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Delouya G, Igidbashian L, Houle A, Bélair M, Boucher L, Cohade C, Beaulieu S, Filion EJ, Coulombe G, Hinse M, Martel C, Després P, Nguyen-Tan PF. ¹⁸F-FDG-PET imaging in radiotherapy tumor volume delineation in treatment of head and neck cancer. Radiother Oncol 2011; 101:362-8. [PMID: 21885143 DOI: 10.1016/j.radonc.2011.07.025] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2011] [Revised: 06/29/2011] [Accepted: 07/13/2011] [Indexed: 11/27/2022]
Abstract
PURPOSE To determine the impact of (18)F-fluorodeoxyglucose positron emission tomography (PET) in radiotherapy target delineation and patient management for head and neck squamous cell carcinoma (HNSCC) compared to computed tomography (CT) alone. MATERIALS AND METHODS Twenty-nine patients with HNSCC were included. CT and PET/CT obtained for treatment planning purposes were reviewed respectively by a neuroradiologist and a nuclear medicine specialist who were blinded to the findings from each other. The attending radiation oncologist together with the neuroradiologist initially defined all gross tumor volume of the primary (GTVp) and the suspicious lymph nodes (GTVn) on CT. Subsequently, the same radiation oncologist and the nuclear medicine specialist defined the GTVp and GTVn on (18)F-FDG-PET/CT. Upon disagreement between CT and (18)F-FDG-PET on the status of a particular lymph node, an ultrasound-guided fine needle aspiration was performed. Volumes based on CT and (18)F-FDG-PET were compared with a paired Student's t-test. RESULTS For the primary disease, four patients had previous diagnostic tonsillectomy and therefore, FDG uptake occurred in 25 patients. For these patients, GTVp contoured on (18)F-FDG-PET (GTVp-PET) were smaller than the GTVp contoured on CT (GTVp-CT) in 80% of the cases, leading to a statistically significant volume difference (p=0.001). Of the 60 lymph nodes suspicious on PET, 55 were also detected on CT. No volume change was observed (p=0.08). Ten biopsies were performed for lymph nodes that were discordant between modalities and all were of benign histology. Distant metastases were found in two patients and one had a newly diagnosed lung adenocarcinoma. CONCLUSIONS GTVp-CT was significantly larger when compared to GTVp-PET. No such change was observed for the lymph nodes. (18)F-FDG-PET modified treatment management in three patients, including two for which no curative radiotherapy was attempted. Larger multicenter studies are needed to ascertain whether combined (18)F-FDG-PET/CT in target delineation can influence the main clinical outcomes.
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Affiliation(s)
- Guila Delouya
- Department of Radiation Oncology, Centre Hospitalier de l'Université de Montréal, Montréal, Canada.
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Stabenau H, Rivera L, Yorke E, Yang J, Lu R, Radke RJ, Jackson A. Reduced order constrained optimization (ROCO): clinical application to lung IMRT. Med Phys 2011; 38:2731-41. [PMID: 21776810 DOI: 10.1118/1.3575416] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE The authors use reduced-order constrained optimization (ROCO) to create clinically acceptable IMRT plans quickly and automatically for advanced lung cancer patients. Their new ROCO implementation works with the treatment planning system and full dose calculation used at Memorial Sloan-Kettering Cancer Center (MSKCC). The authors have implemented mean dose hard constraints, along with the point-dose and dose-volume constraints that the authors used for our previous work on the prostate. METHODS ROCO consists of three major steps. First, the space of treatment plans is sampled by solving a series of optimization problems using penalty-based quadratic objective functions. Next, an efficient basis for this space is found via principal component analysis (PCA); this reduces the dimensionality of the problem. Finally, a constrained optimization problem is solved over this basis to find a clinically acceptable IMRT plan. Dimensionality reduction makes constrained optimization computationally efficient. RESULTS The authors apply ROCO to 12 stage III non-small-cell lung cancer (NSCLC) cases, generating IMRT plans that meet all clinical constraints and are clinically acceptable, and demonstrate that they are competitive with the clinical treatment plans. The authors also test how many samples and PCA modes are necessary to achieve an adequate lung plan, demonstrate the importance of long-range dose calculation for ROCO, and evaluate the performance of nonspecific normal tissue ("rind") constraints in ROCO treatment planning for the lung. Finally, authors show that ROCO can save time for planners, and they estimate that in the clinic, planning using their approach would save a median of 105 min for the patients in the study. CONCLUSIONS New challenges arise when applying ROCO to the lung site, which include the lack of a class solution, a larger treatment site, an increased number of parameters and beamlets, a variable number of beams and beam arrangement, and the customary use of rinds in clinical plans to avoid high-dose areas outside the PTV. In the authors previous work, use of an approximate dose calculation in the hard constraint optimization sometimes meant that clinical constraints were not met when evaluated with the full dose calculation. This difficulty has been removed in the current work by using the full dose calculation in the hard constraint optimization. The authors have demonstrated that ROCO offers a fast and automatic way to create IMRT plans for advanced NSCLC, which extends their previous application of ROCO to prostate cancer IMRT planning.
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Affiliation(s)
- Hans Stabenau
- Memorial Sloan-Kettering Cancer Center, 1275 York Ave., New York, New York 10065, USA.
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Tribius S, Bergelt C. Intensity-modulated radiotherapy versus conventional and 3D conformal radiotherapy in patients with head and neck cancer: is there a worthwhile quality of life gain? Cancer Treat Rev 2011; 37:511-9. [PMID: 21324605 DOI: 10.1016/j.ctrv.2011.01.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2010] [Revised: 01/11/2011] [Accepted: 01/20/2011] [Indexed: 10/18/2022]
Abstract
BACKGROUND Intensity-modulated radiotherapy (IMRT) is a technique that allows delivery of lower doses of radiation to normal tissue, while maintaining or increasing the tumour dose, compared with two-dimensional radiotherapy (2DRT) or three-dimensional conformal radiotherapy (3DCRT). This review of published data was undertaken to assess whether IMRT is associated with quality of life (QoL) benefits versus 2DRT and 3DCRT. DESIGN English-language literature published between January 2005 and August 2010 was searched for studies comparing IMRT versus 2DRT or 3DCRT in head and neck cancers that included QoL evaluation. Fourteen studies (five prospective and nine retrospective) were identified, two in abstract form only. Only one study was randomised. Studies included patients with nasopharyngeal cancer only, oropharyngeal cancer only and mixed populations. RESULTS The EORTC QLQ-C30 was the most widely used instrument, generally supplemented with the head and neck cancer module H&N35. IMRT was associated with statistically significant improvements in certain QoL domains versus 2DRT and 3DCRT, particularly those relating to xerostomia, including dry mouth, sticky saliva and eating-related domains. Improvements in global QoL were also observed in the IMRT groups in some studies. CONCLUSION Based on the studies reviewed, patients treated with IMRT experience statistically significant improvements in several important QoL domains versus 2DRT and 3DCRT. However, studies included heterogeneous populations, different timepoints for measurements and a variety of instruments for QoL assessment. Accepting the difficulties in execution, IMRT should be compared with 3DCRT in prospective randomised studies in homogeneous patient populations, using appropriate QoL assessments and clinical end points, to establish if IMRT provides enough value for the additional resources involved.
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Affiliation(s)
- Silke Tribius
- Department of Radiation Oncology, University Medical Center, Hamburg-Eppendorf, Martinistrasse 52, 20246 Hamburg, Germany.
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Yin Y, Chen J, Xing L, Dong X, Liu T, Lu J, Yu J. Applications of IMAT in cervical esophageal cancer radiotherapy: a comparison with fixed-field IMRT in dosimetry and implementation. J Appl Clin Med Phys 2011; 12:3343. [PMID: 21587177 PMCID: PMC5718659 DOI: 10.1120/jacmp.v12i2.3343] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 10/07/2010] [Accepted: 11/15/2010] [Indexed: 11/23/2022] Open
Abstract
This study aimed to compare fixed-field, intensity-modulated radiotherapy (f-IMRT) with intensity-modulated arc therapy (IMAT) treatment plans in dosimetry and practical application for cervical esophageal carcinoma. For ten cervical esophageal carcinoma cases, f-IMRT plan (seven fixed-fields) and two IMAT plans, namely RA (coplanar 360° arcs) and RAx (coplanar 360° arcs without sectors from 80° to 110°, and 250° to 280°), were generated. DVHs were adopted for the statistics of above parameters, as well as conformal index (CI), homogeneity index (HI), dose-volumetric parameters of normal tissues, total accelerator output MUs and total treatment time. There were differences between RAx and f-IMRT, as well as RA in PTV parameters such as HI, V(95%) and V(110%), but not in CI. RAx reduced lung V₅ from (50.9% ± 9.8% in f-IMRT and (51.4% ± 10.8% in RA to (49.3% ± 10.4% in RAx (p < 0.05). However, lung V₃₀, V₄₀, V₅₀ and MLD increased in RAx. There was no difference in the mean heart dose in three plans. Total MU was reduced from 1174.8 ± 144.6 in f-IMRT to 803.8 ± 122.2 in RA and 736.2 ± 186.9 in RAx (p < 0.05). Compared with f-IMRT, IMAT reduced low dose volumes of lung and total MU on the basis of meeting clinical requirements.
