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Jang H, Park J, Artz M, Zhang Y, Ricci JC, Huh S, Johnson PB, Kim MH, Chun M, Oh YT, Noh OK, Park HJ. Effective Organs-at-Risk Dose Sparing in Volumetric Modulated Arc Therapy Using a Half-Beam Technique in Whole Pelvic Irradiation. Front Oncol 2021; 11:611469. [PMID: 34490075 PMCID: PMC8416480 DOI: 10.3389/fonc.2021.611469] [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: 09/29/2020] [Accepted: 07/19/2021] [Indexed: 11/18/2022] Open
Abstract
Background Although there are some controversies regarding whole pelvic radiation therapy (WPRT) due to its gastrointestinal and hematologic toxicities, it is considered for patients with gynecological, rectal, and prostate cancer. To effectively spare organs-at-risk (OAR) doses using multi-leaf collimator (MLC)’s optimal segments, potential dosimetric benefits in volumetric modulated arc therapy (VMAT) using a half-beam technique (HF) were investigated for WPRT. Methods While the size of a fully opened field (FF) was decided to entirely include a planning target volume in all beam’s eye view across arc angles, the HF was designed to use half the FF from the isocenter for dose optimization. The left or the right half of the FF was alternatively opened in VMAT-HF using a pair of arcs rotating clockwise and counterclockwise. Dosimetric benefits of VMAT-HF, presented with dose conformity, homogeneity, and dose–volume parameters in terms of modulation complex score, were compared to VMAT optimized using the FF (VMAT-FF). Consequent normal tissue complication probability (NTCP) by reducing the irradiated volumes was evaluated as well as dose–volume parameters with statistical analysis for OAR. Moreover, beam-on time and MLC position precision were analyzed with log files to assess plan deliverability and clinical applicability of VMAT-HF as compared to VMAT-FF. Results While VMAT-HF used 60%–70% less intensity modulation complexity than VMAT-FF, it showed superior dose conformity. The small intestine and colon in VMAT-HF showed a noticeable reduction in the irradiated volumes of up to 35% and 15%, respectively, at an intermediate dose of 20–45 Gy. The small intestine showed statistically significant dose sparing at the volumes that received a dose from 15 to 45 Gy. Such a dose reduction for the small intestine and colon in VMAT-HF presented a significant NTCP reduction from that in VMAT-FF. Without sacrificing the beam delivery efficiency, VMAT-HF achieved effective OAR dose reduction in dose–volume histograms. Conclusions VMAT-HF led to deliver conformal doses with effective gastrointestinal-OAR dose sparing despite using less modulation complexity. The dose of VMAT-HF was delivered with the same beam-on time with VMAT-FF but precise MLC leaf motions. The VMAT-HF potentially can play a valuable role in reducing OAR toxicities associated with WPRT.
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Affiliation(s)
- Hyunsoo Jang
- Department of Radiation Oncology, Dongguk University College of Medicine, Gyeongju, South Korea
| | - Jiyeon Park
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, United States.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, United States
| | - Mark Artz
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, United States.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, United States
| | - Yawei Zhang
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, United States.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, United States
| | - Jacob C Ricci
- Department of Radiation Oncology, Orlando Health Cancer Institute, Orlando, FL, United States
| | - Soon Huh
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, United States.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, United States
| | - Perry B Johnson
- Department of Radiation Oncology, University of Florida College of Medicine, Gainesville, FL, United States.,University of Florida Health Proton Therapy Institute, Jacksonville, FL, United States
| | - Mi-Hwa Kim
- Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea
| | - Mison Chun
- Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea
| | - Young-Taek Oh
- Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea
| | - O Kyu Noh
- Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea
| | - Hae-Jin Park
- Department of Radiation Oncology, Ajou University School of Medicine, Suwon, South Korea
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Petrović N, Stanojković TP, Nikitović M. MicroRNAs in prostate cancer following radiotherapy: Towards predicting response to radiation treatment. Curr Med Chem 2021; 29:1543-1560. [PMID: 34348602 DOI: 10.2174/0929867328666210804085135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 06/10/2021] [Accepted: 06/19/2021] [Indexed: 12/24/2022]
Abstract
Prostate cancer (PCa) is the second most frequently diagnosed male cancer worldwide. Early diagnosis of PCa, response to therapy and prognosis still represent a challenge. Nearly 60% of PCa patients undergo radiation therapy (RT) which might cause side effects. In spite of numerous researches in this field, predictive biomarkers for radiation toxicity are still not elucidated. MicroRNAs as posttranscriptional regulators of gene expression are shown to be changed during and after irradiation. Manipulation with miRNA levels might be used to modulate response to RT-to reverse radioresistance-to induce radiosensitivity, or if needed, to reduce sensitivity to treatment to avoid side effects. In this review we have listed and described miRNAs involved in response to RT in PCa, and highlighted potential candidates for future biological tests predicting radiation response to RT, with the special focus on side effects of RT. Individual radiation response is a result of the interactions between physical characteristics of radiation treatment and biological background of each patient, and miRNA expression changes among others. According to described literature we concluded that let-7, miR-21, miR-34a, miR-146a, miR-155, and members of miR-17/92 cluster might be promising candidates for biological tests predicting radiosensitivity of PCa patients undergoing radiation treatment, and as future agents for modulation of radiation response. Predictive miRNA panels, especially for acute and late side effects of RT can serve as a starting point for decisions for individualized RT planning. We believe that this review might be one step closer to understanding molecular mechanisms underlying individual radiation response of patients with PCa.
