Dosimetric Comparison of Accelerated Partial Breast Irradiation Techniques: Multicatheter Interstitial Brachytherapy and Conformal External Beam Radiotherapy
Year: 2024
Type: article
Abstract: Purpose: To compare dosimetric plans obtained in patients with breast cancer (BC) that underwent accelerated partial breast irradiation (APBI) by conformal external beam radiotherapy (EBRT) or interstitial high dose rate brachytherapy (HDRB). Material and methods: From 2017 to 2022 APBI was performed in 210 patients with stage I–II BC (рТ1N0M0–pT2N0M0). APBI was delivered to the tumor bed: in 99 cases — by EBRT, in another 111 patients — by HDRB. Leſt breast was irradiated in 101 women: in 51 women using HDRB, in 50 patients — by EBRT. Following dosimetric parameters were used for comparison of the dosimetric plans: Dmax – maximum dose in the organ at risk; Dmed – mean dose in the organ at risk (heart, leſt main coronary artery and its descending branch, ipsilateral lung, breast, skin and subcutaneous tissues). Results: When the tumor bed was irradiated by HDRB, in comparison with EBRT, Dmax for the skin and subcutaneous tissue decreases from 98.4 % to 68.7 %, р < 0.002. The use of HDRB made it possible to reduce the radiation load on the ipsilateral lung: Dmax decreased from 71.9 % to 42.7 % , р < 0.002; Dmed was 5.5 % for HDRB and 2.9 % for EBRT, р > 0.05. On the contrary EBRT associated with higher dose to the breast Dmed breast — 46 % in comparison with HDRB Dmed breast — 16.5 % , р < 0.002. Dose to the heart was higher with HDBT Dmax heart — 20.2 %, Dmed heart was 4.9 % than with EBRT Dmax heart — 14.4 %, Dmed heart — 0.8 %. Dose to the left coronary artery with HDRB Dmax — 6.5 % , Dmed — 3.9 % was higher than with EBRT Dmax — 3.3 % , Dmed — 1.3 % . Dose to the descending branch of the left coronary artery was higher with HDRB Dmax — 12.6 % , Dmed — 9.3 % than with EBRT Dmax — 8.9 % and Dmed — 3.4 % . But this differences were non-significant (р > 0.05). Conclusions. APBI by HDRB associated by significant reduction of the radiation dose to the ipsilateral breast lung, breast, skin and subcutaneous tissues.
Language: English
Subfield: Radiation
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: diamond
OpenAlex ID: W4402678302