Continuous innovation in precision radio-guided surgery

Since its origins, nuclear medicine has faced technological changes that led to modifying operating modes and adapting protocols. In the field of radioguided surgery, the incorporation of preoperative scintigraphic imaging and intraoperative detection with the gamma probe provided a definitive boost to sentinel lymph node biopsy to become a standard procedure for melanoma and breast cancer. The various technological innovations and consequent adaptation of protocols come together in the coexistence of the disruptive and the gradual. As obvious examples we have the introduction of SPECT/CT in the preoperative field and Drop-in probes in the intraoperative field. Other innovative aspects with possible application in radio-guided surgery are based on the application of artificial intelligence, navigation and telecare.

Abstract P5-01-14: Visualisation of histologic proven breast cancer on the MAMMI-PET: A dedicated PET for hanging breast imaging

Aim: The MAMMI–PET, a high–resolution full–ring system for dedicated hanging breast imaging was originally developed in the context of a EU–founded project to improve the detection of breast cancer. The aim of the present study was to evaluate the performance of the MAMMI–PET device in patients with at least one histologic confirmed primary breast cancer lesion (or index lesion), scanned in two European centres. All patients were included in the study after being scheduled to receive pre–operative chemotherapy (NAC) or radiotherapy.

Material and methods:

From March 2011 to March 2014, we included 234 female patients (mean age 52 y, range 24–82y) with histologically confirmed breast cancer. All patients were scanned with the MAMMI–PET (Oncovision, Valencia, Spain) after giving informed consent. Scans were acquired 110 min after a dose of a mean dose of 197.12 MBq18F–FDG. In both centers the acquisitions, the reconstruction of the images and the data collection were performed using similar standardized methods. We tested the relation between visualization of the primary tumor and possible additional lesions on the MAMMI–PET as well as the influence of various variables; including age, weight, breast cancer subtypes and receptor status, breast length, maximal tumor diameter and affected breast quadrants.

Results: A total of 236 breasts were imaged and 211 (98.4%) of the index lesions (diameter 5–170 mm, mean 32 mm) were located within the MAMMI–PET scanning range. Of all index lesions within the scanning range 1.4% was not FDG avid on the MAMMI–PET images. Lesions that were FDG-avid were either clearly (86.3%) or moderately (12.3%) visible. The overall MAMMI–PET sensitivity increased from 88.6% to 98.6% after exclusion of lesions outside the scanning range. No significant differences in lesion visibility were found due to breast cancer subtypes or breast quadrant location. Of the 35 index lesions touching the pectoral muscle 62.9% reached into the scanning range. A total of 41 additional FDG-avid lesions were detected, not categorized as an index tumor.

Conclusions:

The MAMMI–PET missed only a small percentage of malignant lesions located within the scanning range of the device. Lesions near the pectoral muscle were the subgroup less often visualized. No significant influence on the visualization of the FDG avid lesions was seen due to tumor subgroups, hormone receptor status, and breast quadrant location or tumor size.

Citation Format: Suzana C Teixeira, José Ferrer Rebolleda, Bas B Koolen, Raúl Sánches Jurado, Marcel P Stokkel, María del Puig Cózar Santiago, Emiel J Th Rutgers, Renato A Valdés-Olmos. Visualisation of histologic proven breast cancer on the MAMMI-PET: A dedicated PET for hanging breast imaging [abstract]. In: Proceedings of the Thirty-Seventh Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2014 Dec 9-13; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2015;75(9 Suppl):Abstract nr P5-01-14.