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Affiliation(s)
- Nina Petrović
- Laboratory for Radiobiology and Molecular Genetics, Department of Health and Environment, "VINČA" Institute of Nuclear Sciences-National Institute of the Republic of Serbia, University of Belgrade, Mike Petrovića Alasa 12-14, 11001 Belgrade. Serbia
| | - Tatjana P Stanojković
- Department for Experimental Oncology, Institute for Oncology and Radiology of Serbia, Pasterova 14, 11000 Belgrade. Serbia
| | - Marina Nikitović
- Department of Radiation Oncology, Institute for Oncology and Radiology of Serbia, Belgrade, Serbia, Pasterova 14, 11000 Belgrade. Serbia
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Jadon R, Hanna L, Parsons P, Staffurth J. Dose-Volume Predictors for Patient-reported Late Diarrhoea, Faecal Incontinence and Urgency after Pelvic Radiotherapy. Clin Oncol (R Coll Radiol) 2021; 33:536-545. [PMID: 33875359 DOI: 10.1016/j.clon.2021.03.011] [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: 07/15/2020] [Revised: 02/09/2021] [Accepted: 03/15/2021] [Indexed: 11/30/2022]
Abstract
AIMS Pelvic radiotherapy adds significantly to the curative treatment of many pelvic malignancies. However, this cure comes at a cost for many patients, where late bowel toxicities, such as faecal incontinence, urgency and diarrhoea, adversely affect quality of life. Despite the implementation of advanced radiotherapy techniques in many centres, there are deficiencies in our knowledge of how to make best use of these techniques to minimise these late toxicities, with dose-volume constraints specifically for late effects needing definition. The aims of this study were to establish dose-volume predictors for patient-reported late bowel toxicities and derive constraints for clinical use to reduce the risk of these toxicities. MATERIALS AND METHODS All radiotherapy patients treated in our institution between 2012 and 2014 for gynaecological and urological cancers (bladder, prostate where pelvic nodes are treated) were identified. Patients were sent patient-reported toxicity questionnaires at 12 and 24 months after treatment. Planning computed tomography scans were retrospectively contoured with different definitions of bowel as organs at risk (OARs). Dose-volume data for each OAR were collected and predictors of these toxicities found using multivariate analysis. For those dose-volume predictors found to be significant on multivariate analysis, statistically significant and clinically relevant dose-volume constraints were derived. Furthermore, data collected were used to validate constraints from published studies. RESULTS Faecal urgency, incontinence and diarrhoea rates were found in 52, 23.5 and 18.7% of the 203 patients included at 12 months following radiotherapy. Dose-volume parameters for sigmoid colon and large bowel were significant for these toxicities, and constraints for these OARs were derived, which are promising. A previously published constraint for bowel loops was validated with our data. CONCLUSIONS The sigmoid colon and large bowel are important OARs for the development of faecal urgency, incontinence and diarrhoea. Promising constraints for these OARs were derived, which require further validation before prospective clinical use.
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Affiliation(s)
- R Jadon
- Department of Clinical Oncology, Velindre Cancer Centre, Cardiff, UK; Department of Clinical Oncology, Addenbrooke's Hospital, Cambridge, UK.
| | - L Hanna
- Department of Clinical Oncology, Velindre Cancer Centre, Cardiff, UK
| | - P Parsons
- Department of Medical Physics, Velindre Cancer Centre, Cardiff, UK
| | - J Staffurth
- Department of Clinical Oncology, Velindre Cancer Centre, Cardiff, UK; School of Medicine, Institute of Cancer and Genetics, Cardiff University, Velindre Cancer Centre, Cardiff, UK
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Predicting Radiotherapy Impact on Late Bladder Toxicity in Prostate Cancer Patients: An Observational Study. Cancers (Basel) 2021; 13:cancers13020175. [PMID: 33419144 PMCID: PMC7825573 DOI: 10.3390/cancers13020175] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2020] [Revised: 01/02/2021] [Accepted: 01/04/2021] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND AND PURPOSE The aim of our study was to elaborate a suitable model on bladder late toxicity in prostate cancer (PC) patients treated by radiotherapy with volumetric technique. MATERIALS AND METHODS PC patients treated between September 2010 and April 2017 were included in the analysis. An observational study was performed collecting late toxicity data of any grade, according to RTOG and CTCAE 4.03 scales, cumulative dose volumes histograms were exported for each patient. Vdose, the value of dose to a specific volume of organ at risk (OAR), impact was analyzed through the Mann-Whitney rank-sum test. Logistic regression was used as the final model. The model performance was estimated by taking 1000 samples with replacement from the original dataset and calculating the AUC average. In addition, the calibration plot (Hosmer-Lemeshow goodness-of-fit test) was used to evaluate the performance of internal validation. RStudio Software version 3.3.1 and an in house developed software package "Moddicom" were used. RESULTS Data from 175 patients were collected. The median follow-up was 39 months (min-max 3.00-113.00). We performed Mann-Whitney rank-sum test with continuity correction in the subset of patients with late bladder toxicity grade ≥ 2: a statistically significant p-value with a Vdose of 51.43 Gy by applying a logistic regression model (coefficient 4.3, p value 0.025) for the prediction of the development of late G ≥ 2 GU toxicity was observed. The performance for the model's internal validation was evaluated, with an AUC equal to 0.626. Accuracy was estimated through the elaboration of a calibration plot. CONCLUSIONS Our preliminary results could help to optimize treatment planning procedures and customize treatments.
