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Zhao Y, Haworth A, Reynolds HM, Williams SG, Finnegan R, Rowshanfarzad P, Ebert MA. Towards optimal heterogeneous prostate radiotherapy dose prescriptions based on patient-specific or population-based biological features. Med Phys 2024; 51:3766-3781. [PMID: 38224317 DOI: 10.1002/mp.16936] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2023] [Revised: 12/20/2023] [Accepted: 12/22/2023] [Indexed: 01/16/2024] Open
Abstract
BACKGROUND Escalation of prescribed dose in prostate cancer (PCa) radiotherapy enables improvement in tumor control at the expense of increased toxicity. Opportunities for reduction of treatment toxicity may emerge if more efficient dose escalation can be achieved by redistributing the prescribed dose distribution according to the known heterogeneous, spatially-varying characteristics of the disease. PURPOSE To examine the potential benefits, limitations and characteristics of heterogeneous boost dose redistribution in PCa radiotherapy based on patient-specific and population-based spatial maps of tumor biological features. METHOD High-resolution prostate histology images, from a cohort of 63 patients, annotated with tumor location and grade, provided patient-specific "maps" and a population-based "atlas" of cell density and tumor probability. Dose prescriptions were derived for each patient based on a heterogeneous redistribution of the boost dose to the intraprostatic lesions, with the prescription maximizing patient tumor control probability (TCP). The impact on TCP was assessed under scenarios where the distribution of population-based biological data was ignored, partially included, or fully included in prescription generation. Heterogeneous dose prescriptions were generated for three combinations of maps and atlas, and for conventional fractionation (CF), extreme hypo-fractionation (EH), moderate hypo-fractionation (MH), and whole Pelvic RT + SBRT Boost (WPRT + SBRT). The predicted efficacy of the heterogeneous prescriptions was compared with equivalent homogeneous dose prescriptions. RESULTS TCPs for heterogeneous dose prescriptions were generally higher than those for homogeneous dose prescriptions. TCP escalation by heterogeneous dose prescription was the largest for CF. When only using population-based atlas data, the generated heterogeneous dose prescriptions of 55 to 58 patients (out of 63) had a higher TCP than for the corresponding homogeneous dose prescriptions. The TCPs of the heterogeneous dose prescriptions generated with the population-based atlas and tumor probability maps did not differ significantly from those using patient-specific biological information. The generated heterogeneous dose prescriptions achieved significantly higher TCP than homogeneous dose prescriptions in the posterior section of the prostate. CONCLUSION Heterogeneous dose prescriptions generated via biologically-optimized dose redistribution can produce higher TCP than the homogeneous dose prescriptions for the majority of the patients in the studied cohort. For scenarios where patient-specific biological information was unavailable or partially available, the generated heterogeneous dose prescriptions can still achieve TCP improvement relative to homogeneous dose prescriptions.
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Affiliation(s)
- Yutong Zhao
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Western Australia, Australia
| | - Annette Haworth
- Institute of Medical Physics, School of Physics, The University of Sydney, Camperdown, New South Wales, Australia
| | - Hayley M Reynolds
- Auckland Bioengineering Institute, University of Auckland, Auckland, New Zealand
| | - Scott G Williams
- Sir Peter MacCallum Department of Oncology, University of Melbourne, Melbourne, Victoria, Australia
- Division of Radiation Oncology and Cancer Imaging, Peter MacCallum Cancer Centre, Melbourne, Victoria, Australia
| | - Robert Finnegan
- Institute of Medical Physics, School of Physics, The University of Sydney, Camperdown, New South Wales, Australia
- Northern Sydney Cancer Centre, Royal North Shore Hospital, St Leonards, New South Wales, Australia
- Ingham Institute for Applied Medical Research, Liverpool, New South Wales, Australia
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Western Australia, Australia
| | - Martin A Ebert
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, Western Australia, Australia
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- 5D Clinics, Claremont, Western Australia, Australia
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Zhao Y, Haworth A, Rowshanfarzad P, Ebert MA. Focal Boost in Prostate Cancer Radiotherapy: A Review of Planning Studies and Clinical Trials. Cancers (Basel) 2023; 15:4888. [PMID: 37835581 PMCID: PMC10572027 DOI: 10.3390/cancers15194888] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2023] [Revised: 09/28/2023] [Accepted: 10/05/2023] [Indexed: 10/15/2023] Open
Abstract
BACKGROUND Focal boost radiotherapy was developed to deliver elevated doses to functional sub-volumes within a target. Such a technique was hypothesized to improve treatment outcomes without increasing toxicity in prostate cancer treatment. PURPOSE To summarize and evaluate the efficacy and variability of focal boost radiotherapy by reviewing focal boost planning studies and clinical trials that have been published in the last ten years. METHODS Published reports of focal boost radiotherapy, that specifically incorporate dose escalation to intra-prostatic lesions (IPLs), were reviewed and summarized. Correlations between acute/late ≥G2 genitourinary (GU) or gastrointestinal (GI) toxicity and clinical factors were determined by a meta-analysis. RESULTS By reviewing and summarizing 34 planning studies and 35 trials, a significant dose escalation to the GTV and thus higher tumor control of focal boost radiotherapy were reported consistently by all reviewed studies. Reviewed trials reported a not significant difference in toxicity between focal boost and conventional radiotherapy. Acute ≥G2 GU and late ≥G2 GI toxicities were reported the most and least prevalent, respectively, and a negative correlation was found between the rate of toxicity and proportion of low-risk or intermediate-risk patients in the cohort. CONCLUSION Focal boost prostate cancer radiotherapy has the potential to be a new standard of care.
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Affiliation(s)
- Yutong Zhao
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, WA 6009, Australia; (P.R.); (M.A.E.)
| | - Annette Haworth
- Institute of Medical Physics, School of Physics, The University of Sydney, Camperdown, NSW 2050, Australia;
| | - Pejman Rowshanfarzad
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, WA 6009, Australia; (P.R.); (M.A.E.)
- Centre for Advanced Technologies in Cancer Research (CATCR), Perth, WA 6000, Australia
| | - Martin A. Ebert
- School of Physics, Mathematics and Computing, The University of Western Australia, Crawley, WA 6009, Australia; (P.R.); (M.A.E.)
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, WA 6009, Australia
- 5D Clinics, Claremont, WA 6010, Australia
- School of Medicine and Population Health, University of Wisconsin, Madison WI 53706, USA
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3
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Skrobala A, Kruszyna-Mochalska M, Graczyk K, Ryczkowski A, Fundowicz M, Milecki P, Malicki J. Radiotherapy planning in a prostate cancer phantom model with intraprostatic dominant lesions using stereotactic body radiotherapy with volumetric modulated arcs and a simultaneous integrated boost. Front Oncol 2023; 13:1147593. [PMID: 37188175 PMCID: PMC10175813 DOI: 10.3389/fonc.2023.1147593] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Accepted: 04/10/2023] [Indexed: 05/17/2023] Open
Abstract
Aim In the treatment of prostate cancer with radiation therapy, the addition of a simultaneous integrated boost (SIB) to the dominant intraprostatic lesions (DIL) may improve local control. In this study, we aimed to determine the optimal radiation strategy in a phantom model of prostate cancer using volumetric modulated arc therapy for stereotactic body radiotherapy (SBRT-VMAT) with a SIB of 1-4 DILs. Methods We designed and printed a three-dimensional anthropomorphic phantom pelvis to simulate individual patient structures, including the prostate gland. A total of 36.25 Gy (SBRT) was delivered to the whole prostate. The DILs were irradiated with four different doses (40, 45, 47.5, and 50 Gy) to assess the influence of different SIB doses on dose distribution. The doses were calculated, verified, and measured using both transit and non-transit dosimetry for patient-specific quality assurance using a phantom model. Results The dose coverage met protocol requirements for all targets. However, the dose was close to violating risk constraints to the rectum when four DILs were treated simultaneously or when the DILs were located in the posterior segments of the prostate. All verification plans passed the assumed tolerance criteria. Conclusions Moderate dose escalation up to 45 Gy seems appropriate in cases with DILs located in posterior prostate segments or if there are three or more DILs located in other segments.
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Affiliation(s)
- Agnieszka Skrobala
- Department of Electroradiology, Poznan University of Medical Science, Poznan, Poland
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
- *Correspondence: Agnieszka Skrobala,
| | - Marta Kruszyna-Mochalska
- Department of Electroradiology, Poznan University of Medical Science, Poznan, Poland
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| | - Kinga Graczyk
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| | - Adam Ryczkowski
- Department of Medical Physics, Greater Poland Cancer Centre, Poznan, Poland
| | - Magdalena Fundowicz
- Department of Radiation Oncology I, Greater Poland Cancer Centre, Poznan, Poland
| | - Piotr Milecki
- Department of Electroradiology, Poznan University of Medical Science, Poznan, Poland
- Department of Radiation Oncology I, Greater Poland Cancer Centre, Poznan, Poland
| | - Julian Malicki
- Department of Electroradiology, Poznan University of Medical Science, Poznan, Poland
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4
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Dumas M, Leney M, Kim J, Sevak P, Elshaikh M, Pantelic M, Movsas B, Chetty IJ, Wen N. Magnetic resonance imaging‐only‐based radiation treatment planning for simultaneous integrated boost of multiparametric magnetic resonance imaging‐defined dominant intraprostatic lesions. PRECISION RADIATION ONCOLOGY 2022. [DOI: 10.1002/pro6.1152] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Michael Dumas
- Department of Radiation Oncology Henry Ford Health System Detroit Michigan USA
| | | | - Joshua Kim
- Department of Radiation Oncology Henry Ford Health System Detroit Michigan USA
| | - Parag Sevak
- Columbus Regional Healthcare System Columbus Ohio USA
| | - Mohamed Elshaikh
- Department of Radiation Oncology Henry Ford Health System Detroit Michigan USA
| | - Milan Pantelic
- Department of Radiology Henry Ford Health System Detroit Michigan USA
| | - Benjamin Movsas
- Department of Radiation Oncology Henry Ford Health System Detroit Michigan USA
| | - Indrin J. Chetty
- Department of Radiation Oncology Henry Ford Health System Detroit Michigan USA
| | - Ning Wen
- Department of Radiology Ruijin Hospital Shanghai Jiao Tong University School of Medicine Shanghai China
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Thomas C, Dregely I, Oksuz I, Urbano TG, Greener T, King AP, Barrington SF. Neural-network dose-prediction for rectal spacer stratification in dose-escalated prostate radiotherapy. Med Phys 2022; 49:2172-2182. [PMID: 35218024 PMCID: PMC9311720 DOI: 10.1002/mp.15575] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 01/22/2022] [Accepted: 02/14/2022] [Indexed: 12/03/2022] Open
Abstract
Purpose To develop a knowledge‐based decision‐support system capable of stratifying patients for rectal spacer (RS) insertion based on neural network predicted rectal dose, reducing the need for time‐ and resource‐intensive radiotherapy (RT) planning. Methods Forty‐four patients treated for prostate cancer were enrolled into a clinical trial (NCT03238170). Dose‐escalated prostate RT plans were manually created for 30 patients with simulated boost volumes using a conventional treatment planning system (TPS) and used to train a hierarchically dense 3D convolutional neural network to rapidly predict RT dose distributions. The network was used to predict rectal doses for 14 unseen test patients, with associated toxicity risks calculated according to published data. All metrics obtained using the network were compared to conventionally planned values. Results The neural network stratified patients with an accuracy of 100% based on optimal rectal dose–volume histogram constraints and 78.6% based on mandatory constraints. The network predicted dose‐derived grade 2 rectal bleeding risk within 95% confidence limits of ‐1.9% to +1.7% of conventional risk estimates (risk range 3.5%–9.9%) and late grade 2 fecal incontinence risk within ‐0.8% to +1.5% (risk range 2.3%–5.7%). Prediction of high‐resolution 3D dose distributions took 0.7 s. Conclusions The feasibility of using a neural network to provide rapid decision support for RS insertion prior to RT has been demonstrated, and the potential for time and resource savings highlighted. Directly after target and healthy tissue delineation, the network is able to (i) risk stratify most patients with a high degree of accuracy to prioritize which patients would likely derive greatest benefit from RS insertion and (ii) identify patients close to the stratification threshold who would require conventional planning.
