Open AccessEvaluation of skin dose and skin toxicity in patients undergoing intraoperative radiotherapy for early breast cancer
Author(s) -
Wong Jeannie Hsiu Ding,
Zaili Zainor,
Abdul Malik Rozita,
Bustam Anita Zarina,
Saad Marniza,
Jamaris Suniza,
Mosiun Joanne Aisha,
Mohd Taib Nur Aishah,
Ung Ngie Min,
See MeeHoong
Publication year - 2021
Publication title -
journal of applied clinical medical physics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.83
H-Index - 48
ISSN - 1526-9914
DOI - 10.1002/acm2.13338
Subject(s) - medicine , toxicity , radiation therapy , breast cancer , external beam radiotherapy , dosimetry , nuclear medicine , dosimeter , in vivo , radiology , cancer , brachytherapy , microbiology and biotechnology , biology
Abstract Purpose This study aims to evaluate in vivo skin dose delivered by intraoperative radiotherapy (IORT) and determine the factors associated with an increased risk of radiation‐induced skin toxicity. Methodology A total of 21 breast cancer patients who underwent breast‐conserving surgery and IORT, either as IORT alone or IORT boost plus external beam radiotherapy (EBRT), were recruited in this prospective study. EBT3 film was calibrated in water and used to measure skin dose during IORT at concentric circles of 5 mm and 40 mm away from the applicator. For patients who also had EBRT, the maximum skin dose was estimated using the radiotherapy treatment planning system. Mid‐term skin toxicities were evaluated at 3 and 6 months post‐IORT. Results The average skin dose at 5 mm and 40 mm away from the applicator was 3.07 ± 0.82 Gy and 0.99 ± 0.28 Gy, respectively. Patients treated with IORT boost plus EBRT received an additional skin dose of 41.07 ± 1.57 Gy from the EBRT component. At 3 months post‐IORT, 86% of patients showed no evidence of skin toxicity. However, the number of patients suffering from skin toxicity increased from 15% to 38% at 6 months post‐IORT. We found no association between the IORT alone or with the IORT boost plus EBRT and skin toxicity. Older age was associated with increased risk of skin toxicities. A mathematical model was derived to predict skin dose. Conclusion EBT3 film is a suitable dosimeter for in vivo skin dosimetry in IORT, providing patient‐specific skin doses. Both IORT alone and IORT boost techniques resulted in similar skin toxicity rates.