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Onjukka E, Fiorino C, Cicchetti A, Palorini F, Improta I, Gagliardi G, Cozzarini C, Degli Esposti C, Gabriele P, Valdagni R, Rancati T. Patterns in ano-rectal dose maps and the risk of late toxicity after prostate IMRT. Acta Oncol 2019; 58:1757-1764. [PMID: 31298076 DOI: 10.1080/0284186x.2019.1635267] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Purpose: The aim of this work was to determine how the spatial pattern of dose in the ano-rectal wall is related to late gastro-intestinal toxicity for prostate cancer patients treated with mainly IMRT.Patients and methods: Patients from the DUE-01 multicentre study with patient-reported (prospective) follow-up and available dosimetric data were included. Conventionally fractionated patients received 74-80 Gy and hypofractionated patients received 65-75.2 Gy. A large majority of the patients were treated with intensity-modulated radiotherapy (IMRT). Dose-surface maps (DSMs) for the anal canal and rectum as a single structure, and for the anal canal and the rectum separately, were co-registered rigidly in two dimensions and, for the patients with and without toxicity, respectively, the mean value of the dose in each pixel was calculated. A pixel-wise t-test was used to highlight the anatomical areas where there was a significant difference between the 'mean dose maps' of each group. Univariate models were also fitted to a range of spatial parameters. The endpoints considered were a mean grade ≥1 late fecal incontinence and a maximum grade ≥2 late rectal bleeding.Results: Twenty-six out of 213 patients had fecal incontinence, while 21/225 patients had rectal bleeding. Incontinence was associated with a higher dose in the caudal region of the anal canal; the most relevant spatial parameter was the lateral extent of the low and medium isodoses (5-49 Gy in EQD2). Bleeding was associated with high isodoses reaching the posterior rectal wall. The spatial dose parameters with the highest AUC value (.69) were the lateral extent of the 60-70 Gy isodoses.Conclusions: To avoid fecal incontinence it is important to limit the portion of the anal canal irradiated. Our analysis confirms that rectal bleeding is a function of similar spatial dose parameters for patients treated with IMRT, compared to previous studies on patients treated with three-dimensional conformal radiotherapy.
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Affiliation(s)
- Eva Onjukka
- Karolinska University Hospital, Stockholm, Sweden
| | | | | | | | | | | | | | | | - Pietro Gabriele
- Istituto di Candiolo - Fondazione del Piemonte per l'Oncologia IRCCS, Candiolo, Italy
| | | | - Tiziana Rancati
- Fondazione IRCCS Istituto Nazionale dei Tumori, Milano, Italy
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Detti B, Baki M, Becherini C, Saieva C, Scartoni D, Giacomelli I, Trombetta L, Muntoni C, Olmetto E, Francolini G, Turkaj A, Topulli J, Ciabatti C, Carta G, Poggesi L, Delli Paoli C, Terziani F, Grassi R, Livi L. High-dose intensity-modulated radiation therapy as primary treatment of prostate cancer: genitourinary/gastrointestinal toxicity and outcomes, a single-institution experience. Radiol Med 2019; 124:422-431. [PMID: 30607866 DOI: 10.1007/s11547-018-0977-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2017] [Accepted: 12/05/2018] [Indexed: 12/22/2022]
Abstract
PURPOSE Prostatectomy, radiotherapy and watchful waiting are the main therapeutic options available for local stage of prostate cancer (PCa). We report our experience on 394 patients affected by prostate cancer primarily treated with high-dose, image-guided, IMRT, focusing on gastrointestinal, genitourinary toxicities and biochemical control. METHODS From July 2003 to August 2014, 394 patients were treated with radical high-dose radiotherapy (HDRT) for prostate cancer; the mean total radiation dose was 79 Gy in standard fractions. Hormonal therapy (HT) was administered to 7.6% of low-risk patients, to 20.3% of intermediate-risk patients and to 72% of high-risk patients. Patients were evaluated for biochemical failure, local recurrence (LR) and metastases. RESULTS Ninety-seven patients (26.65%) developed acute GU toxicity at the medium dose of 25.4 Gy, grade 1 (G1) or grade 2 (G2) in 94 cases. Only 16 patients (4.06%) reported chronic GU toxicity (G1 or G2), and one case developed G3 cystitis. No G3 GI acute and late toxicity were detected. Fifty-six (14.2%) patients experienced LR, 26 (6.6%) developed metastases and 70 patients (17.8%) were deceased. Gleason sum score > 7 was predictive for worse overall survival (GS = 7 was borderline) and for metastasis. No factors resulted predictive for local relapse. HT pre-RT had been demonstrated as a negative predictor for OS and DFS-DM. CONCLUSIONS Data confirm the safety of HDRT for PCa. Treatment was efficient with low toxicity profile. Moreover, continued technologic advancements, as image-guided radiotherapy, could lead to further reduction in toxicity, thus increasing the therapeutic index.