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Affiliation(s)
- Yong Yin
- School of Information Science and Engineering, Shandong University, Jinan, China
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Dink D, Langer M, Orcun S, Pekny J, Rardin R, Reklaitis G, Saka B. IMRT Optimization with Both Fractionation and Cumulative Constraints. ACTA ACUST UNITED AC 2011. [DOI: 10.4236/ajor.2011.13018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Lamers-Kuijper E, Heemsbergen W, van Mourik A, Rasch C. Sequentially delivered boost plans are superior to simultaneously delivered plans in head and neck cancer when the boost volume is located further away from the parotid glands. Radiother Oncol 2011; 98:51-6. [DOI: 10.1016/j.radonc.2010.10.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 09/14/2010] [Accepted: 10/30/2010] [Indexed: 10/18/2022]
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Meßmer MB, Thomsen A, Kirste S, Becker G, Momm F. Xerostomia after radiotherapy in the head&neck area: Long-term observations. Radiother Oncol 2011; 98:48-50. [DOI: 10.1016/j.radonc.2010.10.013] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2010] [Revised: 10/12/2010] [Accepted: 10/14/2010] [Indexed: 10/18/2022]
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Yang W, Jones R, Read P, Benedict S, Sheng K. Standardized evaluation of simultaneous integrated boost plans on volumetric modulated arc therapy. Phys Med Biol 2010; 56:327-39. [DOI: 10.1088/0031-9155/56/2/003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Vergeer MR, Doornaert PA, Jonkman A, Kaanders JH, van den Ende PL, de Jong MA, Leemans CR, Slotman BJ, Langendijk JA. Ipsilateral Irradiation for Oral and Oropharyngeal Carcinoma Treated With Primary Surgery and Postoperative Radiotherapy. Int J Radiat Oncol Biol Phys 2010; 78:682-8. [DOI: 10.1016/j.ijrobp.2009.08.042] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2009] [Revised: 08/25/2009] [Accepted: 08/25/2009] [Indexed: 10/19/2022]
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The postradiation neck: evaluating response to treatment and recognizing complications. AJR Am J Roentgenol 2010; 195:W164-71. [PMID: 20651177 DOI: 10.2214/ajr.09.4122] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
OBJECTIVE We summarize the rationale for and physiology of radiation therapy for the treatment of head and neck cancer and review the imaging findings of expected changes and complications after radiation to the neck. It is important to be able to recognize these features at all stages during management of patients with squamous cell carcinoma and other head and neck malignancies and to be able to distinguish these changes from residual or recurrent disease. CONCLUSION Radiation therapy results in imaging findings of tissue edema followed by fibrosis, scarring, and atrophy. Complications from radiation therapy can occur months to years after treatment. Findings of a new mass, lymphadenopathy, or bone or cartilage destruction must be viewed as concerning for recurrent disease.
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Xerostomie. HNO 2010; 58:680-5. [DOI: 10.1007/s00106-010-2084-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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62
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A Novel Dose Constraint to Reduce Xerostomia in Head-and-Neck Cancer Patients Treated With Intensity-Modulated Radiotherapy. Int J Radiat Oncol Biol Phys 2010; 77:269-76. [DOI: 10.1016/j.ijrobp.2009.07.1734] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2008] [Revised: 07/25/2009] [Accepted: 07/29/2009] [Indexed: 11/21/2022]
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Nelms BE, Rasmussen KH, Tome WA. Evaluation of a fast method of EPID-based dosimetry for intensity-modulated radiation therapy. J Appl Clin Med Phys 2010. [PMID: 20592703 PMCID: PMC2897728 DOI: 10.1120/jacmp.v11i2.3185] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
Abstract
Electronic portal imaging devices (EPIDs) could potentially be useful for intensity-modulated radiation therapy (IMRT) QA. The data density, high resolution, large active area, and efficiency of the MV EPID make it an attractive option. However, EPIDs were designed as imaging devices, not dosimeters, and as a result they do not inherently measure dose in tissue equivalent media. EPIDose (Sun Nuclear, Melbourne, FL) is a tool designed for the use of EPIDs in IMRT QA that uses raw MV EPID images (no additional build-up and independent of gantry angle, but with dark and flood field corrections applied) to estimate absolute dose planes normal to the beam axis in a homogeneous media (i.e. similar to conventional IMRT QA methods). However, because of the inherent challenges of the EPID-based dosimetry, validating and commissioning such a system must be done very carefully, by exploring the range of use cases and using well-proven "standards" for comparison. In this work, a multi-institutional study was performed to verify accurate EPID image to dose plane conversion over a variety of conditions. Converted EPID images were compared to 2D diode array absolute dose measurements for 188 fields from 28 clinical IMRT treatment plans. These plans were generated using a number of commercially available treatment planning systems (TPS) covering various treatment sites including prostate, head and neck, brain, and lung. The data included three beam energies (6, 10, and 15 MV) and both step-and-shoot and dynamic MLC fields. Out of 26,207 points of comparison over 188 fields analyzed, the average overall field pass rate was 99.7% when 3 mm/3% DTA criteria were used (range 94.0-100 per field). The pass rates for more stringent criteria were 97.8% for 2mm/2% DTA (range 82.0-100 per field), and 84.6% for 1 mm/1% DTA (range 54.7-100 per field). Individual patient-specific sites as well, as different beam energies, followed similar trends to the overall pass rates.
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Affiliation(s)
- Benjamin E Nelms
- Louisiana State University, Department of Physics and Astronomy, Baton Rouge, LA, USA
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Liu WS, Hsin CH, Chou YH, Liu JT, Wu MF, Tseng SW, Lee JK, Tseng HC, Wang TH, Su MC, Lee H. Long-term results of intensity-modulated radiotherapy concomitant with chemotherapy for hypopharyngeal carcinoma aimed at laryngeal preservation. BMC Cancer 2010; 10:102. [PMID: 20298550 PMCID: PMC3087314 DOI: 10.1186/1471-2407-10-102] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2009] [Accepted: 03/18/2010] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The objective of this retrospective study is to investigate laryngeal preservation and long-term treatment results in hypopharyngeal carcinoma treated with intensity-modulated radiotherapy (IMRT) combined with chemotherapy. METHODS Twenty-seven patients with hypopharyngeal carcinoma (stage II-IV) were enrolled and underwent concurrent chemoradiotherapy. The chemotherapy regimens were monthly cisplatin and 5-fluorouracil for six patients and weekly cisplatin for 19 patients. All patients were treated with IMRT with simultaneous integrated boost technique. Acute and late toxicities were recorded based on CTCAE 3.0 (Common Terminology Criteria for Adverse Events). RESULTS The median follow-up time for survivors was 53.0 months (range 36-82 months). The initial complete response rate was 85.2%, with a laryngeal preservation rate of 63.0%. The 5-year functional laryngeal, local-regional control, disease-free and overall survival rates were 59.7%, 63.3%, 51.0% and 34.8%, respectively. The most common greater than or equal to grade 3 acute and late effects were dysphagia (63.0%, 17 of 27 patients) and laryngeal stricture (18.5%, 5 of 27 patients), respectively. Patients belonging to the high risk group showed significantly higher risk of tracheostomy compared to the low risk group (p = 0.014). CONCLUSIONS After long-term follow-up, our results confirmed that patients with hypopharyngeal carcinoma treated with IMRT concurrent with platinum-based chemotherapy attain high functional laryngeal and local-regional control survival rates. However, the late effect of laryngeal stricture remains a problem, particularly for high risk group patients.
