SAVI SCOUT® localization of metastatic axillary lymph node prior to neoadjuvant chemotherapy for targeted axillary dissection: a pilot study.

PURPOSE: In clinically node-positive breast cancer, axillary staging after neoadjuvant chemotherapy (NAC) is optimized with targeted axillary dissection (TAD), which includes removal of the biopsy-proven metastatic lymph node (LN) in addition to sentinel lymph nodes (SLN). Localization of the clipped node is currently performed post-NAC; however, technical limitations can make detection and localization of the treated LN challenging. We prospectively evaluated the feasibility of localizing the metastatic LN with a SAVI SCOUT® reflector (SAVI) prior to NAC for targeted removal at surgery. METHODS: Twenty-five patients with stage 2/3 breast cancer underwent ultrasound-guided localization of the biopsy-proven LN with SAVI prior to NAC. After NAC, patients with clinical response underwent TAD. Primary outcome measures were rate of successful localization, days between insertion of SAVI and axillary surgery, frequency of retrieval of clipped node, and frequency of SAVI-LN as SLN. RESULTS: After NAC, 23/25 (92%) had clinical axillary down-staging and underwent TAD. Two patients with persistent palpable axillary disease underwent ALND for initial staging. Axillary surgery was performed at an average of 141 days post-SAVI insertion and the SAVI was successfully retrieved in all cases. Among 23 patients undergoing TAD, the SAVI was retrieved within a LN in all patients, whereas clip migration was observed in two patients. The median SLN removed was 4, and SAVI-LN was SLN in 22/23 patients. Axillary pCR rate was 44%. CONCLUSION: Localizing a metastatic LN with SAVI reflector prior to NAC for targeted removal at surgery is feasible and may provide technical and logistical advantages over axillary localization post-NAC. CLINICAL TRIAL REGISTRY: Clinical trials.gov identifier: NCT03411070.

A comparison of two non-radioactive alternatives to wire for the localization of non-palpable breast cancers.

PURPOSE: Multiple wire-free technologies for localization of non-palpable breast cancers have emerged as satisfactory alternatives to wire. However, no study has compared two non-radioactive wire-free approaches to one another. The purpose of this study was to compare outcomes among LOCalizer™ radiofrequency identification (RFID), SAVI Scout® (SAVI), and wire localization (WL). METHODS: This was a retrospective, cross-sectional cohort study of patients undergoing lumpectomy for non-palpable breast cancer at a single institution between August 2017 and February 2019. Patients were divided into three cohorts based on localization technique: RFID, SAVI or WL. Operative times and average tumor volumes were compared using one-way analysis of variance. Positive margin and re-excision rates were compared with Fisher's exact test. RESULTS: Among 104 patients who underwent lumpectomy for non-palpable breast cancer, 33 patients (31.7%) had RFID, 21 (20.2%) had SAVI, and 50 (48.0%) had WL. Operative times were 79 min for RFID, 81 min for SAVI, and 78 min for WL (p = 0.91). Volume of tissue resected was 36.3 cm3, 31.7 cm3, and 35.3 cm3 for RFID, SAVI, and WL, respectively (p = 0.84). Positive margin rates (RFID 3.0% vs SAVI 9.5% vs WL 8.0%, p = 0.67) and re-excision rates (RFID 6.1% vs SAVI 9.5% vs WL 10.0%, p = 0.82) were similar across groups. CONCLUSIONS: Wire-free localization technologies have been compared to WL demonstrating similar efficacy. Our study suggests that RFID and SAVI Scout also perform similarly to one another. Physicians and institutions may consider more nuanced features of each localization system rather than performance alone when choosing a wire-free alternative.

Microchipping the breast: an effective new technology for localizing non-palpable breast lesions for surgery.

PURPOSE: Use of a wire to localize a non-palpable breast lesion for surgery is standard but archaic. We sought to evaluate a new radiofrequency localization system (RFLS) as an effective, non-radioactive alternative to the wire. METHODS: Patients who required surgical excision of a non-palpable breast lesion were consented for the study. Patients underwent localization with a radiofrequency Tag and surgical removal guided by the handheld LOCalizer probe. The primary study endpoint was successful placement and retrieval of the Tag, and secondary endpoints included marker migration; days prior to surgery of Tag insertion; patient, radiologist, and surgeon experience; distance of Tag from skin; and positive margin and re-excision rates for cancer. RESULTS: Fifty patients had successful placement and retrieval of the radiofrequency Tag. Likert questionnaire data revealed that most patients thought the procedure went smoothly and was easier than expected. Radiologists and surgeons thought that the Tag was as reliable as the wire. Of the 33 patients who had surgery for in situ or invasive cancer, one had a positive margin on final pathology (3%) and two underwent re-excision (6%). CONCLUSIONS: Data from this pilot study suggest that the RFLS is an effective localization system for non-palpable breast lesions intended for surgical removal. Unlike most other technologies, the LOCalizer probe detects distance from the Tag, and this unique feature may have contributed to the low positive margin rate seen in this study. The RFLS appears to offer advantages over current localization procedures and should be explored as an alternative to wire. ClinicalTrials.gov Identifier: NCT03202472.

Quantitative bone scan lesion area as an early surrogate outcome measure indicative of overall survival in metastatic prostate cancer.

A clinical validation of the bone scan lesion area (BSLA) as a quantitative imaging biomarker was performed in metastatic castration-resistant prostate cancer (mCRPC). BSLA was computed from whole-body bone scintigraphy at baseline and week 12 posttreatment in a cohort of 198 mCRPC subjects (127 treated and 71 placebo) from a clinical trial involving a different drug from the initial biomarker development. BSLA computation involved automated image normalization, lesion segmentation, and summation of the total area of segmented lesions on bone scan AP and PA views as a measure of tumor burden. As a predictive biomarker, treated subjects with baseline BSLA [Formula: see text] had longer survival than those with higher BSLA ([Formula: see text] and [Formula: see text]). As a surrogate outcome biomarker, subjects were categorized as progressive disease (PD) if the BSLA increased by a prespecified 30% or more from baseline to week 12 and non-PD otherwise. Overall survival rates between PD and non-PD groups were statistically different ([Formula: see text] and [Formula: see text]). Subjects without PD at week 12 had longer survival than subjects with PD: median 398 days versus 280 days. BSLA has now been demonstrated to be an early surrogate outcome for overall survival in different prostate cancer drug treatments.