gallium-ga-68-dotatate and Adenocarcinoma--Follicular

We report a woman with multifocal lesions suggestive of meningiomas in MRI, which also presented with high Ga-DOTATATE uptake in PET, a finding characteristic for meningioma. A whole-body staging due to a pathological fracture revealed multiple neoplastic lesions throughout the body without detection of a primary site. Subsequent pathological workup of a lung lesion revealed multifocal metastases from follicular thyroid cancer despite thyroidectomy 10 years ago (without pathological finding), and posttreatment scans after radioiodine therapy confirmed the multiple brain lesions to be metastases as well. Our case shows that epidural metastases from endocrine origin might represent a clinical pitfall in Ga-DOTATATE PET.

Topics: Adenocarcinoma, Follicular; Diagnosis, Differential; Epidural Neoplasms; Female; Humans; Meningeal Neoplasms; Meningioma; Organometallic Compounds; Positron-Emission Tomography

Somatostatin receptor (Sstr) scintigraphy with radiolabelled somatostatin analogues has been used extensively for the diagnosis and therapy of Sstr-expressing tumours. It has been shown that well-differentiated thyroid cancer (WDTC) cells have a high expression of Sstr2, Sstr3 and Sstr5. Hence, WDTC cells could be an ideal target for the evaluation of lesion uptake of Ga-68 DOTA-1-NaI3-octreotide (DOTA-NOC), which has a high affinity not only to Sstr2 but also to Sstr3 and Sstr5. The aim of the present study was to evaluate the value of Ga-68 DOTA-NOC as a target for Sstr2-expressing, Sstr3-expressing and Sstr5-expressing tumours in WDTC patients and to compare the results with those of Ga-68 DOTA-TATE in the same patient population.. Thirteen patients with WDTC were included in our study: nine with papillary thyroid cancer, three with Hurthle cell carcinoma and one with follicular thyroid carcinoma. All patients had elevated serum thyroglobulin levels and negative post-therapeutic I-131 whole-body scans, which were obtained after the last radioiodine treatment. All patients had undergone two consecutive PET imaging studies with Ga-68 DOTA-D-Phe1-Tyr3-octreotate (DOTA-TATE) and Ga-68 DOTA-NOC, respectively. All images were evaluated visually, and maximum standardized uptake values were calculated.. Both Ga-68 DOTA-TATE and Ga-68 DOTA-NOC PET images gave comparable results. Among the 13 patients, imaging with both Ga-68 DOTA-TATE and Ga-68 DOTA-NOC gave negative results in five (38%) patients and positive results in eight (62%) patients. A total of 45 lesions were identified on Ga-68 DOTA-TATE images and 42 on Ga-68 DOTA-NOC images; three lesions were missed. Lesion uptake was significantly higher on Ga-68 DOTA-TATE images. Maximum standardized uptake values of Ga-68 DOTA-TATE and Ga-68 DOTA-NOC were 12.9±9.1 and 6.3±4.1 (n=54, P<0.001), respectively.. Our study suggested that Ga-68 DOTA-TATE has a higher lesion uptake even in WDTC patients and may have potential advantage over Ga-68 DOTA-NOC.

Topics: Adenocarcinoma, Follicular; Adenoma, Oxyphilic; Adult; Aged; Antineoplastic Agents, Hormonal; Carcinoma; Carcinoma, Papillary; Female; Gallium Radioisotopes; Humans; Male; Middle Aged; Octreotide; Organometallic Compounds; Positron-Emission Tomography; Radiopharmaceuticals; Thyroid Cancer, Papillary; Thyroid Neoplasms; Tomography, X-Ray Computed