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Affiliation(s)
- Beatrice Detti
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Muhammed Baki
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Carlotta Becherini
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Calogero Saieva
- Molecular and Nutritional Epidemiology Unit, Cancer Research and Prevention Institute (ISPO), University of Florence, Florence, Italy
| | - Daniele Scartoni
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Irene Giacomelli
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Laura Trombetta
- Department of Radiation Oncology, University of Florence, Florence, Italy.
| | - Cristina Muntoni
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Emanuela Olmetto
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Giulio Francolini
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Ana Turkaj
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Juliana Topulli
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Cinzia Ciabatti
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Giulio Carta
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Linda Poggesi
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | | | - Francesca Terziani
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Roberta Grassi
- Department of Radiation Oncology, University of Florence, Florence, Italy
| | - Lorenzo Livi
- Department of Radiation Oncology, University of Florence, Florence, Italy
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Cicchetti A, Avuzzi B, Palorini F, Ballarini F, Stucchi C, Fellin G, Gabriele P, Vavassori V, Esposti CD, Cozzarini C, Fiorino C, Rancati T, Valdagni R. Predicting Late Fecal Incontinence Risk After Radiation Therapy for Prostate Cancer: New Insights From External Independent Validation. Int J Radiat Oncol Biol Phys 2018; 102:127-136. [PMID: 29970313 DOI: 10.1016/j.ijrobp.2018.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Revised: 03/30/2018] [Accepted: 05/02/2018] [Indexed: 12/24/2022]
Abstract
PURPOSE This study aimed to validate a previously published predictive model for late fecal incontinence (FI) in a contemporary population of prostate cancer patients treated with radical radiation therapy. METHODS AND MATERIALS The validation included patients treated with intensity-modulated radiation therapy (IMRT) (2010-2014). Prescribed dose range was 65-80 Gy, including conventional and moderate hypo-fractionated treatments. Rectal toxicity was scored using LENT/SOMA, a minimum 2-year follow up was considered. We chose to validate the model published by Rancati et al for predicting chronic FI, developed on a 3-dimensional conformal radiation therapy (3DCRT) population. It considered a longitudinal endpoint defined as the average toxicity grade during the follow up. This continuous endpoint was dichotomized using a cut-off value of mean FI grade >1. The model included mean rectal dose (Dmean), previous diseases of the colon (COLO) and previous abdominal surgery (SURG). Doses were corrected to 2 Gy/fraction using the linear-quadratic model and applying alpha/beta ratio = 4.8 Gy. RESULTS 228 patients constituted the validation population. A mean FI grade >1 was scored in 25 patients (11%). Logistic regression confirmed risk factors reported in the literature, with similar odds ratios (ORs) for Dmean (1.04 ± 0.03 vs 1.06 ± 0.04) and SURG (1.9 ± 1.7 vs 1.6 ± 1.45); COLO was not confirmed. Consequently, the predictive models including Dmean/Dmean + SURG were evaluated using calibration plots. Both showed a clear discriminative trend, but the absolute observed toxicity rates were underestimated (ie, absolute predicted rates were always lower than corresponding absolute observed rates). This result was consistent with an unexpected effect of hypofractionation (OR = 2.20, conventional = 8.1% vs hypofractionated = 17.4%) beyond the standard correction using linear-quadratic model. Nevertheless, the FI rate in the conventionally treated group was almost double the rate observed in the previously studied cohort (4.3% vs 8.1%). CONCLUSIONS The study confirms previously published results indicating that abdominal surgery and rectal mean dose are risk factors for late FI. Calibration plots highlight a possible role of hypofractionation beyond linear-quadratic correction.
