Routine preoperative 111In-octreotide scintigraphy in patients with medullary thyroid cancer

Abstract

Surgery is the only potential cure for patients with medullary thyroid carcinoma (MTC). Preoperative ultrasound, computed tomography and magnetic resonance imaging are not sensitive enough for detection of microscopic disease. The aim of this study was to investigate if routine preoperative (111)In-labelled (DTPA-D-Phe(1))-octreotide scintigraphy (SRS) could be used as a staging procedure in planning primary surgery in patients with MTC. This study included patients with primary sporadic clinically overt MTC diagnosed between 1996 and 2009. All patients underwent conventional imaging of neck and thorax and SRS prior to standardised surgery. The findings on SRS were correlated to the findings on conventional imaging, histopathology and to postoperative biochemical results and survival. A total of 19 patients with sporadic MTC were enrolled. Median follow-up was 77(9-184) months. SRS visualised the primary tumour in 16 (84%) patients. Fifteen (79%) patients had locoregional lymph node metastases, but SRS detected metastatic lesions in only 8 (53%) patients. In three patients with distant spread, SRS failed to detect metastatic lesions in two. At latest follow-up, six (32%) patients had died, nine (47%) patients were alive with elevated tumour markers, and four (21%) patients were considered in complete biochemical remission. This study provided further evidence that SRS, compared to conventional imaging, is fairly sensitive for detection of primary MTC but not metastatic disease. Although preoperative SRS may be of prognostic value, there is no indication for its routine use as a staging procedure in planning primary surgery.