Role of SPECT-CT somatostatin-receptor scintigraphy in the management of Medullary Thyroid Cancer (MTC)

Date 21 October 2018
Event ESMO 2018 Congress
Session Poster display session: Basic science, Endocrine tumours, Gastrointestinal tumours - colorectal & non-colorectal, Head and neck cancer (excluding thyroid), Melanoma and other skin tumours, Neuroendocrine tumours, Thyroid cancer, Tumour biology & pathology
Topics Thyroid Cancer
Imaging
Presenter Sonya Sergieva
Citation Annals of Oncology (2018) 29 (suppl_8): viii645-viii648. 10.1093/annonc/mdy302
Authors S. Sergieva1, M. Atanasova2, A. Fakirova3, S. Velchova4
  • 1Nuclear Medicine, Specialized Hospital for Active Treatment in Oncological Diseases-Sofia City, 1784 - Sofia/BG
  • 2Medical Oncology, UH "City Clinic", 1784 - Sofia/BG
  • 3Pathology, Military Medical Academy, 1341 - Sofia/BG
  • 4Medical Oncology, Sofia Cancer Center, 1784 - Sofia/BG

Abstract

Background

The MTC arises from the parafollicular, calcitonin-secreting malignant transformed thyroid C-cells who express on the surface somatostatin SSTR receptors. The most of aggressive locally advanced/metastatic MTC tumors, found to be positive for RET proto-oncogene mutation, are treated with Vandetanib. SPECT-CT somatostatin-receptor scintigraphy with 99mTc-Tektrotyd should be considered for MTC imaging before and after therapy for exact staging and follow-up of the disease due to its highly sensitivity and specificity for detection of neuroendocrine tumors, expressed SSTR. The aim of this study was to evaluate clinical role of SPECT-CT scintigraphy with 99mTc-Tektrotyd in the management of patients with MTC.

Methods

25pts (7M;18F) with MTC were studied; whole body somatostatin scintigraphy followed by target SPECT-CT studies were performed 2-4 hrs post i.v.inj. of 740 MBq 99mTc-Tektrotyd (Polatom). SPECT-CT camera Symbia T2, Siemens was used. Three of them were studied for initial pre-operative N/M-staging, 17 were follow-up after surgery. In 5 patients with metastatic disease SPECT-CT with 99mTc-Tektrotyd were performed before and after target therapy with Caprelsa (Vandetanib), 300mg/d orally.

Results

Initial pre-operative staging showed 3 positive results for the primary tumor and metastatic lymph nodes and 2 false negative imaging of small 1-4 mm lung metastases. True negative results were obtained in 5 cases after thyroidectomy. True positive results were obtained in 17 cases with local recurrence in the thyroid bed, lymphadenopathy, osteolytic bone metastases, lung and subcutaneous lesions. False positive result was in 1 case with benign ovary cyst. Plasma levels of calcitonin vary from 94 to 5496 pg/ml in all 17 patients with local recurrence and/or metastatic lesions. In 5/17 cases SPECT-CT studies were used to evaluate effect of target therapy, respectively: partial response – in 2 cases, stable disease – in 2 cases and progressive disease – in 1 cases.

Conclusions

SPECT-CT somatostatin-receptor scintigraphy with 99mTc-Tektrotyd is very useful functional imaging modality in patients with MTC in order to determinate personalized therapeutic disease approach.

Clinical trial identification

Legal entity responsible for the study

Sonya Sergieva.

Funding

Has not received any funding.

Editorial Acknowledgement

Disclosure

All authors have declared no conflicts of interest.