Frequency of whole breast radiation therapy after intraoperative radiation therapy due to criteria identified by lumpectomy

Preoperative Predictive Factors of Positive Margin Status After Breast Conserving Therapy (BCT) with Intraoperative Radiation Therapy (IORT): A Retrospective Study of 400 Patients

INTRODUCTION

Single-fraction intraoperative radiation therapy (IORT) has emerged as a therapeutic option in patients undergoing breast conserving therapy (BCT) for early stage breast cancer, often eliminating the need for postoperative external beam radiation therapy. However, if a positive margin is encountered after BCT, the patient will ultimately require external beam radiation therapy. The purpose of this study was to identify preoperative factors from patient demographics, preoperative workup, or biopsy results that may be predictive of postoperative margin status.

MATERIALS AND METHODS

A retrospective chart review was performed on 396 patients who underwent BCT with IORT. Logistic regression models were utilized for statistical analysis.

RESULTS

The majority of studied variables were similar; however, differences were noted for high-grade tumors, in situ status, and progesterone receptor-negative (PR^-) tumors. Grade 3 tumors were significantly associated with positive margin status when compared with Grade 1 (odds ratio, 2.30; P = .036). PR^- status tumors were found to be approximately 2 times more likely to have a positive margin (P = .028). Patients with in situ (stage 0) status tumors were 1.986 times more likely to have positive margins when compared with those with an invasive tumor (P = .030).

CONCLUSIONS

Higher grade PR^- tumors are at increased risk of having a positive margin, which should be taken into consideration when considering treatment with IORT.

Intraoperative high dose rate brachytherapy during breast-conserving surgery: A Prospective Pilot Study

PURPOSE

To evaluate feasibility, quality of life, toxicity, and cosmetic outcome for intraoperative breast cancer brachytherapy after breast-conserving surgery using high dose rate brachytherapy.

METHODS AND MATERIALS

Fifty-two consecutive women, ⩾50 years old, diagnosed with a unifocal non-lobular breast cancer ⩽3 cm, N0, underwent breast-conserving surgery and sentinel node biopsy. Twenty-five women received intraoperative brachytherapy pre-pathology at primary surgery and the others post-pathology, during a second procedure. An applicator, connected to a high dose rate afterloader, was used. Two of the women were excluded due to metastases found per-operatively at a frozen section from the sentinel node. Quality of life was evaluated using two validated health questionnaires. Treatment toxicity was documented according to the LENT-SOMA scale by two oncologists. The cosmetic result was evaluated using the validated freely available software BCCT.core 2.0.

RESULTS

The clinical procedure worked out well logistically. Seven women received supplementary external radiotherapy due to insufficient margins and, in one case, poor adaptation of the breast parenchyma to the applicator. No serious adverse effects from irradiation were registered. The results from the health questionnaires showed no major differences compared with reference groups from the Swedish population. Only two women were registered as having a "poor" cosmetic result while a majority of the women had a "good" outcome.

CONCLUSION

This pilot study shows that intraoperative brachytherapy is a feasible procedure and encourages further trials evaluating its role in treatment of early breast cancer.

Outcomes of selective whole breast irradiation following lumpectomy with intraoperative radiation therapy for hormone receptor positive breast cancer

BACKGROUND

For low risk breast cancer, the TARGIT-A randomized trial supported lumpectomy with intraoperative radiation therapy (IORT) and selective whole breast radiation (WBXRT). Selection criteria for WBXRT vary.

METHODS

Women with hormone-receptor positive, clinically node-negative breast cancer were categorized retrospectively as suitable for IORT alone or also needing WBXRT by TARGIT-A or expanded TARGIT criteria (TARGIT-MCC). We evaluated local recurrence (LR) by selection criteria and receipt of WBXRT.

RESULTS

Among 194 cases followed a median of 44 months, 54 (27.8%) met TARGIT-MCC criteria for WBXRT (34 met TARGIT-A criteria). Thirty patients were recommended and 21 (10.8%) received WBXRT. Of 13 patients with LR, none received WBXRT. LR was 10.5% in patients meeting TARGIT-MCC criteria who did not receive WBXRT versus 0% after WBXRT (p = 0.299).

CONCLUSIONS

Selective WBXRT may have mitigated LR. Nearly all LR were in patients not recommended WBXRT. Further work should refine criteria for WBXRT after IORT.

SUMMARY

Prior work among women with early breast cancer supported lumpectomy with intraoperative radiation therapy and selective adjuvant radiation using a risk-adapted approach. An expanded set of criteria for adjuvant radiation appear to further mitigate local recurrence risk. Local recurrence after lumpectomy with IORT could be further minimized by identification of additional high-risk features, as well as greater adherence to adjuvant endocrine therapy.

Intraoperative radiation therapy for breast cancer patients: current perspectives

Accelerated partial breast irradiation (APBI) provides an attractive alternative to whole breast irradiation (WBI) through normal tissue radiation exposure and reduced treatment duration. Intraoperative radiation therapy (IORT) is a form of APBI with the shortest time interval, as it delivers the entirety of a planned radiation course at the time of breast surgery. However, faster is not always better, and IORT has been met with healthy skepticism. Patients treated with IORT have an increased compliance and overall satisfaction when compared to patients treated with WBI. However, early randomized trial results demonstrated an increased rate of recurrence after IORT, slowing its widespread adoption. Despite these controversies, IORT utilization is increasing nationally and several novel developments are aimed at continuing to minimize the risk of recurrence and treatment-related toxicity while maximizing the patient experience.