Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2025 Jul;32(7):5300-5305.
doi: 10.1245/s10434-025-17330-9. Epub 2025 Apr 25.

The Use of Radar-Guided Localization to Identify Metastatic Melanoma After Neoadjuvant Immunotherapy

Michelle M Dugan  1 , Kate E Beekman  2 , Danielle K DePalo  1   3 , Lily M Parker  2 , Kelly M Elleson  1 , John E Mullinax  4   5 , Amod A Sarnaik  1   5 , Vernon K Sondak  1   5 , Matthew C Perez  1   5 , Jonathan S Zager  6   7   8
Affiliations

The Use of Radar-Guided Localization to Identify Metastatic Melanoma After Neoadjuvant Immunotherapy

Michelle M Dugan et al. Ann Surg Oncol. 2025 Jul.

Abstract

Background: Radar-guided localization (RGL) is a nonradioactive, wireless technique used to localize target lesions for resection via a percutaneously placed intra-tumoral reflector and a handheld probe intraoperatively. RGL plays a critical role in the setting of nonpalpable lesions. This study describes RGL for patients undergoing neoadjuvant immunotherapy (NEO) for metastatic melanoma.

Methods: A retrospective review included stage III-IV melanoma patients who underwent NEO followed by metastasectomy with RGL.

Results: Twenty-three patients were identified. Median age was 65 years; ten were female. Twenty patients had a radiographic response to NEO in the target lesion, and three demonstrated progression on NEO. Fourteen lesions were palpable prior to NEO, and five (36%) remained palpable after NEO. Reflectors were successfully retrieved in all 23 patients at a median of 99 (range 1-282) days after RGL placement. Operations included 18 targeted index lymph node dissections, two complete therapeutic lymph node dissections, and three subcutaneous/soft tissue nodule resections. Nineteen patients had a major pathologic response to NEO (0 to <10% viable tumor), one patient had a partial response (10-50% viable tumor), and three patients had a pathologic nonresponse (>50% viable tumor).

Conclusions: In this series of RGL and resection of metastatic melanoma after NEO, two-thirds of the index lesions became nonpalpable after NEO, and RGL allowed for accurate intraoperative identification and retrieval at any interval (days to months). Specific target lesion marking with fiducial markers for intraoperative identification and targeted resection allows the treating team to examine pathologic response and dictate further therapy on an individualized basis.

Keywords: Intraoperative localization; Metastasectomy; Metastatic melanoma; Neoadjuvant therapy; Radar reflector; SAVI; Surgical guidance; Tumor localization.

PubMed Disclaimer

Conflict of interest statement

Disclosures: Dr. Michelle M. Dugan, Kate E. Beekman, Dr. Danielle K. DePalo, Lily M. Parker, and Dr. Kelly M. Elleson have no conflicts of interest or financial ties to disclose. Dr. John E. Mullinax is an inventor on intellectual property that Moffitt Cancer Center has licensed to Iovance Biotherapeutics. He participates in sponsored research agreements with Iovance Biotherapeutics, Intellia Therapeutics, and SQZ Biotech that are not related to this research. He has received research support that is not related to this research from the following entities: NIH-NCI (K08CA252642), Ocala Royal Dames, and V Foundation. Dr. Mullinax has received consulting fees from Merit Medical, Lyell Therapeutics, and Iovance Biotherapeutics. Dr. Amod A. Sarnaik is a co-inventor on a patent application with Provectus Biopharmaceuticals. Dr. Sarnaik has received consulting fees from Iovance Biotherapeutics, Guidepoint, Defined Health, Huron Consulting Group, KeyQuest Health Inc, Istari, Rising Tide, and Gerson Lehrman Group. Dr. Sarnaik has received speaker fees from the Society for Immunotherapy of Cancer, Physicians’ Educational Resource (PER) LLC, Medscape, and Medstar Health. Dr. Vernon K. Sondak serves in a consulting or advisory role for Merck/Schering Plough, Novartis, Bristol Myers Squibb, Regeneron, Iovance Biotherapeutics, Alkermes, Ultimovacs, Genesis Drug Discovery & Development, and Sun Pharma. He has received research funding to the institution (Moffitt Cancer Center) from Neogene Therapeutics, Turnstone Bio, and Skyline Diagnostics, not related to this research. Dr. Matthew C. Perez has received consulting fees from Replimune and Guidepoint. Dr. Jonathan S. Zager has received payments from Delcath Systems – Medical Advisory Board. He has received fees from Philogen, Merit Medical, Castle Biosciences, Menarini Silicon Biosystems, Replimune and Merck. His department receives research funding from Philogen, SWOG, Delcath Systems, and Provectus. The funders had no role in the design of the study; in the collection, analyses, or interpretation of data; in the writing of the manuscript; or in the decision to publish the results. Ethical Approval: This research was conducted under the approval of the Advarra IRB, approval number Pro00061990 (FWA 00023875), located in Columbia, Maryland (6100 Merriweather Drive, Suite 600, Columbia, MD, USA 21044), approved on March 9, 2022. The Advarra IRB deemed the study as exempt, and patient informed consent was not required

Similar articles

See all similar articles

Cited by

References

    1. NCCN. National comprehensive cancer network (nccn) clinical practice guidelines in (nccn guidelines®), melanoma: Cutaneous. Nccn; 2024. Accessed December 16, 2024.
    1. Reijers ILM, Menzies AM, van Akkooi ACJ, et al. Personalized response-directed surgery and adjuvant therapy after neoadjuvant ipilimumab and nivolumab in high-risk stage III melanoma: the Prado trial. Nat Med. 2022;28(6):1178–88. https://doi.org/10.1038/s41591-022-01851-x . - DOI - PubMed
    1. Schermers B, Franke V, Rozeman EA, et al. Surgical removal of the index node marked using magnetic seed localization to assess response to neoadjuvant immunotherapy in patients with stage iii melanoma. Br J Surg. 2019;106(5):519–22. https://doi.org/10.1002/bjs.11168 . - DOI - PubMed
    1. de Vries M, Hoekstra HJ, Hoekstra-Weebers JE. Quality of life after axillary or groin sentinel lymph node biopsy, with or without completion lymph node dissection, in patients with cutaneous melanoma. Ann Surg Oncol. 2009;16(10):2840–7. https://doi.org/10.1245/s10434-009-0602-6 . - DOI - PubMed - PMC
    1. Beekman KE, DePalo DK, Parker LM, et al. Radar-guided localization and resection for metastatic nodal and soft tissue melanoma: a single-institution retrospective study. Cancer Control. 2024;31:10732748241237908. https://doi.org/10.1177/10732748241237907 . - DOI - PubMed - PMC

LinkOut - more resources