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Affiliation(s)
- Wen-Shan Liu
- Departments of Radiation Oncology, Chung Shan Medical University Hospital, No 110, Sec 1, Chien-Kuo N Rd, Taichung 402, Taiwan
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Impact of patient setup error in the treatment of head and neck cancer with intensity modulated radiation therapy. Phys Med 2010; 26:26-33. [DOI: 10.1016/j.ejmp.2009.05.001] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/14/2008] [Revised: 04/07/2009] [Accepted: 05/20/2009] [Indexed: 11/17/2022] Open
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Abate A, Pressello MC, Benassi M, Strigari L. Comparison of IMRT planning with two-step and one-step optimization: a strategy for improving therapeutic gain and reducing the integral dose. Phys Med Biol 2009; 54:7183-98. [PMID: 19920309 DOI: 10.1088/0031-9155/54/23/010] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The aim of this study was to evaluate the effectiveness and efficiency in inverse IMRT planning of one-step optimization with the step-and-shoot (SS) technique as compared to traditional two-step optimization using the sliding windows (SW) technique. The Pinnacle IMRT TPS allows both one-step and two-step approaches. The same beam setup for five head-and-neck tumor patients and dose-volume constraints were applied for all optimization methods. Two-step plans were produced converting the ideal fluence with or without a smoothing filter into the SW sequence. One-step plans, based on direct machine parameter optimization (DMPO), had the maximum number of segments per beam set at 8, 10, 12, producing a directly deliverable sequence. Moreover, the plans were generated whether a split-beam was used or not. Total monitor units (MUs), overall treatment time, cost function and dose-volume histograms (DVHs) were estimated for each plan. PTV conformality and homogeneity indexes and normal tissue complication probability (NTCP) that are the basis for improving therapeutic gain, as well as non-tumor integral dose (NTID), were evaluated. A two-sided t-test was used to compare quantitative variables. All plans showed similar target coverage. Compared to two-step SW optimization, the DMPO-SS plans resulted in lower MUs (20%), NTID (4%) as well as NTCP values. Differences of about 15-20% in the treatment delivery time were registered. DMPO generates less complex plans with identical PTV coverage, providing lower NTCP and NTID, which is expected to reduce the risk of secondary cancer. It is an effective and efficient method and, if available, it should be favored over the two-step IMRT planning.
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Affiliation(s)
- A Abate
- Laboratory of Medical Physics and Expert Systems, Regina Elena National Cancer Institute, Rome, Italy
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Abstract
Steep dose gradients between two planning target volumes (PTVs) as may be required for simultaneous integrated boosts (SIB) should be an option provided by IMRT algorithms. The aim was to analyse the geometry of the SIB problem and to implement the results in an algorithm for IMRT segment generation denoted two-step intensity modulated radiotherapy (2-Step IMRT). It was hypothesized that a gap between segments directed to the inner and the outer PTV would steepen the dose gradient. The mathematical relationships were derived from the individual dose levels and the geometry (diameters) of the PTVs. The results generated by means of 2-Step IMRT segments were equivalent or better than the segment generation using a commercial IMRT planning system. The dose to both the inner and the outer PTV was clearly more homogeneous and the composite objective value was the lowest. The segment numbers were lower or equal--with better sparing of the surrounding tissue. In summary, it was demonstrated that 2-Step IMRT was able to achieve steep dose gradients for SIB constellations.
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Dogan N, Mihaylov I, Wu Y, Keall PJ, Siebers JV, Hagan MP. Monte Carlo dose verification of prostate patients treated with simultaneous integrated boost intensity modulated radiation therapy. Radiat Oncol 2009; 4:18. [PMID: 19527515 PMCID: PMC2701954 DOI: 10.1186/1748-717x-4-18] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2009] [Accepted: 06/15/2009] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To evaluate the dosimetric differences between Superposition/Convolution (SC) and Monte Carlo (MC) calculated dose distributions for simultaneous integrated boost (SIB) prostate cancer intensity modulated radiotherapy (IMRT) compared to experimental (film) measurements and the implications for clinical treatments. METHODS Twenty-two prostate patients treated with an in-house SIB-IMRT protocol were selected. SC-based plans used for treatment were re-evaluated with EGS4-based MC calculations for treatment verification. Accuracy was evaluated with-respect-to film-based dosimetry. Comparisons used gamma (gamma)-index, distance-to-agreement (DTA), and superimposed dose distributions. The treatment plans were also compared based on dose-volume indices and 3-D gamma index for targets and critical structures. RESULTS Flat-phantom comparisons demonstrated that the MC algorithm predicted measurements better than the SC algorithm. The average PTVprostate D98 agreement between SC and MC was 1.2% +/- 1.1. For rectum, the average differences in SC and MC calculated D50 ranged from -3.6% to 3.4%. For small bowel, there were up to 30.2% +/- 40.7 (range: 0.2%, 115%) differences between SC and MC calculated average D50 index. For femurs, the differences in average D50 reached up to 8.6% +/- 3.6 (range: 1.2%, 14.5%). For PTVprostate and PTVnodes, the average gamma scores were >95.0%. CONCLUSION MC agrees better with film measurements than SC. Although, on average, SC-calculated doses agreed with MC calculations within the targets within 2%, there were deviations up to 5% for some patient's treatment plans. For some patients, the magnitude of such deviations might decrease the intended target dose levels that are required for the treatment protocol, placing the patients in different dose levels that do not satisfy the protocol dose requirements.
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Affiliation(s)
- Nesrin Dogan
- Radiation Oncology Department, Virginia Commonwealth University Medical Center, Richmond, Virginia 23298, USA.
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Clark CH, Miles EA, Urbano MTG, Bhide SA, Bidmead AM, Harrington KJ, Nutting CM. Pre-trial quality assurance processes for an intensity-modulated radiation therapy (IMRT) trial: PARSPORT, a UK multicentre Phase III trial comparing conventional radiotherapy and parotid-sparing IMRT for locally advanced head and neck cancer. Br J Radiol 2009; 82:585-94. [PMID: 19332518 DOI: 10.1259/bjr/31966505] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
The purpose of this study was to compare conventional radiotherapy with parotid gland-sparing intensity-modulated radiation therapy (IMRT) using the PARSPORT trial. The validity of such a trial depends on the radiotherapy planning and delivery meeting a defined standard across all centres. At the outset, many of the centres had little or no experience of delivering IMRT; therefore, quality assurance processes were devised to ensure consistency and standardisation of all processes for comparison within the trial. The pre-trial quality assurance (QA) programme and results are described. Each centre undertook exercises in target volume definition and treatment planning, completed a resource questionnaire and produced a process document. Additionally, the QA team visited each participating centre. Each exercise had to be accepted before patients could be recruited into the trial. 10 centres successfully completed the quality assurance exercises. A range of treatment planning systems, linear accelerators and delivery methods were used for the planning exercises, and all the plans created reached the standard required for participation in this multicentre trial. All 10 participating centres achieved implementation of a comprehensive and robust IMRT programme for treatment of head and neck cancer.
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Affiliation(s)
- C H Clark
- Department of Physics, Royal Marsden NHS Foundation Trust, London and Sutton, Surrey, UK.
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Yu H, Caldwell C, Mah K, Mozeg D. Coregistered FDG PET/CT-based textural characterization of head and neck cancer for radiation treatment planning. IEEE TRANSACTIONS ON MEDICAL IMAGING 2009; 28:374-383. [PMID: 19244009 DOI: 10.1109/tmi.2008.2004425] [Citation(s) in RCA: 123] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Coregistered fluoro-deoxy-glucose (FDG) positron emission tomography/computed tomography (PET/CT) has shown potential to improve the accuracy of radiation targeting of head and neck cancer (HNC) when compared to the use of CT simulation alone. The objective of this study was to identify textural features useful in distinguishing tumor from normal tissue in head and neck via quantitative texture analysis of coregistered 18F-FDG PET and CT images. Abnormal and typical normal tissues were manually segmented from PET/CT images of 20 patients with HNC and 20 patients with lung cancer. Texture features including some derived from spatial grey-level dependence matrices (SGLDM) and neighborhood gray-tone-difference matrices (NGTDM) were selected for characterization of these segmented regions of interest (ROIs). Both K nearest neighbors (KNNs) and decision tree (DT)-based KNN classifiers were employed to discriminate images of abnormal and normal tissues. The area under the curve (AZ) of receiver operating characteristics (ROC) was used to evaluate the discrimination performance of features in comparison to an expert observer. The leave-one-out and bootstrap techniques were used to validate the results. The AZ of DT-based KNN classifier was 0.95. Sensitivity and specificity for normal and abnormal tissue classification were 89% and 99%, respectively. In summary, NGTDM features such as PET Coarseness, PET Contrast, and CT Coarseness extracted from FDG PET/CT images provided good discrimination performance. The clinical use of such features may lead to improvement in the accuracy of radiation targeting of HNC.
