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Integrating external beam and prostate seed implant dosimetry for intermediate and high-risk prostate cancer using biologically effective dose: Impact of image registration technique. Brachytherapy 2022; 21:853-863. [PMID: 35922366 DOI: 10.1016/j.brachy.2022.07.002] [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: 01/21/2022] [Revised: 06/02/2022] [Accepted: 07/06/2022] [Indexed: 12/14/2022]
Abstract
PURPOSE Combining external beam radiation therapy (EBRT) and prostate seed implant (PSI) is efficacious in treating intermediate- and high-risk prostate cancer at the cost of increased genitourinary toxicity. Accurate combined dosimetry remains elusive due to lack of registration between treatment plans and different biological effect. The current work proposes a method to convert physical dose to biological effective dose (BED) and spatially register the dose distributions for more accurate combined dosimetry. METHODS AND MATERIALS A PSI phantom was CT scanned with and without seeds under rigid and deformed transformations. The resulting CTs were registered using image-based rigid registration (RI), fiducial-based rigid registration (RF), or b-spline deformable image registration (DIR) to determine which was most accurate. Physical EBRT and PSI dose distributions from a sample of 91 previously-treated combined-modality prostate cancer patients were converted to BED and registered using RI, RF, and DIR. Forty-eight (48) previously-treated patients whose PSI occurred before EBRT were included as a "control" group due to inherent registration. Dose-volume histogram (DVH) parameters were compared for RI, RF, DIR, DICOM, and scalar addition of DVH parameters using ANOVA or independent Student's t tests (α = 0.05). RESULTS In the phantom study, DIR was the most accurate registration algorithm, especially in the case of deformation. In the patient study, dosimetry from RI was significantly different than the other registration algorithms, including the control group. Dosimetry from RF and DIR were not significantly different from the control group or each other. CONCLUSIONS Combined dosimetry with BED and image registration is feasible. Future work will utilize this method to correlate dosimetry with clinical outcomes.
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Greco C, Pares O, Pimentel N, Louro V, Nunes B, Kociolek J, Stroom J, Vieira S, Mateus D, Cardoso MJ, Soares A, Marques J, Freitas E, Coelho G, Fuks Z. Urethra Sparing With Target Motion Mitigation in Dose-Escalated Extreme Hypofractionated Prostate Cancer Radiotherapy: 7-Year Results From a Phase II Study. Front Oncol 2022; 12:863655. [PMID: 35433469 PMCID: PMC9012148 DOI: 10.3389/fonc.2022.863655] [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: 01/27/2022] [Accepted: 02/24/2022] [Indexed: 11/15/2022] Open
Abstract
Purpose To explore whether the rectal distension-mediated technique, harnessing human physiology to achieve intrafractional prostate motion mitigation, enables urethra sparing by inverse dose painting, thus promoting dose escalation with extreme hypofractionated stereotactic ablative radiotherapy (SABR) in prostate cancer. Materials and Methods Between June 2013 and December 2018, 444 patients received 5 × 9 Gy SABR over 5 consecutive days. Rectal distension-mediated SABR was employed via insertion of a 150-cm3 air-inflated endorectal balloon. A Foley catheter loaded with 3 beacon transponders was used for urethra visualization and online tracking. MRI-based planning using Volumetric Modulated Arc Therapy - Image Guided Radiotherapy (VMAT-IGRT) with inverse dose painting was employed in delivering the planning target volume (PTV) dose and in sculpting exposure of organs at risk (OARs). A 2-mm margin was used for PTV expansion, reduced to 0 mm at the interface with critical OARs. All plans fulfilled Dmean ≥45 Gy. Target motion ≥2 mm/5 s motions mandated treatment interruption and target realignment prior to completion of the planned dose delivery. Results Patient compliance to the rectal distension-mediated immobilization protocol was excellent, achieving reproducible daily prostate localization at a patient-specific retropubic niche. Online tracking recorded ≤1-mm intrafractional target deviations in 95% of treatment sessions, while target realignment in ≥2-mm deviations enabled treatment completion as scheduled in all cases. The cumulative incidence rates of late grade ≥2 genitourinary (GU) and gastrointestinal (GI) toxicities were 5.3% and 1.1%, respectively. The favorable toxicity profile was corroborated by patient-reported quality of life (QOL) outcomes. Median prostate-specific antigen (PSA) nadir by 5 years was 0.19 ng/ml. The cumulative incidence rate of biochemical failure using the Phoenix definition was 2%, 16.6%, and 27.2% for the combined low/favorable–intermediate, unfavorable intermediate, and high-risk categories, respectively. Patients with a PSA failure underwent a 68Ga-labeled prostate-specific membrane antigen (68Ga-PSMA) scan showing a 20.2% cumulative incidence of intraprostatic relapses in biopsy International Society of Urological Pathology (ISUP) grade ≥3. Conclusion The rectal distension-mediated technique is feasible and well tolerated. Dose escalation to 45 Gy with urethra-sparing results in excellent toxicity profiles and PSA relapse rates similar to those reported by other dose-escalated regimens. The existence of intraprostatic recurrences in patients with high-risk features confirms the notion of a high α/β ratio in these phenotypes resulting in diminished effectiveness with hypofractionated dose escalation.
