[(18)F]Fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) physiologic imaging of choroidal melanoma: before and after ophthalmic plaque radiation therapy.
OBJECTIVE
To evaluate changes in [(18)F]fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) standardized uptake values (SUV) in uveal melanoma before and after plaque brachytherapy.


METHODS
A cohort of 217 patients diagnosed with uveal melanoma and eligible for ophthalmic plaque brachytherapy underwent preoperative PET/CT to evaluate their intraocular tumor and screen for metastasis. Subsequent to undergoing plaque brachytherapy, patients' PET/CT SUV were periodically reevaluated over 42 months.


RESULTS
In this series, 37 (17%) choroidal melanoma patients were found to have an SUV of >2.0. Of these, 18 patients were able to undergo interval follow-up PET/CT scanning. There were 3 patients with T2, 11 patients with T3, and 4 patients with T4 melanomas according to 7th edition AJCC-UICC criteria. Mean apical thickness was 8.8 mm (range, 3-12.3 mm), and the largest mean tumor diameter was 15.1 mm (range, 12-19.9 mm). The mean initial SUV was 3.7 (range, 2.1-7.3). Patients were followed for a median 16 months (range, 6-42 months). The median time to a tumor SUV of 0 was 8.0 months (range, 6-18 months). There was one case of one interval increase in SUV that diminished after circumferential laser treatment.


CONCLUSIONS
Intraocular PET/CT imaging provides a physiological assessment of tumor metabolism that can be used to evaluate changes after treatment. In this study, ophthalmic plaque radiation therapy was associated with extinguished tumor PET/CT SUV over time. PET/CT imaging can be used to assess choroidal melanomas for their response to treatment.
Finger
Paul T
PT
The New York Eye Cancer Center, New York City, New York 10065, USA. pfinger@eyecancer.com
Chin
Kimberly J
KJ
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001918:Brachytherapy / Q000379:methods*; D002830:Choroid Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000493:pharmacokinetics; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008545:Melanoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000473:pathology; D009367:Neoplasm Staging; D010165:Palladium / Q000627:therapeutic use; D049268:Positron-Emission Tomography / Q000379:methods*; D011868:Radioisotopes / Q000627:therapeutic use; D019275:Radiopharmaceuticals / Q000493:pharmacokinetics; D012189:Retrospective Studies; D014057:Tomography, X-Ray Computed / Q000379:methods*; D047368:Tumor Burden; D014604:Uveal Neoplasms / Q000000981:diagnostic imaging / Q000473:pathology / Q000532:radiotherapy; D000098943:Uveal Melanoma
D011868:Radioisotopes; D019275:Radiopharmaceuticals; D019788:Fluorodeoxyglucose F18; D010165:Palladium