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Affiliation(s)
- Christopher Thomas
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK.,Medical Physics Department, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
| | - Isabel Dregely
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK.,Computer Science, UAS Technikum Wien, Vienna, Austria
| | - Ilkay Oksuz
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK.,Computer Engineering Department, Istanbul Technical University, Istanbul, Turkey
| | | | - Tony Greener
- Medical Physics Department, Guy's and St Thomas' Hospital NHS Foundation Trust, London, UK
| | - Andrew P King
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK
| | - Sally F Barrington
- School of Biomedical Engineering & Imaging Sciences, King's College London, London, UK.,King's College London and Guy's and St Thomas' PET Centre, School of Biomedical Engineering and Imaging Sciences, King's College London, King's Health Partners, London, UK
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6
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Tree AC, Dearnaley DP. Seven or less Fractions is Not the Standard of Care for Intermediate-Risk Prostate Cancer. Clin Oncol (R Coll Radiol) 2020; 32:175-180. [PMID: 31711737 DOI: 10.1016/j.clon.2019.10.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 09/20/2019] [Indexed: 01/09/2023]
Abstract
Evidence is accumulating for seven and less fractions in localised prostate cancer, including one large randomised trial. However, there is much more evidence yet to come and changing practice in advance of this may be premature. We review the reasons to persist with moderate hypofractionation for prostate cancer radiotherapy, until the results of further phase III studies are known.
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Affiliation(s)
- A C Tree
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK.
| | - D P Dearnaley
- The Royal Marsden NHS Foundation Trust, London, UK; The Institute of Cancer Research, London, UK
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Wang T, Zhou J, Tian S, Wang Y, Patel P, Jani AB, Langen KM, Curran WJ, Liu T, Yang X. A planning study of focal dose escalations to multiparametric MRI-defined dominant intraprostatic lesions in prostate proton radiation therapy. Br J Radiol 2020; 93:20190845. [PMID: 31904261 PMCID: PMC7066949 DOI: 10.1259/bjr.20190845] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 12/05/2019] [Accepted: 12/23/2019] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVES The purpose of this study is to investigate the dosimetric effect and clinical impact of delivering a focal radiotherapy boost dose to multiparametric MRI (mp-MRI)-defined dominant intraprostatic lesions (DILs) in prostate cancer using proton therapy. METHODS We retrospectively investigated 36 patients with pre-treatment mp-MRI and CT images who were treated using pencil beam scanning (PBS) proton radiation therapy to the whole prostate. DILs were contoured on co-registered mp-MRIs. Simultaneous integrated boost (SIB) plans using intensity-modulated proton therapy (IMPT) were created based on conventional whole-prostate-irradiation for each patient and optimized with additional DIL coverage goals and urethral constraints. DIL dose coverage and organ-at-risk (OAR) sparing were compared between conventional and SIB plans. Tumor control probability (TCP) and normal tissue complication probability (NTCP) were estimated to evaluate the clinical impact of the SIB plans. RESULTS Optimized SIB plans significantly escalated the dose to DILs while meeting OAR constraints. SIB plans were able to achieve 125, 150 and 175% of prescription dose coverage in 74, 54 and 17% of 36 patients, respectively. This was modeled to result in an increase in DIL TCP by 7.3-13.3% depending on α / β and DIL risk level. CONCLUSION The proposed mp-MRI-guided DIL boost using proton radiation therapy is feasible without violating OAR constraints and demonstrates a potential clinical benefit by improving DIL TCP. This retrospective study suggested the use of IMPT-based DIL SIB may represent a strategy to improve tumor control. ADVANCES IN KNOWLEDGE This study investigated the planning of mp-MRI-guided DIL boost in prostate proton radiation therapy and estimated its clinical impact with respect to TCP and NTCP.
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Affiliation(s)
- Tonghe Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Jun Zhou
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Sibo Tian
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Yinan Wang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Pretesh Patel
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Ashesh B. Jani
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Katja M. Langen
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Walter J. Curran
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Tian Liu
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
| | - Xiaofeng Yang
- Department of Radiation Oncology and Winship Cancer Institute, Emory University, Atlanta 30322, Georgia
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Alexander EJ, Murray JR, Morgan VA, Giles SL, Riches SF, Hazell S, Thomas K, Sohaib SA, Thompson A, Gao A, Dearnaley DP, DeSouza NM. Validation of T2- and diffusion-weighted magnetic resonance imaging for mapping intra-prostatic tumour prior to focal boost dose-escalation using intensity-modulated radiotherapy (IMRT). Radiother Oncol 2019; 141:181-187. [PMID: 31493904 PMCID: PMC6908966 DOI: 10.1016/j.radonc.2019.07.030] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 07/22/2019] [Accepted: 07/25/2019] [Indexed: 01/28/2023]
Abstract
BACKGROUND AND PURPOSE To assess the diagnostic accuracy and inter-observer agreement of T2-weighted (T2W) and diffusion-weighted (DW) magnetic resonance imaging (MRI) for mapping intra-prostatic tumour lesions (IPLs) for the purpose of focal dose-escalation in prostate cancer radiotherapy. MATERIALS AND METHODS Twenty-six men selected for radical treatment with radiotherapy were recruited prospectively and underwent pre-treatment T2W+DW-MRI and 5 mm spaced transperineal template-guided mapping prostate biopsies (TTMPB). A 'traffic-light' system was used to score both data sets. Radiologically suspicious lesions measuring ≥0.5 cm3 were classified as red; suspicious lesions 0.2-0.5 cm3 or larger lesions equivocal for tumour were classified as amber. The histopathology assessment combined pathological grade and tumour length on biopsy (red = ≥4 mm primary Gleason grade 4/5 or ≥6 mm primary Gleason grade 3). Two radiologists assessed the MRI data and inter-observer agreement was measured with Cohens' Kappa co-efficient. RESULTS Twenty-five of 26 men had red image-defined IPLs by both readers, 24 had red pathology-defined lesions. There was a good correlation between lesions ≥0.5 cm3 classified "red" on imaging and "red" histopathology in biopsies (Reader 1: r = 0.61, p < 0.0001, Reader 2: r = 0.44, p = 0.03). Diagnostic accuracy for both readers for red image-defined lesions was sensitivity 85-86%, specificity 93-98%, positive predictive value (PPV) 79-92% and negative predictive value (NPV) 96%. Inter-observer agreement was good (Cohen's Kappa 0.61). CONCLUSIONS MRI is accurate for mapping clinically significant prostate cancer; diffusion-restricted lesions ≥0.5 cm3 can be confidently identified for radiation dose boosting.
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Affiliation(s)
- E J Alexander
- The Royal Marsden NHS Foundation Trust, Sutton, UK; The Institute of Cancer Research, Sutton, UK.
| | - J R Murray
- The Royal Marsden NHS Foundation Trust, Sutton, UK; The Institute of Cancer Research, Sutton, UK.
| | - V A Morgan
- The Institute of Cancer Research, Sutton, UK.
| | - S L Giles
- The Institute of Cancer Research, Sutton, UK.
| | - S F Riches
- The Institute of Cancer Research, Sutton, UK.
| | - S Hazell
- The Royal Marsden NHS Foundation Trust, Sutton, UK.
| | - K Thomas
- The Royal Marsden NHS Foundation Trust, Sutton, UK
| | - S A Sohaib
- The Royal Marsden NHS Foundation Trust, Sutton, UK.
| | - A Thompson
- The Royal Marsden NHS Foundation Trust, Sutton, UK.
| | - A Gao
- The Royal Marsden NHS Foundation Trust, Sutton, UK; The Institute of Cancer Research, Sutton, UK.
| | - D P Dearnaley
- The Royal Marsden NHS Foundation Trust, Sutton, UK; The Institute of Cancer Research, Sutton, UK.
| | - N M DeSouza
- The Royal Marsden NHS Foundation Trust, Sutton, UK; The Institute of Cancer Research, Sutton, UK.
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Wang T, Press RH, Giles M, Jani AB, Rossi P, Lei Y, Curran WJ, Patel P, Liu T, Yang X. Multiparametric MRI-guided dose boost to dominant intraprostatic lesions in CT-based High-dose-rate prostate brachytherapy. Br J Radiol 2019; 92:20190089. [PMID: 30912959 DOI: 10.1259/bjr.20190089] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
OBJECTIVE The purpose of this study is to investigate the dosimetric feasibility of delivering focal dose to multiparametric (mp) MRI-defined DILs in CT-based high-dose-rate (HDR) prostate brachytherapy with MR/CT registration and estimate its clinical benefit. METHODS We retrospectively investigated a total of 17 patients with mp-MRI and CT images acquired pre-treatment and treated by HDR prostate brachytherapy. 21 dominant intraprostatic lesions (DILs) were contoured on mp-MRI and propagated to CT images using a deformable image registration method. A boost plan was created for each patient and optimized on the original needle pattern. In addition, separate plans were generated using a virtually implanted needle around the DIL to mimic mp-MRI guided needle placement. DIL dose coverage and organ-at-rick (OAR) sparing were compared with original plan results. Tumor control probability (TCP) was estimated to further evaluate the clinical impact on the boost plans. RESULTS Overall, optimized boost plans significantly escalated dose to DILs while meeting OAR constraints. The addition of mp-MRI guided virtual needles facilitate increased coverage of DIL volumes, achieving a V150 > 90% in 85 % of DILs compared with 57 % of boost plan without an additional needle. Compared with original plan, TCP models estimated improvement in DIL control by 28 % for patients with external-beam treatment and by 8 % for monotherapy patients. CONCLUSION With MR/CT registration, the proposed mp-MRI guided DIL boost in CT-based HDR brachytherapy is feasible without violating OAR constraints, and indicates significant clinical benefit in improving TCP of DIL. It may represent a strategy to personalize treatment delivery and improve tumor control. ADVANCES IN KNOWLEDGE This study investigated the feasibility of mp-MRI guided DIL boost in HDR prostate brachytherapy with CT-based treatment planning, and estimated its clinical impact by TCP and NTCP estimation.