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Affiliation(s)
- Carlo Greco
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Oriol Pares
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Nuno Pimentel
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Vasco Louro
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Beatriz Nunes
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Justyna Kociolek
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Joep Stroom
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Sandra Vieira
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Dalila Mateus
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Maria Joao Cardoso
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Ana Soares
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Joao Marques
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Elda Freitas
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Graça Coelho
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - Zvi Fuks
- Department of Radiation Oncology, Champalimaud Centre for the Unknown, Lisbon, Portugal.,Memorial Sloan Kettering Cancer Center, New York, NY, United States
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Ghaderi N, Jung J, Brüningk SC, Subramanian A, Nassour L, Peacock J. A Century of Fractionated Radiotherapy: How Mathematical Oncology Can Break the Rules. Int J Mol Sci 2022; 23:ijms23031316. [PMID: 35163240 PMCID: PMC8836217 DOI: 10.3390/ijms23031316] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 01/17/2022] [Accepted: 01/18/2022] [Indexed: 02/07/2023] Open
Abstract
Radiotherapy is involved in 50% of all cancer treatments and 40% of cancer cures. Most of these treatments are delivered in fractions of equal doses of radiation (Fractional Equivalent Dosing (FED)) in days to weeks. This treatment paradigm has remained unchanged in the past century and does not account for the development of radioresistance during treatment. Even if under-optimized, deviating from a century of successful therapy delivered in FED can be difficult. One way of exploring the infinite space of fraction size and scheduling to identify optimal fractionation schedules is through mathematical oncology simulations that allow for in silico evaluation. This review article explores the evidence that current fractionation promotes the development of radioresistance, summarizes mathematical solutions to account for radioresistance, both in the curative and non-curative setting, and reviews current clinical data investigating non-FED fractionated radiotherapy.
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Affiliation(s)
- Nima Ghaderi
- Department of Biomedical Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA; (N.G.); (J.J.)
| | - Joseph Jung
- Department of Biomedical Engineering, University of Minnesota Twin Cities, Minneapolis, MN 55455, USA; (N.G.); (J.J.)
