Imaging Recommendations for Melanoma

Staging and Diagnostic Recommendations

The National Comprehensive Cancer Network recommends that routine imaging exams like CT, PET/CT, or MRI should not be used for patients with localized melanoma in stages I-II, but should be considered for patients with stage III disease, particularly those with clinically positive lymph nodes or in-transit disease 1, 2, 3
For patients in stages I-II, these exams should only be used to investigate specific signs or symptoms 2, 3
For patients in stages IIB-IIC, a chest radiograph is optional 2, 3
For patients in stage III with clinically evident disease (palpable lymph nodes), 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 scan is recommended in cases of inguino-femoral lymphadenopathy to rule out associated pelvic or retroperitoneal lymphadenopathy 1, 2
Most experts also approve the use of CT chest/abdomen, PET/CT, and/or brain MRI for patients in stage III 2, 4
For patients with distant metastatic disease (stage IV), all experts agree on the opportunity to confirm suspected metastatic disease with FNA (preferred) or open biopsy of the lesion 2
CT chest/abdomen/pelvis, with or without PET/CT, should be considered to define the extent of disease in stage IV 2, 5

PET/CT has shown low yield and poor sensitivity in detecting metastatic disease in patients with clinically localized melanoma 3, 4
In patients with more advanced stage III disease, PET/CT may be more useful 3, 4
PET/CT can help characterize lesions considered indeterminate on CT and can visualize areas of the body not studied with routine body CT scans (e.g., arms, legs) 3, 4

The use of PET/CT in follow-up varies significantly between medical institutions 4
False-positive results are common and can lead to unnecessary invasive procedures or patient anxiety 4