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Affiliation(s)
- Huan Yu
- Department of Medical Biophysics, University of Toronto, Toronto, ON, M4N 3M5 Canada.
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Yu CX, Amies CJ, Svatos M. Planning and delivery of intensity-modulated radiation therapy. Med Phys 2009; 35:5233-41. [PMID: 19175082 DOI: 10.1118/1.3002305] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
Intensity modulated radiation therapy (IMRT) is an advanced form of external beam radiation therapy. IMRT offers an additional dimension of freedom as compared with field shaping in three-dimensional conformal radiation therapy because the radiation intensities within a radiation field can be varied according to the preferences of locations within a given beam direction from which the radiation is directed to the tumor. This added freedom allows the treatment planning system to better shape the radiation doses to conform to the target volume while sparing surrounding normal structures. The resulting dosimetric advantage has shown to translate into clinical advantages of improving local and regional tumor control. It also offers a valuable mechanism for dose escalation to tumors while simultaneously reducing radiation toxicities to the surrounding normal tissue and sensitive structures. In less than a decade, IMRT has become common practice in radiation oncology. Looking forward, the authors wonder if IMRT has matured to such a point that the room for further improvement has diminished and so it is pertinent to ask what the future will hold for IMRT. This article attempts to look from the perspective of the current state of the technology to predict the immediate trends and the future directions. This article will (1) review the clinical experience of IMRT; (2) review what we learned in IMRT planning; (3) review different treatment delivery techniques; and finally, (4) predict the areas of advancements in the years to come.
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Affiliation(s)
- Cedric X Yu
- Department of Radiation Oncology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA.
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Technical and dosimetric considerations in multi-isocenter intensity modulated radiotherapy for nasopharyngeal carcinoma with small multileaf collimator. Med Dosim 2009; 34:9-15. [PMID: 19181249 DOI: 10.1016/j.meddos.2007.05.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2007] [Revised: 05/24/2007] [Accepted: 05/26/2007] [Indexed: 11/21/2022]
Abstract
Multileaf collimator (MLC)-assisted intensity modulated radiotherapy (IMRT) has greatly improved the target coverage and avoidance of organs at risk (OAR) for the treatment of nasopharyngeal carcinoma; however, its implementation is also constrained by the features of the MLC. Nasopharyngeal carcinoma tends to have a large gross target volume (GTV) and clinical target volume (CTV) due to its biological characteristics. More than one isocenter may be needed when small MLCs (i.e., BrainLAB M3, whose largest field is 10 x 10 cm(2)) are used to treat the nasopharyngeal carcinoma. The BrainLAB IMRT system was used to evaluate the effectiveness of a multi-isocenter IMRT plan for treating nasopharyngeal cancers. Dose coverage of GTVs and CTVs were compared among IMRT plans with 1, 2 and 3 isocenters, as were dose objectives for OARs including brainstem, cord, and parotids. The dosimetric variation and the delivery time were also measured with a phantom. IMRT plans with more than 1 isocenter achieved a better dose coverage, homogeneity, and conformity on GTVs and CTVs; however, with risk of higher doses given to OARs. In most cases, one can generate satisfactory IMRT plans using the 2-isocenter IMRT planning strategy. Two-isocenter planning strategy may be a suitable compromise when more isocenters are needed.
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Chen WC, Hwang TZ, Wang WH, Lu CH, Chen CC, Chen CM, Weng HH, Lai CH, Chen MF. Comparison between conventional and intensity-modulated post-operative radiotherapy for stage III and IV oral cavity cancer in terms of treatment results and toxicity. Oral Oncol 2008; 45:505-10. [PMID: 18805047 DOI: 10.1016/j.oraloncology.2008.07.002] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2008] [Revised: 07/04/2008] [Accepted: 07/04/2008] [Indexed: 12/01/2022]
Abstract
The aim of this study was to assess the treatment results and toxicity profiles of post-operative conventional radiotherapy (Conv-RT) and intensity-modulated radiotherapy (IMRT) for stage III and IV oral cavity cancer. During the period from April 2002 to December 2005, a total of 49 patients with stage III and IV squamous cell carcinoma of the oral cavity were treated with radical surgery followed by post-operative RT. Twenty-seven patients received Conv-RT while 22 received IMRT. Only three patients received adjuvant chemotherapy. With a median follow-up time of 3.3 years, the 3-year overall survival and disease-free survival rates for patients who received Conv-RT vs IMRT were comparable. There was no significant difference in acute toxicity between the two different RT techniques. However, in terms of late toxicity, patients receiving IMRT had significantly less moderate to severe xerostomia and dysphagia than those receiving Conv-RT (36% vs 82%, p=0.01 for xerostomia and 21% vs 59%, p=0.02 for dysphagia). Post-operative Conv-RT and IMRT are equally effective in terms of tumor control for locally advanced oral cavity cancer. Patients receiving IMRT had comparable acute and significant less late toxicity than those receiving Conv-RT.
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Affiliation(s)
- Wen-Cheng Chen
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Chia-Yi, #6, Chia-Pu Road, Putz City, Chiayi, Hsien, Taiwan
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74
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Fenkell L, Kaminsky I, Breen S, Huang S, Van Prooijen M, Ringash J. Dosimetric comparison of IMRT vs. 3D conformal radiotherapy in the treatment of cancer of the cervical esophagus. Radiother Oncol 2008; 89:287-91. [PMID: 18789828 DOI: 10.1016/j.radonc.2008.08.008] [Citation(s) in RCA: 111] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2008] [Revised: 07/30/2008] [Accepted: 08/09/2008] [Indexed: 12/21/2022]
Abstract
BACKGROUND AND PURPOSE Radiotherapy planning for cervical esophageal cancer is challenging. We compared IMRT and 3D conformal radiotherapy (CRT) with respect to conformality of target coverage and normal tissue sparing. MATERIALS AND METHODS We selected five patients with cervical esophagus cancer, who represented the heterogeneity of clinical cases, treated to radical dose and planned with Pinnacle v6.2. Target doses for CRT plans were 50, 60, and 70Gy (single-phase IMRT 56, 63, and 70). We compared PTV coverage by the 95% isodose (PTV(95)), conformality ratio (CR), conformation number (CN), and maximum or mean doses (D(max), D(mean)) to normal structures. RESULTS Median PTV(95) for IMRT plans for PTV70, PTV63, and PTV56 were 97%, 99%, and 98% (CRT 91%, 98%, and 85%). IMRT plans demonstrated lower D(max) to the spinal cord and brainstem (42 and 36Gy) compared to CRT (46 and 39Gy). Median left parotid D(mean) was 35Gy (IMRT) vs. 53Gy (CRT). Median right parotid D(mean) was 35Gy (IMRT) vs. 36Gy (CRT). The median CR50/56Gy was 1.4 (CRT) vs. 1.2 (IMRT), CR70Gy 1.7 (CRT) vs. 1.1 (IMRT). CN50/56 and CN70 values were 0.80 and 0.85 (IMRT) vs. 0.56 and 0.5 (CRT). CONCLUSIONS IMRT provides superior target volume coverage and conformality, with decreased dose to normal structures.
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Affiliation(s)
- Louis Fenkell
- Department of Radiation Oncology, Princess Margaret Hospital, Toronto, ON, Canada
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Amirul Islam M, Yanagi T, Mizoe JE, Mizuno H, Tsujii H. Comparative study of dose distribution between carbon ion radiotherapy and photon radiotherapy for head and neck tumor. ACTA ACUST UNITED AC 2008; 26:415-21. [PMID: 18769999 DOI: 10.1007/s11604-008-0252-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2007] [Accepted: 04/14/2008] [Indexed: 11/27/2022]
Abstract
PURPOSE A comparative treatment planning study has been performed between carbon ion radiotherapy (CIRT) and photon radiotherapy [three-dimensional conformal radiotherapy (3D-CRT) and intensity-modulated radiotherapy (IMRT)] to assess the potential improvements and limitations that could result for locally advanced, nonresectable head and neck tumors. MATERIALS AND METHODS Seven patients, originally treated with CIRT, were randomly selected for the comparative study. The evaluations analyzed using dose-volume histogram parameters, conformity index, inhomogeneity coefficient, and dose to the organs at risk (OARs). RESULTS The mean conformity index was 1.46, 1.43, and 1.22 for 3D-CRT, IMRT, and CIRT, respectively. The mean inhomogeneity coefficient was 0.05, 0.07, and 0.02 for 3D-CRT, IMRT, and CIRT respectively. Photon plans resulted in greater volumes of normal tissues at 10% to 95% isodose levels compared with the corresponding carbon ion plans where the volumes increased by a factor of 1.2 to 2.7 for 3D-CRT and 1.2 to 2.0 for IMRT. CONCLUSION CIRT has the potential to improve the target dose conformity, inhomogeneity coefficient, and OAR sparing when compared with 3D-CRT and IMRT. Compared with 3D-CRT, normal tissue exposure was reduced mainly in the mid-to low-isodose levels using IMRT. Additional improvement was obtained using CIRT.