| | - Sarah C. Brüningk
- Machine Learning & Computational Biology Lab, Department of Biosystems Science and Engineering, ETH Zurich, 4058 Basel, Switzerland;
- Swiss Institute for Bioinformatics (SIB), 1015 Lausanne, Switzerland
| | - Ajay Subramanian
- Department of Radiation Oncology, Stanford University, Stanford, CA 94305, USA;
| | - Lauren Nassour
- Department of Radiation Oncology, University of Alabama Birmingham, Birmingham, AL 35205, USA;
| | - Jeffrey Peacock
- Department of Radiation Oncology, University of Alabama Birmingham, Birmingham, AL 35205, USA;
- Correspondence:
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Marcello M, Denham JW, Kennedy A, Haworth A, Steigler A, Greer PB, Holloway LC, Dowling JA, Jameson MG, Roach D, Joseph DJ, Gulliford SL, Dearnaley DP, Sydes MR, Hall E, Ebert MA. Reduced Dose Posterior to Prostate Correlates With Increased PSA Progression in Voxel-Based Analysis of 3 Randomized Phase 3 Trials. Int J Radiat Oncol Biol Phys 2020; 108:1304-1318. [PMID: 32739320 DOI: 10.1016/j.ijrobp.2020.07.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2020] [Revised: 07/13/2020] [Accepted: 07/20/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE Reducing margins during treatment planning to decrease dose to healthy organs surrounding the prostate can risk inadequate treatment of subclinical disease. This study aimed to investigate whether lack of dose to subclinical disease is associated with increased disease progression by using high-quality prostate radiation therapy clinical trial data to identify anatomically localized regions where dose variation is associated with prostate-specific antigen progression (PSAP). METHODS AND MATERIALS Planned dose distributions for 683 patients of the Trans-Tasman Radiation Oncology Group 03.04 Randomized Androgen Deprivation and Radiotherapy (RADAR) trial were deformably registered onto a single exemplar computed tomography data set. These were divided into high-risk and intermediate-risk subgroups for analysis. Three independent voxel-based statistical tests, using permutation testing, Cox regression modeling, and least absolute shrinkage selection operator feature selection, were applied to identify regions where dose variation was associated with PSAP. Results from the intermediate-risk RADAR subgroup were externally validated by registering dose distributions from the RT01 (n = 388) and Conventional or Hypofractionated High Dose Intensity Modulated Radiotherapy for Prostate Cancer Trial (CHHiP) (n = 253) trials onto the same exemplar and repeating the tests on each of these data sets. RESULTS Voxel-based Cox regression revealed regions where reduced dose was correlated with increased prostate-specific androgen progression. Reduced dose in regions associated with coverage at the posterior prostate, in the immediate periphery of the posterior prostate, and in regions corresponding to the posterior oblique beams or posterior lateral beam boundary, was associated with increased PSAP for RADAR and RT01 patients, but not for CHHiP patients. Reduced dose to the seminal vesicle region was also associated with increased PSAP for RADAR intermediate-risk patients. CONCLUSIONS Ensuring adequate dose coverage at the posterior prostate and immediately surrounding posterior region (including the seminal vesicles), where aggressive cancer spread may be occurring, may improve tumor control. It is recommended that particular care be taken when defining margins at the prostate posterior, acknowledging the trade-off between quality of life due to rectal dose and the preferences of clinicians and patients.
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Affiliation(s)
- Marco Marcello
- Department of Physics, University of Western Australia, Perth, Western Australia, Australia; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia.
| | - James W Denham
- School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - Angel Kennedy
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia
| | - Annette Haworth
- School of Physics, University of Sydney, Sydney, New South Wales, Australia
| | - Allison Steigler
- Prostate Cancer Trials Group, School of Medicine and Public Health, University of Newcastle, Newcastle, New South Wales, Australia
| | - Peter B Greer
- School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, New South Wales, Australia; Department of Radiation Oncology, Calvary Mater Newcastle, Newcastle, New South Wales, Australia
| | - Lois C Holloway
- Department of Medical Physics, Liverpool Cancer Centre, Sydney, New South Wales, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, New South Wales, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia
| | - Jason A Dowling
- School of Mathematical and Physical Sciences, University of Newcastle, Newcastle, New South Wales, Australia; CSIRO, Brisbane, Queensland, Australia
