Tumor bed boost in breast cancer: Brachytherapy versus electron beam

BACKGROUND: The prospective study aimed to evaluate the effectiveness of Electron beam or HDR 192Ir Interstitial Implant used as a boost in breast Conservation cases after completion of EBRT. The two therapeutic modalities were compared in terms of the following parameters; i.e. cosmesis, optimization of tumor bed boost, local control, toxicity, and DFS. MATERIALS AND METHODS: The EBRT dose used was 50 Gy in 25 fractions over 5 weeks time. Target delineation of boost treatment was done by CT scan or by high resolution USG. EBRT will be immediately followed by local boost at the primary tumor bearing site of breast with 8 to12 MeV electron beam to a dose of 15 Gy in 6 fractions (Arm A) or with HDR 192Ir interstitial brachytherapy to a dose of 15 Gy in 3 fractions at 6 hours apart (Arm B). RESULTS: The excellent cosmesis achieved with electron beam therapy in Arm A was found to be statistically significant (P = 0.025). Local relapse was absent in both the arms. One distant metastasis occurred in Arm A within 10 months of initiation of treatment and one distant metastasis in Arm B came out within 3 months of starting of therapy. CONCLUSION: The study has shown good cosmetic result with electron boost and 100% local control with both the technique. However if there is a more number of patients with longer period of follow up we could have got the actual picture to verify our results and assess long term survival data.