Pentavalent Tc-99m DMSA scintigraphy. Prospective evaluation of its role in the management of patients with medullary carcinoma of the thyroid.

Ten patients with suspected primary, recurrent or metastatic medullary carcinoma of the thyroid (MCT) were studied prospectively with Tc-99m(V) DMSA. Of these, two patients had primary disease, seven patients were asymptomatic but had persistent and serial elevations in serum calcitonin following previous thyroid resections for MCT, and one asymptomatic patient with normal serum calcitonin was studied because of suspected hilar nodes metastases. The serial calcitonin peak in the patients was 0.04-43ng/ml (normal less than 0.08ng/ml). Scintigraphy was considered positive in seven of the asymptomatic patients and equivocal in one. The two patients with primary disease had increased uptake before but not after thyroidectomy. Primary disease, localized recurrence and distant metastases in soft tissue (nine patients) and bone (one patient) were detected in these patients, and this resulted in early surgical resection (five patients) and radiotherapy (one patient). We conclude that Tc-99m(V) DMSA is a useful imaging agent in the evaluation of asymptomatic MCT patients with hypercalcitonemia.     

Technetium-99m tetrofosmin single photon emission computed tomography to detect metastatic papillary thyroid carcinoma in patients with elevated human serum thyroglobulin levels but negative I-131 whole body scan

AIM: The aim of this study was to evaluate the effectiveness of technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of the neck and chest to detect metastatic lesions in papillary thyroid carcinoma (PTC) after near total thyroidectomy and radioiodine (I-131) treatment in patients who present with elevated serum human thyroglobulin (hTg) levels but negative I-131 whole body scan (WBS). MATERIALS AND METHODS: Twenty patients with PTC treated by near total thyroidectomy and I-131 treatments were included in this study. All 20 patients had negative I-131 WBS results and elevated hTg levels (hTg 2.0 microIU/ml) under thyroid-stimulating hormone (TSH) stimulation (TSH 30 microIU/ml). Nineteen of the 20 cases were confirmed to have metastases by operation/biopsy histopathological findings or clinical follow-up longer than 1 year by additional morphological imaging techniques. The remaining patient has been followed up closely and has been disease free for 10 months. Tc-99m TF SPECT was performed to detect metastatic lesions. RESULTS: Tc-99m TF SPECT demonstrated lesions in 11/19 patients; a sensitivity of 57.9%. Tc-99m TF SPECT failed to demonstrate lesions in eight patients including smaller lymph nodes and miliary lung metastases. CONCLUSIONS: We conclude that Tc-99m TF SPECT is a useful additional tool to detect metastatic lesions in PTC with elevated hTg but negative I-131 WBS. However, smaller lymph nodes and miliary lung metastases may be missed.     

Tc-99m(V) DMSA imaging. A new approach to studying metastases from breast carcinoma.

Combined Tc-99m MDP skeletal imaging and Tc-99m(V) DMSA whole body scans to detect metastases were performed during the follow-up of 30 patients who underwent surgery for breast carcinoma. Eight patients had normal Tc-99m MDP and Tc-99m(V) DMSA scans and were declared free of metastatic disease, further confirmed by no change in symptomatology over a 1-year follow-up period. Twenty-two patients had positive Tc-99m MDP scans with varied skeletal involvement. Tc-99m(V) DMSA scans showed matched areas of increased radiotracer concentration in bony metastases in 20 of these patients. Tc-99m(V) DMSA concentration was not seen in traumatic vertebral collapse or in coexistent osteoarthritic disease in vertebral metastatic involvement. Interestingly, Tc-99m(V) DMSA showed increased concentration in brain and liver metastases. Pentavalent Tc-99m(V) DMSA appears useful for detecting skeletal and soft-tissue metastases in breast carcinoma, and can improve the specificity of Tc-99m MDP bone scans in screening for bone metastases.     

