Effect of volume rotation intensity-modulated radiotherapy on skin toxicity and pulmonary fibrosis of bilateral breast cancer / 中国医师进修杂志

ABSTRACT

Objective:To investigate the effects of volume-modulated intensity-modulated radiotherapy on acute and advanced skin toxicity and radiation-induced pulmonary fibrosis in patients with bilateral breast cancer after conservative surgery.Methods:The study period was from January 2017 to December 2018. A total of 236 patients with bilateral breast cancer who received treatment in Zhejiang Cancer Hospital were included in the study.All patients received volume-modulated arc light (VMAT/RapidArc ?) treatment. The treatment was performed during and after treatment. Clinical examination was performed to detect radiation-related skin toxicity, and pulmonary fibrosis was evaluated and analyzed by high-resolution computed tomography (HRCT) during follow-up. Results:A total of 220 patients underwent deep inhalation breath holding (DIBH) scans. The remaining 16 patients underwent free breathing (FB) scans due to poor adherence (patients could not tolerate holding for at least 20 s). There was a significant difference in lung capacity between DIBH and FB [right lung (2 416.3 ± 550.8) cc vs. (1 278.6 ± 514.3) cc, P = 0.001; left Lung (2 125.4 ± 428.6) cc vs. (1 058.9 ± 520.5) cc vs. P <0.001]. One hundred and sixty-nine patients (71.6%) had grade 1 skin toxicity, 56 patients (23.7%) were grade 2, 2 patients (0.8%) were grade 3, and 9 patients did not have any skin toxicity. There were no symptomatic radiation pneumonitis and pulmonary fibrosis cases during radiotherapy and 6 months after radiotherapy. Advanced skin toxicity evaluation showed that most patients had no obvious skin toxicity. The major skin toxicity reactions were capillary telangiectasia, breast edema, and skin atrophy. Pulmonary fibrosis appeared in 12 patients, and mean follow-up was detected. The time was 12-28 (12.5 ± 0.6) months. The average volume of pulmonary fibrotic lesions was 1.5-18.3 (6.6 ± 1.0) cc. Partial volumes (V 20, V 30, V 40, and V 50) were significantly associated with the risk of pulmonary fibrosis ( P < 0.01). Recurrence-free survival (RFS) during an average follow-up time was 12-33 (28.6 ± 1.2) months, and overall survival (OS) were both 100.0%. Conclusions:Based on the evaluation of acute and advanced skin toxicity and radiation-induced pulmonary fibrosis, volume-rotation IMRT is safe and effective for patients with bilateral breast cancer after conservative surgery, and it is worthy of clinical reference and application.