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Affiliation(s)
- Tonghe Wang
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Robert H Press
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Matt Giles
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Ashesh B Jani
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Peter Rossi
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Yang Lei
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Walter J Curran
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Pretesh Patel
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Tian Liu
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
| | - Xiaofeng Yang
- 1 Department of Radiation Oncology and Winship Cancer Institute, Emory University , Atlanta, GA , USA
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10
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Gago-Arias A, Sánchez-Nieto B, Espinoza I, Karger CP, Pardo-Montero J. Impact of different biologically-adapted radiotherapy strategies on tumor control evaluated with a tumor response model. PLoS One 2018; 13:e0196310. [PMID: 29698534 PMCID: PMC5919644 DOI: 10.1371/journal.pone.0196310] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 04/10/2018] [Indexed: 11/26/2022] Open
Abstract
Motivated by the capabilities of modern radiotherapy techniques and by the recent developments of functional imaging techniques, dose painting by numbers (DPBN) was proposed to treat tumors with heterogeneous biological characteristics. This work studies different DPBN optimization techniques for virtual head and neck tumors assessing tumor response in terms of cell survival and tumor control probability with a previously published tumor response model (TRM). Uniform doses of 2 Gy are redistributed according to the microscopic oxygen distribution and the density distribution of tumor cells in four virtual tumors with different biological characteristics. In addition, two different optimization objective functions are investigated, which: i) minimize tumor cell survival (OFsurv) or; ii) maximize the homogeneity of the density of surviving tumor cells (OFstd). Several adaptive schemes, ranging from single to daily dose optimization, are studied and the treatment response is compared to that of the uniform dose. The results show that the benefit of DPBN treatments depends on the tumor reoxygenation capability, which strongly differed among the set of virtual tumors investigated. The difference between daily (fraction by fraction) and three weekly optimizations (at the beginning of weeks 1, 3 and 4) was found to be small, and higher benefit was observed for the treatments optimized using OFsurv. This in silico study corroborates the hypothesis that DPBN may be beneficial for treatments of tumors which show reoxygenation during treatment, and that a few optimizations may be sufficient to achieve this therapeutic benefit.
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Affiliation(s)
- Araceli Gago-Arias
- Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile
- * E-mail:
| | | | - Ignacio Espinoza
- Instituto de Física, Pontificia Universidad Católica de Chile, Santiago, Chile
| | - Christian P. Karger
- National Center for Radiation Research in Oncology (NCRO), Heidelberg Institute for Radiation Oncology (HIRO), Heidelberg, Germany
| | - Juan Pardo-Montero
- Grupo de Imaxe Molecular, Instituto de Investigación Sanitaria (IDIS), Santiago de Compostela, Spain
- Servizo de Radiofísica e Protección Radiolóxica, Complexo Hospitalario Universitario de Santiago de Compostela, Santiago de Compostela, Spain
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11
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Sánchez-Nieto B, Romero-Expósito M, Terrón JA, Sánchez-Doblado F. Uncomplicated and Cancer-Free Control Probability (UCFCP): A new integral approach to treatment plan optimization in photon radiation therapy. Phys Med 2017; 42:277-284. [PMID: 28392313 DOI: 10.1016/j.ejmp.2017.03.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 03/24/2017] [Accepted: 03/29/2017] [Indexed: 12/25/2022] Open
Abstract
PURPOSE Biological treatment plan evaluation does not currently consider second cancer induction from peripheral doses associated to photon radiotherapy. The aim is to propose a methodology to characterize the therapeutic window by means of an integral radiobiological approach, which considers not only Tumour Control Probability (TCP) and Normal Tissue Complication Probability (NTCP) but also Secondary Cancer Probability (SCP). METHODS Uncomplicated and Cancer-Free Control Probability (UCFCP) function has been proposed assuming a statistically uncorrelated response for tumour and normal tissues. The Poisson's and Lyman's models were chosen for TCP and NTCP calculations, respectively. SCP was modelled as the summation of risks associated to photon and neutron irradiation of radiosensitive organs. For the medium (>4Gy) and low dose regions, mechanistic and linear secondary cancer risks models were used, respectively. Two conformal and intensity-modulated prostate plans at 15MV (same prescription dose) were selected to illustrate the UCFCP features. RESULTS UCFCP exhibits a bell-shaped behaviour with its maximum inside the therapeutic window. SCP values were not different for the plans analysed (∼2.4%) and agreed with published epidemiological results. Therefore, main differences in UCFCP came from differences in rectal NTCP (18% vs 9% for 3D-CRT and IMRT, respectively). According to UCFCP values, the evaluated IMRT plan ranked first. CONCLUSIONS The level of SCP was found to be similar to that of NTCP complications which reinforces the importance of considering second cancer risks as part of the possible late sequelae due to treatment. Previous concerns about the effect of peripheral radiation, especially neutrons, in the induction of secondary cancers can be evaluated by quantifying the UCFCP.
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Affiliation(s)
- Beatriz Sánchez-Nieto
- Instituto de Física, Pontificia Universidad Católica de Chile, Av. Vicuña Mackenna 4880, Macul, Santiago, Chile.
| | - Maite Romero-Expósito
- Departament de Física, Universitat Autònoma de Barcelona, Edifici C, Campus UAB E-08193, Bellaterra, Spain.
| | - José A Terrón
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Av. Doctor Fedriani, 3, 41009 Sevilla, Spain.
| | - Francisco Sánchez-Doblado
- Servicio de Radiofísica, Hospital Universitario Virgen Macarena, Av. Doctor Fedriani, 3, 41009 Sevilla, Spain; Departamento de Fisiología Médica y Biofísica, Universidad de Sevilla, Av. Doctor Fedriani S/N, 41009 Sevilla, Spain.
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Pathmanathan AU, Alexander EJ, Huddart RA, Tree AC. The delineation of intraprostatic boost regions for radiotherapy using multimodality imaging. Future Oncol 2016; 12:2495-2511. [PMID: 27322113 DOI: 10.2217/fon-2016-0129] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Dose escalation to the prostate improves tumor control but at the expense of increased rectal toxicity. Modern imaging can be used to detect the most common site of recurrence, the intraprostatic lesion (IPL), which has led to the concept of focusing dose escalation to the IPL in order to improve the therapeutic ratio. Imaging must be able to detect lesions with adequate sensitivity and specificity to accurately delineate the IPL. This information must be carefully integrated into the radiotherapy planning process to ensure the dose is targeted to the IPL. This review will consider the role and challenges of multiparametric MRI and PET computed tomography in delineating a tumor boost to be delivered by external beam radiotherapy.
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Affiliation(s)
| | - Emma J Alexander
- The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, SM2 5PT, UK
| | - Robert A Huddart
- The Institute of Cancer Research, 123 Old Brompton Road, London, SW7 3RP, UK
| | - Alison C Tree
- The Royal Marsden NHS Foundation Trust, Downs Road, Sutton, SM2 5PT, UK
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Walsh S, Roelofs E, Kuess P, Lambin P, Jones B, Georg D, Verhaegen F. A validated tumor control probability model based on a meta-analysis of low, intermediate, and high-risk prostate cancer patients treated by photon, proton, or carbon-ion radiotherapy. Med Phys 2016; 43:734-47. [PMID: 26843237 DOI: 10.1118/1.4939260] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE A fully heterogeneous population averaged mechanistic tumor control probability (TCP) model is appropriate for the analysis of external beam radiotherapy (EBRT). This has been accomplished for EBRT photon treatment of intermediate-risk prostate cancer. Extending the TCP model for low and high-risk patients would be beneficial in terms of overall decision making. Furthermore, different radiation treatment modalities such as protons and carbon-ions are becoming increasingly available. Consequently, there is a need for a complete TCP model. METHODS A TCP model was fitted and validated to a primary endpoint of 5-year biological no evidence of disease clinical outcome data obtained from a review of the literature for low, intermediate, and high-risk prostate cancer patients (5218 patients fitted, 1088 patients validated), treated by photons, protons, or carbon-ions. The review followed the preferred reporting item for systematic reviews and meta-analyses statement. Treatment regimens include standard fractionation and hypofractionation treatments. Residual analysis and goodness of fit statistics were applied. RESULTS The TCP model achieves a good level of fit overall, linear regression results in a p-value of <0.000 01 with an adjusted-weighted-R(2) value of 0.77 and a weighted root mean squared error (wRMSE) of 1.2%, to the fitted clinical outcome data. Validation of the model utilizing three independent datasets obtained from the literature resulted in an adjusted-weighted-R(2) value of 0.78 and a wRMSE of less than 1.8%, to the validation clinical outcome data. The weighted mean absolute residual across the entire dataset is found to be 5.4%. CONCLUSIONS This TCP model fitted and validated to clinical outcome data, appears to be an appropriate model for the inclusion of all clinical prostate cancer risk categories, and allows evaluation of current EBRT modalities with regard to tumor control prediction.
