. The foundation of molecular imaging-guided radiation therapy lies in the use of advanced imaging technology for improved definition of tumor target volumes, thus relating the absorbed dose information to image-based patient representations. This review documents technological advancements in the field concentrating on the conceptual role of molecular PET/CT imaging in radiation therapy treatment planning and related image processing issues with special emphasis on segmentation of medical images for the purpose of defining target volumes. There is still much more work to be done and many of the techniques reviewed are themselves not yet widely implemented in clinical settings.
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Abstract
Our understanding of how radiation kills normal and tumour cells has been based on an intimate knowledge of the direct induction of DNA damage and its cellular consequences. What has become clear is that, as well as responses to direct DNA damage, cell-cell signalling -- known as the bystander effect -- mediated through gap junctions and inflammatory responses may have an important role in the response of cells and tissues to radiation exposure and also chemotherapy agents. This Review outlines the key aspects of radiation-induced intercellular signalling and assesses its relevance for existing and future radiation-based therapies.
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Affiliation(s)
- Kevin M Prise
- Centre for Cancer Research & Cell Biology, Queen's University Belfast, Belfast, UK.
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Fogliata A, Yartsev S, Nicolini G, Clivio A, Vanetti E, Wyttenbach R, Bauman G, Cozzi L. On the performances of Intensity Modulated Protons, RapidArc and Helical Tomotherapy for selected paediatric cases. Radiat Oncol 2009; 4:2. [PMID: 19144155 PMCID: PMC2672932 DOI: 10.1186/1748-717x-4-2] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2008] [Accepted: 01/14/2009] [Indexed: 11/27/2022] Open
Abstract
Background To evaluate the performance of three different advanced treatment techniques on a group of complex paediatric cancer cases. Methods CT images and volumes of interest of five patients were used to design plans for Helical Tomotherapy (HT), RapidArc (RA) and Intensity Modulated Proton therapy (IMP). The tumour types were: extraosseous, intrathoracic Ewing Sarcoma; mediastinal Rhabdomyosarcoma; metastastis of base of skull with bone, para-nasal and left eye infiltration from Nephroblastoma of right kidney; metastatic Rhabdomyosarcoma of the anus; Wilm's tumour of the left kidney with multiple liver metastases. Cases were selected for their complexity regardless the treatment intent and stage. Prescribed doses ranged from 18 to 53.2 Gy, with four cases planned using a Simultaneous Integrated Boost strategy. Results were analysed in terms of dose distributions and dose volume histograms. Results For all patients, IMP plans lead to superior sparing of organs at risk and normal healthy tissue, where in particular the integral dose is halved with respect to photon techniques. In terms of conformity and of spillage of high doses outside targets (external index (EI)), all three techniques were comparable; CI90% ranged from 1.0 to 2.3 and EI from 0 to 5%. Concerning target homogeneity, IMP showed a variance (D5%–D95%) measured on the inner target volume (highest dose prescription) ranging from 5.9 to 13.3%, RA from 5.3 to 11.8%, and HT from 4.0 to 12.2%. The range of minimum significant dose to the same target was: (72.2%, 89.9%) for IMP, (86.7%, 94.1%) for RA, and (79.4%, 94.8%) for HT. Similarly, for maximum significant doses: (103.8%, 109.4%) for IMP, (103.2%, 107.4%) for RA, and (102.4%, 117.2%) for HT. Treatment times (beam-on time) ranged from 123 to 129 s for RA and from 146 to 387 s for HT. Conclusion Five complex pediatric cases were selected as representative examples to compare three advanced radiation delivery techniques. While differences were noted in the metrics examined, all three techniques provided satisfactory conformal avoidance and conformation.
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Affiliation(s)
- Antonella Fogliata
- Oncology Institute of Southern Switzerland, Medical Physics Unit, Bellinzona, Switzerland.