| | - Michael G Jameson
- Department of Medical Physics, Liverpool Cancer Centre, Sydney, New South Wales, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, New South Wales, Australia; Centre for Medical Radiation Physics, University of Wollongong, Wollongong, New South Wales, Australia; Cancer Research Team, Ingham Institute for Applied Medical Research, Sydney, New South Wales, Australia
| | - Dale Roach
- Department of Medical Physics, Liverpool Cancer Centre, Sydney, New South Wales, Australia; South Western Sydney Clinical School, University of New South Wales, Sydney, New South Wales, Australia; Cancer Research Team, Ingham Institute for Applied Medical Research, Sydney, New South Wales, Australia
| | - David J Joseph
- School of Surgery, University of Western Australia, Perth, Western Australia, Australia; 5D Clinics, Claremont, Perth, Western Australia, Australia; GenesisCare WA, Perth, Western Australia, Australia
| | - Sarah L Gulliford
- Radiotherapy Department, University College London Hospitals NHS Foundation Trust, London, United Kingdom; Department of Medical Physics and Biomedical Engineering, University College London, London, United Kingdom
| | - David P Dearnaley
- Academic UroOncology Unit, The Institute of Cancer Research and the Royal Marsden NHS Trust, London, United Kingdom
| | - Matthew R Sydes
- MRC Clinical Trials Unit, Institute of Clinical Trials and Methodology, University College London, London, United Kingdom
| | - Emma Hall
- Clinical Trials and Statistics Unit, The Institute of Cancer Research, London, United Kingdom
| | - Martin A Ebert
- Department of Physics, University of Western Australia, Perth, Western Australia, Australia; Department of Radiation Oncology, Sir Charles Gairdner Hospital, Perth, Western Australia, Australia; 5D Clinics, Claremont, Perth, Western Australia, Australia
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Franzese C, Badalamenti M, Di Brina L, D'Agostino G, Franceschini D, Comito T, Clerici E, Navarria P, Reggiori G, Mancosu P, Tomatis S, Scorsetti M. Linac-based stereotactic body radiation therapy for low and intermediate-risk prostate cancer : Long-term results and factors predictive for outcome and toxicity. Strahlenther Onkol 2020; 196:608-616. [PMID: 32303782 DOI: 10.1007/s00066-020-01619-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 03/30/2020] [Indexed: 12/25/2022]
Abstract
INTRODUCTION Stereotactic body radiation therapy (SBRT) is considered an effective and safe treatment in patients with low- and intermediate-risk prostate cancer (PC). However, due to a lack of long-term follow-up and late toxicity data, this treatment is not universally accepted. The present study aimed to evaluate outcome and early and late toxicity in a cohort of patients with low- and intermediate-risk PC treated prospectively with linear accelerator (linac)-based SBRT. PATIENTS AND METHODS Patients with low- or intermediate-risk (NCCN criteria) PC were included. All patients received linac-based SBRT to 35 Gy in 5 fractions delivered on alternate days. Endpoints were toxicity, biochemical relapse-free survival (BRFS), metastatic progression-free survival (mPFS), and overall survival (OS). RESULTS From 2012 to 2018, 178 patients were treated. Median baseline prostate-specific antigen (iPSA) was 6.37 ng/ml (range 1.78-20). Previous transurethral resection of the prostate (TURP) was present in 23 (12.9%) patients. Median follow-up was 58.9 months (range 9.7-89.9). BRFS rates at 1, 3, and 5 years were 98.3 (95% confidence interval, CI, 94.7-99.4%), 94.4 (95%CI 89.4-97), and 91.6% (95%CI 85.4-95.2), respectively. In univariate analysis, performance status (PS), iPSA, and nadir PSA (nPSA) were correlated with BRFS. In multivariable analysis iPSA and nPSA remained significant. BRFS rates at 5 years were 94.9% (95%CI 86.8-98) for International Society of Urological Pathology (ISUP) grade group 1, 93.2% (95%CI 80.5-97.7) for ISUP group 2, and 74.8% (95%CI 47.1-89.5) for ISUP group 3. At 1, 3, and 5 years, mPFS rates were 98.8 (95%CI 95.5-99.7), 96.2 (95%CI 91.9-98.3), and 92.9% (95%CI 87.2-96.2), respectively; OS rates were 100, 97.2 (95%CI 92.9-98.9), and 95.1% (95%CI 90-97.6), respectively. One (0.56%) case of grade 3 acute genitourinary (GU), one case of acute gastrointestinal (GI), and one case of grade 3 late GU toxicity were observed. GI toxicity positively correlated with prostate volume. CONCLUSION At long-term follow-up, linac-based SBRT continues to be a valid option for the management localized PC. Biochemical control remains high at 5 years, albeit with some concerns regarding the optimal schedule for unfavorable intermediate-risk PC. Considering the excellent prognosis, patient selection is crucial for prevention of severe late toxicity.
