Intraoperative Localization Using an Implanted Radar Reflector Facilitates Resection of Non-Palpable Trunk and Extremity Sarcoma

Radio-Guided Occult Lesion Localization With 99m Tc for the Localization of Nonpalpable Melanoma and Soft Tissue Sarcoma Lesions: A Feasibility Study

PURPOSE OF THE REPORT

Localization techniques are needed to facilitate resection of nonpalpable lesions. In this study, the feasibility of radio-guided occult lesion localization (ROLL) with 99m Tc is investigated for the localization of nonpalpable, small, suspicious, or proven melanoma or soft tissue sarcoma lesions at various locations throughout the body.

PATIENTS AND METHODS

Patients with nonpalpable, suspicious, or proven melanoma or soft tissue sarcoma lesions were selected for this study. Within 24 hours before surgery, a median dose of 33.92 MBq 99m Tc-labeled human albumin particles ( 99m Tc-NA or 99m Tc-MAA) was injected in the lesion under ultrasound guidance. A hand-held gamma probe was used to detect the radioactive signal and guidance during surgery.

RESULTS

In this study, 20 patients with a total of 25 lesions were included and analyzed. The median size of the lesions was 1.8 cm (interquartile range [IQR], 1.8-4.0 cm), of which 44% were intramuscular located and 36% were subcutaneous, and 20% consisted of suspicious lymph nodes, mostly in the lower extremity. At median 4 hours (IQR, 3-6 hours) postinjection, 99m Tc ROLL showed a 100% intraoperative identification rate with proper signal identification with the gamma probe in all patients. With a median surgery time of 76 minutes (IQR, 45-157 minutes), all targeted lesions could be resected without 99m Tc-related complications, resulting in 88% microscopically margin-negative resection. No reoperations were needed for the same lesion.

CONCLUSIONS

The 99m Tc ROLL procedure is feasible for the localization and excision of small, nonpalpable melanoma and soft tissue sarcoma lesions at various locations in the body.

Radar-Guided Localization and Resection for Metastatic Nodal and Soft Tissue Melanoma: A Single-Institution Retrospective Study

BACKGROUND

Radar-guided localization (RGL) offers a wire-free, nonradioactive surgical guidance method consisting of a small percutaneously-placed radar reflector and handheld probe. This study investigates the feasibility, timing, and outcomes of RGL for melanoma metastasectomy.

METHODS

We retrospectively identified patients at our cancer center who underwent RGL resection of metastatic melanoma between December 2020-June 2023. Data pertaining to patients' melanoma history, management, reflector placement and retrieval, and follow-up was extracted from patient charts and analyzed using descriptive statistics.

RESULTS

Twenty-three RGL cases were performed in patients with stage III-IV locoregional or oligometastatic disease, 10 of whom had reflectors placed prior to neoadjuvant therapy. Procedures included soft tissue nodule removals (8), index lymph node removals (13), and therapeutic lymph node dissections (2). Reflectors were located and retrieved intraoperatively in 96% of cases from a range of 2 to 282 days after placement; the last reflector was not able to be located during surgery via probe or intraoperative ultrasound. One retrieved reflector had migrated from the index lesion, thus overall success rate of reflector and associated index lesion removal was 21 of 23 (91%). All RGL-localized and retrieved index lesions that contained viable tumor (10) had microscopically negative margins. There were no complications attributable to reflector insertion and no unexpected complications of RGL surgery.

CONCLUSION

In our practice, RGL is a safe and effective surgical localization method for soft tissue and nodal melanoma metastases. The inert nature of the reflector enables implantation prior to neoadjuvant therapy with utility in index lymph node removal.

Radioguided surgery of mesenchymal tumors with 125I seeds

INTRODUCTION

Radioguided surgery uses radioactive substances to identify and remove hard-to-locate lesions. Mesenchymal tumors constitute a heterogeneous group of neoplasms derived from the mesoderm, including benign lesions and malignant sarcomas. The aim of this study was to evaluate the ability of 125I radioactive seeds to guide intraoperative localization of mesenchymal tumors, analyzing the complication rates and evaluating the margins of the surgical specimens retrieved.

METHODS

Retrospective observational study of all consecutive patients undergoing radioguided surgery of a mesenchymal tumor with a 125I radioactive seed from January 2012 to January 2020 at a tertiary referral center in Spain. The seed was inserted percutaneously guided by ultrasound or computed tomography in an outpatient setting.

RESULTS

Fifteen lesions were resected in 11 interventions in 11 patients, recovering all lesions marked (100%) with a 125I seed. The lesions included areas of benign fibrosis (26.7%), cellular angiofibroma (6.7%), desmoid tumor (20%), solitary fibrous tumor (13.3%), chondrosarcoma (6.7%), and pleomorphic sarcoma (26.7%), with a high rate of recurrent tumors (60%). There was only one complication (6.7%) due to the seed falling within the surgical bed. According to the UICC classification of residual tumors, 80% of the lesions resulted in an R0 resection, 6.7% were R1 resections, and 13.3% were R2 resections.

CONCLUSION

Radioguided surgery is an accurate technique for the resection of hard-to-locate mesenchymal tumors.

125I Radioactive Seed Localization vs. Conventional Surgery for the Treatment of Mesenchymal Tumours: A Propensity Score Matching Analysis

PURPOSE

Radioguided localization can assist the surgery of hard-to-find lesions. The aim was to evaluate the results of the 125I Radioactive Seed Localization (RSL) technique to guide a margin-free tumoral resection of mesenchymal tumours compared to conventional surgery and its influence in oncological outcomes.

METHODS

Retrospective observational study of all consecutive patients who underwent 125I RSL for the surgery of a mesenchymal tumour from January 2012 to January 2020 in a tertiary referral centre in Spain. The control group was formed by patients with conventional surgery in the same period and centre. A Propensity Score matching at 1:4 ratio selected the cases for analysis.

