Cargando…

Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons

PURPOSE: To evaluate the dosimetric impact and plan robustness of using Pencil Beam Scanning (PBS) in patients that requires prophylactic pelvic lymph nodes (PLNs) irradiation for prostate cancer. MATERIAL AND METHODS: Five intermediate to high-risk prostate patients previously treated using volumet...

Descripción completa

Detalles Bibliográficos
Autores principales: Ong, Ashley L.K., Ang, K.W., Master, Zubin, Wong, Sharon M.M., Tuan, Jeffrey K.L.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Elsevier 2018
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7033791/
https://www.ncbi.nlm.nih.gov/pubmed/32095573
http://dx.doi.org/10.1016/j.tipsro.2018.02.001
_version_ 1783499740677144576
author Ong, Ashley L.K.
Ang, K.W.
Master, Zubin
Wong, Sharon M.M.
Tuan, Jeffrey K.L.
author_facet Ong, Ashley L.K.
Ang, K.W.
Master, Zubin
Wong, Sharon M.M.
Tuan, Jeffrey K.L.
author_sort Ong, Ashley L.K.
collection PubMed
description PURPOSE: To evaluate the dosimetric impact and plan robustness of using Pencil Beam Scanning (PBS) in patients that requires prophylactic pelvic lymph nodes (PLNs) irradiation for prostate cancer. MATERIAL AND METHODS: Five intermediate to high-risk prostate patients previously treated using volumetric modulated arc therapy (VMAT), were selected for this study. Comparative proton radiotherapy plans were generated, where a three-field intensity modulated proton therapy (IMPT) plan was for the phase 1 planning target volume (PTV1) with PLNs. A technique with two posterior oblique fields using single field uniform dose (SFUD) was used for phase 2 (PTV2) volume, that comprises of the prostate and proximal seminal vesicles (Pro + proxSVs). Plan evaluation was performed on PTV coverage and dose to the organs at risk (OARs) using VMAT plans as a baseline (BL). Robust analysis on clinical target volume (CTV) coverage for the PBS plans was simulated with a 3 and 5 mm setup errors and a 3.5% range uncertainty. RESULTS: For target coverage, PTV1 and PTV2 showed negligible differences with a comparable homogeneity index (HI) values for both modalities. Proton plans produced a statistically significant lower mean dose to the bladder (32.5 Gy(RBE) vs. 46.5 Gy) and rectum (33.6 Gy(RBE) vs. 42.7 Gy). Dose to the bladder and rectum was equivalent at the high dose region. For the bowel cavity, the mean dose for proton plans were 45% lower compared to VMAT plans. Similarly, proton plans were able to achieve an overall reduction in integral dose for both treatment phase. CTV coverage remained high with all the simulated setup and range errors. CONCLUSIONS: Proposed beam geometries for PTV1 and PTV2 proton plans presented good treatment accuracy with similar target coverage as the VMAT plans. Better sparing of OARs was achieved at the low-medium dose region for the proton plans.
format Online
Article
Text
id pubmed-7033791
institution National Center for Biotechnology Information
language English
publishDate 2018
publisher Elsevier
record_format MEDLINE/PubMed
spelling pubmed-70337912020-02-24 Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons Ong, Ashley L.K. Ang, K.W. Master, Zubin Wong, Sharon M.M. Tuan, Jeffrey K.L. Tech Innov Patient Support Radiat Oncol Research article PURPOSE: To evaluate the dosimetric impact and plan robustness of using Pencil Beam Scanning (PBS) in patients that requires prophylactic pelvic lymph nodes (PLNs) irradiation for prostate cancer. MATERIAL AND METHODS: Five intermediate to high-risk prostate patients previously treated using volumetric modulated arc therapy (VMAT), were selected for this study. Comparative proton radiotherapy plans were generated, where a three-field intensity modulated proton therapy (IMPT) plan was for the phase 1 planning target volume (PTV1) with PLNs. A technique with two posterior oblique fields using single field uniform dose (SFUD) was used for phase 2 (PTV2) volume, that comprises of the prostate and proximal seminal vesicles (Pro + proxSVs). Plan evaluation was performed on PTV coverage and dose to the organs at risk (OARs) using VMAT plans as a baseline (BL). Robust analysis on clinical target volume (CTV) coverage for the PBS plans was simulated with a 3 and 5 mm setup errors and a 3.5% range uncertainty. RESULTS: For target coverage, PTV1 and PTV2 showed negligible differences with a comparable homogeneity index (HI) values for both modalities. Proton plans produced a statistically significant lower mean dose to the bladder (32.5 Gy(RBE) vs. 46.5 Gy) and rectum (33.6 Gy(RBE) vs. 42.7 Gy). Dose to the bladder and rectum was equivalent at the high dose region. For the bowel cavity, the mean dose for proton plans were 45% lower compared to VMAT plans. Similarly, proton plans were able to achieve an overall reduction in integral dose for both treatment phase. CTV coverage remained high with all the simulated setup and range errors. CONCLUSIONS: Proposed beam geometries for PTV1 and PTV2 proton plans presented good treatment accuracy with similar target coverage as the VMAT plans. Better sparing of OARs was achieved at the low-medium dose region for the proton plans. Elsevier 2018-04-03 /pmc/articles/PMC7033791/ /pubmed/32095573 http://dx.doi.org/10.1016/j.tipsro.2018.02.001 Text en © 2018 The Authors. Published by Elsevier B.V. on behalf of European Society for Radiotherapy & Oncology. 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 Research article
Ong, Ashley L.K.
Ang, K.W.
Master, Zubin
Wong, Sharon M.M.
Tuan, Jeffrey K.L.
Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons
title Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons
title_full Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons
title_fullStr Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons
title_full_unstemmed Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons
title_short Intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: A dosimetric and plan robustness study between photons and protons
title_sort intensity-modulated radiotherapy for whole pelvis irradiation in prostate cancer: a dosimetric and plan robustness study between photons and protons
topic Research article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7033791/
https://www.ncbi.nlm.nih.gov/pubmed/32095573
http://dx.doi.org/10.1016/j.tipsro.2018.02.001
work_keys_str_mv AT ongashleylk intensitymodulatedradiotherapyforwholepelvisirradiationinprostatecanceradosimetricandplanrobustnessstudybetweenphotonsandprotons
AT angkw intensitymodulatedradiotherapyforwholepelvisirradiationinprostatecanceradosimetricandplanrobustnessstudybetweenphotonsandprotons
AT masterzubin intensitymodulatedradiotherapyforwholepelvisirradiationinprostatecanceradosimetricandplanrobustnessstudybetweenphotonsandprotons
AT wongsharonmm intensitymodulatedradiotherapyforwholepelvisirradiationinprostatecanceradosimetricandplanrobustnessstudybetweenphotonsandprotons
AT tuanjeffreykl intensitymodulatedradiotherapyforwholepelvisirradiationinprostatecanceradosimetricandplanrobustnessstudybetweenphotonsandprotons