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Affiliation(s)
- Alessandro Cicchetti
- Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy; Università degli Studi di Pavia, Physics Department, Pavia, Italy
| | - Barbara Avuzzi
- Fondazione IRCCS Istituto Nazionale dei Tumori, Radiation Oncology 1, Milan, Italy
| | - Federica Palorini
- Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy
| | - Francesca Ballarini
- Università degli Studi di Pavia, Physics Department, Pavia, Italy; INFN-Section of Pavia, Pavia, Italy
| | - Claudio Stucchi
- Fondazione IRCCS Istituto Nazionale dei Tumori, Medical Physics, Milan, Italy
| | | | - Pietro Gabriele
- Istituto di Candiolo- Fondazione del Piemonte per l'Oncologia IRCCS, Radiotherapy, Torino, Italy
| | | | | | - Cesare Cozzarini
- San Raffaele Scientific Institute, Radiation Oncology, Milan, Italy
| | - Claudio Fiorino
- San Raffaele Scientific Institute, Medical Physics, Milan, Italy
| | - Tiziana Rancati
- Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy.
| | - Riccardo Valdagni
- Fondazione IRCCS Istituto Nazionale dei Tumori, Prostate Cancer Program, Milan, Italy; Fondazione IRCCS Istituto Nazionale dei Tumori, Radiation Oncology 1, Milan, Italy; Università degli Studi di Milano, Department of Oncology and Hemato-oncology, Milan, Italy
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Bellezzo M, Fonseca GP, Verrijssen AS, Voncken R, Van den Bosch MR, Yoriyaz H, Reniers B, Berbée M, Van Limbergen EJ, Verhaegen F. A novel rectal applicator for contact radiotherapy with HDR 192Ir sources. Brachytherapy 2018; 17:1037-1044. [PMID: 30122346 DOI: 10.1016/j.brachy.2018.07.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 07/09/2018] [Accepted: 07/12/2018] [Indexed: 01/04/2023]
Abstract
PURPOSE Dose escalation to rectal tumors leads to higher complete response rates and may thereby enable omission of surgery. Important advantages of endoluminal boosting techniques include the possibility to apply a more selective/localized boost than using external beam radiotherapy. A novel brachytherapy (BT) rectal applicator with lateral shielding was designed to be used with a rectoscope for eye-guided positioning to deliver a dose distribution similar to the one of contact x-ray radiotherapy devices, using commonly available high-dose-rate 192Ir BT sources. METHODS AND MATERIALS A cylindrical multichannel BT applicator with lateral shielding was designed by Monte Carlo modeling, validated experimentally with film dosimetry and compared with results found in the literature for the Papillon 50 (P50) contact x-ray radiotherapy device regarding rectoscope dimensions, radiation beam shape, dose fall-off, and treatment time. RESULTS The multichannel applicator designed is able to deliver 30 Gy under 13 min with a 20350 U (5 Ci) source. The use of multiple channels and lateral shielding provide a uniform circular treatment surface with 22 mm in diameter. The resulting dose fall-off is slightly steeper (maximum difference of 5%) than the one generated by the P50 device with the 22 mm applicator. CONCLUSIONS A novel multichannel rectal applicator for contact radiotherapy with high-dose-rate 192Ir sources that can be integrated with commercially available treatment planning systems was designed to produce a dose distribution similar to the one obtained by the P50 device.
