Comparison of two radiation techniques for the breast boost in patients undergoing neoadjuvant treatment for breast cancer

Abstract

Objective: After breast conservative surgery (BCS) and whole-breast radiotherapy (WBRT), the use of boost irradiation is recommended especially in patients at high risk. However, the standard technique and the definition of the boost volume have not been well defined. Methods: We retrospectively compared an anticipated pre-operative photon boost on the tumour, administered with low-dose fractionated radiotherapy, and neoadjuvant chemotherapy with two different sequential boost techniques, administered after BCS and standard adjuvant WBRT: (1) a standard photon beam (2) and an electron beam technique on the tumour bed of the same patients. The plans were analyzed for the dosimetric coverage of the CT-delineated irradiated volume. The minimal dose received by 95% of the target volume (D 95 ), the minimal dose received by 90% of the target volume (D 90 ) and geographic misses were evaluated. Results: 15 patients were evaluated. The sequential photon and electron boost techniques resulted in inferior target volume coverage compared with the anticipated boost technique, with a median D 95 of 96.3% (range 94.7-99.6%) and 0.8% (range 0-30%) and a median D 90 of 99.1% (range 90.2-100%) and 54.7% (range 0-84.8%), respectively. We observed a geographic miss in 26.6% of sequential electron plans. The results of the anticipated boost technique were better: 99.4% (range 96.5-100%) and 97.1% (range 86.2-99%) for median D 90 and median D 95 , respectively, and no geographic miss was observed. We observed a dose reduction to the heart, with left-sided breast irradiation, using the anticipated pre-operative boost technique, when analyzed for all dose-volume parameters. When compared with the sequential electron plans, the pre-operative photon technique showed a higher median ipsilateral lung D max . Conclusion: Our data show that an anticipated preoperative photon boost results in a better coverage with respect to the standard sequential boost while also saving the organs at risk and consequently fewer side effects. Advances in knowledge: This is the first dosimetric study that evaluated the association between an anticipated boost and neoadjuvant chemotherapy treatment.

Extended Hypofractionated Cancer Radiation Therapy Against Aged and Non-aged Breast Carcinomas Patients

“…These kinds of inmates possibly expanded danger restorative result along with standard chemotherapy, so hypo fractionation would prompt a result that would be any more awful than that with standard treatment. We didn't utilize support illumination, on the grounds that at the time the examination was started, the adequacy of lift light had not been exhibited and we needed to stay away from the jumbling impact that help illumination could have on nearby repeat or bosom cosmesis [93]- [95]. Since the fruition of our preliminary, the consequences of different preliminaries, offering help for the utilization of lift light [96], [97], and stimulant radio therapy was utilized more frequently than in our primarily.…”

Interobserver variability (between radiation oncologist and radiation therapist) in tumor bed contouring after breast-conserving surgery

“…6–9 The introduction of fusion image software has enabled coregistered diagnostic testing and treatment planning CT, and this has considerably improved the geographic matching of the preoperative area with the target area for the boost, but more needs to be done. Some authors have proposed using surgical clips to outline the TB 13,14,20,26–28 and the use of 3 or more 30 clips generally increases the overlap between the 2 areas. The use of scar-based contouring has proved from 10% to 67% less accurate than clip-based contouring for the purposes of defining the target area.…”