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Affiliation(s)
- Ciro Franzese
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy. .,Department of Biomedical Sciences, Humanitas University, Rozzano, Via Manzoni 113, 20089, Milan, Italy.
| | - Marco Badalamenti
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Lucia Di Brina
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Giuseppe D'Agostino
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Davide Franceschini
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Tiziana Comito
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Elena Clerici
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Pierina Navarria
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Giacomo Reggiori
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Pietro Mancosu
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Stefano Tomatis
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy
| | - Marta Scorsetti
- Radiotherapy and Radiosurgery Department, Humanitas Clinical and Research Hospital-IRCCS, Via Manzoni 56, Rozzano, Milan, Italy.,Department of Biomedical Sciences, Humanitas University, Rozzano, Via Manzoni 113, 20089, Milan, Italy
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6
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Quel rapport alpha/bêta pour le cancer prostatique en 2019 ? Cancer Radiother 2019; 23:342-345. [DOI: 10.1016/j.canrad.2019.01.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 12/29/2018] [Accepted: 01/06/2019] [Indexed: 12/13/2022]
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Alfonso JCL, Berk L. Modeling the effect of intratumoral heterogeneity of radiosensitivity on tumor response over the course of fractionated radiation therapy. Radiat Oncol 2019; 14:88. [PMID: 31146751 PMCID: PMC6543639 DOI: 10.1186/s13014-019-1288-y] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 05/06/2019] [Indexed: 01/31/2023] Open
Abstract
Background Standard radiobiology theory of radiation response assumes a uniform innate radiosensitivity of tumors. However, experimental data show that there is significant intratumoral heterogeneity of radiosensitivity. Therefore, a model with heterogeneity was developed and tested using existing experimental data to show the potential effects from the presence of an intratumoral distribution of radiosensitivity on radiation therapy response over a protracted radiation therapy treatment course. Methods The standard radiation response curve was modified to account for a distribution of radiosensitivity, and for variations in the repopulation rates of the tumor cell subpopulations. Experimental data from the literature were incorporated to determine the boundaries of the model. The proposed model was then used to show the changes in radiosensitivity of the tumor during treatment, and the effects of fraction size, α/β ratio and variation of the repopulation rates of tumor cells. Results In the presence of an intratumoral distribution of radiosensitivity, there is rapid selection of radiation-resistant cells over a course of fractionated radiation therapy. Standard treatment fractionation regimes result in the near-complete replacement of the initial population of sensitive cells with a population of more resistant cells. Further, as treatment progresses, the tumor becomes more resistant to further radiation treatment, making each fractional dose less efficacious. A wider initial distribution induces increased radiation resistance. Hypofractionation is more efficient in a heterogeneous tumor, with increased cell kill for biologically equivalent doses, while inducing less resistance. The model also shows that a higher growth rate in resistant cells can account for the accelerated repopulation that is seen during the clinical treatment of patients. Conclusions Modeling of tumor cell survival with radiosensitivity heterogeneity alters the predicted tumor response, and explains the induction of radiation resistance by radiation treatment, the development of accelerated repopulation, and the potential beneficial effects of hypofractionation. Tumor response to treatment may be better predicted by assaying for the distribution of radiosensitivity, or the extreme of the radiosensitivity, rather than measuring the initial, general radiation sensitivity of the untreated tumor.