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Affiliation(s)
- Murillo Bellezzo
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands; Centro de Engenharia Nuclear, Instituto de Pesquisas Energéticas e Nucleares IPEN-CNEN/SP, São Paulo, Brazil
| | - Gabriel P Fonseca
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - An-Sofie Verrijssen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Robert Voncken
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Michiel R Van den Bosch
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Hélio Yoriyaz
- Centro de Engenharia Nuclear, Instituto de Pesquisas Energéticas e Nucleares IPEN-CNEN/SP, São Paulo, Brazil
| | - Brigitte Reniers
- Research group NuTeC, Centre for Environmental Sciences, Hasselt University, Diepenbeek, Belgium
| | - Maaike Berbée
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Evert J Van Limbergen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands
| | - Frank Verhaegen
- Department of Radiation Oncology (MAASTRO), GROW School for Oncology and Developmental Biology, Maastricht University Medical Center, Maastricht, The Netherlands.
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Kotabe K, Nakayama H, Takashi A, Takahashi A, Tajima T, Kume H. Association between rectal bleeding and the absolute dose volume of the rectum following image-guided radiotherapy for patients with prostate cancer. Oncol Lett 2018; 16:2741-2749. [PMID: 30013669 DOI: 10.3892/ol.2018.8888] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Accepted: 04/20/2018] [Indexed: 01/02/2023] Open
Abstract
The association between rectal bleeding and the received dose relative to the volume of the rectum is well established in prostate cancer patients who have undergone radiotherapy. The relative volume of the rectum is affected by the rectal anatomical volume, which depends on the definition of rectal length. Compared with the relative rectal volume, the absolute volume of the rectum may be more associated with rectal bleeding. The present study investigated the absolute volume of the rectum that may be used to predict late rectal bleeding following intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT). The cases of 82 patients of prostate cancer, who underwent IMRT and IGRT, were retrospectively evaluated by evaluating dose volume histograms. The median patient age was 73.4 years (range, 51.3-85.9 years). The median total prescribed dose was 76 Gy given in 38 fractions. The absolute and relative dose volumes of the rectum were evaluated by multivariate analysis, and the optimal dose to prevent rectal bleeding was determined. The actuarial ≥grade 1 rectal bleeding rate at 4 years was 4.5% (95% confidence interval, 1.5-13.4%) with a median observation period of 45.3 months. The absolute rectal volume (ml) treated with 60 Gy was the only significant risk factor for rectal bleeding (P<0.05), but the relative rectal volume (%) was not identified as a significant factor by the multivariate analysis. When the rectal volume of 5 or 10 ml received 60 Gy (D5cc and D10cc), rectal bleeding was expected to occur in 3.3 and 7.3% of the patients, respectively. Rectal D5cc ≤60 Gy is recommended to prevent late ≥grade 1 rectal bleeding in IGRT.
