Dosimetric Comparison and Risk of Skin Toxicity in Breast Cancer Radiotherapy: Conventional vs. Hypofractionated Approaches

Radiation therapy is a crucial cancer treatment, utilizing high doses of radiation to eliminate cancer cells and reduce tumors. In breast cancer, one common side effect is skin toxicity, impact a patient's emotional well-being, treatment adherence, and overall outcomes. The comparison between conventional and hypofractionated radiotherapy is vital, as hypofractionation delivers higher doses in a shorter timeframe, raising concerns about increased skin reactions. Yet, research indicates that hypofractionation often leads to similar or even fewer skin issues. This comparison helps physicians select. This study aims to compare the incidence of skin toxicity between hypofractionated and conventional radiotherapy in breast cancer patients. Methods: This prospective cohort study was conducted at Milad Hospital, Isfahan, in ۲۰۲۳. Fifty breast cancer patients undergoing either conventional or hypofractionated radiotherapy, with whole or partial breast irradiation, were included. Prior to radiotherapy, skin assessments were conducted using the Radiation Therapy Oncology Group (RTOG) Common Toxicity Criteria. Skin toxicity was evaluated during treatment and up to ۴۰ days post-radiotherapy in both groups. For conventional radiotherapy, a total dose of ۵۰۰۰ cGy was administered in ۲۵ fractions, while in hypofractionated radiotherapy, ۴۲۵۰ cGy was delivered in ۱۶ fractions. After contouring with the Prowess Panther treatment planning system, the skin was defined as an organ at risk, and dosimetric data (mean, maximum, and minimum doses) were extracted from dose-volume histograms. The dosimetric values were compared between the two techniques, and data analysis was conducted using SPSS-۲۶. Results: This study evaluated skin reactions in ۵۰ breast cancer patients (۲۵ receiving hypofractionated radiotherapy and ۲۵ receiving conventional radiotherapy) with a mean age of ۵۲.۵ ± ۱۲.۱۹ years. Skin reactions were assessed during treatment and for ۴۰ days post-treatment. Results demonstrated that the conventional technique led to a higher incidence of grade ۲ (۴۰%) and grade ۳ (۲۸%) skin reactions compared to the hypofractionated technique, which did not induce any grade ۳ reactions. Furthermore, dosimetric data (mean, maximum, and minimum dose) collected ۴۰ days post-radiotherapy revealed a significantly higher incidence of skin reactions in the conventional group compared to the hypofractionated group (p-value < ۰.۰۵). Conclusion: The results indicated a higher incidence of skin adverse effects in conventional treatment compared to hypofractionation, with all dosimetric parameters demonstrating higher values in the conventional technique. However, further experimental studies and longer-term patient follow-up are required to determine the impact of dose per fraction on skin and other sensitive organ damage. This would allow for a more definitive understanding of the effects of these two distinct fractionation regimens and their relationship to the dosimetric factors under investigation. Based on the obtained dosimetric data, the application of hypofractionation treatment schedules in breast radiotherapy not only reduces treatment time but also leads to a decrease in mean organ doses and dosimetric factors related to sensitive organs.

کلیدواژه ها:

breast cancer ، radiation therapy ، skin toxicity ، hypofractionation