The new technology of combined transmission and emission tomography in evaluation of endocrine neoplasms

The clinical value of a novel technology of combined transmission and emiss ion tomography (TET) was assessed in patients with endocrine tumors. Method s: TET technology, which combines simultaneous acquisition of SPECT and CT images, using the same imaging device, allows correct fusion of images of b oth modalities. TET was performed on 27 patients with known dr suspected en docrine tumors. The radiopharmaceuticals used for the emission part of the study were chosen according to the tumor type: In-111-octreotide for patien ts with neuroendocrine tumors (n = 10), Tc-99m-sestamibi for patients with primary hyperparathyroidism (n = 8),I-131 for patients with thyroid cancer (n = 4),and I-123-metaiodobenzylguanidine and Se-75-cholesterol for patient s with adrenal masses (n = 3 and n = 2, respectively). The additional infor mation provided by TET compared with scintigraphy was assessed for both ima ge interpretation and clinical utility. Results: TET did not provide any ad ditional data in 16 patients (59%), including 5 patients with normal scinti graphy. In 11 patients (41%) with abnormal SPECT findings, TET improved ima ge interpretation by providing a better anatomic localization of SPECT-dete cted lesions. It showed unsuspected bone involvement in 4 patients, it iden tified the organs involved and the relationship of the lesions to neighbori ng structures in 5 patients, and it differentiated physiologic uptake from tumor uptake in 2 patients. TET provided additional information of clinical value in 9 patients (33%). It assisted in better planning of surgery in 2 patients with neuroendocrine tumors and in 2 patients with ectopic parathyr oid adenomas. II changed the treatment approach in 2 patients with neuroend ocrine tumors and 1 patient with thyroid carcinoma, and it altered prognosi s in 2 patients with thyroid malignancy. Conclusion: TET enhances the alrea dy unique role of nuclear medicine procedures in the assessment and managem ent of patients with endocrine neoplasms.