Location of functioning metastases from differentiated thyroid carcinoma by simultaneous double isotope acquisition of I-131 whole body scan and bone scan.
In a young patient with differentiated thyroid carcinoma (DTC), previously submitted to total thyroidectomy and I-131 therapy for ablation of thyroid remnant, a follow-up 1-131 diagnostic whole body scan (WBS) demonstrated four small abnormal I-131 uptake areas. Two of these were projected over the thoracic region and corresponded to lung nodules, as later demonstrated by lung computerized tomography (CT)-scan. The remaining two areas were found in the lumbar-pelvic region, but their precise location could not be determined. Standard bone Rx examination and bone scan were negative. After I-131 therapy, we simultaneously acquired a I-131 WBS and a Tc-99m oxidronate bone scan by setting a dual window on the gamma camera. Comparing the I-131 and bone images we were able to identify the 4th lumbar vertebra and right ilium as the bone segments to be studied by a radiological approach. Eventually, the thin slice CT-scan demonstrated the presence of two small osteolytic lesions in these areas. In conclusion, the simultaneous acquisition of images both from I-131 and a bone-seeking agent may be useful to locate functioning bone metastases from DTC.
Ceccarelli
C
C
Department of Endocrinology, University of Pisa, Pisa, Italy. claudiac@endoc.med.unipi.it
Bianchi
F
F
Trippi
D
D
Brozzi
F
F
Di Martino
F
F
Santini
P
P
Elisei
R
R
Pinchera
A
A
D000328:Adult; D002291:Carcinoma, Papillary / Q000175:diagnosis* / Q000556:secondary*; D006801:Humans; D007457:Iodine Radioisotopes; D008297:Male; D011877:Radionuclide Imaging; D019275:Radiopharmaceuticals; D013125:Spinal Neoplasms / Q000175:diagnosis* / Q000556:secondary*; D013669:Technetium Tc 99m Medronate / Q000031:analogs & derivatives*; D013964:Thyroid Neoplasms / Q000473:pathology*; D014057:Tomography, X-Ray Computed
D007457:Iodine Radioisotopes; D019275:Radiopharmaceuticals; C024226:technetium Tc 99m hydroxymethylene diphosphonate; D013669:Technetium Tc 99m Medronate