Follow-up of Melanoma using PET/CT

Recommendations by Stage

• The National Comprehensive Cancer Network recommends that routine imaging exams like CT, PET/CT, or MRI are not recommended for patients with stage I-II melanoma 1, 3
• For patients with stage I-II, these exams should only be used to investigate specific signs or symptoms 2, 4
• For patients with stage IIB-IIC, a chest radiograph is optional 3, 4
• The National Comprehensive Cancer Network recognizes the low yield of screening CT or PET/CT exams for patients with stage III melanoma 1, 2
• In the absence of conclusive data, the extent of imaging is left to the discretion of the treating physician 1, 3
• For patients with clinically positive lymph nodes in stage III, it is appropriate to confirm suspected regional metastatic disease, preferably with fine-needle aspiration (FNA) or open biopsy of the clinically enlarged lymph node 1, 2
• A pelvic CT is recommended to rule out associated pelvic or retroperitoneal lymphadenopathy in cases of inguino-femoral lymphadenopathy 3, 4
• The majority of the NCCN panel also approved CT chest/abdomen, PET/CT, and/or brain MRI 3, 4
• For patients with distant metastatic disease (stage IV), all panel members agree on the opportunity to confirm suspected metastatic disease with FNA (preferred) or open biopsy of the lesion 3, 4
• CT chest/abdomen/pelvis, with or without PET/CT, should be considered to define the extent of disease in stage IV 3, 4
• Since patients with metastatic melanoma have a high incidence of brain metastases, a brain MRI or CT with contrast should be performed 3, 4

Utility of PET/CT in Follow-up

• PET/CT has shown low yield and poor sensitivity in detecting metastatic disease in patients with clinically localized melanoma 5, 6
• In patients with more advanced stage III disease, PET/CT may be more useful 7, 8
• PET/CT can help characterize lesions deemed indeterminate on CT and can visualize areas of the body not studied with routine body CTs (e.g., arms, legs) 1, 2

Considerations on Diagnostic Performance

• The use of PET/CT in follow-up varies significantly among medical institutions 1, 3
• False-positive results are common and can lead to unnecessary invasive procedures or patient anxiety 7, 1
• There is no consensus on the optimal timing, frequency of follow-up visits, or utility of imaging and blood tests for patients with resected melanoma 9