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Affiliation(s)
- M Amirul Islam
- RNPD, INST, Atomic Energy Research Establishment, Ganakbari, Savar, Dhaka, 1349, Bangladesh.
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Ghalibafian M, Beaudre A, Girinsky T. Heart and coronary artery protection in patients with mediastinal Hodgkin lymphoma treated with intensity-modulated radiotherapy: Dose constraints to virtual volumes or to organs at risk? Radiother Oncol 2008; 87:82-8. [DOI: 10.1016/j.radonc.2007.10.016] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2007] [Revised: 09/26/2007] [Accepted: 10/06/2007] [Indexed: 11/15/2022]
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Vosmik M, Cermanova M, Odrazka K, Maisnar V, Zouhar M, Kordac P, Petera J. Solitary extramedullary plasmacytoma in the oropharynx: advantages of intensity-modulated radiation therapy. ACTA ACUST UNITED AC 2008; 7:434-7. [PMID: 17621412 DOI: 10.3816/clm.2007.n.025] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We report a case of a 59-year-old man with solitary extramedullary plasmacytoma in his oropharynx. Because the diagnosis is rare and there is only limited experience in the literature based on retrospective data, the optimal planning target volume and optimal dose of radiation therapy (RT) are still controversial. The frequently discussed problem is the necessity of first echelon lymph node irradiation because it is associated with a higher rate of complications such as xerostomia caused by damage to salivary glands. In order to prevent late toxicity, intensity-modulated RT with the use of simultaneous integrated boost and parotid salivary gland sparing was used in this patient's treatment. The RT was performed in 23 identical fractions, the primary tumor region was irradiated with a dose of 46 Gy and the first echelon lymph node region with the risk of subclinical disease with a dose of 41.4 Gy; the dose per fraction was 2 Gy and 1.8 Gy, respectively. The patient is alive and well > 20 months after the irradiation, without any evidence of disease. Parotid gland function remained intact, and no xerostomia occurred. This is the first report of the use of intensity-modulated RT with parotid gland sparing in the treatment of solitary extramedullary plasmacytoma in the head and neck region.
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Affiliation(s)
- Milan Vosmik
- Department of Oncology and Radiotherapy, Charles University Medical School and Teaching Hospital in Hradec Kralove, 500 05 Hradec Kralove, Czech Republic.
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Adaptation de l’irradiation à l’activité tumorale en radiothérapie conformationnelle avec modulation d’intensité pour les cancers tête et cou. Étude préliminaire sur fantômes. Ing Rech Biomed 2008. [DOI: 10.1016/j.rbmret.2007.12.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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79
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Reddy NM, Mazur AK, Sampath S, Osian A, Sood BM, Ravi A, Nori D. The Potential for Dose Dumping in Normal Tissues with IMRT for Pelvic and H&N Cancers. Med Dosim 2008; 33:55-61. [DOI: 10.1016/j.meddos.2007.05.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2007] [Revised: 05/14/2007] [Accepted: 05/15/2007] [Indexed: 11/26/2022]
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Han C, Chen YJ, Liu A, Schultheiss TE, Wong JY. Actual Dose Variation of Parotid Glands and Spinal Cord for Nasopharyngeal Cancer Patients During Radiotherapy. Int J Radiat Oncol Biol Phys 2008; 70:1256-62. [DOI: 10.1016/j.ijrobp.2007.10.067] [Citation(s) in RCA: 103] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2007] [Revised: 10/27/2007] [Accepted: 10/31/2007] [Indexed: 11/26/2022]
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81
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VOŠMIK M, KORDAČ P, PALUSKA P, ZOUHAR M, PETERA J, ODRÁŽKA K, VESELÝ P, DVOŘÁK J. IMRT using simultaneous integrated boost (66 Gy in 6 weeks) with and without concurrent chemotherapy in head and neck cancer – toxicity evaluation. Rep Pract Oncol Radiother 2008. [DOI: 10.1016/s1507-1367(10)60087-9] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Muren LP, Wasbø E, Helle SI, Hysing LB, Karlsdottir A, Odland OH, Valen H, Ekerold R, Johannessen DC. Intensity-modulated radiotherapy of pelvic lymph nodes in locally advanced prostate cancer: planning procedures and early experiences. Int J Radiat Oncol Biol Phys 2008; 71:1034-41. [PMID: 18249502 DOI: 10.1016/j.ijrobp.2007.11.060] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Revised: 11/16/2007] [Accepted: 11/21/2007] [Indexed: 11/27/2022]
Abstract
PURPOSE We present planning and early clinical outcomes of a study of intensity-modulated radiotherapy (IMRT) for locally advanced prostate cancer. METHODS AND MATERIALS A total of 43 patients initially treated with an IMRT plan delivering 50 Gy to the prostate, seminal vesicles, and pelvic lymph nodes, followed by a conformal radiotherapy (CRT) plan delivering 20 Gy to the prostate and seminal vesicles, were studied. Dose-volume histogram (DVH) data for the added plans were compared with dose-volume histogram data for the sum of two CRT plans for 15 cases. Gastrointestinal (GI) and genitourinary (GU) toxicity, based on the Radiation Therapy Oncology Group scoring system, was recorded weekly throughout treatment as well as 3 to 18 months after treatment and are presented. RESULTS Treatment with IMRT both reduced normal tissue doses and increased the minimum target doses. Intestine volumes receiving more than 40 and 50 Gy were significantly reduced (e.g., at 50 Gy, from 81 to 19 cm(3); p = 0.026), as were bladder volumes above 40, 50, and 60 Gy, rectum volumes above 30, 50, and 60 Gy, and hip joint muscle volumes above 20, 30, and 40 Gy. During treatment, Grade 2 GI toxicity was reported by 12 of 43 patients (28%), and Grade 2 to 4 GU toxicity was also observed among 12 patients (28%). With 6 to 18 months of follow-up, 2 patients (5%) experienced Grade 2 GI effects and 7 patients (16%) experienced Grade 2 GU effects. CONCLUSIONS Use of IMRT for pelvic irradiation in prostate cancer reduces normal tissue doses, improves target coverage, and has a promising toxicity profile.
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Affiliation(s)
- Ludvig Paul Muren
- Department of Oncology and Medical Physics, Haukeland University Hospital, Bergen, Norway.
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83
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Comparing two strategies of dynamic intensity modulated radiation therapy (dIMRT) with 3-dimensional conformal radiation therapy (3DCRT) in the hypofractionated treatment of high-risk prostate cancer. Radiat Oncol 2008; 3:1. [PMID: 18179695 PMCID: PMC2249591 DOI: 10.1186/1748-717x-3-1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2007] [Accepted: 01/07/2008] [Indexed: 11/27/2022] Open
Abstract
Background To compare two strategies of dynamic intensity modulated radiation therapy (dIMRT) with 3-dimensional conformal radiation therapy (3DCRT) in the setting of hypofractionated high-risk prostate cancer treatment. Methods 3DCRT and dIMRT/Helical Tomotherapy(HT) planning with 10 CT datasets was undertaken to deliver 68 Gy in 25 fractions (prostate) and simultaneously delivering 45 Gy in 25 fractions (pelvic lymph node targets) in a single phase. The paradigms of pelvic vessel targeting (iliac vessels with margin are used to target pelvic nodes) and conformal normal tissue avoidance (treated soft tissues of the pelvis while limiting dose to identified pelvic critical structures) were assessed compared to 3DCRT controls. Both dIMRT/HT and 3DCRT solutions were compared to each other using repeated measures ANOVA and post-hoc paired t-tests. Results When compared to conformal pelvic vessel targeting, conformal normal tissue avoidance delivered more homogenous PTV delivery (2/2 t-test comparisons; p < 0.001), similar nodal coverage (8/8 t-test comparisons; p = ns), higher and more homogenous pelvic tissue dose (6/6 t-test comparisons; p < 0.03), at the cost of slightly higher critical structure dose (Ddose, 1–3 Gy over 5/10 dose points; p < 0.03). The dIMRT/HT approaches were superior to 3DCRT in sparing organs at risk (22/24 t-test comparisons; p < 0.05). Conclusion dIMRT/HT nodal and pelvic targeting is superior to 3DCRT in dose delivery and critical structure sparing in the setting of hypofractionation for high-risk prostate cancer. The pelvic targeting paradigm is a potential solution to deliver highly conformal pelvic radiation treatment in the setting of nodal location uncertainty in prostate cancer and other pelvic malignancies.
