Exp Clin Endocrinol Diabetes 2013; 121 - OP2_09
DOI: 10.1055/s-0033-1336617

[123I]Iodometomidate imaging in adrenocortical carcinoma

MC Kreissl 1, A Schirbel 2, M Fassnacht 3, H Hänscheid 2, FA Verburg 4, S Bock 5, W Saeger 6, P Knödler 7, C Reiners 2, AK Buck 2, B Allolio 5, S Hahner 5
  • 1Klinikum Augsburg, Nuclear Medicine, Augsburg, Germany
  • 2Universitätsklinik Würzburg, Nuclear Medicine, Würzburg, Germany
  • 3Universitätsklinik München, Klinikum Innenstadt, Endocrinology and Diabetology, München, Germany
  • 4Universitätsklinik Aachen, Nuclear medicine, Aachen, Germany
  • 5Universitätsklinik Würzburg, Endocrinology and Diabetology, Würzburg, Germany
  • 6Marienkrankenhaus Hamburg, Hamburg, Germany
  • 7Universitätsklinik Würzburg, Radiology, Würzburg, Germany

Context: Imaging with [123I]iodometomidate ([123I]IMTO) has been shown to diagnose adrenocortical lesions with high sensitivity and specificity.

Objective: Clinical utility of [123I]IMTO SPECT imaging in adrenocortical carcinoma (ACC).

Patients and Interventions: 61 patients with histologically confirmed ACC (ENSAT stage I n = 1, stage III n = 2, stage IV n = 58) received 185 MBq of the radiotracer [123I]IMTO. Sequential planar whole body scans until 24 hours p.i. and SPECT/CT hybrid imaging 4 – 6h p.i. were performed.

Main Outcome Measures: Sensitivity of [123I]IMTO imaging for detection of ACC lesions. Number of patients with metastatic disease non-invasively characterized as ACC by [123I]IMTO. Number of patients eligible for [131I]IMTO therapy.

Results: Of the 437 lesions detected by conventional imaging, 30% showed strong, 8% moderate and 62% no relevant tracer accumulation. 12 additional lesions were found by [123I]IMTO in 6 patients. 37 of the 61 (61%) patients had at least one [123I]IMTO-positive lesion. Cortisol and aldosterone secretion by ACC was positively correlated to [123I]IMTO uptake; cytotoxic chemotherapy and mitotane treatment did presumably not influence tracer uptake. 23 patients (37.7%) had radiotracer uptake in all lesions ≥2 cm and therefore were potential candidates for targeted systemic radiotherapy with [131I]IMTO.

Conclusion: [123I]IMTO detects both primaries and metatastatic lesions of ACC. However, a substantial percentage of lesions fails to show [123I]IMTO uptake. Based on [123I]IMTO imaging more than a third of patients are eligible for radionuclide therapy with [131I]IMTO.