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Affiliation(s)
- J C L Alfonso
- Department of Systems Immunology and Braunschweig Integrated Centre of Systems Biology, Helmholtz Centre for Infection Research, Braunschweig, Germany.
| | - L Berk
- Division of Radiation Oncology, Department of Radiology, Morsani School of Medicine at the University of South Florida, Tampa, FL, USA
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van Leeuwen CM, Oei AL, Crezee J, Bel A, Franken NAP, Stalpers LJA, Kok HP. The alfa and beta of tumours: a review of parameters of the linear-quadratic model, derived from clinical radiotherapy studies. Radiat Oncol 2018. [PMID: 29769103 DOI: 10.1186/s13014a018-1040-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
BACKGROUND Prediction of radiobiological response is a major challenge in radiotherapy. Of several radiobiological models, the linear-quadratic (LQ) model has been best validated by experimental and clinical data. Clinically, the LQ model is mainly used to estimate equivalent radiotherapy schedules (e.g. calculate the equivalent dose in 2 Gy fractions, EQD2), but increasingly also to predict tumour control probability (TCP) and normal tissue complication probability (NTCP) using logistic models. The selection of accurate LQ parameters α, β and α/β is pivotal for a reliable estimate of radiation response. The aim of this review is to provide an overview of published values for the LQ parameters of human tumours as a guideline for radiation oncologists and radiation researchers to select appropriate radiobiological parameter values for LQ modelling in clinical radiotherapy. METHODS AND MATERIALS We performed a systematic literature search and found sixty-four clinical studies reporting α, β and α/β for tumours. Tumour site, histology, stage, number of patients, type of LQ model, radiation type, TCP model, clinical endpoint and radiobiological parameter estimates were extracted. Next, we stratified by tumour site and by tumour histology. Study heterogeneity was expressed by the I2 statistic, i.e. the percentage of variance in reported values not explained by chance. RESULTS A large heterogeneity in LQ parameters was found within and between studies (I2 > 75%). For the same tumour site, differences in histology partially explain differences in the LQ parameters: epithelial tumours have higher α/β values than adenocarcinomas. For tumour sites with different histologies, such as in oesophageal cancer, the α/β estimates correlate well with histology. However, many other factors contribute to the study heterogeneity of LQ parameters, e.g. tumour stage, type of LQ model, TCP model and clinical endpoint (i.e. survival, tumour control and biochemical control). CONCLUSIONS The value of LQ parameters for tumours as published in clinical radiotherapy studies depends on many clinical and methodological factors. Therefore, for clinical use of the LQ model, LQ parameters for tumour should be selected carefully, based on tumour site, histology and the applied LQ model. To account for uncertainties in LQ parameter estimates, exploring a range of values is recommended.
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Affiliation(s)
- C M van Leeuwen
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - A L Oei
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
- Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - J Crezee
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - A Bel
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - N A P Franken
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
- Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L J A Stalpers
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - H P Kok
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands.
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van Leeuwen CM, Oei AL, Crezee J, Bel A, Franken NAP, Stalpers LJA, Kok HP. The alfa and beta of tumours: a review of parameters of the linear-quadratic model, derived from clinical radiotherapy studies. Radiat Oncol 2018; 13:96. [PMID: 29769103 PMCID: PMC5956964 DOI: 10.1186/s13014-018-1040-z] [Citation(s) in RCA: 267] [Impact Index Per Article: 44.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Accepted: 04/30/2018] [Indexed: 12/16/2022] Open
Abstract
Background Prediction of radiobiological response is a major challenge in radiotherapy. Of several radiobiological models, the linear-quadratic (LQ) model has been best validated by experimental and clinical data. Clinically, the LQ model is mainly used to estimate equivalent radiotherapy schedules (e.g. calculate the equivalent dose in 2 Gy fractions, EQD2), but increasingly also to predict tumour control probability (TCP) and normal tissue complication probability (NTCP) using logistic models. The selection of accurate LQ parameters α, β and α/β is pivotal for a reliable estimate of radiation response. The aim of this review is to provide an overview of published values for the LQ parameters of human tumours as a guideline for radiation oncologists and radiation researchers to select appropriate radiobiological parameter values for LQ modelling in clinical radiotherapy. Methods and materials We