Response to the article by Evangelista et al.: Use of a portable gamma camera for guiding surgical treatment in locally advanced breast cancer in a post-neoadjuvant therapy setting. Breast Cancer Res Treat 2014.

Abstract

Neoadjuvant chemotherapy (nCT) was originally introduced as a treatment option for patients with locally advanced breast cancer in an attempt to convert nonoperable cancers into surgically resectable ones [1, 2]. Soon after positive results were achieved, the concept was extended to earlier, operable stages, with the aim of increasing the rate of breast-conserving surgery (BCS). The main benefit of nCT is a reduction of tumor size, which can allow BCS in patients who otherwise would have required mastectomy (MT). Breast conservation is associated with less morbidity, better cosmetic results, and improved body image when compared to MT [3]. In the latest issue of Breast Cancer Res Treat, Evangelista et al. [4] evaluated the benefit of a portable gamma camera (Sentinella) for guiding surgical treatment in locally advanced breast cancer after nCT. We were interested to read this article, which nonetheless raises several issues. At the end of nCT and before breast surgery, an intravenous injection of 99mTc-Sestamibi was made to detect residual tumor. The sensitivity of Sentinella to identify focal uptake of tracer in the breast before surgery was only 50 %, higher than conventional scintigraphy (26.6 %). The sensitivity of Sentinella to identify lymph node residual metastasis was lower (33.3 %). On the other hand, the specificity of Sentinella was excellent to detect residual breast lesion (100 %) and axillary lymph node metastasis (83.3 %). This new nuclear imaging device using intravenous injection of 99mTc-Sestamibi appears to be an attractive technique in breast cancer. Unfortunately, the first results reported in this article do not show a clear benefit for guiding breast tumor surgery. Indeed, the low sensitivity for the detection of residual breast lesion (50 %) attributed to the limited resolving power of the gamma camera does not identify all residual breast lesions after nCT. However, breast surgery is always recommended after nCT, even if no clinical or radiological lesion is detected. The use of Sentinella does not avoid pre-operative tumor localization by wire-guided or radio-guided localization. Moreover, the authors were unable to evaluate complete resection and re-excision rates in patients requiring BCS after nCT. Unfortunately, these parameters were not assessed. With only 39 % of patients (N = 7) undergoing breastconserving surgery, the authors are not entitles to conclude that the portable gamma camera is of interest for breast surgery management. In contrast, we believe that this procedure with its excellent specificity and given the persistence of focal tracer uptake in the axillary lymph node could be useful in selecting patients not requiring sentinel node biopsy after nCT. Performances of this new nuclear device seem to be superior to axillary ultrasound for the detection of lymph node metastasis. Currently, we believe that the use of a portable gamma camera could offer an alternative to wire-guided localization for guiding surgical excision of non-palpable breast cancer [5]. A. Bricou Department of Gynecology–Obstetrics, Bobigny University, APHP, Hopital Jean-Verdier, avenue du 14-Juillet, 93143 Bondy, France