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Affiliation(s)
- Seán Walsh
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC+), Maastricht 6229 ET, The Netherlands and Department of Oncology, Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Erik Roelofs
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC+), Maastricht 6229 ET, The Netherlands
| | - Peter Kuess
- Department of Radiation Oncology and Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna 1090, Austria
| | - Philippe Lambin
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC+), Maastricht 6229 ET, The Netherlands
| | - Bleddyn Jones
- Department of Oncology, Gray Institute for Radiation Oncology and Biology, University of Oxford, Oxford OX3 7DQ, United Kingdom
| | - Dietmar Georg
- Department of Radiation Oncology and Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, Vienna 1090, Austria
| | - Frank Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW-School for Oncology and Developmental Biology, Maastricht University Medical Center (MUMC+), Maastricht 6229 ET, The Netherlands and Medical Physics Unit, Department of Oncology, McGill University, Montréal, Québec H4A 3J1, Canada
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Is IMRT Superior or Inferior to 3DCRT in Radiotherapy for NSCLC? A Meta-Analysis. PLoS One 2016; 11:e0151988. [PMID: 27100968 PMCID: PMC4839644 DOI: 10.1371/journal.pone.0151988] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2016] [Accepted: 03/07/2016] [Indexed: 12/25/2022] Open
Abstract
Introduction There are no adequate data to determine whether intensity-modulated radiotherapy (IMRT) is superior to three-dimensional conformal radiotherapy (3DCRT) in the treatment of non-small cell lung cancer (NSCLC). This meta-analysis was conducted to compare the clinical outcomes of IMRT and 3DCRT in the treatment of NSCLC. Methods No exclusions were made based on types of study design. We performed a literature search in PubMed, EMBASE and the Cochrane library databases from their inceptions to April 30, 2015. The overall survival (OS) and relative risk (RR) of radiation pneumonitis and radiation oesophagitis were evaluated. Two authors independently assessed the methodological quality and extracted data. Publication bias was evaluated by funnel plot using Egger’s test results. Results From the literature search, 10 retrospective studies were collected, and of those, 5 (12,896 patients) were selected for OS analysis, 4 (981 patients) were selected for radiation pneumonitis analysis, and 4 (1339 patients) were selected for radiation oesophagitis analysis. Cox multivariate proportional hazards models revealed that 3DCRT and IMRT had similar OS (HR = 0.96, P = 0.477) but that IMRT reduced the incidence of grade 2 radiation pneumonitis (RR = 0.74, P = 0.009) and increased the incidence of grade 3 radiation oesophagitis (RR = 2.47, P = 0.000). Conclusions OS of IMRT for NSCLC is not inferior to that of 3DCRT, but IMRT significantly reduces the risk of radiation pneumonitis and increases the risk of radiation oesophagitis compared to 3DCRT.
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Abstract
The use of magnetic resonance imaging (MRI) in radiotherapy (RT) planning is rapidly expanding. We review the wide range of image contrast mechanisms available to MRI and the way they are exploited for RT planning. However a number of challenges are also considered: the requirements that MR images are acquired in the RT treatment position, that they are geometrically accurate, that effects of patient motion during the scan are minimized, that tissue markers are clearly demonstrated, that an estimate of electron density can be obtained. These issues are discussed in detail, prior to the consideration of a number of specific clinical applications. This is followed by a brief discussion on the development of real-time MRI-guided RT.
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Affiliation(s)
- Maria A Schmidt
- Cancer Research UK Cancer Imaging Centre, Royal Marsden Hospital and the Institute of Cancer Research, Downs Road, Sutton, Surrey, SM2 5PT, UK
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Shrimali RK, Mahata A, Reddy GD, Franks KN, Chatterjee S. Pitfalls and Challenges to Consider before Setting up a Lung Cancer Intensity-modulated Radiotherapy Service: A Review of the Reported Clinical Experience. Clin Oncol (R Coll Radiol) 2015; 28:185-97. [PMID: 26329504 DOI: 10.1016/j.clon.2015.08.002] [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] [Received: 09/04/2014] [Revised: 05/27/2015] [Accepted: 08/12/2015] [Indexed: 12/25/2022]
Abstract
Intensity-modulated radiotherapy (IMRT) is being increasingly used for the treatment of non-small cell lung cancer (NSCLC), despite the absence of published randomised controlled trials. Planning studies and retrospective series have shown a decrease in known predictors of lung toxicity (V20 and mean lung dose) and the maximum spinal cord dose. Potential dosimetric advantages, accessibility of technology, a desire to escalate dose or a need to meet normal organ dose constraints are some of the factors recognised as supporting the use of IMRT. However, IMRT may not be appropriate for all patients being treated with radical radiotherapy. Unique problems with using IMRT for NSCLC include organ and tumour motion because of breathing and the potential toxicity from low doses of radiotherapy to larger amounts of lung tissue. Caution should be exercised as there is a paucity of prospective data regarding the efficacy and safety of IMRT in lung cancer when compared with three-dimensional conformal radiotherapy and IMRT data from other cancer sites should not be extrapolated. This review looks at the use of IMRT in NSCLC, addresses the challenges and highlights the potential benefits of using this complex radiotherapy technique.
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Affiliation(s)
- R K Shrimali
- Department of Radiation Oncology, Tata Medical Center, Kolkata, India.
| | - A Mahata
- Medical Physics, Tata Medical Center, Kolkata, India
| | - G D Reddy
- Department of Radiation Oncology, Tata Medical Center, Kolkata, India
| | - K N Franks
- Leeds Cancer Centre, St James's University Hospital, Leeds, UK
| | - S Chatterjee
- Department of Radiation Oncology, Tata Medical Center, Kolkata, India
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Kuang Y, Wu L, Hirata E, Miyazaki K, Sato M, Kwee SA. Volumetric modulated arc therapy planning for primary prostate cancer with selective intraprostatic boost determined by 18F-choline PET/CT. Int J Radiat Oncol Biol Phys 2015; 91:1017-25. [PMID: 25832692 PMCID: PMC4405528 DOI: 10.1016/j.ijrobp.2014.12.052] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2014] [Revised: 12/23/2014] [Accepted: 12/29/2014] [Indexed: 02/05/2023]
Abstract
PURPOSE This study evaluated expected tumor control and normal tissue toxicity for prostate volumetric modulated arc therapy (VMAT) with and without radiation boosts to an intraprostatically dominant lesion (IDL), defined by (18)F-choline positron emission tomography/computed tomography (PET/CT). METHODS AND MATERIALS Thirty patients with localized prostate cancer underwent (18)F-choline PET/CT before treatment. Two VMAT plans, plan79 Gy and plan100-105 Gy, were compared for each patient. The whole-prostate planning target volume (PTVprostate) prescription was 79 Gy in both plans, but plan100-105 Gy added simultaneous boost doses of 100 Gy and 105 Gy to the IDL, defined by 60% and 70% of maximum prostatic uptake on (18)F-choline PET (IDLsuv60% and IDLsuv70%, respectively, with IDLsuv70% nested inside IDLsuv60% to potentially enhance tumor specificity of the maximum point dose). Plan evaluations included histopathological correspondence, isodose distributions, dose-volume histograms, tumor control probability (TCP), and normal tissue complication probability (NTCP). RESULTS Planning objectives and dose constraints proved feasible in 30 of 30 cases. Prostate sextant histopathology was available for 28 cases, confirming that IDLsuv60% adequately covered all tumor-bearing prostate sextants in 27 cases and provided partial coverage in 1 case. Plan100-105 Gy had significantly higher TCP than plan79 Gy across all prostate regions for α/β ratios ranging from 1.5 Gy to 10 Gy (P<.001 for each case). There were no significant differences in bladder and femoral head NTCP between plans and slightly lower rectal NTCP (endpoint: grade ≥ 2 late toxicity or rectal bleeding) was found for plan100-105 Gy. CONCLUSIONS VMAT can potentially increase the likelihood of tumor control in primary prostate cancer while observing normal tissue tolerances through simultaneous delivery of a steep radiation boost to a (18)F-choline PET-defined IDL.
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Affiliation(s)
- Yu Kuang
- Department of Medical Physics, University of Nevada Las Vegas, Las Vegas, Nevada
| | - Lili Wu
- Department of Medical Physics, University of Nevada Las Vegas, Las Vegas, Nevada; Department of Radiation Oncology, Cancer Hospital of Shantou University Medical College, Shantou, Guangdong, China
| | - Emily Hirata
- Hamamatsu/Queen's PET Imaging Center and Departments of Radiation Oncology and Oncology Research, The Queen's Medical Center, Honolulu, Hawaii
| | - Kyle Miyazaki
- Hamamatsu/Queen's PET Imaging Center and Departments of Radiation Oncology and Oncology Research, The Queen's Medical Center, Honolulu, Hawaii
| | - Miles Sato
- Hamamatsu/Queen's PET Imaging Center and Departments of Radiation Oncology and Oncology Research, The Queen's Medical Center, Honolulu, Hawaii
| | - Sandi A Kwee
- Hamamatsu/Queen's PET Imaging Center and Departments of Radiation Oncology and Oncology Research, The Queen's Medical Center, Honolulu, Hawaii; John A. Burns School of Medicine, University of Hawaii, Honolulu, Hawaii.
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Ngwa W, Kumar R, Sridhar S, Korideck H, Zygmanski P, Cormack RA, Berbeco R, Makrigiorgos GM. Targeted radiotherapy with gold nanoparticles: current status and future perspectives. Nanomedicine (Lond) 2014; 9:1063-82. [PMID: 24978464 PMCID: PMC4143893 DOI: 10.2217/nnm.14.55] [Citation(s) in RCA: 112] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Radiation therapy (RT) is the treatment of cancer and other diseases with ionizing radiation. The ultimate goal of RT is to destroy all the disease cells while sparing healthy tissue. Towards this goal, RT has advanced significantly over the past few decades in part due to new technologies including: multileaf collimator-assisted modulation of radiation beams, improved computer-assisted inverse treatment planning, image guidance, robotics with more precision, better motion management strategies, stereotactic treatments and hypofractionation. With recent advances in nanotechnology, targeted RT with gold nanoparticles (GNPs) is actively being investigated as a means to further increase the RT therapeutic ratio. In this review, we summarize the current status of research and development towards the use of GNPs to enhance RT. We highlight the promising emerging modalities for targeted RT with GNPs and the corresponding preclinical evidence supporting such promise towards potential clinical translation. Future prospects and perspectives are discussed.
