Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women

Background and purpose: Cancer affects 1 in 1000–2000 pregnancies annually worldwide, creating challenges in balancing cancer treatment and fetal safety. This study compares out-of-field radiation doses between two treatment modalities: 6MV external photon radiotherapy (XRT) and pencil beam scanning...

Full description

Saved in:
Bibliographic Details
Main Authors: Menke Weessies, Murillo Bellezzo, Britt J.P. Hupkens, Frank Verhaegen, Gloria Vilches-Freixas
Format: Article
Language:English
Published: Elsevier 2025-01-01
Series:Physics and Imaging in Radiation Oncology
Subjects:
Online Access:http://www.sciencedirect.com/science/article/pii/S2405631625000260
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1823864410512293888
author Menke Weessies
Murillo Bellezzo
Britt J.P. Hupkens
Frank Verhaegen
Gloria Vilches-Freixas
author_facet Menke Weessies
Murillo Bellezzo
Britt J.P. Hupkens
Frank Verhaegen
Gloria Vilches-Freixas
author_sort Menke Weessies
collection DOAJ
description Background and purpose: Cancer affects 1 in 1000–2000 pregnancies annually worldwide, creating challenges in balancing cancer treatment and fetal safety. This study compares out-of-field radiation doses between two treatment modalities: 6MV external photon radiotherapy (XRT) and pencil beam scanning proton-therapy (PBS-PRT) for breast cancer, including imaging, to evaluate PBS-PRT as a potential new treatment option. Materials and methods: For breast cancer involving lymph node levels 1–4 and the intramammary lymph nodes, treatment plans were created for XRT (with Flattening Filter (FF) and FF-Free (FFF)) and PBS-PRT, prescribing 15 × 2.67 Gy(RBE). Measurements were conducted using an adapted anthropomorphic phantom representing 20- and 30-week pregnancy. Bubble detectors placed in the phantom’s abdomen assessed neutron dose from PBS-PRT, while a Farmer ion chamber was used for imaging and XRT dose. Results: At 20 weeks, PBS-PRT including imaging delivered 22.4 mSv, reducing dose 3.4-fold versus 6FF XRT and 2.5-fold versus 6FFF XRT. At 30 weeks, the PBS-PRT dose was 25.4 mSv, resulting in 7.6-fold and 6.3-fold reductions compared to 6FF and 6FFF XRT, respectively. Conclusions: This study presents the first one-by-one comparison between PBS-PRT and different XRT modalities for pregnant breast cancer patients with an adapted anthropomorphic phantom. PBS-PRT measurements showed that the total equivalent dose was below the 100 mSv threshold outlined in AAPM Task Group Report No. 36 for a 30-week pregnancy, even under a worst-case scenario, maintaining treatment goals. These findings support the adoption of PBS-PRT as the preferred approach for treating pregnant breast cancer patients, should radiotherapy be required.
format Article
id doaj-art-84991dc4825a4ef88d5198d3e92a1353
institution Kabale University
issn 2405-6316
language English
publishDate 2025-01-01
publisher Elsevier
record_format Article
series Physics and Imaging in Radiation Oncology
spelling doaj-art-84991dc4825a4ef88d5198d3e92a13532025-02-09T05:00:37ZengElsevierPhysics and Imaging in Radiation Oncology2405-63162025-01-0133100721Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant womenMenke Weessies0Murillo Bellezzo1Britt J.P. Hupkens2Frank Verhaegen3Gloria Vilches-Freixas4Corresponding author at: Doctor Tanslaan 12, 6229 ET Maastricht, The Netherlands.; Department of Radiation Oncology (Maastro) GROW School for Oncology and Reproduction Maastricht University Medical Centre Maastricht The NetherlandsDepartment of Radiation Oncology (Maastro) GROW School for Oncology and Reproduction Maastricht University Medical Centre Maastricht The NetherlandsDepartment of Radiation Oncology (Maastro) GROW School for Oncology and Reproduction Maastricht University Medical Centre Maastricht The NetherlandsDepartment of Radiation