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Caulfield S, Menezes G, Marignol L, Poole C. Nomograms are key decision-making tools in prostate cancer radiation therapy. Urol Oncol 2018; 36:283-292. [PMID: 29680180 DOI: 10.1016/j.urolonc.2018.03.017] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Revised: 02/16/2018] [Accepted: 03/22/2018] [Indexed: 12/25/2022]
Abstract
BACKGROUND The use of nomograms for predicting clinical endpoints has been well documented. Nomograms provide an individualized prognosis and help clinicians determine the effectiveness of treatment for a given patient. Early identification of potential treatment failure or toxicity allows alternative approaches to be considered, reducing unnecessary treatment, morbidity, and cost. This review aims to evaluate clinical potential of nomogram use for the management of prostate cancer radiotherapy patients. METHODS PubMed, Embase, and Scopus were searched for literature published between 2006 and 2016. The reported correlation between measured and nomogram-predicted probabilities of biochemical control, disease progression, survival and toxicity was reviewed, through an analysis of concordance indexes and areas under the curves. RESULTS Sixteen studies were reviewed. Outcomes predicted by the nomogram were very close to outcomes measured (concordance index of 0.7 and above) in the majority. But a combination of under and overestimation of outcome was also reported. The predictive accuracy of nomograms was very variable, however, most nomograms had accuracy greater than chance, indicated by a concordance index higher than 0.5. CONCLUSION Nomograms can be used as prognostic guides to aid clinical decision-making for prostate cancer patients until further research addresses the limitations presented in this review. Strict definitions of end points should be added to future models and perhaps models could be enhanced with the incorporation of genomic variables or tumor specific parameters.
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Affiliation(s)
- Sarah Caulfield
- Trinity College Dublin, Applied Radiation Therapy Trinity Research Group, Discipline of Radiation Therapy, School of Medicine, Dublin, Ireland
| | - Gerard Menezes
- Trinity College Dublin, Applied Radiation Therapy Trinity Research Group, Discipline of Radiation Therapy, School of Medicine, Dublin, Ireland
| | - Laure Marignol
- Trinity College Dublin, Applied Radiation Therapy Trinity Research Group, Discipline of Radiation Therapy, School of Medicine, Dublin, Ireland
| | - Claire Poole
- Trinity College Dublin, Applied Radiation Therapy Trinity Research Group, Discipline of Radiation Therapy, School of Medicine, Dublin, Ireland.
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Zhu J, Simon A, Haigron P, Lafond C, Acosta O, Shu H, Castelli J, Li B, De Crevoisier R. The benefit of using bladder sub-volume equivalent uniform dose constraints in prostate intensity-modulated radiotherapy planning. Onco Targets Ther 2016; 9:7537-7544. [PMID: 28003767 PMCID: PMC5161391 DOI: 10.2147/ott.s116508] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Background To assess the benefits of bladder wall sub-volume equivalent uniform dose (EUD) constraints in prostate cancer intensity-modulated radiotherapy (IMRT) planning. Methods Two IMRT plans, with and without EUD constraints on the bladder wall, were generated using beams that deliver 80 Gy to the prostate and 46 Gy to the seminal vesicles and were compared in 53 prostate cancer patients. The bladder wall was defined as the volume between the external manually delineated wall and a contraction of 7 mm apart from it. The bladder wall was then separated into two parts: the internal-bladder wall (bla-in) represented by the portion of the bladder wall that intersected with the planning target volume (PTV) plus 5 mm extension; the external-bladder wall (bla-ex) represented by the remaining part of the bladder wall. In the IMRT plan with EUD constraints, the values of “a” parameter for the EUD models were 10.0 for bla-in and 2.3 for bla-ex. The plans with and without EUD constraints were compared in terms of dose–volume histograms, 5-year bladder and rectum normal tissue complication probability values, as well as tumor control probability (TCP) values. Results The use of bladder sub-volume EUD constraints decreased both the doses to the bladder wall (V70: 22.76% vs 19.65%, Dmean: 39.82 Gy vs 35.45 Gy) and the 5-year bladder complication probabilities (≥LENT/SOMA Grade 2: 20.35% vs 17.96%; bladder bleeding: 10.63% vs 8.64%). The doses to the rectum wall and the rectum complication probabilities were also slightly decreased by the EUD constraints compared to physical constraints only. The minimal dose and the V76Gy of PTVprostate were, however, slightly decreased by EUD optimization, nevertheless without significant difference in TCP values between the two plans, and the PTV parameters finally respected the Groupe d’Etude des Tumeurs Uro-Génitales recommendations. Conclusion Separating the bladder wall into two parts with appropriate EUD optimization may reduce bladder toxicity in prostate IMRT. Combining biological constraints with physical constraints in the organs at risk at the inverse planning step of IMRT may improve the dose distribution.