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Affiliation(s)
- Wilfred Ngwa
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
| | - Rajiv Kumar
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
- Electronic Materials Research Institute & Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Srinivas Sridhar
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
- Electronic Materials Research Institute & Department of Physics, Northeastern University, Boston, MA 02115, USA
| | - Houari Korideck
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
| | - Piotr Zygmanski
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
| | - Robert A Cormack
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
| | - Ross Berbeco
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
| | - G Mike Makrigiorgos
- Department of Radiation Oncology, Dana-Farber Cancer Institute, Brigham & Women’s Hospital & Harvard Medical School, Boston, MA 02215, USA
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Potential interest of developing an integrated boost dose escalation for stereotactic irradiation of primary prostate cancer. Phys Med 2014; 30:320-5. [DOI: 10.1016/j.ejmp.2013.09.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/24/2013] [Revised: 09/19/2013] [Accepted: 09/23/2013] [Indexed: 12/31/2022] Open
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Murray LJ, Lilley J, Thompson CM, Cosgrove V, Mason J, Sykes J, Franks K, Sebag-Montefiore D, Henry AM. Prostate stereotactic ablative radiation therapy using volumetric modulated arc therapy to dominant intraprostatic lesions. Int J Radiat Oncol Biol Phys 2014; 89:406-15. [PMID: 24685447 PMCID: PMC4018668 DOI: 10.1016/j.ijrobp.2014.01.042] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2013] [Revised: 01/20/2014] [Accepted: 01/25/2014] [Indexed: 12/25/2022]
Abstract
PURPOSE To investigate boosting dominant intraprostatic lesions (DILs) in the context of stereotactic ablative radiation therapy (SABR) and to examine the impact on tumor control probability (TCP) and normal tissue complication probability (NTCP). METHODS AND MATERIALS Ten prostate datasets were selected. DILs were defined using T2-weighted, dynamic contrast-enhanced and diffusion-weighted magnetic resonance imaging. Four plans were produced for each dataset: (1) no boost to DILs; (2) boost to DILs, no seminal vesicles in prescription; (3) boost to DILs, proximal seminal vesicles (proxSV) prescribed intermediate dose; and (4) boost to DILs, proxSV prescribed higher dose. The prostate planning target volume (PTV) prescription was 42.7 Gy in 7 fractions. DILs were initially prescribed 115% of the PTV(Prostate) prescription, and PTV(DIL) prescriptions were increased in 5% increments until organ-at-risk constraints were reached. TCP and NTCP calculations used the LQ-Poisson Marsden, and Lyman-Kutcher-Burman models respectively. RESULTS When treating the prostate alone, the median PTV(DIL) prescription was 125% (range: 110%-140%) of the PTV(Prostate) prescription. Median PTV(DIL) D50% was 55.1 Gy (range: 49.6-62.6 Gy). The same PTV(DIL) prescriptions and similar PTV(DIL) median doses were possible when including the proxSV within the prescription. TCP depended on prostate α/β ratio and was highest with an α/β ratio = 1.5 Gy, where the additional TCP benefit of DIL boosting was least. Rectal NTCP increased with DIL boosting and was considered unacceptably high in 5 cases, which, when replanned with an emphasis on reducing maximum dose to 0.5 cm(3) of rectum (Dmax(0.5cc)), as well as meeting existing constraints, resulted in considerable rectal NTCP reductions. CONCLUSIONS Boosting DILs in the context of SABR is technically feasible but should be approached with caution. If this therapy is adopted, strict rectal constraints are required including Dmax(0.5cc). If the α/β ratio of prostate cancer is 1.5 Gy or less, then high TCP and low NTCP can be achieved by prescribing SABR to the whole prostate, without the need for DIL boosting.
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Affiliation(s)
- Louise J Murray
- Department of Clinical Oncology, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom; University of Leeds, Leeds, United Kingdom
| | - John Lilley
- Department of Medical Physics, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom
| | - Christopher M Thompson
- Department of Medical Physics, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom
| | - Vivian Cosgrove
- Department of Medical Physics, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom
| | - Josh Mason
- Department of Medical Physics, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom; University of Leeds, Leeds, United Kingdom
| | - Jonathan Sykes
- Department of Medical Physics, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom
| | - Kevin Franks
- Department of Clinical Oncology, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom
| | - David Sebag-Montefiore
- Department of Clinical Oncology, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom; University of Leeds, Leeds, United Kingdom
| | - Ann M Henry
- Department of Clinical Oncology, Leeds Cancer Centre, St. James's University Hospital, Leeds, United Kingdom.
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Tree A, Alexander E, Van As N, Dearnaley D, Khoo V. Biological Dose Escalation and Hypofractionation: What is There to be Gained and How Will it Best be Done? Clin Oncol (R Coll Radiol) 2013; 25:483-98. [DOI: 10.1016/j.clon.2013.05.003] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2013] [Accepted: 05/09/2013] [Indexed: 12/12/2022]
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Maggio A, Carillo V, Cozzarini C, Perna L, Rancati T, Valdagni R, Gabriele P, Fiorino C. Impact of the radiotherapy technique on the correlation between dose–volume histograms of the bladder wall defined on MRI imaging and dose–volume/surface histograms in prostate cancer patients. Phys Med Biol 2013; 58:N115-23. [DOI: 10.1088/0031-9155/58/7/n115] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
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Walsh S, van der Putten W. A TCP model for external beam treatment of intermediate-risk prostate cancer. Med Phys 2013; 40:031709. [DOI: 10.1118/1.4790469] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Isebaert S, Van den Bergh L, Haustermans K, Joniau S, Lerut E, De Wever L, De Keyzer F, Budiharto T, Slagmolen P, Van Poppel H, Oyen R. Multiparametric MRI for prostate cancer localization in correlation to whole-mount histopathology. J Magn Reson Imaging 2012; 37:1392-401. [PMID: 23172614 DOI: 10.1002/jmri.23938] [Citation(s) in RCA: 131] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Accepted: 10/04/2012] [Indexed: 11/08/2022] Open
Affiliation(s)
- Sofie Isebaert
- Department of Radiation Oncology, University Hospitals Leuven, Leuven, Belgium.
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Isebaert S, De Keyzer F, Haustermans K, Lerut E, Roskams T, Roebben I, Van Poppel H, Joniau S, Oyen R. Evaluation of semi-quantitative dynamic contrast-enhanced MRI parameters for prostate cancer in correlation to whole-mount histopathology. Eur J Radiol 2012; 81:e217-22. [DOI: 10.1016/j.ejrad.2011.01.107] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2010] [Accepted: 01/28/2011] [Indexed: 10/18/2022]
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Alexander EJ, Harris VA, Sohaib A, Dearnaley D. Reducing the side effects of external beam radiotherapy in prostate cancer: role of imaging techniques. ACTA ACUST UNITED AC 2012. [DOI: 10.2217/iim.11.65] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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Housri N, Ning H, Ondos J, Choyke P, Camphausen K, Citrin D, Arora B, Shankavaram U, Kaushal A. Parameters favorable to intraprostatic radiation dose escalation in men with localized prostate cancer. Int J Radiat Oncol Biol Phys 2011; 80:614-20. [PMID: 20932672 PMCID: PMC3580994 DOI: 10.1016/j.ijrobp.2010.06.050] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2010] [Revised: 05/15/2010] [Accepted: 06/29/2010] [Indexed: 11/26/2022]
Abstract
PURPOSE To identify , within the framework of a current Phase I trial, whether factors related to intraprostatic cancer lesions (IPLs) or individual patients predict the feasibility of high-dose intraprostatic irradiation. METHODS AND MATERIALS Endorectal coil MRI scans of the prostate from 42 men were evaluated for dominant IPLs. The IPLs, prostate, and critical normal tissues were contoured. Intensity-modulated radiotherapy plans were generated with the goal of delivering 75.6 Gy in 1.8-Gy fractions to the prostate, with IPLs receiving a simultaneous integrated boost of 3.6 Gy per fraction to a total dose of 151.2 Gy, 200% of the prescribed dose and the highest dose cohort in our trial. Rectal and bladder dose constraints were consistent with those outlined in current Radiation Therapy Oncology Group protocols. RESULTS Dominant IPLs were identified in 24 patients (57.1%). Simultaneous integrated boosts (SIB) to 200% of the prescribed dose were achieved in 12 of the 24 patients without violating dose constraints. Both the distance between the IPL and rectum and the hip-to-hip patient width on planning CT scans were associated with the feasibility to plan an SIB (p = 0.002 and p = 0.0137, respectively). CONCLUSIONS On the basis of this small cohort, the distance between an intraprostatic lesion and the rectum most strongly predicted the ability to plan high-dose radiation to a dominant intraprostatic lesion. High-dose SIB planning seems possible for select intraprostatic lesions.
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Affiliation(s)
- Nadine Housri
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Holly Ning
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - John Ondos
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Peter Choyke
- Molecular Imaging Program, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Kevin Camphausen
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Deborah Citrin
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Barbara Arora
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Uma Shankavaram
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
| | - Aradhana Kaushal
- Radiation Oncology Branch Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, MD
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Maggio A, Fiorino C, Mangili P, Cozzarini C, de Cobelli F, Cattaneo GM, Rancati T, Maschio AD, Muzio ND, Calandrino R. Feasibility of safe ultra-high (EQD(2)>100 Gy) dose escalation on dominant intra-prostatic lesions (DILs) by Helical Tomotheraphy. Acta Oncol 2011; 50:25-34. [PMID: 21174609 DOI: 10.3109/0284186x.2010.530688] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE to verify the possibility of using Helical Tomotherapy to safely escalate dose to single or multiple highly radioresistant dominant intra-prostatic lesions (DILs) as assessed by functional magnetic resonance imaging (MRI). MATERIAL in seven intermediate/high risk patients, T2WI, T1WI and DWI MRI imaging showed evidence of one DIL in four patients and two DILs in three patients in the peripheral zone of the prostate. The planning strategy was to deliver median doses of 80, 90, 100 and 120 Gy to PTVDIL while delivering 71.4 Gy/28 fractions (EQD(2)=75 Gy) to the remaining portion of PTV. A higher priority was assigned to rectal constraints relative to DIL coverage. Rectal NTCP calculations were performed using the most recently available model data. RESULTS the median dose to DIL could safely be escalated to at least 100 Gy (EQD(2,α/β=10)=113 Gy) without violating safe constraints for the organs at risk. Typical rectal NTCP values were around or below 1-3% for G3 toxicity and 5-7% for G2-G3 toxicity. For the 100 Gy DIL dose boost strategy, mean D95% of DIL and PTVDIL were 98.8 Gy and 86.7 Gy, respectively. The constraints for bladder, urethra and femoral heads were always respected. CONCLUSIONS IGRT by Helical Tomotherapy may permit the safe escalation of EQD(2,α/β=10) to at least 113 Gy to DILs without significantly increasing rectal NTCP compared to plans without dose escalation. A Phase I-II clinical study is warranted.
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Affiliation(s)
- Angelo Maggio
- Medical Physics, San Raffaele Scientific Institute, Milano, Italy
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Button M, Staffurth J. Clinical Application of Image-guided Radiotherapy in Bladder and Prostate Cancer. Clin Oncol (R Coll Radiol) 2010; 22:698-706. [DOI: 10.1016/j.clon.2010.06.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2010] [Accepted: 06/30/2010] [Indexed: 11/28/2022]
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Abe E, Mizowaki T, Norihisa Y, Narita Y, Matsuo Y, Narabayashi M, Nagata Y, Hiraoka M. Impact of multileaf collimator width on intraprostatic dose painting plans for dominant intraprostatic lesion of prostate cancer. J Appl Clin Med Phys 2010; 11:3193. [PMID: 21081876 PMCID: PMC5720410 DOI: 10.1120/jacmp.v11i4.3193] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2009] [Revised: 06/21/2010] [Accepted: 07/12/2010] [Indexed: 11/23/2022] Open
Abstract
The aim of this study was to investigate the impact of multileaf collimator width (MLC‐W) on intraprostatic dose painting plans for prostate cancer. Prostate cancer maps based on the histopathological findings were superimposed onto simulation CT images. Clinical target volume (CTV) 1 was defined as the prostate and the base of the seminal vesicles, and CTV2 was defined as the dominant intraprostatic lesions. Planning target volume (PTV) 1 and PTV2 were delineated by adding 5 mm margins to CTV1 and CTV2, respectively. For each case, two dose painting plans were created to deliver 74 Gy to PTV1 and 84 Gy to PTV2 with dynamic multileaf collimator technique using two different MLCs: m3 (MLC‐W: 3 mm) and Millennium (5 mm). Plans were evaluated by comparing the conformation number (CN), a quantity that defines the degree of conformality. The CNs for plans using the m3 and Millennium were 0.68 and 0.67 for PTV1 and 0.59 and 0.58 for PTV2, respectively. The CNs tended to be higher for a thinner leaf width (p<0.05). Dosimetric advantages associated with smaller leaves were observed. However, differences between 3 mm and 5 mm leaf width were relatively small, which suggested that 5 mm leaf width would be acceptable in dose painting plans for prostate cancer. PACS numbers: 87.56.N‐, 87.56.nk, 87.55.D‐
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Affiliation(s)
- Eisuke Abe
- Division of Radiation Oncology, Department of Molecular Genetics, Course for Molecular and Cellular Medicine, Graduate School of Medical and Dental Sciences, Niigata University, Niigata, Japan.
