Abstract Background and purpose To fit an NTCP model including clinical risk factors to late rectal toxicities after radiotherapy for prostate cancer. Methods and materials Data of 669 patients were considered. The probability of late toxicity within 36months (bleeding and incontinence) was fitted with the original and a modified Logit-EUD model, including clinical factors by fitting a subset specific TD 50 s: the ratio of TD 50 s with and without including the clinical variable was the dose-modifying factor ( D mod ). Results Abdominal surgery (surg) was a risk factor for G2–G3 bleeding, reflecting in a TD 50 =82.7Gy and 88.4Gy for patients with and without surg ( D mod =0.94; 0.90 for G3 bleeding); acute toxicity was also an important risk factor for G2–G3 bleeding ( D mod =0.93). Concerning incontinence, surg and previous diseases of the colon were the clinical co-factors. D mod (surg) and D mod (colon) were 0.50 and 0.42, respectively for chronic incontinence and 0.73 and 0.64, respectively for mean incontinence score ⩾1. Best-fit n values were 0.03–0.05 and 1 for bleeding and incontinence, respectively. The inclusion of clinical factors always improved the predictive value of the models. Conclusions The inclusion of predisposing clinical factors improves NTCP estimation; the assessment of other clinical and genetic factors will be useful to reduce parameter uncertainties.
#2Michael W. Kattan(Cleveland Clinic Lerner College of Medicine)H-Index: 10
Last. C. Fiorino(UniSR: Vita-Salute San Raffaele University)H-Index: 7
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Purpose Development of user-friendly tools for the prediction of single-patient probability of late rectal toxicity after conformal radiotherapy for prostate cancer. Methods and Materials This multicenter protocol was characterized by the prospective evaluation of rectal toxicity through self-assessed questionnaires (minimum follow-up, 36 months) by 718 adult men in the AIROPROS 0102 trial. Doses were between 70 and 80 Gy. Nomograms were created based on multivariable logistic regression analysi...
Last. Joos V. Lebesque(NKI-AVL: Netherlands Cancer Institute)H-Index: 76
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Purpose To study the impact of clinical predisposing factors on rectal normal tissue complication probability modeling using the updated results of the Dutch prostate dose-escalation trial. Methods and Materials Toxicity data of 512 patients (conformally treated to 68 Gy [ n = 284] and 78 Gy [ n = 228]) with complete follow-up at 3 years after radiotherapy were studied. Scored end points were rectal bleeding, high stool frequency, and fecal incontinence. Two traditional dose-based models (Lyman-...
Purpose To model late fecal incontinence after high-dose prostate cancer radiotherapy (RT) in patients accrued in the AIROPROS (prostate working group of the Italian Association of Radiation Oncology) 0102 trial using different endpoint definitions. Methods and Materials The self-reported questionnaires (before RT, 1 month after RT, and every 6 months for ≤3 years after RT) of 586 patients were available. The peak incontinence (P_INC) and two longitudinal definitions (chronic incontinence [C_INC...
Background Faecal incontinence (FI) after radiotherapy is a known phenomenon, but has received little attention to date. This article aimed to review current knowledge on faecal incontinence related to radiotherapy for prostate cancer. Methods PubMed was searched for English-language articles published from January 1966 to December 2009 using the primary keywords ‘faecal incontinence’, ‘prostate cancer’ and ‘radiotherapy’. Prospective, retrospective and controlled trials reporting FI as a compli...
Abstract Purpose To compare helical tomotherapy (HT) and intensity modulated proton therapy (IMPT) on early stage prostate cancer treatments delivered with simultaneous integrated boost (SIB) in moderate hypofractionation. Material/methods Eight patients treated with HT were replanned with two-field IMPT (2fIMPT) and five-field IMPT (5fIMPT), using a small pencil beam size (3 mm sigma). The prescribed dose was 74.3 Gy in 28 fractions on PTV1 (prostate) and PTV2 (proximal seminal vesicles), 65.5 ...
Abstract Background and purpose Radiotherapy is the standard treatment in locally advanced prostate cancer. The latest technological improvement is modulated rotational radiotherapy, where one single rotation of the treatment machine is used to conform the dose delivery to the target and spare organs at risk, requiring less than 2min of beam-on time per treatment fraction. Materials and methods We report herein our experience from the first 46 patients treated for prostate cancer, clinical stage...
#1Susan L. Tucker(University of Texas MD Anderson Cancer Center)H-Index: 90
#2Lei Dong(University of Texas MD Anderson Cancer Center)H-Index: 73
Last. James D. Cox(University of Texas MD Anderson Cancer Center)H-Index: 91
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Purpose To estimate the parameters of the Lyman normal-tissue complication probability model using censored time-to-event data for Grade ≥2 late rectal toxicity among patients treated on Radiation Therapy Oncology Group 94-06, a dose-escalation trial designed to determine the maximum tolerated dose for three-dimensional conformal radiotherapy of prostate cancer. Methods and Materials The Lyman normal-tissue complication probability model was fitted to data from 1,010 of the 1,084 patients accrue...
The ability to predict individual normal tissue complication risk prior to radiotherapy has been referred to as ‘the Holy Grail of radiobiology’ [1]. This saying implies that a reliable and clinically useful predictive assay for normal tissue radiosensitivity has been something long sought but never found. In the 1990s, efforts were made to develop predictive assays based on in vitro irradiation of various cell types. Though some studies have reported significant associations between normal tiss...