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Affiliation(s)
- Jian Zhu
- Laboratory of Image Science and Technology, Southeast University, Nanjing, Jiangsu; Department of Radiation Oncology, Shandong Cancer Hospital & Institute, Jinan; Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People's Republic of China
| | - Antoine Simon
- Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People's Republic of China; Institut National de la Sante et de la Recherche Medicale, U1099; Laboratory of Signal and Image Processing (LTSI), University of Rennes 1
| | - Pascal Haigron
- Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People's Republic of China; Institut National de la Sante et de la Recherche Medicale, U1099; Laboratory of Signal and Image Processing (LTSI), University of Rennes 1
| | - Caroline Lafond
- Institut National de la Sante et de la Recherche Medicale, U1099; Laboratory of Signal and Image Processing (LTSI), University of Rennes 1; Department of Radiotherapy, Centre Eugène Marquis, Rennes, France
| | - Oscar Acosta
- Institut National de la Sante et de la Recherche Medicale, U1099; Laboratory of Signal and Image Processing (LTSI), University of Rennes 1
| | - Huazhong Shu
- Laboratory of Image Science and Technology, Southeast University, Nanjing, Jiangsu; Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People's Republic of China
| | - Joel Castelli
- Institut National de la Sante et de la Recherche Medicale, U1099; Laboratory of Signal and Image Processing (LTSI), University of Rennes 1; Department of Radiotherapy, Centre Eugène Marquis, Rennes, France
| | - Baosheng Li
- Laboratory of Image Science and Technology, Southeast University, Nanjing, Jiangsu; Department of Radiation Oncology, Shandong Cancer Hospital & Institute, Jinan; Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People's Republic of China
| | - Renaud De Crevoisier
- Centre de Recherche en Information Biomédicale Sino-français, Nanjing, People's Republic of China; Institut National de la Sante et de la Recherche Medicale, U1099; Laboratory of Signal and Image Processing (LTSI), University of Rennes 1; Department of Radiotherapy, Centre Eugène Marquis, Rennes, France
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Acute and Late Genitourinary Toxicity after 72 Gy of Conventionally Fractionated Conformal Radiotherapy for Localised Prostate Cancer: Impact of Individual and Clinical Parameters. Clin Oncol (R Coll Radiol) 2016; 28:577-86. [DOI: 10.1016/j.clon.2016.04.041] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 03/10/2016] [Accepted: 03/15/2016] [Indexed: 01/17/2023]
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Fromme EK, Holliday EB, Nail LM, Lyons KS, Hribar MR, Thomas CR. Computerized patient-reported symptom assessment in radiotherapy: a pilot randomized, controlled trial. Support Care Cancer 2015; 24:1897-906. [PMID: 26471280 DOI: 10.1007/s00520-015-2983-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 10/05/2015] [Indexed: 11/12/2022]
Abstract
PURPOSE Computer-based, patient-reported symptom survey tools have been described for patients undergoing chemotherapy. We hypothesized that patients undergoing radiotherapy might also benefit, so we developed a computer application to acquire symptom ratings from patients and generate summaries for use at point of care office visits and conducted a randomized, controlled pilot trial to test its feasibility. METHODS Subjects were randomized prior to beginning radiotherapy. Both control and intervention group subjects completed the computerized symptom assessment, but only for the intervention group were printed symptom summaries made available before each weekly office visit. Metrics compared included the Global Distress Index (GDI), concordance of patient-reported symptoms and symptoms discussed by the physician and numbers of new and/or adjusted symptom management medications prescribed. RESULTS One hundred twelve patients completed the study: 54 in the control and 58 in the intervention arms. There were no differences in GDI over time between the control and intervention groups. In the intervention group, more patient-reported symptoms were actually discussed in radiotherapy office visits: 46/202 vs. 19/230. A sensitivity analysis to account for within-subjects correlation yielded 23.2 vs. 10.3 % (p = 0.03). Medications were started or adjusted at 15.4 % (43/280) of control visits compared to 20.4 % (65/319) of intervention visits (p = 0.07). CONCLUSIONS This computer application is easy to use and makes extensive patient-reported outcome data available at the point of care. Although no differences were seen in symptom trajectory, patients who had printed symptom summaries had improved communication during office visits and a trend towards a more active symptom management during radiotherapy.
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Affiliation(s)
- Erik K Fromme
- Division of Hematology & Medical Oncology, OHSU Knight Cancer Institute, Oregon Health & Science University, Mail Code: L586, Portland, OR, 97239, USA.
| | - Emma B Holliday
- Division of Radiation Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Blvd Unit 97, Houston, TX, 78240, USA.
