Accelerated partial breast irradiation-Redefining the treatment target for women with early stage breast cancer

Following breast conserving surgery, the standard of care has been to deliver adjuvant radiation therapy directed to the whole breast (WBI) over a period of 3-7 weeks. Over the past decade, increasing data have supported the concept that treatment to the whole breast may not be required in selected patients, allowing for the emergence of partial breast irradiation (PBI). Multiple randomized trials with 5-10 years of follow-up have been published documenting the safety and efficacy associated with PBI using multiple techniques. Questions that remain to be answered include (a) what is the optimal PBI technique for each clinical scenario, (b) are there additional patients that can be effectively managed with PBI approaches, and (c) are there different techniques/dose schedules that allow for further reduction in treatment duration and/or toxicities? Partial breast irradiation represents a standard approach for appropriately selected patients. PBI provides comparable clinical outcomes to WBI while allowing for a reduction in the duration treatment and the potential for reduced toxicities. Future studies may also help to better define which patients require no radiation, PBI, hypofractionated WBI or conventional WBI, based upon patient, clinical, pathologic features as well as potentially using tumor genetics.

Accelerated partial breast irradiation with perioperative multicatheter interstitial brachytherapy-A feasibility study

PURPOSE

To assess the feasibility of high-dose-rate perioperative multicatheter interstitial brachytherapy to deliver accelerated partial breast irradiation (APBI) in selected patients with early breast cancer.

METHODS AND MATERIALS

Perioperative multicatheter interstitial brachytherapy for APBI has been used at our department since 2012 for patients with low-risk breast cancer. Interstitial catheters were inserted perioperatively via hollow needles immediately following tumorectomy with sentinel node biopsy. APBI started on Day 6 after surgery. The prescribed dose was 34 Gy (10 fractions of 3.4 Gy bid). Hormonal therapy was prescribed in all cases.

RESULTS

Between June 2012 and December 2017, 125 patients were scheduled for APBI. Of these, APBI was not performed in 12 patients (9.6%) due to adverse prognostic factors identified on the definitive biopsy. We observed wound dehiscence in 2/113 cases (1.8%), inflammatory complications requiring antibiotics in 7/113 cases (6.2%), transient Grade I radiodermatitis in 6/113 patients (4.4%), and seroma which resolved spontaneously in 3/113 patients (2.7%). With median followup of 39 months (range 3.3-75.3) no relapses were observed. No late complications in Radiation Therapy Oncology Group Grade 3 or higher were documented. Cosmetic outcome in patients with followup > 2 years was excellent or good in 92%.

CONCLUSION

Our preliminary results show that the perioperative multicatheter interstitial high-dose-rate brachytherapy for APBI in selected patients with early breast cancer is feasible. This treatment schedule reduces treatment duration, spares the patients of repeated anesthesia, and enables precise application of the afterloading tubes under direct visual control.