Compare FDG-PET and Tc-99m tetrofosmin SPECT to detect metastatic thyroid carcinoma

RATIONALE AND OBJECTIVES: The effectiveness of 18-fluoro-2-deoxyglucose (FDG) positron emission tomography (PET) and technetium-99m tetrofosmin (Tc-99m TF) single photon emission computed tomography (SPECT) of neck and chest was evaluated to detect metastatic lesions in well-differentiated thyroid carcinoma after nearly total thyroidectomy and radioiodine (I-131) treatment who present with elevated serum human thyroglobulin levels but negative I-131 whole body scan. MATERIALS AND METHODS: Twenty-three patients with differentiated thyroid carcinoma who underwent nearly total thyroidectomy and I-131 treatments were included in this study. RESULTS: All of the 23 patients had negative I-131 whole body scan and elevated human thyroglobulin levels under thyroid-stimulating hormone stimulation. Metastatic lesions were detected by FDG-PET in 20 patients, while Tc-99m TF SPECT revealed metastatic lesions in only 11 of the 20 patients. Both FDG-PET and Tc-99m TF SPECT failed to demonstrate miliary pulmonary metastases in two of the remaining three patients. The other patient did not show any lesion on FDG-PET, Tc-99m TF SPECT, chest computed tomography, or other imaging techniques. CONCLUSION: This study demonstrated that FDG-PET is more sensitive than Tc-99m TF SPECT to detect metastatic lesions in differentiated thyroid carcinoma with elevated human thyroglobulin but negative I-131 whole body scan. However, miliary pulmonary metastases could be missed by the both techniques.     

Disappointing results with Tc-99m tetrofosmin for detecting medullary thyroid carcinoma metastases comparison with Tc-99m VDMSA and TI-201.

PURPOSE: This prospective study assessed the detectability of metastatic lesions by Tc-99m tetrofosmin in medullary thyroid carcinoma and to compare the results with Tc-99m penta dimercapto succinic acid (VDMSA) and TI-201. METHODS: A prospective study was performed on 24 patients (10 men, 14 women; ages 23 to 76 years) with medullary thyroid carcinoma after total thyroidectomy. Five cases were sporadic and 19 were familial. After the injection of 740 MBq (20 mCi) tetrofosmin, 740 MBq (20 mCi) VDMSA and 74 MBq (20 mCi) TI-201, whole-body scans and 5-minute static images of the head, neck, chest, abdomen and pelvis were obtained. All scintigraphic studies were compared with calcitonin levels, radiologic findings, histopathologic results, and clinical follow-up. RESULTS: Thirty-four metastatic sites were detected in 12 patients on the basis clinical, radiologic, and histopathologic findings. Patients were divided into three groups according to the calcitonin levels and scintigraphic findings. Group 1 consisted of patients with elevated calcitonin levels and positive scintigraphic findings. Among 34 metastatic sites, 30 could be detected with VDMSA. Only 21 and 20 metastatic sites could be visualized with TI-201 and tetrofosmin, respectively. All 30 lesions showed intense VDMSA uptake but only faint or no uptake with TI-201 and tetrofosmin. Patients in group 2 were accepted to have micrometastases. In this group, calcitonin was minimally elevated, and the results of all three scintigraphs were negative. Group 3 included patients with true-negative results. All patients had normal calcitonin levels and negative results of scintigraphic studies. CONCLUSIONS: Tetrofosmin has no role in the detection of medullary thyroid carcinoma metastases. These results show that VDMSA is clearly superior to TI-201 and tetrofosmin in the follow-up of patients with medullary thyroid carcinoma.     

Observations on the sequential use of Tc-99m phosphonate and Ga-67 imaging in untreated primary and secondary malignant tumors of the head and neck

Scintigraphy using both Tc-99m phosphonate and Ga-67 was performed in 55 cases of untreated primary and secondary tumors of the head and neck. In 21 patients with primary tumors of jaws, eye, tongue, or parotid gland, Ga-67 scintigraphy visualized the primary tumor in all cases and metastases in 12. Scintigraphy using Tc-99m phosphonate disclosed primary bone involvement in 12 cases and skeletal metastases in two. In eight of 13 patients with metastatic lesions of jaws and skull, bone scintigraphy showed skeletal metastases. In seven of these patients, Ga-67 scintigraphy detected the primary tumor and in 11 cases detected metastases. Bone scintigraphy disclosed skeletal metastases in six of 21 patients with malignant neck tumors. In 13 of these patients, Ga-67 scintigraphy visualized the primary tumor, whereas it showed metastases in seven. It is concluded that Ga-67 scintigraphy should be used in the investigation of untreated primary or secondary malignant tumors of the head and neck. Bone scintigraphy may be indicated as an additional study in selected cases only.     