| | - Lillian M Nail
- School of Nursing, Oregon Health & Science University, Portland, OR, USA
| | - Karen S Lyons
- School of Nursing, Oregon Health & Science University, Portland, OR, USA
| | - Michelle R Hribar
- Department of Medical Informatics and Clinical Epidemiology, Oregon Health & Science University, Portland, OR, USA
| | - Charles R Thomas
- Department of Radiation Medicine, OHSU Knight Cancer Institute, Oregon Health & Science University, Portland, OR, USA
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Yamazaki H, Nakamura S, Nishimura T, Yoshida K, Yoshioka Y, Koizumi M, Ogawa K. Transitioning from conventional radiotherapy to intensity-modulated radiotherapy for localized prostate cancer: changing focus from rectal bleeding to detailed quality of life analysis. JOURNAL OF RADIATION RESEARCH 2014; 55:1033-1047. [PMID: 25204643 PMCID: PMC4229926 DOI: 10.1093/jrr/rru061] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 05/27/2014] [Accepted: 06/09/2014] [Indexed: 06/02/2023]
Abstract
With the advent of modern radiation techniques, we have been able to deliver a higher prescribed radiotherapy dose for localized prostate cancer without severe adverse reactions. We reviewed and analyzed the change of toxicity profiles of external beam radiation therapy (EBRT) from the literature. Late rectal bleeding is the main adverse effect, and an incidence of >20% of Grade ≥2 adverse events was reported for 2D conventional radiotherapy of up to 70 Gy. 3D conformal radiation therapy (3D-CRT) was found to reduce the incidence to ∼10%. Furthermore, intensity-modulated radiation therapy (IMRT) reduced it further to a few percentage points. However, simultaneously, urological toxicities were enhanced by dose escalation using highly precise external radiotherapy. We should pay more attention to detailed quality of life (QOL) analysis, not only with respect to rectal bleeding but also other specific symptoms (such as urinary incontinence and impotence), for two reasons: (i) because of the increasing number of patients aged >80 years, and (ii) because of improved survival with elevated doses of radiotherapy and/or hormonal therapy; age is an important prognostic factor not only for prostate-specific antigen (PSA) control but also for adverse reactions. Those factors shift the main focus of treatment purpose from survival and avoidance of PSA failure to maintaining good QOL, particularly in older patients. In conclusion, the focus of toxicity analysis after radiotherapy for prostate cancer patients is changing from rectal bleeding to total elaborate quality of life assessment.
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Affiliation(s)
- Hideya Yamazaki
- Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Satoaki Nakamura
- Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Takuya Nishimura
- Department of Radiology, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajiicho Kawaramachi Hirokoji, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Ken Yoshida
- Department of Radiology, Osaka Medical College, 2-7 Daigaku-machi, Takatsuki-City, Osaka, 569-8686, Japan
| | - Yasuo Yoshioka
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, 565-0871 Osaka, Japan
| | - Masahiko Koizumi
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, 565-0871 Osaka, Japan
| | - Kazuhiko Ogawa
- Department of Radiation Oncology, Osaka University Graduate School of Medicine, Yamadaoka 2-2, Suita, 565-0871 Osaka, Japan
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10
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Lewinshtein DJ, Porter CR, Nelson PS. Genomic predictors of prostate cancer therapy outcomes. Expert Rev Mol Diagn 2014; 10:619-36. [DOI: 10.1586/erm.10.53] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Bellardita L, Rancati T, Valdagni R. Editorial Comment to Health-related quality of life after carbon-ion radiotherapy for prostate cancer: a 3-year prospective study. Int J Urol 2013; 21:375-6. [PMID: 24224716 DOI: 10.1111/iju.12342] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Lara Bellardita
- Prostate Cancer Program, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan, Italy.
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12
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Nomograms to predict late urinary toxicity after prostate cancer radiotherapy. World J Urol 2013; 32:743-51. [PMID: 23990073 DOI: 10.1007/s00345-013-1146-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2013] [Accepted: 08/02/2013] [Indexed: 10/26/2022] Open
Abstract
OBJECTIVE To analyze late urinary toxicity after prostate cancer radiotherapy (RT): symptom description and identification of patient characteristics or treatment parameters allowing for the generation of nomograms. METHODS Nine hundred and sixty-five patients underwent RT in seventeen French centers for localized prostate cancer. Median total dose was 70 Gy (range, 65-80 Gy), using different fractionations (2 or 2.5 Gy/day) and techniques. Late urinary toxicity and the corresponding symptoms (urinary frequency, incontinence, dysuria/decreased stream, and hematuria) were prospectively assessed in half of the patients using the LENT-SOMA classification. Univariate and multivariate Cox regression models addressed patient or treatment-related predictors of late urinary toxicity (≥grade 2). Nomograms were built up, and their performance was assessed. RESULTS The median follow-up was 61 months. The 5-year (≥grade 2) global urinary toxicity, urinary frequency, hematuria, dysuria, and urinary incontinence rates were 15, 10, 5, 3 and 1 %, respectively. The 5-year (≥grade 3) urinary toxicity rate was 3 %. The following parameters significantly increased the 5-year risk of global urinary toxicity (≥grade 2): anticoagulant treatment (RR = 2.35), total dose (RR = 1.09), and age (RR = 1.06). Urinary frequency was increased by the total dose (RR = 1.07) and diabetes (RR = 4). Hematuria was increased by anticoagulant treatment (RR = 2.9). Dysuria was increased by the total dose (RR = 1.1). Corresponding nomograms and their calibration plots were generated. Nomogram performance should be validated with external data. CONCLUSIONS The first nomograms to predict late urinary toxicity but also specific urinary symptoms after prostate RT were generated, contributing to prostate cancer treatment decision.