Abstract Purpose/objective Whole pelvis irradiation with IMRT (WPRT–IMRT) after prostatectomy is efficient in reducing acute toxicity: however, a number of patients still experience moderate acute bowel toxicity. Materials and methods Ninety-six patients treated with WPRT–IMRT after prostatectomy with adjuvant or salvage intent were analysed. A number of parameters were individually recovered, including the DVHs of the intestinal cavity outside PTV and of the loops referred to both the WPRT phas...
#1Martin A. Ebert(SCGH: Sir Charles Gairdner Hospital)H-Index: 26
#2Sarah L. Gulliford(UCLH: University College London Hospitals NHS Foundation Trust)H-Index: 23
Last. Claudio Fiorino(UniSR: Vita-Salute San Raffaele University)H-Index: 54
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For decades, dose-volume information for segmented anatomy has provided the essential data for correlating radiotherapy dosimetry with treatment-induced complications. Dose-volume information has formed the basis for modelling those associations via normal tissue complication (NTCP) models and for driving treatment planning. Limitations to this approach have been identified. Many studies have emerged demonstrating that the incorporation of information describing the spatial nature of the dose di...
The power of predictive modeling for radiotherapy outcomes has historically been limited by an inability to adequately capture patient-specific variabilities; however, next-generation platforms together with imaging technologies and powerful bioinformatic tools have facilitated strategies and provided optimism. Integrating clinical, biological, imaging, and treatment-specific data for more accurate prediction of tumor control probabilities or risk of radiation-induced side effects are high-dimen...
The treatment of cancer with proton radiation therapy was first suggested in 1946 followed by the first treatments in the 1950s. As of 2020, almost 200,000 patients have been treated with proton beams worldwide and the number of operating proton therapy facilities will soon reach one hundred. Proton therapy has long moved from research institutions into hospital-based facilities that are increasingly being utilized with workflows similar to conventional radiation therapy. While proton therapy ha...
Background: Acute skin toxicity is a common and usually transient side-effect of breast radiotherapy although, if sufficiently severe, it can affect breast cosmesis, aftercare costs and the patient's quality-of-life. The aim of this study was to develop predictive models for acute skin toxicity using published risk factors and externally validate the models in patients recruited into the prospective multi-center REQUITE (validating pREdictive models and biomarkers of radiotherapy toxicity to red...
#1R. Bijman(EUR: Erasmus University Rotterdam)H-Index: 4
#2L. Rossi(EUR: Erasmus University Rotterdam)H-Index: 5
Last. Ben J.M. Heijmen(EUR: Erasmus University Rotterdam)H-Index: 64
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Background: Currently, radiation-oncologists generally evaluate a single treatment plan for each patient that is possibly adapted by the planner prior to final approval. There is no systematic exploration of patient-specific trade-offs between planning aims, using a set of treatment plans with a-priori defined (slightly) different balances. To this purpose, we developed an automated workflow and explored its use for prostate cancer. Materials and Methods: For each of the 50 study patients, seven...
Last. Paolo Zunino(Polytechnic University of Milan)H-Index: 28
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Abstract Background Radiation-induced organ dysfunction are frequently described by Normal Tissue Complication Probability models. The approximations of this radiobiological approach do not allow to consider the important role played by the microvasculature not only in the dose–response of the blood vessels but also of the organs where it is located. To this purpose, we presented a computational model that describes the fluid dynamics of microcirculation when the parameters of the network and th...
Abstract Purpose/Objective(s) Previously a phase III trial of a hydrogel rectal spacer during prostate RT found decreased toxicity and a clinically significant improvement in bowel quality of life (QOL) at 3-years by Expanded Prostate Cancer Index (EPIC). We performed a secondary analysis to identify men less likely to benefit. Materials/Methods Clinical and dosimetric data for the 222 patients enrolled on the *** trial were analyzed. The volume of rectum treated to 70 Gy (V70) as well as the QU...
Abstract Aim To investigate the predictive value of convenience of rectum dosimetry with Quantitative Analysis of Normal Tissue Effects in the Clinic (QUANTEC) dose limits, maximum rectum dose (Dmax), total rectal volume (TVrectum), rectal volume included in PTV (VrectumPTV) on Grade 2–3 acute rectal toxicity for utilization in clinical practice. Background Numerous previous data have reported frequent acute proctitis after external-beam RT of prostate cancer. Predicting toxicity limited with do...
BACKGROUND: Rectum and bladder are hallow structures and considered as critical organs in prostate cancer intensity modulated radiotherapy (IMRT). Therefore, dose received by these organ walls must be considered for prediction of radiobiological effects. Contouring the real organ walls is quite difficult and time consuming in CT/MRI images, so the easy contouring artificial walls with uniform thickness could be appropriated alternatives. OBJECTIVE: To compare reconstructed artificial walls with ...
Last. William Li(The Queen's Medical Center)H-Index: 1
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Abstract Purpose REQUITE aimed to establish a resource for multi-national validation of models and biomarkers that predict risk of late toxicity following radiotherapy. The purpose of this article is to provide summary descriptive data. Methods An international, prospective cohort study recruited cancer patients in 26 hospitals in eight countries between April 2014 and March 2017. Target recruitment was 5300 patients. Eligible patients had breast, prostate or lung cancer and planned potentially ...