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Kazi A, Godwin G, Simpson J, Sasso G. MRS-guided HDR brachytherapy boost to the dominant intraprostatic lesion in high risk localised prostate cancer. BMC Cancer 2010; 10:472. [PMID: 20809986 PMCID: PMC2941503 DOI: 10.1186/1471-2407-10-472] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2009] [Accepted: 09/01/2010] [Indexed: 11/30/2022] Open
Abstract
Background It is known that the vast majority of prostate cancers are multifocal. However radical radiotherapy historically treats the whole gland rather than individual cancer foci. Magnetic resonance spectroscopy (MRS) can be used to non-invasively locate individual cancerous tumours in prostate. Thus an intentionally non-uniform dose distribution treating the dominant intraprostatic lesion to different dose levels than the remaining prostate can be delivered ensuring the maximum achievable tumour control probability. The aim of this study is to evaluate, using radiobiological means, the feasibility of a MRS-guided high dose rate (HDR) brachytherapy boost to the dominant lesion. Methods Computed tomography and MR/MRS were performed for treatment planning of a high risk localised prostate cancer. Both were done without endorectal coil, which distorts shape of prostate during the exams. Three treatment plans were compared: - external beam radiation therapy (EBRT) only - combination of EBRT and HDR brachytherapy - combination of EBRT and HDR brachytherapy with a synchronous integrated boost to the dominant lesion The criteria of plan comparison were: the minimum, maximum and average doses to the targets and organs at risk; dose volume histograms; biologically effective doses for organs at risk and tumour control probability for the target volumes consisting of the dominant lesion as detected by MR/MRS and the remaining prostate volume. Results Inclusion of MRS information on the location of dominant lesion allows a safe increase of the dose to the dominant lesion while dose to the remaining target can be even substantially decreased keeping the same, high tumour control probability. At the same time an improved urethra sparing was achieved comparing to the treatment plan using a combination of EBRT and uniform HDR brachytherapy. Conclusions MRS-guided HDR brachytherapy boost to dominant lesion has the potential to spare the normal tissue, especially urethra, while keeping the tumour control probability high.
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Affiliation(s)
- Aleksandra Kazi
- Department of Medical Physics, Townsville Teaching Hospital, Townsville, Queensland, Australia.
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Carbon-11 acetate PET/CT based dose escalated IMRT in prostate cancer. Radiother Oncol 2009; 93:234-40. [DOI: 10.1016/j.radonc.2009.08.010] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 07/31/2009] [Accepted: 08/04/2009] [Indexed: 11/18/2022]
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Liao ZX, Komaki RR, Thames HD, Liu HH, Tucker SL, Mohan R, Martel MK, Wei X, Yang K, Kim ES, Blumenschein G, Hong WK, Cox JD. Influence of technologic advances on outcomes in patients with unresectable, locally advanced non-small-cell lung cancer receiving concomitant chemoradiotherapy. Int J Radiat Oncol Biol Phys 2009; 76:775-81. [PMID: 19515503 DOI: 10.1016/j.ijrobp.2009.02.032] [Citation(s) in RCA: 210] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Revised: 11/15/2008] [Accepted: 02/17/2009] [Indexed: 12/17/2022]
Abstract
PURPOSE In 2004, our institution began using four-dimensional computed tomography (4DCT) simulation and then intensity-modulated radiotherapy (IMRT) (4DCT/IMRT) instead of three-dimensional conformal radiotherapy (3DCRT) for the standard treatment of non-small-cell lung cancer (NSCLC). This retrospective study compares disease outcomes and toxicity in patients treated with concomitant chemotherapy and either 4DCT/IMRT or 3DCRT. METHODS AND MATERIALS A total of 496 NSCLC patients have been treated at M. D. Anderson Cancer Center between 1999 and 2006 with concomitant chemoradiotherapy. Among these, 318 were treated with CT/3DCRT and 91 with 4DCT/IMRT. Both groups received a median dose of 63 Gy. Disease end points were locoregional progression (LRP), distant metastasis (DM), and overall survival (OS). Disease covariates were gross tumor volume (GTV), nodal status, and histology. The toxicity end point was Grade >or=3 radiation pneumonitis; toxicity covariates were GTV, smoking status, and dosimetric factors. Data were analyzed using Cox proportional hazards models. RESULTS Mean follow-up times in the 4DCT/IMRT and CT/3DCRT groups were 1.3 (range, 0.1-3.2) and 2.1 (range, 0.1-7.9) years, respectively. The hazard ratios for 4DCT/IMRT were <1 for all disease end points; the difference was significant only for OS. The toxicity rate was significantly lower in the IMRT/4DCT group than in the CT/3DCRT group. V20 was significantly higher in the 3DCRT group and was a significant factor in determining toxicity. Freedom from DM was nearly identical in both groups. CONCLUSIONS Treatment with 4DCT/IMRT was at least as good as that with 3DCRT in terms of the rates of freedom from LRP and DM. There was a significant reduction in toxicity and a significant improvement in OS.
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Affiliation(s)
- Zhongxing X Liao
- Department of Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, USA
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Onal C, Topkan E, Efe E, Yavuz M, Sonmez S, Yavuz A. Comparison of rectal volume definition techniques and their influence on rectal toxicity in patients with prostate cancer treated with 3D conformal radiotherapy: a dose-volume analysis. Radiat Oncol 2009; 4:14. [PMID: 19432953 PMCID: PMC2684071 DOI: 10.1186/1748-717x-4-14] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2009] [Accepted: 05/11/2009] [Indexed: 11/22/2022] Open
Abstract
Background To evaluate the impact of four different rectum contouring techniques and rectal toxicities in patients with treated with 3D conformal radiotherapy (3DCRT). Methods Clinical and dosimetric data were evaluated for 94 patients who received a total dose 3DCRT of 70 Gy, and rectal doses were compared in four different rectal contouring techniques: the prostate-containing CT sections (method 1); 1 cm above and below the planning target volume (PTV) (method 2); 110 mm starting from the anal verge (method 3); and from the anal verge to the sigmoid flexure (method 4). The percentage of rectal volume receiving RT doses (30–70 Gy) and minimum, mean rectal doses were assessed. Results Median age was 69 years. Percentage of rectal volume receiving high doses (≥ 70 Gy) were higher with the techniques that contoured smaller rectal volumes. In methods 2 and 3, the percentage of rectal volume receiving ≥ 70 Gy was significantly higher in patients with than without rectal bleeding (method 2: 30.8% vs. 22.5%, respectively (p = 0.03); method 3: 26.9% vs. 18.1%, respectively (p = 0.006)). Mean rectal dose was significant predictor of rectal bleeding only in method 3 (48.8 Gy in patients with bleeding vs. 44.4 Gy in patients without bleeding; p = 0.02). Conclusion Different techniques of rectal contouring significantly influence the calculation of radiation doses to the rectum and the prediction of rectal toxicity. Rectal volume receiving higher doses (≥ 70 Gy) and mean rectal doses may significantly predict rectal bleeding for techniques contouring larger rectal volumes, as was in method 3.
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Affiliation(s)
- Cem Onal
- Department of Radiation Oncology, Baskent University Medical Faculty, Adana, Turkey.
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Organisational Standards for the Delivery of Intensity-modulated Radiation Therapy in Ontario. Clin Oncol (R Coll Radiol) 2009; 21:192-203. [DOI: 10.1016/j.clon.2008.10.005] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2008] [Accepted: 10/09/2008] [Indexed: 11/19/2022]
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JACKSON ASN, REINSBERG SA, SOHAIB SA, CHARLES-EDWARDS EM, JHAVAR S, CHRISTMAS TJ, THOMPSON AC, BAILEY MJ, CORBISHLEY CM, FISHER C, LEACH MO, DEARNALEY DP. Dynamic contrast-enhanced MRI for prostate cancer localization. Br J Radiol 2009; 82:148-56. [DOI: 10.1259/bjr/89518905] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Huang SH, Catton C, Jezioranski J, Bayley A, Rose S, Rosewall T. The Effect of Changing Technique, Dose, and PTV Margin on Therapeutic Ratio During Prostate Radiotherapy. Int J Radiat Oncol Biol Phys 2008; 71:1057-64. [DOI: 10.1016/j.ijrobp.2007.11.055] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2007] [Revised: 08/28/2007] [Accepted: 11/14/2007] [Indexed: 02/07/2023]
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Conformal and intensity-modulated radiotherapy for cervical cancer. Clin Oncol (R Coll Radiol) 2008; 20:417-25. [PMID: 18558480 DOI: 10.1016/j.clon.2008.04.004] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2008] [Revised: 04/01/2008] [Accepted: 04/17/2008] [Indexed: 12/28/2022]
Abstract
Three-dimensional radiotherapy planning techniques, including conformal radiotherapy and intensity-modulated radiotherapy, have potential for improving outcomes in cervical cancer. Accurate target volume definition is essential in order to maximise normal tissue sparing while minimising the risk of a geographical miss. This reduction in toxicity provides the option of dose escalation, particularly with simultaneous integrated boost intensity-modulated radiotherapy. The evidence for the current use and potential applications of these techniques in the treatment of cervical cancer are discussed.
