Recurrence of Melanoma After Initial Treatment: Diagnostic Performance of FDG PET in Posttreatment Surveillance
In malignant melanoma, recurrence is often observed in distant areas from the primary site. While FDG PET is a sensitive imaging for detecting malignant lesions, the role of FDG PET in posttreatment surveillance period has not been investigated sufficiently. The aim of this study was to evaluate the value of PET during posttreatment surveillance in melanoma.
A total of 76 melanoma patients who underwent FDG PET during surveillance period after completion of the first treatment were retrospectively enrolled. PET scans were grouped according to the purpose and clinical situations, routine surveillance, or evaluating clinical suspicion. Final diagnosis of recurrence was determined by complete clinical evaluation or long-term follow-up. In each situation, the diagnostic role of FDG PET was assessed.
A total of 143 scans of 76 patients were analyzed: 51 for clinical suspicion and 92 for routine surveillance. In the clinical suspicion group, PET correctly diagnosed non-recurrence in 10 cases (20%). In routine surveillance group, 16 cases (17%) presented recurrence, all of which was correctly diagnosed on PET. NPV and PPV were 100% and 76%, respectively. In subgroup analysis, sensitivity and NPV were higher in the low-risk group (stages I–IIA) than in the high-risk group (stages IIB–IV), while specificity and PPV were higher in the high-risk group.
In conclusion, FDG PET is an effective diagnostic tool in posttreatment surveillance of melanoma. Even in cases without clinical suspicion, melanoma recurs in a considerable proportion of patients, which can be sensitively diagnosed on PET.
KeywordsFDG PET-CT Melanoma Surveillance
Compliance with Ethical Standards
Conflict of Interest
Hwan Hee Lee, Jin Chul Paeng, Gi Jeong Cheon, Dong Soo Lee, June-Key Chung, and Keon Wook Kang declare that they have no conflict of interest.
All procedures performed in studies involving human participants were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards.
The study design of the retrospective analysis and exemption of informed consent were approved by the Institutional Review Board of the Seoul National University Hospital (H-1804-008-932).
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