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Ahmed AA, Egleston B, Alcantara P, Li L, Pollack A, Horwitz EM, Buyyounouski MK. A novel method for predicting late genitourinary toxicity after prostate radiation therapy and the need for age-based risk-adapted dose constraints. Int J Radiat Oncol Biol Phys 2013; 86:709-15. [PMID: 23664324 DOI: 10.1016/j.ijrobp.2013.03.020] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2012] [Revised: 03/12/2013] [Accepted: 03/18/2013] [Indexed: 11/18/2022]
Abstract
BACKGROUND There are no well-established normal tissue sparing dose-volume histogram (DVH) criteria that limit the risk of urinary toxicity from prostate radiation therapy (RT). The aim of this study was to determine which criteria predict late toxicity among various DVH parameters when contouring the entire solid bladder and its contents versus the bladder wall. The area under the histogram curve (AUHC) was also analyzed. METHODS AND MATERIALS From 1993 to 2000, 503 men with prostate cancer received 3-dimensional conformal RT (median follow-up time, 71 months). The whole bladder and the bladder wall were contoured in all patients. The primary endpoint was grade ≥2 genitourinary (GU) toxicity occurring ≥3 months after completion of RT. Cox regressions of time to grade ≥2 toxicity were estimated separately for the entire bladder and bladder wall. Concordance probability estimates (CPE) assessed model discriminative ability. Before training the models, an external random test group of 100 men was set aside for testing. Separate analyses were performed based on the mean age (≤ 68 vs >68 years). RESULTS Age, pretreatment urinary symptoms, mean dose (entire bladder and bladder wall), and AUHC (entire bladder and bladder wall) were significant (P<.05) in multivariable analysis. Overall, bladder wall CPE values were higher than solid bladder values. The AUHC for bladder wall provided the greatest discrimination for late bladder toxicity when compared with alternative DVH points, with CPE values of 0.68 for age ≤68 years and 0.81 for age >68 years. CONCLUSION The AUHC method based on bladder wall volumes was superior for predicting late GU toxicity. Age >68 years was associated with late grade ≥2 GU toxicity, which suggests that risk-adapted dose constraints based on age should be explored.
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Affiliation(s)
- Awad A Ahmed
- Temple University School of Medicine, Philadelphia, Pennsylvania, USA
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Huyghe E, Delaunay B, Njomnang Soh P, Delannes M, Walschaerts M, Delavierre D, Soulie M, Bachaud JM. Proposal for a predictive model of erectile function after permanent 125I prostate brachytherapy for localized prostate cancer. Int J Impot Res 2013; 25:121-6. [DOI: 10.1038/ijir.2013.3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2012] [Revised: 11/23/2012] [Accepted: 01/16/2013] [Indexed: 11/09/2022]
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Park JY, Lee JW, Chung JB, Choi KS, Kim YL, Park BM, Kim Y, Kim J, Choi J, Kim JS, Hong S, Suh TS. Radiobiological model-based bio-anatomical quality assurance in intensity-modulated radiation therapy for prostate cancer. JOURNAL OF RADIATION RESEARCH 2012; 53:978-988. [PMID: 22915778 PMCID: PMC3483850 DOI: 10.1093/jrr/rrs049] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/18/2012] [Revised: 06/11/2012] [Accepted: 06/12/2012] [Indexed: 06/01/2023]
Abstract
A bio-anatomical quality assurance (QA) method employing tumor control probability (TCP) and normal tissue complication probability (NTCP) is described that can integrate radiobiological effects into intensity-modulated radiation therapy (IMRT). We evaluated the variations in the radiobiological effects caused by random errors (r-errors) and systematic errors (s-errors) by evaluating TCP and NTCP in two groups: patients with an intact prostate (G(intact)) and those who have undergone prostatectomy (G(tectomy)). The r-errors were generated using an isocenter shift of ±1 mm to simulate a misaligned patient set-up. The s-errors were generated using individual leaves that were displaced inwardly and outwardly by 1 mm on multileaf collimator field files. Subvolume-based TCP and NTCP were visualized on computed tomography (CT) images to determine the radiobiological effects on the principal structures. The bio-anatomical QA using the TCP and NTCP maps differentiated the critical radiobiological effects on specific volumes, particularly at the anterior rectal walls and planning target volumes. The s-errors showed a TCP variation of -40-25% in G(tectomy) and -30-10% in G(intact), while the r-errors were less than 1.5% in both groups. The r-errors for the rectum and bladder showed higher NTCP variations at ±20% and ±10%, respectively, and the s-errors were greater than ±65% for both. This bio-anatomical method, as a patient-specific IMRT QA, can provide distinct indications of clinically significant radiobiological effects beyond the minimization of probable physical dose errors in phantoms.