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Fogliata A, Clivio A, Nicolini G, Vanetti E, Cozzi L. Intensity modulation with photons for benign intracranial tumours: a planning comparison of volumetric single arc, helical arc and fixed gantry techniques. Radiother Oncol 2008; 89:254-62. [PMID: 18760851 DOI: 10.1016/j.radonc.2008.07.021] [Citation(s) in RCA: 163] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2008] [Revised: 07/07/2008] [Accepted: 07/12/2008] [Indexed: 01/29/2023]
Abstract
BACKGROUND AND PURPOSE The potential benefits and limitations of the new RapidArc treatment concept compared to Helical Tomotherapy and fixed gantry intensity modulation techniques have been assessed at treatment planning level on 12 patients presenting with 'benign' brain tumours. MATERIALS AND METHODS Plans for five acoustic neurinomas, five meningiomas and two pituitary adenomas were computed for an Helical Tomotherapy (HT) unit, for RapidArc delivery (RA) on a linac equipped with two types of MLC (RA_HD120 with the new High Definition MLC with 2.5mm leaf width at isocentre and RA_M120 with the standard Millennium with 5mm resolution) and for fixed beam IMRT with the High Definition MLC. Analysis was mostly performed on physical quantities derived from Dose-Volume Histograms (DVHs). RESULTS Target coverage resulted basically equivalent among techniques. V(95%) (in %) was higher than 99% for all techniques, minimum significant dose (D(99%)) was 95.5+/-1.4 for IMRT, 96.2+/-1.4 and 97.0+/-1.2 for the RA_HD120 and RA_M120 approaches and 96.8+/-1.7 for HT, maximum significant dose (D(1%), in %) was 102.2+/-0.8, 102.7+/-0.5, 102.4+/-0.5 and 103.0+/-1.1, respectively, standard deviation (in %) was 1.4+/-0.4, 1.3+/-0.3, 1.1+/-0.2 and 0.8+/-0.3, respectively. Conformity Index (CI(95%)) was 0.47+/-0.12, 0.46+/-0.12, 0.43+/-0.11 and 0.38+/-0.11, respectively. For organs at risk all techniques respected planning objectives. Concerning the healthy tissue: V(10 Gy) (in %) was 9.4+/-5.5, 9.9+/-6.1, 9.2+/-6.1 and 12.1+/-8.8, respectively. Integral dose measured on the healthy tissue was 7.5+/-3.3, 9.7+/-3.4, 8.7+/-3.4, 10.4+/-4.2 10(3) Gy cm(3), respectively. CONCLUSIONS For the class of tumours investigated in this report, HT and RA and IMRT proved to be adequate to properly treat patients. Further studies on more complex cases need to be investigated in order to assess the effectiveness of this new technique in a broader clinical perspective.
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Affiliation(s)
- Antonella Fogliata
- Oncology Institute of Southern Switzerland, Radiation Oncology Department, Bellinzona, Switzerland
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Min BS, Kim NK, Sohn SK, Cho CH, Lee KY, Baik SH. Isolated paraaortic lymph-node recurrence after the curative resection of colorectal carcinoma. J Surg Oncol 2008; 97:136-40. [PMID: 17963247 DOI: 10.1002/jso.20926] [Citation(s) in RCA: 70] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
BACKGROUND AND OBJECTIVES Isolated paraaortic lymph-node recurrence (IPLR) after curative surgery for colorectal carcinoma is rare and no previous report has specifically addressed this type of recurrence. We investigated the clinical features of IPLR and analyzed prognostic factors. METHODS Of 2,916 patients who underwent curative surgery for colorectal carcinoma, IPLR was identified in 38 patients (1.3%). The clinical features and prognostic factors of these patients were analyzed. RESULTS IPLR was first detected by increased serum carcinoembryonic antigen (CEA) levels (63.2%) or by routine follow-up computed tomography (CT) (36.8%). Curative resection of IPLR was performed in six patients (15.8%). A total of 19 patients (50.0%) received chemoradiation therapy and 13 patients (34.2%) received chemotherapy only. The median survival from IPLR was 13 months (range: 5-60 months). The median survival time from IPLR for the resected patients was 34 months, whereas it was 12 months for those who did not undergo resection (P = 0.034). The factors associated with the prognosis were histological grade (P = 0.003), location (P = 0.032), and resection of IPLR (P = 0.034). CONCLUSIONS IPLR after curative surgery for colorectal carcinoma is rare. Although it is generally associated with poor prognosis, better survival might be achieved through curative resection in selected cases.
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Affiliation(s)
- Byung Soh Min
- Department of Surgery, Yonsei University College of Medicine, Seodamun-Gu, Seoul, Korea.
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Keum KC. Helical Tomotherapy: Image-guided Intensity Modulated Radiation Therapy. JOURNAL OF THE KOREAN MEDICAL ASSOCIATION 2008. [DOI: 10.5124/jkma.2008.51.7.619] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Ki Chang Keum
- Department of Radiation Oncology, Yonsei University College of Medicine, Korea.
