The clinical role of N-isopropyl-p-[123I]-iodoamphetamine single photon emission computed tomography in the follow-up of choroidal melanoma after radiotherapy.

BACKGROUND

Single photon emission computed tomography (SPECT) images with N-isopropyl-p-[123I]-iodoamphetamine (123I-IMP) have recently been used for the sensitive and specific detection of melanoma.

CASES

Using 123I-IMP SPECT, we observed three patients over a period of 18 months in whom choroidal melanoma had been diagnosed. Two underwent radiotherapy (cyber knife) in our clinic; the other patient was referred to us after 8 months of proton beam irradiation at another clinic.

OBSERVATIONS

In two of the three cases, no metastasis or tumor recurrence has been observed up to the present time. In these individuals, the average 123I-IMP uptake in the pathological eye gradually and progressively decreased after radiotherapy to levels seen in the fellow eye. One eye of the three patients examined here, however, exhibited tumor recurrence in the ciliary body as well as hepatic metastasis 12 months after radiation treatment. In the pathological eye of this patient, the average 123I-IMP uptake gradually decreased, but never reached the levels in the fellow eye during the observation period.

CONCLUSIONS

123I-IMP SPECT is a useful examination method not only for diagnosis but also for the follow-up of patients with choroidal melanoma.