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Hensel JM, Ménard C, Chung PWM, Milosevic MF, Kirilova A, Moseley JL, Haider MA, Brock KK. Development of Multiorgan Finite Element-Based Prostate Deformation Model Enabling Registration of Endorectal Coil Magnetic Resonance Imaging for Radiotherapy Planning. Int J Radiat Oncol Biol Phys 2007; 68:1522-8. [PMID: 17674983 DOI: 10.1016/j.ijrobp.2007.04.004] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2006] [Revised: 04/03/2007] [Accepted: 04/03/2007] [Indexed: 11/25/2022]
Abstract
PURPOSE Endorectal coil (ERC) magnetic resonance imaging (MRI) provides superior visualization of the prostate compared with computed tomography at the expense of deformation. This study aimed to develop a multiorgan finite element deformable method, Morfeus, to accurately co-register these images for radiotherapy planning. METHODS Patients with prostate cancer underwent fiducial marker implantation and computed tomography simulation for radiotherapy planning. A series of axial MRI scans were acquired with and without an ERC. The prostate, bladder, rectum, and pubic bones were manually segmented and assigned linear elastic material properties. Morfeus mapped the surface of the bladder and rectum between two imaged states, calculating the deformation of the prostate through biomechanical properties. The accuracy of deformation was measured as fiducial marker error and residual surface deformation between the inferred and actual prostate. The deformation map was inverted to deform from 100 cm(3) to no coil. RESULTS The data from 19 patients were analyzed. Significant prostate deformation occurred with the ERC (mean intrapatient range, 0.88 +/- 0.25 cm). The mean vector error in fiducial marker position (n = 57) was 0.22 +/- 0.09 cm, and the mean vector residual surface deformation (n = 19) was 0.15 +/- 0.06 cm for deformation from no coil to 100-cm(3) ERC, with an image vector resolution of 0.22 cm. Accurately deformed MRI scans improved soft-tissue resolution of the anatomy for radiotherapy planning. CONCLUSIONS This method of multiorgan deformable registration enabled accurate co-registration of ERC-MRI scans with computed tomography treatment planning images. Superior structural detail was visible on ERC-MRI, which has potential for improving target delineation.
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Affiliation(s)
- Jennifer M Hensel
- Radiation Medicine Program, Princess Margaret Hospital, Toronto, ON, Canada
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Zhang P, Osterman KS, Liu T, Li X, Kessel J, Wu L, Schiff P, Kutcher GJ. How does performance of ultrasound tissue typing affect design of prostate IMRT dose-painting protocols? Int J Radiat Oncol Biol Phys 2007; 67:362-8. [PMID: 17236962 PMCID: PMC2901543 DOI: 10.1016/j.ijrobp.2006.08.061] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2006] [Revised: 08/03/2006] [Accepted: 08/24/2006] [Indexed: 10/23/2022]
Abstract
PURPOSE To investigate how the performance characteristics of ultrasound tissue typing (UTT) affect the design of a population-based prostate dose-painting protocol. METHODS AND MATERIALS The performance of UTT is evaluated using the receiver operating characteristic curve. As the imager's sensitivity increases, more tumors are detected, but the specificity worsens, causing more false-positive results. The UTT tumor map, obtained with a specific sensitivity and specificity setup, was used with the patient's CT image to guide intensity-modulated radiotherapy (IMRT) planning. The optimal escalation dose to the UTT positive region, as well as the safe dose to the negative background, was obtained by maximizing the uncomplicated control (i.e., a combination of tumor control probability and weighted normal tissue complication probability). For high- and low-risk tumors, IMRT plans guided by conventional ultrasound or UTT with a one-dimensional or two-dimensional spectrum analysis technique were compared with an IMRT plan in which the whole prostate was dose escalated. RESULTS For all imaging modalities, the specificity of 0.9 was chosen to reduce complications resulting from high false-positive results. If the primary tumors were low risk, the IMRT plans guided by all imaging modalities achieved high tumor control probability and reduced the normal tissue complication probability significantly compared with the plan with whole gland dose escalation. However, if the primary tumors were high risk, the accuracy of the imaging modality was critical to maintain the tumor control probability and normal tissue complication probability at acceptable levels. CONCLUSION The performance characteristics of an imager have important implications in dose painting and should be considered in the design of dose-painting protocols.
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Affiliation(s)
- Pengpeng Zhang
- Department of Radiation Oncology, Columbia University Medical Center, New York, NY 10032-3784, USA.
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Newbold K, Partridge M, Cook G, Sohaib SA, Charles-Edwards E, Rhys-Evans P, Harrington K, Nutting C. Advanced imaging applied to radiotherapy planning in head and neck cancer: a clinical review. Br J Radiol 2006; 79:554-61. [PMID: 16823059 DOI: 10.1259/bjr/48822193] [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: 11/05/2022] Open
Abstract
Head and neck squamous cell carcinoma represents an ideal model to investigate the application of recent advances in medical imaging to radiotherapy planning. Tumours usually remain localized, and are potentially curable with local radiation. The steep radiation dose-response relationships support the strategies of radiation dose escalation to increase local control. Two-dimensional simulator-based planning and CT planning have significant drawbacks in terms of accurate target volume definition. MRI has enhanced soft tissue delineation, but has to be fused with CT to allow dose calculation. Functional imaging using dynamic contrast enhanced CT or MRI sequences may allow improved knowledge of tumour function. Positron emission tomography (PET) may allow further physiological information to be determined. This review summarizes the current techniques in clinical development in this area.
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Affiliation(s)
- K Newbold
- The Royal Marsden NHS Trust, Fulham Road, London SW3 6JJ, UK
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Livi L, Paiar F, Banci-Buonamici F, Simontacchi G, Detti B, Gacci M, Mondaini N, Nelli F, Bastiani P, Pertici M, Mungai R, Ponticelli P, Biti G. Localized Prostate Cancer Treated with Intensity-Modulated Radiotherapy. TUMORI JOURNAL 2006; 92:197-201. [PMID: 16869235 DOI: 10.1177/030089160609200302] [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: 12/25/2022]
Abstract
Aims and background The development and use of new radiotherapy techniques, especially 3D conformal radiotherapy or intensity-modulated radiotherapy, has allowed the safe application of high doses of external beam radiotherapy without increasing toxicity. The aim of this analysis was to describe the acute and when possible late toxicity and the feasibility on using intensity-modulated radiotherapy into our routine work. Patients and methods From June 2003 to December 2004, 60 patients with prostate cancer underwent high dose (80 Gy) radiotherapy treatment with intensity-modulated radiotherapy at the University of Florence. In the current analysis, we included patients without clinical or radiographic evidence of distant disease at the time of the first evaluation in the radiotherapy unit. Results Intensity-modulated radiotherapy treatments were delivered successfully without any interruption or technical problem. High-dose intensity-modulated radiotherapy was well tolerated acutely. Four patients (10%) developed grade 1 late rectal toxicity after completion of intensity-modulated radiotherapy and 8 patients (20%) developed grade 1 late urinary symptoms. Conclusions Intensity-modulated radiotherapy is the approach of choice for high-dose radiotherapy delivery. No patient had severe toxicity (grade 3) despite the high dose delivered. From a cost-benefit point of view, our experience shows that delivery of intensity-modulated radiotherapy requires only minor corrections to the ordinary activity schedule.
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Affiliation(s)
- Lorenzo Livi
- Radiotherapy Department, Florence University, Italy.
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van Lin ENJT, Fütterer JJ, Heijmink SWTPJ, van der Vight LP, Hoffmann AL, van Kollenburg P, Huisman HJ, Scheenen TWJ, Witjes JA, Leer JW, Barentsz JO, Visser AG. IMRT boost dose planning on dominant intraprostatic lesions: Gold marker-based three-dimensional fusion of CT with dynamic contrast-enhanced and 1H-spectroscopic MRI. Int J Radiat Oncol Biol Phys 2006; 65:291-303. [PMID: 16618584 DOI: 10.1016/j.ijrobp.2005.12.046] [Citation(s) in RCA: 136] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2005] [Revised: 12/19/2005] [Accepted: 12/19/2005] [Indexed: 11/20/2022]
Abstract
PURPOSE To demonstrate the theoretical feasibility of integrating two functional prostate magnetic resonance imaging (MRI) techniques (dynamic contrast-enhanced MRI [DCE-MRI] and 1H-spectroscopic MRI [MRSI]) into inverse treatment planning for definition and potential irradiation of a dominant intraprostatic lesion (DIL) as a biologic target volume for high-dose intraprostatic boosting with intensity-modulated radiotherapy (IMRT). METHODS AND MATERIALS In 5 patients, four gold markers were implanted. An endorectal balloon was inserted for both CT and MRI. A DIL volume was defined by DCE-MRI and MRSI using different prostate cancer-specific physiologic (DCE-MRI) and metabolic (MRSI) parameters. CT-MRI registration was performed automatically by matching three-dimensional gold marker surface models with the iterative closest point method. DIL-IMRT plans, consisting of whole prostate irradiation to 70 Gy and a DIL boost to 90 Gy, and standard IMRT plans, in which the whole prostate was irradiated to 78 Gy were generated. The tumor control probability and rectal wall normal tissue complication probability were calculated and compared between the two IMRT approaches. RESULTS Combined DCE-MRI and MRSI yielded a clearly defined single DIL volume (range, 1.1-6.5 cm3) in all patients. In this small, selected patient population, no differences in tumor control probability were found. A decrease in the rectal wall normal tissue complication probability was observed in favor of the DIL-IMRT plan versus the plan with IMRT to 78 Gy. CONCLUSION Combined DCE-MRI and MRSI functional image-guided high-dose intraprostatic DIL-IMRT planned as a boost to 90 Gy is theoretically feasible. The preliminary results have indicated that DIL-IMRT may improve the therapeutic ratio by decreasing the normal tissue complication probability with an unchanged tumor control probability. A larger patient population, with more variations in the number, size, and localization of the DIL, and a feasible mechanism for treatment implementation has to be studied to extend these preliminary tumor control and toxicity estimates.
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Affiliation(s)
- Emile N J T van Lin
- Department of Radiation Oncology, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands.
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Ahmad S, Vlachaki MT. Impact of margin on tumour and normal tissue dosimetry in prostate cancer patients treated with IMRT using an endorectal balloon for prostate immobilization. ACTA ACUST UNITED AC 2005; 28:209-15. [PMID: 16506617 DOI: 10.1007/bf03178720] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
In IMRT treatment, margin for planning target volume is determined by organ motion and set-up error. The margin width that achieves the desired dose escalation, while minimizing normal tissue exposure is dependent upon patient immobilization and/or organ localization techniques. In this study, we compare the impact of margin width on the dosimetry of tumour and normal tissues using an endorectal balloon filled with 100 cc of air. Plans were generated for ten patients using margin widths of 0, 3, 5, 8 and 10 mm. The prescription dose to prostate and seminal vesicles was 70 Gy in 35 fractions with 15% of bladder allowed to receive above 65 Gy, 15% of rectum above 68 Gy and 10% of femurs above 45 Gy. Margins above 5 mm produced significantly lower mean doses for both prostate and seminal vesicles without affecting TCP. For normal tissues, mean doses, percent volumes above prescription constraints and NTCP increased as a function of margin width, especially when this was 5 mm or above. We conclude that planning with tighter margins of < or =5 mm improves IMRT dosimetry for prostate and normal tissues and is only possible when target localization and/or immobilization devices are routinely used.
