Cargando…

Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer

AIMS: Pelvic lymph node (PLN) radiotherapy for high-risk prostate cancer is limited by late gastrointestinal toxicity. Application of rectal and bowel constraints may reduce risks of side-effects. We evaluated associations between intensity-modulated radiotherapy (IMRT) dose-volume data and long-ter...

Descripción completa

Detalles Bibliográficos
Autores principales: Ferreira, M.R., Thomas, K., Truelove, L., Khan, A., Parker, C., Dearnaley, D.P., Gulliford, S.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: W.B. Saunders 2019
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6505687/
https://www.ncbi.nlm.nih.gov/pubmed/30902559
http://dx.doi.org/10.1016/j.clon.2019.02.012
_version_ 1783416803931717632
author Ferreira, M.R.
Thomas, K.
Truelove, L.
Khan, A.
Parker, C.
Dearnaley, D.P.
Gulliford, S.
author_facet Ferreira, M.R.
Thomas, K.
Truelove, L.
Khan, A.
Parker, C.
Dearnaley, D.P.
Gulliford, S.
author_sort Ferreira, M.R.
collection PubMed
description AIMS: Pelvic lymph node (PLN) radiotherapy for high-risk prostate cancer is limited by late gastrointestinal toxicity. Application of rectal and bowel constraints may reduce risks of side-effects. We evaluated associations between intensity-modulated radiotherapy (IMRT) dose-volume data and long-term gastrointestinal toxicity. MATERIALS AND METHODS: Data from a single-centre dose-escalation trial of PLN-IMRT were analysed, including conventionally fractionated (CFRT) and hypofractionated (HFRT) radiotherapy schedules. Associations between volumes of rectum and bowel receiving specified doses and clinician- and patient-reported toxicity outcomes were investigated independently. A metric, δ median (δM), was defined as the difference in the medians of a volume between groups with and without toxicity at a specified dose and was used to test for statistically significant differences. RESULTS: Constraints were respected in most patients and, when exceeded, led to higher rates of gastrointestinal toxicity. Biologically relevant associations between rectum dose-points and toxicity were more numerous with both mild and moderate toxicity thresholds, but statistical significance was limited after correction for false discovery rate. Rectal V50Gy (CFRT) associated with grade 2+ bleeding; bowel V43Gy and V47 (HFRT/4 days/week schedule) associated with patient-reported loose stools and diarrhoea, respectively. Further investigation showed that CFRT patients with rectal bleeding had a mean rectal V50Gy above the treatment planning constraint. CONCLUSIONS: When dose-volume parameters are kept below tight constraints, toxicity is low. Residual dosimetry loses much of its predictive power for gastrointestinal toxicity in the setting of PLN-IMRT for prostate cancer. We have benchmarked dose-volume constraints for safely delivering PLN-IMRT using CFRT or HFRT.
format Online
Article
Text
id pubmed-6505687
institution National Center for Biotechnology Information
language English
publishDate 2019
publisher W.B. Saunders
record_format MEDLINE/PubMed
spelling pubmed-65056872019-06-01 Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer Ferreira, M.R. Thomas, K. Truelove, L. Khan, A. Parker, C. Dearnaley, D.P. Gulliford, S. Clin Oncol (R Coll Radiol) Article AIMS: Pelvic lymph node (PLN) radiotherapy for high-risk prostate cancer is limited by late gastrointestinal toxicity. Application of rectal and bowel constraints may reduce risks of side-effects. We evaluated associations between intensity-modulated radiotherapy (IMRT) dose-volume data and long-term gastrointestinal toxicity. MATERIALS AND METHODS: Data from a single-centre dose-escalation trial of PLN-IMRT were analysed, including conventionally fractionated (CFRT) and hypofractionated (HFRT) radiotherapy schedules. Associations between volumes of rectum and bowel receiving specified doses and clinician- and patient-reported toxicity outcomes were investigated independently. A metric, δ median (δM), was defined as the difference in the medians of a volume between groups with and without toxicity at a specified dose and was used to test for statistically significant differences. RESULTS: Constraints were respected in most patients and, when exceeded, led to higher rates of gastrointestinal toxicity. Biologically relevant associations between rectum dose-points and toxicity were more numerous with both mild and moderate toxicity thresholds, but statistical significance was limited after correction for false discovery rate. Rectal V50Gy (CFRT) associated with grade 2+ bleeding; bowel V43Gy and V47 (HFRT/4 days/week schedule) associated with patient-reported loose stools and diarrhoea, respectively. Further investigation showed that CFRT patients with rectal bleeding had a mean rectal V50Gy above the treatment planning constraint. CONCLUSIONS: When dose-volume parameters are kept below tight constraints, toxicity is low. Residual dosimetry loses much of its predictive power for gastrointestinal toxicity in the setting of PLN-IMRT for prostate cancer. We have benchmarked dose-volume constraints for safely delivering PLN-IMRT using CFRT or HFRT. W.B. Saunders 2019-06 /pmc/articles/PMC6505687/ /pubmed/30902559 http://dx.doi.org/10.1016/j.clon.2019.02.012 Text en © 2019 Elsevier Ltd on behalf of The Royal College of Radiologists. All rights reserved. http://creativecommons.org/licenses/by-nc-nd/4.0/ This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
spellingShingle Article
Ferreira, M.R.
Thomas, K.
Truelove, L.
Khan, A.
Parker, C.
Dearnaley, D.P.
Gulliford, S.
Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer
title Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer
title_full Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer
title_fullStr Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer
title_full_unstemmed Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer
title_short Dosimetry and Gastrointestinal Toxicity Relationships in a Phase II Trial of Pelvic Lymph Node Radiotherapy in Advanced Localised Prostate Cancer
title_sort dosimetry and gastrointestinal toxicity relationships in a phase ii trial of pelvic lymph node radiotherapy in advanced localised prostate cancer
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6505687/
https://www.ncbi.nlm.nih.gov/pubmed/30902559
http://dx.doi.org/10.1016/j.clon.2019.02.012
work_keys_str_mv AT ferreiramr dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer
AT thomask dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer
AT truelovel dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer
AT khana dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer
AT parkerc dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer
AT dearnaleydp dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer
AT gullifords dosimetryandgastrointestinaltoxicityrelationshipsinaphaseiitrialofpelviclymphnoderadiotherapyinadvancedlocalisedprostatecancer