Abstract
Purpose :
Metastases that are already present at the time of initial diagnosis of uveal melanoma (UM) are rare, occurring in only ~3% of patients. There is no consensus on the ideal imaging fields for the initial systemic staging evaluation. Imaging that is too limited may miss cases of metastatic disease, while extraneous imaging identifies incidental findings that lead to unnecessary tests, and adds cost to the healthcare system. The purpose of this study is to identify which imaging fields (e.g., abdomen, chest and abdomen, etc.) are necessary and sufficient to identify cases of synchronous metastatic disease at the time of initial staging. A secondary goal was to identify the imaging modality (e.g. computed tomography [CT], magnetic resonance imaging [MRI], positron emission tomography [PET], etc.) that is most effective at identifying definite metastatic lesions.
Methods :
100 consecutive patients with a new diagnosis of UM were included. The field and modality of each initial staging imaging study were recorded, as were the findings, including incidental findings, as well as the subsequent imaging and invasive testing that ensued.
Results :
2/100 patients could not get imaging due to insurance issues. 90/98 patients (91.8%) had imaging with CT alone. Of these 90, all included the abdomen, 80 also included the chest, and 32 included the chest/abdomen/pelvis. 7 patients were initially imaged with whole-body PET-CT, and 1 patient with MRI abdomen/CT chest. 3 patients were found to have lesions on the initial staging imaging that was ultimately confirmed to be UM metastasis. 2/3 had metastases involving the liver only, and 1 with widespread metastatic disease (including both liver and lungs). No patients had metastases outside the chest and abdomen without also having metastases within the chest/abdomen imaging fields, and no metastases were identified on PET that were not also visible on the CT component.
Conclusions :
Initial staging imaging for UM that includes the chest and abdomen identified all cases of metastatic disease. Metastases outside the chest/abdomen (such as pelvis or extremities) were only seen in the context of widespread metastatic disease. These data suggest that imaging of just the chest and abdomen using CT alone is sufficient to identify cases of synchronous metastases, while including the pelvis and extremities, or using PET, adds little value to the initial staging work-up.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.