Conventional Versus Different Hypofractionated Radiotherapy Dosage Schedules in Postmastectomy Advanced Breast Cancer

The standard treatment for advanced breast cancer is surgery consisting of breast-conserving surgery or modified radical mastectomy (MRM) postneoadjuvant chemotherapy followed by adjuvant radiation treatment (RT). Conventionally-fractionated whole breast irradiation has been the standard RT regimen, but recently shorter courses of hypofractionated whole breast or chest wall irradiation have been advocated for patient convenience and reduction in health-care costs and resources. Radiation is delivered through the same technique, but tumors receive a higher dose of radiation per treatment session with hypofractionation.

The aim of the study was to compare different fractionation schedules of radiotherapy in postoperative cancer breast with respect to locoregional control and toxicities.

One hundred and eighty-eight patients of cancer breast, who received RT between January 2017 and December 2019 were assessed. Since hypofractionation is well documented and established and being practiced in prestigious institutes, we treated the patients as per their choice to receive 10.15 or 25 fractions. 72 patients (Group A) were treated with conventional fractionation to a dose of 50 Gy/25 fractions/5 weeks. Second group of 62 patients (Group B) were given 40.5 Gy/15 fractions/3 weeks and third group of 54 patients (Group C) were treated with 34 Gy/10 fractions/2 weeks. All patients were T3 or more and underwent MRM after neoadjuvant chemotherapy. They were in the age group of 30-65 years. All of them received adjuvant chemotherapy and hormone therapy in case of estrogen/and progesterone receptor positivity and anti-Her2neu target therapy in case of Her2neu positivity. They were assessed for locoregional control and acute and chronic toxicities.

Grade 3 and 4 skin toxicity was similar in all three groups. At 6 months postcompletion of RT, two patients in Group A, 3 in Group B, and 5 in Group C lost to follow-up. In rest of the subjects, there was no locoregional failure. At 1 year, 1 patient from Group A, 2 from Group B, and 1 from Group C developed locoregional recurrence. There were no major chronic toxicities. Arm edema and Telangiectasia were similar in three groups. No rib fracture or major cardiotoxicity and pulmonary toxicity was seen.

Hypofractionated RT is a part of the typical treatment regimen for breast cancer nowadays. The major advantage is of convenience to the patients as it is completed the full course of RT in fewer sessions. With both conventional and hypofractionated radiation, the patient receives radiation 5 days a week. In the conventional regimen, though the schedule lasts for 5 weeks, whereas hypofractionation therapy is completed in 2 to 3 weeks. Local control wise both conventional and hypofractionated regimen is similar in locoregional control and toxicity. Therefore, hypofractionated RT should be practiced in cancer breast as it is economical, convenient, and toxicity wise and result wise similar to conventional radiotherapy.