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Lecchi M, Fossati P, Elisei F, Orecchia R, Lucignani G. Current concepts on imaging in radiotherapy. Eur J Nucl Med Mol Imaging 2007; 35:821-37. [PMID: 17972074 DOI: 10.1007/s00259-007-0631-y] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2007] [Accepted: 10/02/2007] [Indexed: 11/29/2022]
Abstract
New high-precision radiotherapy (RT) techniques, such as intensity-modulated radiation therapy (IMRT) or hadrontherapy, allow better dose distribution within the target and spare a larger portion of normal tissue than conventional RT. These techniques require accurate tumour volume delineation and intrinsic characterization, as well as verification of target localisation and monitoring of organ motion and response assessment during treatment. These tasks are strongly dependent on imaging technologies. Among these, computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography (US) and positron emission tomography (PET) have been applied in high-precision RT. For tumour volume delineation and characterization, PET has brought an additional dimension to the management of cancer patients by allowing the incorporation of crucial functional and molecular images in RT treatment planning, i.e. direct evaluation of tumour metabolism, cell proliferation, apoptosis, hypoxia and angiogenesis. The combination of PET and CT in a single imaging system (PET/CT) to obtain a fused anatomical and functional dataset is now emerging as a promising tool in radiotherapy departments for delineation of tumour volumes and optimization of treatment plans. Another exciting new area is image-guided radiotherapy (IGRT), which focuses on the potential benefit of advanced imaging and image registration to improve precision, daily target localization and monitoring during treatment, thus reducing morbidity and potentially allowing the safe delivery of higher doses. The variety of IGRT systems is rapidly expanding, including cone beam CT and US. This article examines the increasing role of imaging techniques in the entire process of high-precision radiotherapy.
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Affiliation(s)
- Michela Lecchi
- Institute of Radiological Sciences, University of Milan, Milan, Italy
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Kim Y, Tomé WA. On the radiobiological impact of metal artifacts in head-and-neck IMRT in terms of tumor control probability (TCP) and normal tissue complication probability (NTCP). Med Biol Eng Comput 2007; 45:1045-51. [PMID: 17574487 DOI: 10.1007/s11517-007-0196-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2006] [Accepted: 05/08/2007] [Indexed: 11/25/2022]
Abstract
To investigate the effects of distorted head-and-neck (H&N) intensity-modulated radiation therapy (IMRT) dose distributions (hot and cold spots) on normal tissue complication probability (NTCP) and tumor control probability (TCP) due to dental-metal artifacts. Five patients' IMRT treatment plans have been analyzed, employing five different planning image data-sets: (a) uncorrected (UC); (b) homogeneous uncorrected (HUC); (c) sinogram completion corrected (SCC); (d) minimum-value-corrected (MVC); and (e) streak-artifact-reduction including minimum-value-correction (SAR-MVC), which has been taken as the reference data-set. The effects on NTCP and TCP were evaluated using the Lyman-NTCP model and the Logistic-TCP model, respectively. When compared to the predicted NTCP obtained using the reference data-set, the treatment plan based on the original CT data-set (UC) yielded an increase in NTCP of 3.2 and 2.0% for the spared parotid gland and the spinal cord, respectively. While for the treatment plans based on the MVC CT data-set the NTCP increased by a 1.1% and a 0.1% for the spared parotid glands and the spinal cord, respectively. In addition, the MVC correction method showed a reduction in TCP for target volumes (MVC: delta TCP = -0.6% vs. UC: delta TCP = -1.9%) with respect to that of the reference CT data-set. Our results indicate that the presence of dental-metal-artifacts in H&N planning CT data-sets has an impact on the estimates of TCP and NTCP. In particular dental-metal-artifacts lead to an increase in NTCP for the spared parotid glands and a slight decrease in TCP for target volumes.
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Affiliation(s)
- Yusung Kim
- Department of Medical Physics, University of Wisconsin, Madison, WI 53792, USA
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Franko J, Greer JB, Moran CM, Khalid A, Moser AJ. Multimodality therapy for pancreatic cancer. Gastroenterol Clin North Am 2007; 36:391-411, x. [PMID: 17533086 DOI: 10.1016/j.gtc.2007.03.004] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Neoadjuvant chemoradiotherapy can be administered safely to patients with pancreatic cancer. Complete pathologic responses are rare, however, and the benefits of this approach compared with standard adjuvant therapy are uncertain. The only way to evaluate the efficacy of neoadjuvant chemoradiotherapy is a prospective trial involving a uniform patient population comparing the results of neoadjuvant and adjuvant therapy and a cohort receiving surgery alone. Such a study can be designed in an ethically sound manner but requires the collaboration of numerous institutions and careful coordination to achieve statistically conclusive results. The future of pancreatic cancer research rests on the availability and rapid transfer of new therapies from the laboratory to clinical research.
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Affiliation(s)
- Jan Franko
- Division of Surgical Oncology, University of Pittsburgh Medical Center, 497 Scaife Hall, 3550 Terrace Street, Pittsburgh, PA 15261, USA
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Webb S, Evans PM. Innovative Techniques in Radiation Therapy: Editorial, Overview, and Crystal Ball Gaze to the Future. Semin Radiat Oncol 2006; 16:193-8. [PMID: 17010901 DOI: 10.1016/j.semradonc.2006.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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