RESULTS

A total of 10 lesions excised in 8 radioguided surgeries were compared to 40 lesions excised in 40 conventional surgeries, with equal proportion of histological subtypes in each group. There was a higher proportion of recurrent tumours in the RSL group (80 % [8/10] vs. 27.5 % [11/40]; p: 0.004). An R0 was achieved in 80 % (8/10) of the RSL group and 65 % (26/40) of the conventional surgery group. The R1 rate was 0 % and 15 % (6/40), and the R2 rate was 20 % (2/10 and 8/40) in the RSL group and conventional surgery group, respectively (p: 0.569). No differences were detected in disease-free or overall survival between the different histological subtypes in the subgroup analysis.

CONCLUSION

The 125I RSL technique of a challenging sample of mesenchymal tumours achieved a similar margin-free tumoral resection and oncological outcomes as conventional surgery.

Image-Guided Radar Reflector Localization for Small Soft-Tissue Lesions in the Musculoskeletal System

Preoperative localization of nonpalpable breast lesions using a radar reflector surgical guidance system has become commonplace, but the clinical utility of this emerging technology in the musculoskeletal system has not yet been well established. The system components include a console, a handpiece, an implanted radiofrequency reflector that works as a lesion marker, and an infrared light-emitting probe to guide the surgeon. The reflector can be deployed to localize small nonpalpable nodules within the subcutaneous fat as well as lesions within the deeper soft tissues. It can also be used for lymph nodes and foreign bodies. Localization can be performed both before and after treatment. The objective of this article is to describe the potential applications and our technique and initial experience for radar reflector localization within the musculoskeletal system.

Optimal localization strategies for non-palpable breast cancers –A network meta-analysis of randomized controlled trials

Purpose

Mammographic screening programmes have increased detection rates of non-palpable breast cancers. In these cases, wire-guided localization (WGL) is the most common approach used to guide breast conserving surgery (BCS). Several RCTs have compared WGL to a range of novel localization techniques. We aimed to perform a network meta-analysis (NMA) of randomized controlled trials (RCTs) comparing methods of non-palpable breast cancer localization.

Methods

A NMA was performed according to PRISMA-NMA guidelines. Analysis was performed using R packages and Shiny.

Results

24 RCTs assessing 9 tumour localization methods in 4236 breasts were included. Margin positivity and reoperation rates were 16.9% (714/4236) and 14.3% (409/2870) respectively. Cryo-assisted localization had the highest margin positivity (28.2%, 58/206) and reoperation (18.9%, 39/206) rates. Compared to WGL (n = 2045 from 24 RCTs) only ultrasound guided localization (USGL) (n = 316 from 3 RCTs) significantly lowered margin positivity (odds ratio (OR): 0.192, 95% confidence interval (CI): 0.079–0.450) and reoperation rates (OR: 0.182, 95%CI: 0.069–0.434). Anchor-guided localization (n = 52, 1 RCT) significantly lowered margin positivity (OR: 0.229, 95%CI: 0.050–0.938) and magnetic-marker localization improved patient satisfaction (OR: 0.021, 95%CI: 0.001–0.548). There was no difference in operation duration, overall complications, haematoma, seroma, surgical site infection rates, or specimen size/vol/wt between methods.

Conclusion

USGL and AGL are non-inferior to WGL for the localization of non-palpable breast cancers. The reported data suggests that these techniques confer reduced margin positivity rates and requirement for re-operation. However, caution when interpreting results relating to RCTs with small sample sizes and further validation is required in larger prospective, randomized studies.

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Ultrasound-guided (USGL) and anchor-guided (AGL) localization had optimal outcomes.

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These methods significantly lowered margin positivity (odds ratio: 0.192 & 0.229).

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However, small sample sizes in trials evaluating USGL and AGL limit these results.

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Operation duration, complications, or specimen data were comparable for all methods.

From the Reading Room to Operating Room: Retrospective Data and Pictorial Review After 806 SCOUT Placements

OBJECTIVE

Non-wire localization techniques are becoming more common. SCOUT surgical guidance system has been shown to increase flexibility in scheduling patients for surgery. The objective of this article is to provide institutional experiences with pictorial review after placement of 806 SCOUT devices.

MATERIALS AND METHODS

Radiology procedure reports of SCOUT device placements from January 11, 2018 to May 19, 2020 were reviewed to assess demographics of patient population, imaging method of placement, size of reflector delivery system used, placement approach, and time spent in the radiology suite or Turn Around Time (TAT). TAT was compared to that of wire placement using a Two-tailed Mann-Whitney U Test. Reports were assessed for those with absent signal at time of placement. In cases where signal was absent, migration was found, or complications noted, further case review was performed using the Electronic Medical Record to assess whether the devices were successfully retrieved.

RESULTS

There were 806 total SCOUT placements identified from radiology procedure reports in patients aged 12-92 with 64.3% (518/806) placed using ultrasound-guidance and 35.7% (288/806) by mammographic-guidance. The most common delivery device was a 7.5 cm needle. Only 0.9% (7/806) of SCOUT reflectors were >1cm from target, all of which were successfully excised. After radiology placement, signal was not heard in 1.4% (9/806) of cases and individual case review revealed that all were successfully excised. In 2019, TATs of SCOUT procedures were significantly lower than TATs from wire localizations (P = 0.00024).

CONCLUSIONS

SCOUT localization for breast surgery can provide solutions to problems encountered by patients and providers. A year after implementation, SCOUT use was found to result in shorter TATs in radiology. In addition, 100% of devices that were either migrated or inaudible at the time of radiology placement were successfully excised.