Whole-body 18 FDG PET/CT imaging for lymph node and metastatic staging of conjunctival melanoma

To evaluate 18-fluoro-2-deoxyglucose (FDG) whole-body positron emission tomography/computed radiographic tomography (PET/CT) for lymph node and metastatic staging of patients with conjunctival melanoma.

Fourteen patients with T3 (n = 13) and T4 (n = 1) conjunctival melanoma (as defined in Chapter 42 of the AJCC staging manual) were staged for metastatic disease with PET/CT imaging with fusion. The patients had lymph node and clinical staging evaluations before PET/CT imaging. PET/CT images were studied for the presence and distribution of metastatic conjunctival melanoma (determined by standardised uptake values) and later confirmed by biopsy. MRI imaging was performed if abnormalities were noted on PET/CT images.

Fourteen patients with conjunctival melanoma underwent PET/CT imaging. Seven were newly diagnosed (presurgical screening), and seven had undergone prior treatment (follow-up group). Only one patient with conjunctival melanoma (7.1%) was found to have metastatic disease on PET/CT imaging. Abnormal foci were found in the liver, lung, peritoneal cavity, lumbar spine as well as a supraclavicular node (T4N1M4). All liver function tests were normal. The mean length of follow-up after PET/CT imaging was 13 months (range 4-30 months).

PET/CT imaging did not reveal any regional or systemic metastasis among 14 patients with advanced, diffuse and multifocal disease.