Hypofractionated Radiotherapy for Breast Cancers - Preliminary Results from a Tertiary Care Center in Eastern India

다국어 초록 (Multilingual Abstract)

Background: The standard radiotherapy (RT) fractionation practiced in India and worldwide is 50Gy in 25 fractions over 5 weeks to the chest wall or whole breast followed by tumour bed boost in case of breast conservation (BCS). A body of validated data exists regarding hypofractionation in breast cancer. We here report initial results for 135 patients treated at our center with the START-B type of fractionation. Materials and Methods: From May 2011 till July 2012, women with all stages of breast cancer (excluding metastatic), who had undergone BCS or mastectomy were planned for 40Gy in 15 fractions over 3weeks to chest wall/whole breast and supraclavicular fossa (where indicated) followed by tumour bed boost in BCS patients. Planning was done using Casebow's technique. The primary end point was to assess the acute toxicity and the cosmetic outcomes. Using cosmetic scales; patients were assessed during radiotherapy and at subsequent follow up visits with the radiation oncologist. Results: Of the 135 patients, 62 had undergone BCS and 73 mastectomy. Median age of the population was 52 years. Some 80% were T1&T2 tumours in BCS whereas most patients in mastectomy group were T3&T4 tumours (60%). 45% were node negative in BCS group whilst it was 23% in the mastectomy group. Average NPI scores were 3.9 and 4.9, respectively. Most frequently reported histopathology report was infiltrating ductal carcinoma (87%), grade III being most common (58%), and 69% were ER positive tumours, and 30% were Her 2 Neu positive. Triple negative tumours accounted for 13% and their mean age was young (43 yrs.) The maximum acute skin toxicity at the end of treatment was Grade 1 in 94% of the mastectomy grouppatients and 71% in BCS patients. Grade 2 toxicity was 6% in mast group and 23% in BCS group. Grade 3 was 6% in BCS group, no grade 3 toxicity in mastectomy patients and there was no grade 4 skin toxicity in any case. Post RT at 1 month; 39% of BCS patients had persisting Grade I skin reaction which was only 2% in mastectomy patients. At 3 months post RT, 18% patients had persisting hyperpigmentation. At 6 months 8% patients had persisting erythema in the BCS group only. Some 3% BCS and 8% mastectomy patients had lymph edema till the date of evaluation. Cosmetic outcome in BCS patients remained good to excellent 6 months post surgery and radiotherapy. 1 patient of BCS and 3 patients of mast had developed metastatic disease at the time of evaluation. Conclusions: Hypofractionated RT is well tolerated in Indian population with reduced acute skin toxicity and good cosmetic outcome. Regimens such as these should be encouraged in other centers to increase machine output time. The study is on-going to assess long term results.