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Affiliation(s)
- Kazuki Kotabe
- Department of Radiation Oncology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
| | - Hidetsugu Nakayama
- Department of Radiation Oncology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
| | - Aruga Takashi
- Department of Radiation Oncology, Funabashi Municipal Medical Center, Tokyo 162-8655, Japan
| | - Atsuko Takahashi
- Department of Urology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
| | - Tsuyoshi Tajima
- Department of Radiology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
| | - Haruki Kume
- Department of Urology, National Center for Global Health and Medicine, Tokyo 162-8655, Japan
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Jensen L, Yuh B, Wong JYC, Schultheiss T, Cheng J, Ruel N, Twardowski P, Sampath S. Outcomes and toxicity of 313 prostate cancer patients receiving helical tomotherapy after radical prostatectomy. Adv Radiat Oncol 2017; 2:597-607. [PMID: 29204527 PMCID: PMC5707427 DOI: 10.1016/j.adro.2017.08.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 04/28/2017] [Accepted: 08/03/2017] [Indexed: 01/19/2023] Open
Abstract
Purpose There are limited long-term data on patients treated with image guided intensity modulated radiation therapy (IG-IMRT) for prostate cancer recurrence or high-risk disease features after radical prostatectomy. We report single-institution results for patients treated with IG-IMRT and identify variables associated with outcome. Methods and materials This is a retrospective chart review consisting of 313 consecutive patients who were treated with adjuvant or salvage IG-IMRT from 2004 to 2013. Cox proportional hazards analysis was used to identify factors related to survival and toxicity. Toxicity was graded using the Common Terminology Criteria for Adverse Events Version 4.0. Results The median follow-up was 55 months (range, 6-131 months). The median pre-radiation therapy (RT) prostate-specific antigen (PSA) was 0.3 ng/mL (range, <0.01-55.4). The vast majority of patients (87%) received elective pelvic nodal irradiation (median dose: 45 Gy). Androgen deprivation therapy (ADT) was given to 39% of patients for a median of 9 months. Five-year biochemical progression-free survival and distant metastasis-free survival were 59% (95% confidence interval, 53%-66%) and 89% (95% confidence interval, 85%-93%), respectively. On multivariate analysis, higher pre-RT PSA (>0.2 ng/mL), biopsy Gleason score (≥7 [4+3]), and duration of ADT (>6 months) were significantly associated (P < .05) with biochemical progression-free survival. Actuarial late grade 3 genitourinary and gastrointestinal toxicities at 5 years were 10% and 2%, respectively. Conclusion Our results suggest that lower pre-RT PSA level and longer duration of ADT are associated with improved biochemical control. The incidence of late grade 3 gastrointestinal toxicity was low, but late grade 3 genitourinary toxicity was higher than anticipated.
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Affiliation(s)
- Lindsay Jensen
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California
| | - Bertram Yuh
- Department of Urology, City of Hope National Medical Center, Duarte, California
| | - Jeffrey Y C Wong
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California
| | - Timothy Schultheiss
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California
| | | | - Nora Ruel
- Department of Biostatistics, City of Hope National Medical Center, Duarte, California
| | | | - Sagus Sampath
- Department of Radiation Oncology, City of Hope National Medical Center, Duarte, California
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Landoni V, Fiorino C, Cozzarini C, Sanguineti G, Valdagni R, Rancati T. Predicting toxicity in radiotherapy for prostate cancer. Phys Med 2016; 32:521-32. [PMID: 27068274 DOI: 10.1016/j.ejmp.2016.03.003] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 02/15/2016] [Accepted: 03/02/2016] [Indexed: 02/08/2023] Open
Abstract
This comprehensive review addresses most organs at risk involved in planning optimization for prostate cancer. It can be considered an update of a previous educational review that was published in 2009 (Fiorino et al., 2009). The literature was reviewed based on PubMed and MEDLINE database searches (from January 2009 up to September 2015), including papers in press; for each section/subsection, key title words were used and possibly combined with other more general key-words (such as radiotherapy, dose-volume effects, NTCP, DVH, and predictive model). Publications generally dealing with toxicity without any association with dose-volume effects or correlations with clinical risk factors were disregarded, being outside the aim of the review. A focus was on external beam radiotherapy, including post-prostatectomy, with conventional fractionation or moderate hypofractionation (<4Gy/fraction); extreme hypofractionation is the topic of another paper in this special issue. Gastrointestinal and urinary toxicity are the most investigated endpoints, with quantitative data published in the last 5years suggesting both a dose-response relationship and the existence of a number of clinical/patient related risk factors acting as dose-response modifiers. Some results on erectile dysfunction, bowel toxicity and hematological toxicity are also presented.