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84
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Intensity-modulated radiation therapy in head and neck cancer: Prescribed dose, clinical challenges and results. Radiother Oncol 2007; 85:392-8. [DOI: 10.1016/j.radonc.2007.10.045] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2007] [Revised: 10/26/2007] [Accepted: 10/30/2007] [Indexed: 11/21/2022]
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85
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El-Bassiouni M, Ciernik IF, Davis JB, El-Attar I, Reiner B, Burger C, Goerres GW, Studer GM. [18FDG] PET-CT-based intensity-modulated radiotherapy treatment planning of head and neck cancer. Int J Radiat Oncol Biol Phys 2007; 69:286-93. [PMID: 17707283 DOI: 10.1016/j.ijrobp.2007.04.053] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2006] [Revised: 04/30/2007] [Accepted: 04/30/2007] [Indexed: 01/24/2023]
Abstract
PURPOSE To define the best threshold for tumor volume delineation of the (18) fluoro-2-deoxy-glucose positron emission tomography ((18)FDG-PET) signal for radiotherapy treatment planning of intensity-modulated radiotherapy (IMRT) in head and neck cancer. METHODS AND MATERIALS In 25 patients with head-and-neck cancer, CT-based gross tumor volume (GTV(CT)) was delineated. After PET-CT image fusion, window level (L) was adapted to best fit the GTV(CT), and GTV(PET) was delineated. Tumor maximum (S) and background uptake (B) were measured, and the threshold of the background-subtracted tumor maximum uptake (THR) was used for PET signal segmentation. Gross tumor volumes were expanded to planning target volumes (PTVs) and analyzed. RESULTS The mean value of S was 40 kBq/mL, S/B ratio was 16, and THR was 26%. The THR correlated with S (r = -0.752), but no correlation between THR and the S/B ratio was seen (r = -0.382). In 77% of cases, S was >30 kBq/mL, and in 23% it was </=30 kBq/mL, with a mean THR of 21.4% and 41.6%, respectively (p < 0.001). Using PTV(PET) in radiotherapy treatment planning resulted in a reduced PTV in 72% of cases, while covering 88.2% of GTV(CT), comparable to the percentage of GTV(PET) covered by PTV(CT) (p = 0.15). CONCLUSIONS A case-specific PET signal threshold is optimal in PET-based radiotherapy treatment planning. Signal gating using a THR of 20% in tumors with S >30% +/- 1.6% kBq/mL and 40% in tumors with S </=30% +/- 1.6% kBq/mL is suitable.
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Affiliation(s)
- Mazen El-Bassiouni
- Department of Radiation Oncology, Zurich University Hospital, University of Zurich, Zurich
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86
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Lu H, Yao M. The current status of intensity-modulated radiation therapy in the treatment of nasopharyngeal carcinoma. Cancer Treat Rev 2007; 34:27-36. [PMID: 17910906 DOI: 10.1016/j.ctrv.2007.08.004] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2007] [Revised: 08/21/2007] [Accepted: 08/21/2007] [Indexed: 01/29/2023]
Abstract
Radiation therapy is the mainstay of treatment in nasopharyngeal carcinoma, alone or in combination with chemotherapy. In the early stage, it can be managed by radiotherapy alone. For locally advanced-stage disease, several meta-analyses have demonstrated the role of concurrent chemoradiotherapy. Conventional radiation therapy results in significant side effects, particular xerostomia, leading to poor quality of life. With the maturity of intensity-modulated radiation therapy in the recent 10 years, more and more evidences have shown the advantages of intensity-modulated radiation therapy over conventional radiation therapy, regarding the local-regional control, survival rate and quality of life. This article reviews the utilization of intensity-modulated radiation therapy in the management of nasopharyngeal carcinoma with respect to its technical advantages, clinical outcome, critical organ sparing and quality of life, and the dilemma in target delineation. In particular, an issue of treatment-related dysphagia will also be discussed.
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Affiliation(s)
- Heming Lu
- Department of Radiation Oncology, The People's Hospital of Guangxi Zhuang Autonomous Region, Nanning City, PR China.
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87
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Williams MJ, Bailey M, Forstner D, Metcalfe PE. Multicentre quality assurance of intensity-modulated radiation therapy plans: A precursor to clinical trials. ACTA ACUST UNITED AC 2007; 51:472-9. [PMID: 17803801 DOI: 10.1111/j.1440-1673.2007.01873.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
A multicentre planning study comparing intensity-modulated radiation therapy (IMRT) plans for the treatment of a head and neck cancer has been carried out. Three Australian radiotherapy centres, each with a different planning system, were supplied a fully contoured CT dataset and requested to generate an IMRT plan in accordance with the requirements of an IMRT-based radiation therapy oncology group clinical trial. Plan analysis was carried out using software developed specifically for reviewing multicentre clinical trial data. Two out of the three plans failed to meet the prescription requirements with one misinterpreting the prescription and the third failed to meet one of the constraints. Only one plan achieved all of the dose objectives for the critical structures and normal tissues. Although each centre used very similar planning parameters and beam arrangements the resulting plans were quite different. The subjective interpretation and application of the prescription and planning objectives emphasize one of the many difficulties in carrying out multicentre IMRT planning studies. The treatment prescription protocol in a clinical trial must be both lucid and unequivocally stated to avoid misinterpretation. Australian radiotherapy centres must show that they can produce a quality IMRT plan and that they can adhere to protocols for IMRT planning before using it in a clinical trial.
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Affiliation(s)
- M J Williams
- Department of Radiation Oncology, Illawarra Cancer Care Centre, Wollongong Hospital, Wollongong, New South Wales, Australia.
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88
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Goleń M, Składowski K, Wygoda A, Pilecki B, Przeorek W, Sąsiadek W, Rutkowski T, d'Amico A, Kołosza Z. The influence of radiation technique on xerostomia in head and neck cancer patients – prospective study. Rep Pract Oncol Radiother 2007. [DOI: 10.1016/s1507-1367(10)60063-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022] Open
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Guerrero Urbano MT, Clark CH, Kong C, Miles E, Dearnaley DP, Harrington KJ, Nutting CM. Target volume definition for head and neck intensity modulated radiotherapy: pre-clinical evaluation of PARSPORT trial guidelines. Clin Oncol (R Coll Radiol) 2007; 19:604-13. [PMID: 17706404 DOI: 10.1016/j.clon.2007.07.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2006] [Revised: 06/09/2007] [Accepted: 07/05/2007] [Indexed: 10/23/2022]
Abstract
AIMS There is considerable controversy surrounding target volume definition for parotid-sparing intensity modulated radiotherapy (IMRT) for head and neck cancer. The aim of this study was to evaluate the dosimetric and radiobiological predictors of outcome anticipated by application of the detailed target volume definition guidelines agreed for the UK multicentre randomised controlled trial of parotid-sparing IMRT (PARSPORT). MATERIALS AND METHODS Five patients eligible for the study were delineated using the trial guidelines. Following the protocol, plans were produced to treat these volumes with three-dimensional radiotherapy (control arm) and IMRT aimed to spare dose to the contralateral parotid gland (experimental arm). Dosimetric comparisons were made between plans, and normal tissue complication probability (NTCP) modelling for salivary glands was carried out. RESULTS Doses delivered to the planning target volumes (PTV) were similar with each technique, although IMRT produced more homogeneous irradiation of the PTV. Mean doses to the contralateral parotid gland were 22.4+/-1.7 Gy with the IMRT plans vs 60.0+/-7.2 Gy with three-dimensional radiotherapy, P=0.0003. Calculated contralateral parotid gland NTCP values for grade 2 xerostomia were 20-22% for IMRT and 98-100% for three-dimensional radiotherapy (P<0.0001). CONCLUSION Pre-clinical evaluation of the PARSPORT trial target volume definition guidelines provides theoretical support for a significant reduction in xerostomia rates. These data await confirmation from the clinical trial results.
