Helical tomotherapy experience in breast cancer adjuvant radiotherapy and acute toxicity results

This study aimed to evaluate acute toxicity and oncological outcomes of breast cancer patients who underwent adjuvant radiotherapy (RT) with tomotherapy.

The results of 114 patients who underwent adjuvant RT with Tomotherapy device between 17.08.10-12.06.2021 in Ankara Atatürk Training and Research Hospital and Ankara City Hospital were evaluated retrospectively. The primary endpoint of the study was acute adverse events, and the secondary endpoints were overall survival (OS) and disease-free survival (DFS).

The results of 103 patients who met the inclusion criteria were analyzed. The median follow-up was 21 (range 1-125.8) months. Grade +3 esophagitis was not observed in any patient; no esophagitis was observed in 60 (58.3%) patients. Grade 3 dermatitis was observed in 3 (2.9%) patients. In addition, dermatitis was not observed in 47 (45.6%) patients. The relationship between chest wall volume and esophagitis development was statistically significant (p = 0.006; Z score: -2769). The median OS was 24.1 (range 1-128.5) and median disease-free survival was 21.1 (range 1-125.8) months. Five patients (4.9%) died and 9 patients (8.7%) relapsed. Local recurrence was observed in only 1 (1%) patient. There was a statistically significant correlation between OS and contralateral lung V20 dose [p < 0.001; Spearman Correlation Coefficient (SCC) -406) and heart mean dose (p < 0.001; SCC -370)]. There was a statically significant correlation between DFS and cN (p < 0.001); pN (p < 0.001); heart mean dose (p < 0.001; SCC -351); contralateral lung V5 dose (p = 0.041; SCC -213); contralateral lung V20 dose (p < 0.001; SCC -434).

Acute toxicity results show improvement in breast cancer adjuvant radiotherapy with helical tomotherapy.