Radioisotope-guided surgery in patients with pheochromocytoma and recurrent medullary thyroid carcinoma: a comparison of preoperative and intraoperative tumor localization with histopathologic findings.
BACKGROUND
The objective of this study was to appraise the detection of metastases of medullary thyroid carcinoma (MTC) and pheochromocytoma using radioguided surgery (RGS) and to compare the results with external imaging modalities, surgical palpation, and histopathologic findings.


METHODS
Twenty-five patients with recurrent MTC underwent preoperative scintigraphic imaging with 500 megabecquerels (MBq) of technetium 99m(V)-dimercaptosuccinic acid [(99m)Tc(V)-DMSA] and 222 MBq of indium 111 ((111)In)-pentetreotide. The radiopharmaceutical that showed the greatest preoperative tumor uptake was selected for intraoperative RGS. Surgery was performed 24 hours after the administration of (111)In-pentetreotide or 4 hours after the injection of (99m)Tc(V)-DMSA. Furthermore, three male patients underwent surgery who suffered from recurrent pheochromocytoma (injection of 180 MBq iodine 123-labeled metaiodobenzylguanidine [(123)I-MIBG] 4--5 hours before surgery).


RESULTS
Overall, lesion detection sensitivities in patients with MTC for computed tomography, (111)In-pentetreotide, and (99m)Tc(V)-DMSA were 32%, 34%, and 65%, respectively. Surgical palpation identified lymph node metastases of recurrent MTC with a sensitivity of 65%, whereas RGS localized 64 malignant lesions (sensitivity, 97%). Altogether, 71 lesions could be excised, 5 of which were adjudged false positive with respect to MTC metastases. Both surgical palpation and RGS localized all paravertebral subdiaphragmatic lesions (size > or = 2 cm) of recurrent pheochromocytoma seen in the preoperative MIBG scan.


CONCLUSIONS
RGS was capable of localizing more and smaller metastases of MTC compared with conventional imaging modalities and surgical palpation. However, the relatively high radioligand accumulation in the kidneys ((111)In-pentetreotide) and the dense hepatic and biliary signals using MIBG limited their use for intraoperative detection of tumors in the area of the adrenal gland.
Adams
S
S
Department of Nuclear Medicine, Johann Wolfgang Goethe University Medical Center, Frankfurt/Main, Germany. adams@em.uni-frankfurt.de
Acker
P
P
Lorenz
M
M
Staib-Sebler
E
E
Hör
G
G
D000328:Adult; D000368:Aged; D018276:Carcinoma, Medullary / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007205:Indium Radioisotopes; D008024:Ligands; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009362:Neoplasm Metastasis / Q000175:diagnosis*; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D010673:Pheochromocytoma / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D011300:Preoperative Care; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D012680:Sensitivity and Specificity; D019783:Technetium Tc 99m Dimercaptosuccinic Acid; D013964:Thyroid Neoplasms / Q000000981:diagnostic imaging* / Q000473:pathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome
D007205:Indium Radioisotopes; D008024:Ligands; D019275:Radiopharmaceuticals; D019783:Technetium Tc 99m Dimercaptosuccinic Acid