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Affiliation(s)
- Ji-Yeon Park
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
- Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul 137-701, Korea
| | - Jeong-Woo Lee
- Research Institute of Health Science, College of Health Science, Korea University, Seoul 136-703, Korea
- Department of Radiation Oncology, Konkuk University Medical Center, Seoul 143-729, Korea
| | - Jin-Beom Chung
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea
| | - Kyoung-Sik Choi
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
- Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul 137-701, Korea
- Department of Radiation Oncology, Anyang SAM Hospital, Anyang 430-733, Korea
| | - Yon-Lae Kim
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
- Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul 137-701, Korea
- Department of Radiology, Choonhae College of Health Science, Ulsan 689-784, Korea
| | - Byung-Moon Park
- Department of Radiation Oncology, Konkuk University Medical Center, Seoul 143-729, Korea
| | - Youhyun Kim
- Department of Radiologic Science, College of Health Science, Korea University, Seoul 136-703, Korea
| | - Jungmin Kim
- Department of Radiologic Science, College of Health Science, Korea University, Seoul 136-703, Korea
| | - Jonghak Choi
- Department of Radiologic Science, College of Health Science, Korea University, Seoul 136-703, Korea
| | - Jae-Sung Kim
- Department of Radiation Oncology, Seoul National University Bundang Hospital, Seongnam 463-707, Korea
| | - Semie Hong
- Department of Radiation Oncology, Konkuk University Medical Center, Seoul 143-729, Korea
| | - Tae-Suk Suh
- Department of Biomedical Engineering, College of Medicine, The Catholic University of Korea, Seoul 137-701, Korea
- Research Institute of Biomedical Engineering, The Catholic University of Korea, Seoul 137-701, Korea
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Pettersson A, Johansson B, Persson C, Berglund A, Turesson I. Effects of a dietary intervention on acute gastrointestinal side effects and other aspects of health-related quality of life: a randomized controlled trial in prostate cancer patients undergoing radiotherapy. Radiother Oncol 2012; 103:333-40. [PMID: 22633817 DOI: 10.1016/j.radonc.2012.04.006] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2010] [Revised: 10/17/2011] [Accepted: 04/28/2012] [Indexed: 01/04/2023]
Abstract
PURPOSE To study the effect of a dietary intervention on acute gastrointestinal side effects and other aspects of health-related quality of life (HRQOL) in prostate cancer patients referred to radiotherapy. MATERIALS AND METHODS A total of 130 patients were randomly assigned to one of two groups: an intervention group (IG, n=64), instructed to reduce their intake of insoluble dietary fibres and lactose, a standard care group (SC, n=66), instructed to continue their normal diet. Gastrointestinal side effects and other aspects of HRQOL were evaluated from baseline up to 2 months after completed radiotherapy, using the EORTC QLQ-C30 and QLQ-PR25 and the study-specific Gastrointestinal Side Effects Questionnaire (GISEQ). A scale indicating adherence to dietary instructions was developed from a Food Frequency Questionnaire (FFQ), with lower scores representing better compliance. Descriptive and inferential statistical analyses were conducted. RESULTS There was an interaction effect between randomization and time in the FFQ Scores (p<0.001), indicating that both groups followed their assigned dietary instructions. The dietary intervention had no effect on gastrointestinal side effects or other aspects of HRQOL. During radiotherapy, the percentage of patients with bowel symptoms and bloated abdomen was lower in IG compared to SC, but the between-group differences were not statistically significant. During radiotherapy, the percentage of patients with bowel symptoms, urinary symptoms, pain, fatigue and diminished physical and role functioning increased in both groups. CONCLUSIONS The dietary intervention had no effect on gastrointestinal side effects or other aspects of HRQOL. The tendency towards lower prevalence of bowel symptoms in IG may indicate some positive effect of the dietary intervention, but methodological refinements, clearer results and longer follow-up are needed before the value of diet change can be established with certainty.
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Affiliation(s)
- Anna Pettersson
- Department of Radiology, Oncology and Radiation Science, Uppsala University, Uppsala, Sweden.
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Tomatis S, Rancati T, Fiorino C, Vavassori V, Fellin G, Cagna E, Mauro FA, Girelli G, Monti A, Baccolini M, Naldi G, Bianchi C, Menegotti L, Pasquino M, Stasi M, Valdagni R. Late rectal bleeding after 3D-CRT for prostate cancer: development of a neural-network-based predictive model. Phys Med Biol 2012; 57:1399-412. [PMID: 22349550 DOI: 10.1088/0031-9155/57/5/1399] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The aim of this study was to develop a model exploiting artificial neural networks (ANNs) to correlate dosimetric and clinical variables with late rectal bleeding in prostate cancer patients undergoing radical radiotherapy and to compare the ANN results with those of a standard logistic regression (LR) analysis. 718 men included in the AIROPROS 0102 trial were analyzed. This multicenter protocol was characterized by the prospective evaluation of rectal toxicity, with a minimum follow-up of 36 months. Radiotherapy doses were between 70 and 80 Gy. Information was recorded for comorbidity, previous abdominal surgery, use of drugs and hormonal therapy. For each patient, a rectal dose-volume histogram (DVH) of the whole treatment was recorded and the equivalent uniform dose (EUD) evaluated as an effective descriptor of the whole DVH. Late rectal bleeding of grade ≥ 2 was considered to define positive events in this study (52 of 718 patients). The overall population was split into training and verification sets, both of which were involved in model instruction, and a test set, used to evaluate the predictive power of the model with independent data. Fourfold cross-validation was also used to provide realistic results for the full dataset. The LR was performed on the same data. Five variables were selected to predict late rectal bleeding: EUD, abdominal surgery, presence of hemorrhoids, use of anticoagulants and androgen deprivation. Following a receiver operating characteristic analysis of the independent test set, the areas under the curves (AUCs) were 0.704 and 0.655 for ANN and LR, respectively. When evaluated with cross-validation, the AUC was 0.714 for ANN and 0.636 for LR, which differed at a significance level of p = 0.03. When a practical discrimination threshold was selected, ANN could classify data with sensitivity and specificity both equal to 68.0%, whereas these values were 61.5% for LR. These data provide reasonable evidence that results obtained with ANNs are superior to those achieved with LR when predicting late radiotherapy-related rectal bleeding. The future introduction of patient-related personal characteristics, such as gene expression profiles, might improve the predictive power of statistical classifiers. More refined morphological aspects of the dose distribution, such as dose surface mapping, might also enhance the overall performance of ANN-based predictive models.