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Yao M, Karnell LH, Funk GF, Lu H, Dornfeld K, Buatti JM. Health-related quality-of-life outcomes following IMRT versus conventional radiotherapy for oropharyngeal squamous cell carcinoma. Int J Radiat Oncol Biol Phys 2007; 69:1354-60. [PMID: 17689885 DOI: 10.1016/j.ijrobp.2007.05.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 04/25/2007] [Accepted: 05/02/2007] [Indexed: 11/25/2022]
Abstract
PURPOSE To compare health-related quality-of-life (HRQOL) outcomes of patients with oropharyngeal squamous cell carcinoma treated using intensity-modulated radiotherapy (IMRT) vs. conventional radiotherapy (CRT). PATIENTS AND METHODS Patients with oropharyngeal squamous cell carcinoma were extracted from the database of an ongoing longitudinal Outcome Assessment Project. Eligible criteria included (1) treated with definitive radiation, and (2) provided 12-month posttreatment HRQOL data. Excluded were 7 patients who received IMRT before October 1, 2002, during this institution's developmental phase of the IMRT technique. The HRQOL outcomes of patients treated with IMRT were compared with those of patients who received CRT. RESULTS Twenty-six patients treated using IMRT and 27 patients treated using CRT were included. Patients in the IMRT group were older and had more advanced-stage diseases and more patients received concurrent chemotherapy. However, the IMRT group had higher mean Head and Neck Cancer Inventory scores (which represent better outcomes) for each of the four head-and-neck cancer-specific domains, including eating, speech, aesthetics, and social disruption, at 12 months after treatment. A significantly greater percentage of patients in the CRT group had restricted diets compared with those in the IMRT group (48.0% vs. 16.0%, p = 0.032). At 3 months after treatment, both groups had significant decreases from pretreatment eating scores. However, the IMRT group had a significant improvement during the first year, but the CRT group had only small improvement. CONCLUSIONS Proper delivery of IMRT can improve HRQOL for patients with oropharyngeal cancer compared with CRT.
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Affiliation(s)
- Min Yao
- Department of Radiation Oncology, The Carver College of Medicine, University of Iowa, Iowa City, IA, USA.
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91
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Braam PM, Raaijmakers C, Terhaard C. In Reply to Dr. Ozyigit et al. Int J Radiat Oncol Biol Phys 2007. [DOI: 10.1016/j.ijrobp.2007.02.048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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92
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Scrimger R, Kanji A, Parliament M, Warkentin H, Field C, Jha N, Hanson J. Correlation between saliva production and quality of life measurements in head and neck cancer patients treated with intensity-modulated radiotherapy. Am J Clin Oncol 2007; 30:271-7. [PMID: 17551304 DOI: 10.1097/01.coc.0000258081.70643.3d] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE To investigate the strength of correlation between measured saliva flow rates and various toxicity endpoints commonly used in head and neck cancer (HNC) treatment. MATERIALS AND METHODS All patients enrolled in a phase II study using intensity modulated radiotherapy (IMRT) for HNC treatment underwent whole mouth saliva flow measurements (stimulated and unstimulated). They were also assessed for salivary gland toxicity using Radiation Therapy Oncology Group (RTOG) late toxicity grading and 9 items representing patient-graded toxicities from 2 questionnaires (Xerostomia questionnaire and University of Washington quality of life). For each patient, saliva flow rates and quality of life (QOL) data were collected preradiotherapy (RT) and at 3 intervals post-RT (3, 6, and 12 months). RESULTS A total of 188 sets of coregistered data were obtained for 47 patients over a period of approximately 4 years. Saliva production and mean QOL dropped significantly immediately after RT, but there was a statistically significant recovery in both parameters between 3- and 12-month post-RT. By 12 months, post-RT the mean QOL scores had returned to pre-RT baseline, although mean stimulated saliva production remained 58% below baseline. CONCLUSION Patients with HNC treated with IMRT experienced a small drop in QOL which recovered to baseline by 12 months post-RT. There was no statistically significant correlation seen between global health-related QOL scores and stimulated saliva production rates in the post-RT period.
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Affiliation(s)
- Rufus Scrimger
- Department of Radiation Oncology, Cross Cancer Institute, University of Alberta, Edmonton, Alberta, Canada.
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93
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Siebers JV, Kawrakow I, Ramakrishnan V. Performance of a hybrid MC dose algorithm for IMRT optimization dose evaluation. Med Phys 2007; 34:2853-63. [PMID: 17821993 DOI: 10.1118/1.2745236] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
This paper presents a hybrid intensity modulated radiation therapy (IMRT) optimization strategy which combines the speed of pencil beam (PB) and the accuracy of Monte Carlo (MC) dose calculations. After an initial deliverable-based optimization using a PB algorithm, doses are recomputed using the VMC++ MC code to determine dose correction factors, which are then utilized during further PB-based optimization. The hybrid method is benchmarked with respect to full MC deliverable-based optimization for ten prostate and ten head-and-neck IMRT plans. Final optimized plans are compared in terms of dose-volume indices used for the plan optimization. Dose prediction errors (DPEs) and optimization convergence errors (OCEs) at intermediate steps of the hybrid sequence are evaluated. The hybrid method is found to produce optimized plans that are clinically equivalent to full MC-based optimization, yet requires only 40% of the number of MC dose calculations. With the hybrid strategy presented here, MC-based optimization results are achieved in 35 min or less on a modest computing cluster. While the initial PB-deliverable-based optimization is found to have DPEs and OCEs of up to 3 Gy relative to the 65-73 Gy prescription doses, application of the first MC correction reduces the average DPEs to less than 0.3 Gy for the prostate plans and less than 0.06 Gy for the head and neck plans. The maximum observed DPE or OCE is 0.7 Gy after 1 MC dose correction, indicating that a single MC dose calculation correction might be sufficient for IMRT optimization.
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Affiliation(s)
- Jeffrey V Siebers
- Department of Radiation Oncology and Massey Cancer Center, Virginia Commonwealth University, 401 College Street, Richmond, Virginia 23298, USA.
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94
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Yao M, Epstein JB, Modi BJ, Pytynia KB, Mundt AJ, Feldman LE. Current surgical treatment of squamous cell carcinoma of the head and neck. Oral Oncol 2007; 43:213-23. [PMID: 16978911 DOI: 10.1016/j.oraloncology.2006.04.013] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2006] [Accepted: 04/26/2006] [Indexed: 11/27/2022]
Abstract
Historically treatment of head and neck cancers involved surgical resection followed by radiation therapy for advanced tumors. Concurrent chemoradiation therapies have shown equal survival to surgical resection with better preservation of function. However, concurrent therapy does entail significant morbidity, and recent advances have been used to minimize that morbidity. Newer tumor specific medical therapies are anticipated to be less toxic while maintaining a high degree of efficacy. For resectable cancer, transoral laser microsurgery is a new trend in surgery for complete resection of tumors with preservation of function. Advanced reconstructive techniques that allow free transfer of soft tissue and bone from all over the body improve the functional and aesthetic outcomes following major ablative surgery. With successful surgical reconstruction, dental and prosthetic rehabilitation choices are enhanced. Advances in rehabilitation of speech following removal of the larynx have improved the quality of life post-laryngectomy patients. With these newer therapies and methods of reconstruction, each patient needs to be carefully evaluated to maximize the possibility of cure and level of function, and minimize the morbidity associated with treatment. Combined chemotherapy and radiation protocols are associated with increased acute and chronic toxicities that may affect the quality of life due to the impact upon oral disease and oral function. Oral care providers must be aware of advances in cancer management and implications for patient care to effectively care for these patients.
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Affiliation(s)
- Mike Yao
- University of Illinois at Chicago, Department of Otolaryngology, 1855 W. Taylor Street, M/C 648, Chicago, IL 60612, United States.