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Affiliation(s)
- S Ahmad
- The University of Oklahoma Health Sciences Center, Department of Radiation Oncology, Oklahoma City 73104, USA.
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Abstract
The increased incidence and awareness of prostate cancer, together with developments in treatment, has generated a significant need for appropriate imaging to detect and stage the tumour initially, guide radiotherapy delivery and monitor disease on follow-up. Transrectal ultrasound is usually the first imaging investigation, and its role is primarily to guide prostate needle biopsy. It also has an established role in imaging-guided treatments, such as brachytherapy. Magnetic resonance imaging has developed considerably in recent years, and is now the principal staging investigation before treatment. Innovations in functional and biological imaging of the prostate will, in the future, contribute valuable information to support parallel developments in radiotherapy techniques for prostate cancer. The ultimate goal is a coordinated diagnostic and therapeutic approach to individualise and optimise the treatment plan for patients with prostate cancer.
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Affiliation(s)
- B M Carey
- Cookridge Hospital, Leeds, Hospital Lane, Leeds, UK.
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Abstract
BACKGROUND Intensity-modulated radiation therapy (IMRT) is a novel approach to the planning and delivery of radiation therapy. The prevalence of IMRT use among radiation oncologists in the U.S. appears to be increasing, despite limited data evaluating its risks and benefits. METHODS A random sample of radiation oncologists in the U.S., including a cohort of 441 physicians who were surveyed in 2002, was surveyed regarding IMRT use. IMRT users were questioned regarding their frequency of use, clinical applications, and reasons for adopting IMRT. IMRT nonusers were asked their reasons for not using IMRT, whether they planned to use it in the future, and reasons for wanting to adopt IMRT. Differences in responses between 2002 and 2004 were compared. RESULTS The survey was conducted between July 1, 2004 and August 31, 2004. Of 368 evaluable participants, 239 physicians (64.9%) responded. The proportion of respondents who used IMRT was 73.2% (175 physicians), compared with 32.0% in 2002. The adoption rate of IMRT among nonusers from 2002 to 2004 was 62.7% (95% confidence interval, 51.9-73.5%). Many IMRT users (81.0%) had used IMRT to deliver higher than conventional doses of radiation, predominantly in patients with genitourinary and head and neck tumors. Major reasons cited for IMRT adoption were permitting normal tissue sparing (88.0%), dose escalation (85.1%), and economic competition (62.4%). Ninety-one percent of nonusers planned to adopt IMRT in the future. CONCLUSIONS IMRT use among radiation oncologists in the U.S. has increased significantly since 2002. Standardized guidelines and careful, prospective analyses evaluating its risks and benefits are needed.
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Affiliation(s)
- Loren K Mell
- Department of Radiation and Cellular Oncology, University of Chicago, IL 60637, USA.
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47
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Huisman HJ, Fütterer JJ, van Lin ENJT, Welmers A, Scheenen TWJ, van Dalen JA, Visser AG, Witjes JA, Barentsz JO. Prostate Cancer: Precision of Integrating Functional MR Imaging with Radiation Therapy Treatment by Using Fiducial Gold Markers. Radiology 2005; 236:311-7. [PMID: 15983070 DOI: 10.1148/radiol.2361040560] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The use of intensity-modulated radiation therapy for treatment of dominant intraprostatic lesions may require integration of functional magnetic resonance (MR) imaging with treatment-planning computed tomography (CT). The purpose of this study was to compare prospectively the landmark and iterative closest point methods for registration of CT and MR images of the prostate gland after placement of fiducial markers. The study was approved by the institutional ethics review board, and informed consent was obtained. CT and MR images were registered by using fiducial gold markers that were inserted into the prostate. Two image registration methods--a commonly available landmark method and dedicated iterative closest point method--were compared. Precision was assessed for a data set of 21 patients by using five operators. Precision of the iterative closest point method (1.1 mm) was significantly better (P < .01) than that of the landmark method (2.0 mm). Furthermore, a method is described by which multimodal MR imaging data are reduced into a single interpreted volume that, after registration, can be incorporated into treatment planning.
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Affiliation(s)
- Henkjan J Huisman
- Department of Radiology, Radboud University Nijmegen Medical Center, Geert Grooteplein zuid 10, NL 6500 HB, Nijmegen, Netherlands.
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48
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Jhavar SG, Fisher C, Jackson A, Reinsberg SA, Dennis N, Falconer A, Dearnaley D, Edwards SE, Edwards SM, Leach MO, Cummings C, Christmas T, Thompson A, Woodhouse C, Sandhu S, Cooper CS, Eeles RA. Processing of radical prostatectomy specimens for correlation of data from histopathological, molecular biological, and radiological studies: a new whole organ technique. J Clin Pathol 2005; 58:504-8. [PMID: 15858122 PMCID: PMC1770644 DOI: 10.1136/jcp.2004.021808] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To develop a method of processing non-formalin fixed prostate specimens removed at radical prostatectomy to obtain fresh tissue for research and for correlating diagnostic and molecular results with preoperative imaging. METHODS/RESULTS The method involves a prostate slicing apparatus comprising a tissue slicer with a series of juxtaposed planar stainless steel blades linked to a support, and a cradle adapted to grip the tissue sample and receive the blades. The fresh prostate gland is held in the cradle and the blades are moved through the cradle slits to produce multiple 4 mm slices of the gland in a plane perpendicular to its posterior surface. One of the resulting slices is preserved in RNAlater. The areas comprising tumour and normal glands within this preserved slice can be identified by matching it to the haematoxylin and eosin stained sections of the adjacent slices that are formalin fixed and paraffin wax embedded. Intact RNA can be extracted from the identified tumour and normal glands within the RNAlater preserved slice. Preoperative imaging studies are acquired with the angulation of axial images chosen to be similar to the slicing axis, such that stained sections from the formalin fixed, paraffin wax embedded slices match their counterparts on imaging. CONCLUSIONS A novel method of sampling fresh prostate removed at radical prostatectomy that allows tissue samples to be used both for diagnosis and molecular analysis is described. This method also allows the integration of preoperative imaging data with histopathological and molecular data obtained from the prostate tissue slices.
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Affiliation(s)
- S G Jhavar
- Section of Molecular Carcinogenesis, Institute of Cancer Research, Sutton, Surrey SM2 5NG, UK
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49
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Mangar SA, Huddart RA, Parker CC, Dearnaley DP, Khoo VS, Horwich A. Technological advances in radiotherapy for the treatment of localised prostate cancer. Eur J Cancer 2005; 41:908-21. [PMID: 15808957 DOI: 10.1016/j.ejca.2004.12.028] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2004] [Accepted: 12/02/2004] [Indexed: 10/25/2022]
Abstract
There is good evidence that radiation dose escalation in localised prostate cancer is associated with increased cell kill. The traditional two-dimensional (2D) technique of treatment planning and delivery is limited by normal tissue toxicity, such that the dose that can be safely delivered to the prostate by external beam radiotherapy is 65-70 Gy. Several technological advances over the last 20 years have enhanced the precision of external beam radiotherapy (EBRT), and have resulted in improved outcomes. The three-dimensional conformal radiotherapy (3D-CRT) approach reduces the dose-limiting late side-effect of proctitis and has allowed for dose escalation to the whole prostate to 78 Gy. More recently, intensity modulated radiotherapy (IMRT), an advanced form of conformal therapy, has resulted in reduced rectal toxicity when using doses greater than 80 Gy. In addition, IMRT can potentially escalate the dose to specific parts of the prostate where there are resistant subpopulations of tumour clonogens, or can be used to extend the high-dose region to pelvic lymph nodes. The addition of androgen deprivation to conventional radiotherapy has an impact on survival and local control. Initial hormone therapy causes cytoreduction of the prostate cancer allowing for a reduction in radiotherapy volume as well as an additive effect on cell kill. Long-term adjuvant androgen deprivation has been shown to improve overall survival in more advanced tumours. Prostate brachytherapy is now a recognised treatment for those with low-risk disease. It achieves similar long-term outcome to other treatment modalities. Brachytherapy can be used as monotherapy for localised disease, or as boost treatment following conventional EBRT for locally advanced disease. New techniques are available to improve the precision of both target definition and treatment verification. This so-called image-guided radiotherapy will help to enhance the accuracy of dose delivery by correcting both for inter-fraction positional variation and for intra-fraction movement of the prostate in real-time and will allow for tighter tumour margins and avoidance of normal tissues, thereby enhancing the safety of treatment.
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Affiliation(s)
- Stephen A Mangar
- Academic Unit of Radiotherapy and Oncology, The Royal Marsden NHS Foundation Trust and The Institute of Cancer Research, Downs Road, Sutton SM2 5NG, UK.
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50
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van Lin ENJT, van der Vight LP, Witjes JA, Huisman HJ, Leer JW, Visser AG. The effect of an endorectal balloon and off-line correction on the interfraction systematic and random prostate position variations: A comparative study. Int J Radiat Oncol Biol Phys 2005; 61:278-88. [PMID: 15629621 DOI: 10.1016/j.ijrobp.2004.09.042] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2004] [Revised: 09/23/2004] [Accepted: 09/24/2004] [Indexed: 11/28/2022]
Abstract
PURPOSE To investigate the effect of an endorectal balloon (ERB) and an off-line correction protocol on the day-to-day, interfraction prostate gland motion, in patients receiving external beam radiotherapy for prostate cancer. METHODS AND MATERIALS In 22 patients, irradiated with an ERB in situ (ERB group) and in 30 patients without an ERB (No-ERB group), prostate displacements were measured daily in three orthogonal directions with portal images. Implanted gold markers and an off-line electronic portal imaging correction protocol were used for prostate position verification and correction. Movie loops were analyzed to evaluate prostate motion and rectal filling variations. RESULTS The off-line correction protocol reduced the systematic prostate displacements, equally for the ERB and No-ERB group, to 1.3-1.8 mm (1 SD). The mean 3D displacement was reduced to 2.8 mm and 2.4 mm for the ERB and No-ERB group, respectively. The random interfraction displacements, relative to the treatment isocenter, were not reduced by the ERB and remained nearly unchanged in all three directions: 3.1 mm (1 SD) left-right, 2.6 mm (1 SD) superior-inferior, and 4.7 mm (1 SD) for the anterior-posterior direction. These day-to-day prostate position variations can be explained by the presence of gas and stool beside the ERB. CONCLUSIONS The off-line corrections on the fiducial markers are effective in reducing the systematic prostate displacements. The investigated ERB does not reduce the interfraction prostate motion. Although the overall mean displacement is low, the day-to-day interfraction motion, especially in anterior-posterior direction, remains high compared with the systematic displacements.
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Affiliation(s)
- Emile N J Th van Lin
- Department of Radiation Oncology, University Medical Centre Nijmegen, Nijmegen, The Netherlands.
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