Compare the impact of simultaneous integrated boost radiotherapy and conventional radiotherapy with sequential boost to early breast cancer patients

Purpose: In this study, we aimed to evaluate the toxicity and the irradiated volume of the organs at risk (OAR) of two radiotherapy (RT) techniques for breast cancer patients after breast conservative surgery (BCS) for 10 years. Methods: 140 patients with early breast cancer (T0 similar to 2N0 similar to 1M0, stage I similar to II) participated in this study. Half of the patients received simultaneous integrated boost (SIB) and other half received conventional radiotherapy (CRT). We compared the toxic effects on cosmetic outcome (CO), volume to the OAR and recurrence-free period (RFP) between SIB and CRT. Results: The incidence of acute grade 1 skin toxicity (X-2 = 8.400, p = 0.040) and chronic skin reactions (X-2 = 11.020, p = 0.001) were significantly different between the two RT techniques (p < 0.05). All patients were satisfied with the CO (X-2 = 0.714, p = 0.398). There was no serious organ damage during the process of radiotherapy. There was less volume leakage to the lungs with 20Gy volume (p < 0.05). No significant difference in the volume to the lungs at 1000 cGy and heart at 1000/3000 cGy was observed between SIB and CRT (p >= 0.05). Patients in the SIB group were hospitalised and treated for a significantly shorter period of time than those in the CRT group (p < 0.05). All patients were alive at the last follow-up. There were no significant differences in RFP between the two techniques (p >= 0.05). Conclusion: Compared with patients in the CRT group, the SIB group has a shorter treatment duration without increased toxicity, with advantages in terms of dose-limiting capacity and cosmetic results of treatment. The recurrence-free rate in the SIB group is satisfactory and is a recommended treatment.