Oncology (Maastro) GROW School for Oncology and Reproduction Maastricht University Medical Centre Maastricht The NetherlandsDepartment of Radiation Oncology (Maastro) GROW School for Oncology and Reproduction Maastricht University Medical Centre Maastricht The NetherlandsBackground and purpose: Cancer affects 1 in 1000–2000 pregnancies annually worldwide, creating challenges in balancing cancer treatment and fetal safety. This study compares out-of-field radiation doses between two treatment modalities: 6MV external photon radiotherapy (XRT) and pencil beam scanning proton-therapy (PBS-PRT) for breast cancer, including imaging, to evaluate PBS-PRT as a potential new treatment option. Materials and methods: For breast cancer involving lymph node levels 1–4 and the intramammary lymph nodes, treatment plans were created for XRT (with Flattening Filter (FF) and FF-Free (FFF)) and PBS-PRT, prescribing 15 × 2.67 Gy(RBE). Measurements were conducted using an adapted anthropomorphic phantom representing 20- and 30-week pregnancy. Bubble detectors placed in the phantom’s abdomen assessed neutron dose from PBS-PRT, while a Farmer ion chamber was used for imaging and XRT dose. Results: At 20 weeks, PBS-PRT including imaging delivered 22.4 mSv, reducing dose 3.4-fold versus 6FF XRT and 2.5-fold versus 6FFF XRT. At 30 weeks, the PBS-PRT dose was 25.4 mSv, resulting in 7.6-fold and 6.3-fold reductions compared to 6FF and 6FFF XRT, respectively. Conclusions: This study presents the first one-by-one comparison between PBS-PRT and different XRT modalities for pregnant breast cancer patients with an adapted anthropomorphic phantom. PBS-PRT measurements showed that the total equivalent dose was below the 100 mSv threshold outlined in AAPM Task Group Report No. 36 for a 30-week pregnancy, even under a worst-case scenario, maintaining treatment goals. These findings support the adoption of PBS-PRT as the preferred approach for treating pregnant breast cancer patients, should radiotherapy be required.http://www.sciencedirect.com/science/article/pii/S2405631625000260Cancer during pregnancyOut-of-field dosimetryFetus radiationProton radiationProton therapyRadiation therapy
spellingShingle Menke Weessies
Murillo Bellezzo
Britt J.P. Hupkens
Frank Verhaegen
Gloria Vilches-Freixas
Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
Physics and Imaging in Radiation Oncology
Cancer during pregnancy
Out-of-field dosimetry
Fetus radiation
Proton radiation
Proton therapy
Radiation therapy
title Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
title_full Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
title_fullStr Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
title_full_unstemmed Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
title_short Out-of-field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
title_sort out of field dose assessment for pencil beam scanning proton radiotherapy versus photon radiotherapy for breast cancer in pregnant women
topic Cancer during pregnancy
Out-of-field dosimetry
Fetus radiation
Proton radiation
Proton therapy
Radiation therapy
url http://www.sciencedirect.com/science/article/pii/S2405631625000260
work_keys_str_mv AT menkeweessies outoffielddoseassessmentforpencilbeamscanningprotonradiotherapyversusphotonradiotherapyforbreastcancerinpregnantwomen
AT murillobellezzo outoffielddoseassessmentforpencilbeamscanningprotonradiotherapyversusphotonradiotherapyforbreastcancerinpregnantwomen
AT brittjphupkens outoffielddoseassessmentforpencilbeamscanningprotonradiotherapyversusphotonradiotherapyforbreastcancerinpregnantwomen
AT frankverhaegen outoffielddoseassessmentforpencilbeamscanningprotonradiotherapyversusphotonradiotherapyforbreastcancerinpregnantwomen
AT gloriavilchesfreixas outoffielddoseassessmentforpencilbeamscanningprotonradiotherapyversusphotonradiotherapyforbreastcancerinpregnantwomen