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Affiliation(s)
- Valeria Landoni
- Medical Physics, Istituto Nazionale Tumori Regina Elena, Rome, Italy
| | - Claudio Fiorino
- Medical Physics, Raffaele Scientific Institute IRCCS, Milan, Italy
| | | | | | - Riccardo Valdagni
- Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; Radiation Oncology 1, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy; Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Tiziana Rancati
- Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
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Casares-Magaz O, Thor M, Liao D, Frøkjær JB, Kræmer P, Krogh K, Drewes AM, Gregersen H, Moiseenko V, Høyer M, Muren LP. An image-based method to quantify biomechanical properties of the rectum in radiotherapy of prostate cancer. Acta Oncol 2015. [PMID: 26198656 DOI: 10.3109/0284186x.2015.1066933] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Gastrointestinal morbidity after radiotherapy (RT) for prostate cancer may be related to the biomechanical properties of the rectum. In this study we present a magnetic resonance imaging (MRI)-based method to quantitate the thickness and elasticity of the rectal wall in prostate cancer patients treated with RT. MATERIAL AND METHODS Four patients previously treated with RT for prostate cancer underwent an MRI session with stepwise rectal bag deflation (from a maximum tolerable volume to 0 ml, in 50 ml steps), with a probe inserted inside the bag to monitor the internal rectal pressure. MRIs were acquired using Dixon sequences (4 mm axial slice thickness) at each deflation step. Rectal walls were defined from the recto-sigmoid junction to 3 cm above the anal canal as the space between the inner and outer wall surfaces. The wall thickness was determined and biomechanical properties (strain and stress) were calculated from the pressure measurements and the MRI-segmented rectal walls. RESULTS The integral rectal pressure varied for the maximum tolerable volume (range 150-250 ml) across patients and ranged from 1.3 to 4.0 kPa (SD = 1.2 kPa). Wall thickness was found to vary between patients and also across different rectum segments, with a mean (SD) thickness for the different segments at the 50 ml distension volume of 1.8-4.0 (0.6) mm. Stress showed larger variation than strain, with mean (SD) values for the different segments ranging between 1.5 and 7.0 (1.5) kPa. CONCLUSION We have developed a method to quantify biomechanical properties of the rectal wall. The resulting rectal wall thickness, strain and stress differed between patients, as well as across different rectal wall sections. These findings could provide guidance in future predictive outcome modelling in order to better understand the rectal dose-volume response relationship.
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Affiliation(s)
- Oscar Casares-Magaz
- a Department of Medical Physics , Aarhus University Hospital/Aarhus University , Denmark
| | - Maria Thor
- b Department of Medical Physics , Memorial Sloan Kettering Cancer Center , New York , USA
| | - Donghua Liao
- c GIOME Academia, Department of Clinical Medicine , Aarhus University , Denmark
| | - Jens B Frøkjær
- d Department of Clinical Medicine , Aalborg University Hospital , Denmark
- e Department of Radiology , Aalborg University Hospital , Denmark
| | - Pia Kræmer
- f Department of Oncology , Aarhus University Hospital/Aarhus University , Denmark
| | - Klaus Krogh
- g Department of Hepatology and Gastroenterology , Aarhus University Hospital/Aarhus University , Denmark
| | - Asbjørn M Drewes
- d Department of Clinical Medicine , Aalborg University Hospital , Denmark
- h Department of Gastroenterology , Aalborg University Hospital , Denmark
| | - Hans Gregersen
- i GIOME, College of Bioengineering, Chongqing University , Chongqing , China
| | - Vitali Moiseenko
- j Department of Radiation Medicine and Applied Science , University of California San Diego , San Diego , USA
| | - Morten Høyer
- f Department of Oncology , Aarhus University Hospital/Aarhus University , Denmark
| | - Ludvig P Muren
- a Department of Medical Physics , Aarhus University Hospital/Aarhus University , Denmark
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Høyer M, Muren LP, Glimelius B. The evolution of radiotherapy techniques in the management of prostate cancer. Acta Oncol 2015; 54:821-4. [PMID: 25973556 DOI: 10.3109/0284186x.2015.1048555] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Morten Høyer
- Dept of Oncology, Aarhus University/Aarhus University Hospital , Aarhus , Denmark
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