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95
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Braam PM, Raaijmakers CPJ, Terhaard CHJ. Cranial location of level II lymph nodes in laryngeal cancer: Implications for elective nodal target volume delineation. Int J Radiat Oncol Biol Phys 2007; 67:462-8. [PMID: 17236968 DOI: 10.1016/j.ijrobp.2006.10.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2006] [Revised: 10/04/2006] [Accepted: 10/04/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To analyze the cranial distribution of level II lymph nodes in patients with laryngeal cancer to optimize the elective radiation nodal target volume delineation. METHODS AND MATERIALS The most cranially located metastatic lymph node was delineated in 67 diagnostic CT data sets. The minimum distance from the base of the skull (BOS) to the lymph node was determined. RESULTS A total of 98 lymph nodes were delineated including 62 ipsilateral and 36 contralateral lymph nodes. The mean ipsilateral and contralateral distance from the top of the most cranial metastatic lymph node to the BOS was 36 mm (range, -9-120; standard deviation [SD], 17.9) and 35 mm (range, 14-78; SD 15.0), respectively. Only 5% and 12% of the ipsilateral and 3% and 9% of the contralateral metastatic lymph nodes were located within 15 mm and 20 mm below the BOS, respectively. No significant differences were found between patients with only ipsilateral metastatic lymph nodes and patients with bilateral metastatic lymph nodes. Between tumors that do cross the midline and those that do not, no significant difference was found in the distance of the most cranial lymph node to the BOS and the occurrence ipsilateral or contralateral. CONCLUSIONS Setting the cranial border of the nodal target volume 1.5 cm below the base of the skull covers 95% of the lymph nodes and should be considered in elective nodal irradiation for laryngeal cancer. Bilateral neck irradiation is mandatory, including patients with unilateral laryngeal cancer, when elective irradiation is advised.
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Affiliation(s)
- Pètra M Braam
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands.
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96
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Kubs F, Aletti P, Wolf D, Millasseau S, Marchesi V. Irradiation adaptation to the tumor activity with the help of intensity-modulated radiation therapy for head and neck cancers. ANNUAL INTERNATIONAL CONFERENCE OF THE IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. IEEE ENGINEERING IN MEDICINE AND BIOLOGY SOCIETY. ANNUAL INTERNATIONAL CONFERENCE 2007; 2007:3434-3437. [PMID: 18002735 DOI: 10.1109/iembs.2007.4353069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The aim of this study was to set up the appropriate geometry to perform a high-precision irradiation, based on tumor activity (TA). The elaboration of a new treatment protocol based on TA required a specific geometry in order to use this type of irradiation. Using a treatment planning system TPS and two head and neck phantoms specially created, we have performed TPS characterization according to different treatment plans. Two models were created and used: a simplistic and an anatomical model. Our results showed that high-precision radiotherapy in limited zones is possible with intensity modulated radiation therapy (IMRT) when several conditions such as location, number of Organs at risk (OAR's), distance between planning target volume (PTV) and OAR, presence, volume and location of the TA, number of fields are met. In order to use this irradiation method adapted to the TA, a precise geometry will be necessary. However such high total and fractionated doses should be carefully evaluated before being prescribed clinically.
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Affiliation(s)
- F Kubs
- CRAN-UMR7039, Nancy-University, CNRS, F54500, Vandoeuvre-lès-Nancy, France.
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97
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Aydogan B, Mundt AJ, Roeske JC. Linac-based intensity modulated total marrow irradiation (IM-TMI). Technol Cancer Res Treat 2006; 5:513-19. [PMID: 16981794 DOI: 10.1177/153303460600500508] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
Abstract
Total body irradiation (TBI) has been used as a form of systemic therapy for the treatment of hematological malignancies and as a pre-conditioning regimen prior to bone marrow transplant. However, standard techniques are associated with both acute and chronic toxicities due to the large volumes of normal tissue irradiated. Intensity modulated radiation therapy (IMRT), with its ability to conform the high dose region to the shape of the target, offers a method to reduce radiation related sequelae and potentially allow for the delivery of higher than conventional doses. The goal of this study is to investigate the feasibility of a linac-based approach to intensity modulated total marrow irradiation (IM-TMI) and to discuss the challenges associated with its clinical implementation. The successful development of linac-based IM-TMI would represent advancement in the field of radiotherapy and potentially reduce the incidence and severity of complications associated with current TBI techniques.
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Affiliation(s)
- Bulent Aydogan
- Department of Radiation and Cellular Oncology, University of Chicago, 5758 S. Maryland Avenue, MC 9006, Chicago, IL 60637, USA.
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98
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Bangalore M, Matthews S, Suntharalingam M. Recent Advances in Radiation Therapy for Head and Neck Cancer. ORL J Otorhinolaryngol Relat Spec 2006; 69:1-12. [PMID: 17085946 DOI: 10.1159/000096710] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2005] [Accepted: 05/26/2005] [Indexed: 11/19/2022]
Abstract
The treatment of locally advanced or recurrent head and neck cancers has improved from single modality interventions of surgery and radiation therapy alone to include combined modality therapy with surgery, chemotherapy and radiation. Combined therapy has led to improved local control and disease-free survival. New developments in radiation oncology such as altered fractionation, three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, stereotactic radiosurgery, fractionated stereotactic radiotherapy, charged-particle radiotherapy, neutron-beam radiotherapy, and brachytherapy have helped to improve this outlook even further. These recent advances allow for a higher dose to be delivered to the tumor while minimizing the dose delivered to the surrounding normal tissue. This article provides an update of the new developments in radiotherapy in the management of head and neck cancers.
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99
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Braam PM, Terhaard CHJ, Roesink JM, Raaijmakers CPJ. Intensity-modulated radiotherapy significantly reduces xerostomia compared with conventional radiotherapy. Int J Radiat Oncol Biol Phys 2006; 66:975-80. [PMID: 16965864 DOI: 10.1016/j.ijrobp.2006.06.045] [Citation(s) in RCA: 109] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2006] [Revised: 06/13/2006] [Accepted: 06/20/2006] [Indexed: 12/12/2022]
Abstract
PURPOSE Xerostomia is a severe complication after radiotherapy for oropharyngeal cancer, as the salivary glands are in close proximity with the primary tumor. Intensity-modulated radiotherapy (IMRT) offers theoretical advantages for normal tissue sparing. A Phase II study was conducted to determine the value of IMRT for salivary output preservation compared with conventional radiotherapy (CRT). METHODS AND MATERIALS A total of 56 patients with oropharyngeal cancer were prospectively evaluated. Of these, 30 patients were treated with IMRT and 26 with CRT. Stimulated parotid salivary flow was measured before, 6 weeks, and 6 months after treatment. A complication was defined as a stimulated parotid flow rate <25% of the preradiotherapy flow rate. RESULTS The mean dose to the parotid glands was 48.1 Gy (SD 14 Gy) for CRT and 33.7 Gy (SD 10 Gy) for IMRT (p < 0.005). The mean parotid flow ratio 6 weeks and 6 months after treatment was respectively 41% and 64% for IMRT and respectively 11% and 18% for CRT. As a result, 6 weeks after treatment, the number of parotid flow complications was significantly lower after IMRT (55%) than after CRT (87%) (p = 0.002). The number of complications 6 months after treatment was 56% for IMRT and 81% for CRT (p = 0.04). CONCLUSIONS IMRT significantly reduces the number of parotid flow complications for patients with oropharyngeal cancer.
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Affiliation(s)
- Pètra M Braam
- Department of Radiotherapy, University Medical Center Utrecht, Utrecht, The Netherlands.
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100
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Mendenhall WM, Amdur RJ, Palta JR. Intensity-modulated radiotherapy in the standard management of head and neck cancer: promises and pitfalls. J Clin Oncol 2006; 24:2618-23. [PMID: 16763274 DOI: 10.1200/jco.2005.04.7225] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The purpose of this article is to review the role of intensity-modulated radiotherapy (IMRT) in the standard management of patients with head and neck cancer through a critical review of the pertinent literature. IMRT may result in a dose distribution that is more conformal than that achieved with three-dimensional conformal radiotherapy (3D CRT), allowing dose reduction to normal structures and thus decreasing toxicity and possibly enhancing locoregional control through dose escalation. Disadvantages associated with IMRT include increased risk of a marginal miss, decreased dose homogeneity, increased total body dose, and increased labor and expense. Outcomes data after IMRT are limited, and follow-up is relatively short. Locoregional control rates appear to be comparable to those achieved with 3D CRT and, depending on the location and extent of the tumor, late toxicity may be lower. Despite limited data on clinical outcomes, IMRT has been widely adopted as a standard technique in routine practice and clinical trials. The use of IMRT involves a learning curve for the practitioner and will continue to evolve, requiring continuing education and monitoring of outcomes from routine practice. Additional standards pertaining to a variety of issues, including target definitions and dose specification, need to be developed. Phase III trials will better define the role of IMRT in coming years.
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Affiliation(s)
- William M Mendenhall
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, USA.
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