performed a systematic literature search and found sixty-four clinical studies reporting α, β and α/β for tumours. Tumour site, histology, stage, number of patients, type of LQ model, radiation type, TCP model, clinical endpoint and radiobiological parameter estimates were extracted. Next, we stratified by tumour site and by tumour histology. Study heterogeneity was expressed by the I2 statistic, i.e. the percentage of variance in reported values not explained by chance. Results A large heterogeneity in LQ parameters was found within and between studies (I2 > 75%). For the same tumour site, differences in histology partially explain differences in the LQ parameters: epithelial tumours have higher α/β values than adenocarcinomas. For tumour sites with different histologies, such as in oesophageal cancer, the α/β estimates correlate well with histology. However, many other factors contribute to the study heterogeneity of LQ parameters, e.g. tumour stage, type of LQ model, TCP model and clinical endpoint (i.e. survival, tumour control and biochemical control). Conclusions The value of LQ parameters for tumours as published in clinical radiotherapy studies depends on many clinical and methodological factors. Therefore, for clinical use of the LQ model, LQ parameters for tumour should be selected carefully, based on tumour site, histology and the applied LQ model. To account for uncertainties in LQ parameter estimates, exploring a range of values is recommended. Electronic supplementary material The online version of this article (10.1186/s13014-018-1040-z) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- C M van Leeuwen
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - A L Oei
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands.,Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - J Crezee
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - A Bel
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - N A P Franken
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands.,Laboratory for Experimental Oncology and Radiobiology (LEXOR)/Center for Experimental Molecular Medicine, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands
| | - L J A Stalpers
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands
| | - H P Kok
- Department of Radiation Oncology, Academic Medical Center, University of Amsterdam, Meibergdreef 9, 1105, Amsterdam, AZ, The Netherlands.
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Cosset JM. [Hypofractionated irradiation of prostate cancer: What is the radiobiological understanding in 2017?]. Cancer Radiother 2017; 21:447-453. [PMID: 28847464 DOI: 10.1016/j.canrad.2017.06.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2017] [Accepted: 06/16/2017] [Indexed: 01/10/2023]
Abstract
For prostate cancer, hypofractionation has been based since 1999 on radiobiological data, which calculated a very low alpha/beta ratio (1.2 to 1.5Gy). This suggested that a better local control could be obtained, without any toxicity increase. Consequently, two types of hypofractionated schemes were proposed: "moderate" hypofractionation, with fractions of 2.5 to 4Gy, and "extreme" hypofractionation, utilizing stereotactic techniques, with fractions of 7 to 10Gy. For moderate hypofractionation, the linear-quadratic (LQ) model has been used to calculate the equivalent doses of the new protocols. The available trials have often shown a "non-inferiority", but no advantage, while the equivalent doses calculated for the hypofractionated arms were sometimes very superior to the doses of the conventional arms. This finding could suggest either an alpha/beta ratio lower than previously calculated, or a negative impact of other radiobiological parameters, which had not been taken into account. For "extreme" hypofractionation, the use of the LQ model is discussed for high dose fractions. Moreover, a number of radiobiological questions are still pending. The reduced overall irradiation time could be either a positive point (better local control) or a negative one (reduced reoxygenation). The prolonged duration of the fractions could lead to a decrease of efficacy (because allowing for reparation of sublethal lesions). Finally, the impact of the large fractions on the microenvironment and/or immunity remains discussed. The reported series appear to show encouraging short to mid-term results, but the results of randomized trials are still awaited. Today, it seems reasonable to only propose those extreme hypofractionated schemes to well-selected patients, treating small volumes with high-level stereotactic techniques.
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Affiliation(s)
- J-M Cosset
- GIE Charlebourg, groupe Amethyst, 65, avenue Foch, 92250 La Garenne-Colombes, France.
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Long-term outcomes of a phase II trial of moderate hypofractionated image-guided intensity modulated radiotherapy (IG-IMRT) for localized prostate cancer. Radiother Oncol 2017; 122:93-98. [DOI: 10.1016/j.radonc.2016.10.017] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Revised: 10/14/2016] [Accepted: 10/24/2016] [Indexed: 11/23/2022]
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