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Affiliation(s)
- S Tomatis
- Department of Medical Physics, Fondazione IRCCS Istituto Nazionale Tumori, via Venezian 1, 20133 Milano, Italy.
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Rosewall T, Potvin M, Bayley A, Catton C, Currie G, Wheat J, Milosevic M. The Effects of External Beam Radiotherapy on the Normal Urinary Bladder—A Histopathological Review. J Med Imaging Radiat Sci 2011; 42:189-197. [DOI: 10.1016/j.jmir.2011.03.002] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2010] [Revised: 03/17/2011] [Accepted: 03/28/2011] [Indexed: 01/31/2023]
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The Impact of Clinical Factors on the Development of Late Radiation Toxicity: Results from the Medical Research Council RT01 Trial (ISRCTN47772397). Clin Oncol (R Coll Radiol) 2011; 23:613-24. [DOI: 10.1016/j.clon.2011.03.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Revised: 03/02/2011] [Accepted: 03/03/2011] [Indexed: 12/17/2022]
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West CM, Barnett GC. Genetics and genomics of radiotherapy toxicity: towards prediction. Genome Med 2011; 3:52. [PMID: 21861849 PMCID: PMC3238178 DOI: 10.1186/gm268] [Citation(s) in RCA: 121] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Radiotherapy is involved in many curative treatments of cancer; millions of survivors live with the consequences of treatment, and toxicity in a minority limits the radiation doses that can be safely prescribed to the majority. Radiogenomics is the whole genome application of radiogenetics, which studies the influence of genetic variation on radiation response. Work in the area focuses on uncovering the underlying genetic causes of individual variation in sensitivity to radiation, which is important for effective, safe treatment. In this review, we highlight recent advances in radiotherapy and discuss results from four genome-wide studies of radiotoxicity.
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Affiliation(s)
- Catharine M West
- School of Cancer and Enabling Sciences, The University of Manchester, Manchester Academic Health Science Centre, The Christie, Wilmslow Road, Manchester M20 4BX, UK.
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Inclusion of clinical risk factors into NTCP modelling of late rectal toxicity after high dose radiotherapy for prostate cancer. Radiother Oncol 2011; 100:124-30. [DOI: 10.1016/j.radonc.2011.06.032] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2011] [Revised: 06/14/2011] [Accepted: 06/14/2011] [Indexed: 12/25/2022]
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Qualité de vie après radiothérapie pour un cancer localisé de la prostate. Cancer Radiother 2010; 14:519-25. [DOI: 10.1016/j.canrad.2010.06.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2010] [Accepted: 06/04/2010] [Indexed: 01/05/2023]
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Rosewall T, Catton C, Currie G, Bayley A, Chung P, Wheat J, Milosevic M. The relationship between external beam radiotherapy dose and chronic urinary dysfunction – A methodological critique. Radiother Oncol 2010; 97:40-7. [DOI: 10.1016/j.radonc.2010.08.002] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2009] [Revised: 04/09/2010] [Accepted: 08/13/2010] [Indexed: 11/24/2022]
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López Rodríguez M, Martín Martín M, Cerezo Padellano L, Marín Palomo A, Ibáñez Puebla Y. Gastrointestinal toxicity associated to radiation therapy. Clin Transl Oncol 2010; 12:554-61. [DOI: 10.1007/s12094-010-0553-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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de Crevoisier R, Fiorino C, Dubray B. Radiothérapie prostatique : prédiction de la toxicité tardive à partir des données dosimétriques. Cancer Radiother 2010; 14:460-8. [DOI: 10.1016/j.canrad.2010.07.225] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2010] [Accepted: 07/12/2010] [Indexed: 12/25/2022]
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Current World Literature. Curr Opin Support Palliat Care 2010; 4:207-27. [DOI: 10.1097/spc.0b013e32833e8160] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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27
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Current World Literature. Curr Opin Support Palliat Care 2010; 4:46-51. [DOI: 10.1097/spc.0b013e3283372479] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Clinical and dosimetric predictors of late rectal toxicity after conformal radiation for localized prostate cancer: Results of a large multicenter observational study. Radiother Oncol 2009; 93:197-202. [DOI: 10.1016/j.radonc.2009.09.004] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2009] [Revised: 09/09/2009] [Accepted: 09/12/2009] [Indexed: 11/23/2022]
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Fiorino C, Valdagni R, Rancati T, Sanguineti G. Dose–volume effects for normal tissues in external radiotherapy: Pelvis. Radiother Oncol 2009; 93:153-67. [DOI: 10.1016/j.radonc.2009.08.004] [Citation(s) in RCA: 225] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2009] [Revised: 08/11/2009] [Accepted: 08/11/2009] [Indexed: 02/07/2023]
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