Diagnostic value of 18F-FDG PET/CT in the follow-up of metastatic uveal melanoma.
To evaluate the accuracy of fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT) in detecting metastatic uveal melanoma (UM) using both per-patient and per-lesion analyses, while also characterizing lesion detectability across various metastatic sites.
In this retrospective study conducted from January 2011 to September 2024, UM participants underwent PET/CT scans for follow-up or suspected recurrence. The lesion uptake were quantified by maximum standardized uptake value (SUVmax). Pathology and clinical follow-up served as reference standard.
Fifty-five participants (mean age, 49.2 ± 12.7; 26 females) were evaluated, and the average recurrent time was 30.7 months (IQR, 18.0-89.2). On per-patient level, 31 patients (56%) were confirmed to have metastatic lesions through pathology or clinical follow-up, of which 28/31 (90.3%) patients were successfully detected by 18F-FDG PET/CT and 3/31 (9.7%) patients with liver metastases were missed. Seventeen of 31 patients (54.8%) had multiple organ involvement. On per-lesion level, a total of 270 lesions were comfirmed, of which 245 (90.7%) were detected by 18F-FDG PET/CT, including metastasis to liver (103 of 128, 80.5%), bone (64 of 64, 100%), lymph node (24 of 24, 100%), lung (33 of 33, 100%), and other uncommen sites (21 of 21, 100%). The detection ability of 18F-FDG for liver metastases was positively correlated with the diameter of the lesions (r2 = 0.671, p = 0.000). 18F-FDG successfully detected all bone, lymph node, and lung metastases, with 30 of 64 (46.9%) bone metastases showing no changes on CT and 12 of 24 (50%) lymph node metastases being less than 10 mm, making them prone to misdiagnosis on CT.
18F-FDG PET/CT may be a useful diagnostic tool in detecting metastatic UM, especially for early bone metastases and small lymph nodes. Added contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) may be still needed for tiny liver metastases detection.
In this retrospective study conducted from January 2011 to September 2024, UM participants underwent PET/CT scans for follow-up or suspected recurrence. The lesion uptake were quantified by maximum standardized uptake value (SUVmax). Pathology and clinical follow-up served as reference standard.
Fifty-five participants (mean age, 49.2 ± 12.7; 26 females) were evaluated, and the average recurrent time was 30.7 months (IQR, 18.0-89.2). On per-patient level, 31 patients (56%) were confirmed to have metastatic lesions through pathology or clinical follow-up, of which 28/31 (90.3%) patients were successfully detected by 18F-FDG PET/CT and 3/31 (9.7%) patients with liver metastases were missed. Seventeen of 31 patients (54.8%) had multiple organ involvement. On per-lesion level, a total of 270 lesions were comfirmed, of which 245 (90.7%) were detected by 18F-FDG PET/CT, including metastasis to liver (103 of 128, 80.5%), bone (64 of 64, 100%), lymph node (24 of 24, 100%), lung (33 of 33, 100%), and other uncommen sites (21 of 21, 100%). The detection ability of 18F-FDG for liver metastases was positively correlated with the diameter of the lesions (r2 = 0.671, p = 0.000). 18F-FDG successfully detected all bone, lymph node, and lung metastases, with 30 of 64 (46.9%) bone metastases showing no changes on CT and 12 of 24 (50%) lymph node metastases being less than 10 mm, making them prone to misdiagnosis on CT.
18F-FDG PET/CT may be a useful diagnostic tool in detecting metastatic UM, especially for early bone metastases and small lymph nodes. Added contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI) may be still needed for tiny liver metastases detection.