Imaging of medullary carcinoma of the thyroid using 111In-labelled anti-CEA monoclonal antibody fragments.

The distribution of 111In-labelled anti-carcinoembryonic antigen (CEA) monoclonal antibody fragments [F(Ab')2] was studied in five patients either with known inoperable medullary carcinoma of the thyroid (MCT) or evidence of recurrence/metastases based on elevated calcitonin (hCT) levels. All five cases had elevated serum CEA levels and positive immunohistochemical stains for both hCT and CEA prior to scintigraphy. In two patients with identified inoperable disease both planar and SPECT scans were positive. In the remaining three patients, where the recurrence/metastatic sites were unknown, SPECT images were positive in two. Of these, only one had positive planar images. These results indicate that 111In-labelled anti-CEA F(ab')2 scintigraphy, especially in conjunction with SPECT, is useful for the diagnostic evaluation of patients with MCT. The limiting factor of this technique is the high level of non-specific uptake, particularly in the liver, but improvements in the specificity of newer anti-CEA antibodies and the ability to label these with 99Tcm is addressing this problem.     

The role of Tc-99m (V) DMSA scintigraphy in the evaluation of superscan on bone scintigraphy

PURPOSE: This study evaluated the biodistribution of Tc-99m (V) DMSA in patients with superscans on bone imaging and defined its role in differentiating the underlying cause. METHODS: Nine patients (five with metastatic and four with metabolic bone disease) with classical superscans were entered into the study. All patients had the necessary radiologic and biochemical studies and a final diagnosis was reached accordingly. Tc-99m (V) DMSA scintigraphy was performed 1 week after Tc-99m MDP whole-body bone imaging. RESULTS: In four of five patients with widespread skeletal metastases, Tc-99m (V) DMSA scan showed diffusely increased bone uptake. In the remaining patient, the Tc-99m (V) DMSA scan showed a normal distribution pattern. All patients with metabolic bone disease had increased bone uptake on Tc-99m (V) DMSA scans. CONCLUSION: Tc-99m (V) DMSA shows increased bone uptake in patients having a superscan appearance in metastatic or metabolic bone disease. Tc-99m (V) DMSA imaging may play a role in the evaluation of patients with equivocal bone scan findings for a superscan.     

Clinical importance of technetium-99m-methoxyisobutylisonitrile (MIBI) scintigraphy in differentiated thyroid carcinoma patients with elevated thyroglobulin levels and negative I-131 scanning results

AIMS AND BACKGROUND: The aim of this study was to evaluate the potential contribution of Tc-99m-MIBI scintigraphy to the follow-up of patients with differentiated thyroid carcinoma, who had elevated Tg levels and negative I-131 whole-body scan results. MATERIALS AND METHODS: In this retrospective study, we evaluated 28 patients with differentiated thyroid carcinoma, who had total or near total thyroidectomy followed by an ablative dose of I-131 at various time intervals (15 women, 13 men; mean age 43 +/- 17 years). All patients were treated with T4 suppression. After a mean follow-up period of 6.1 years (range 3-15) all patients were determined to have a high serum Tg concentrations (>2 ng/ml) and previous negative I-131 WBS results. All patients were examined for metastatic sites using Tc-99m-MIBI scan. Scans were visually evaluated for detecting lymph node metastases and/or local recurrence, lung metastases and skeletal metastases. RESULTS: Tc-99m-MIBI scan demonstrated lesions in 23 patients (83.3%). In five patients with negative Tc-99m-MIBI scan findings (FN results): Chest CT showed small-sized mediastinal LN metastases in 2 patients and lung metastases in another 2 patients (<1 cm). Neck CT showed small-sized cervical LN involvement in 1 patient. The sensitivity of detection for neck was 94.4%, for lung 63.6%, and for bone lesions 100%. For all scan sites taken together, the sensitivity of disease detection was 83.3%, the specificity was 50%, positive predictive value (PPV) was 96.2%, and finally negative predictive value (NPV) was 16.7%. CONCLUSION: We concluded that Tc-99m-MIBI scan should be considered as a supplementary scintigraphic method for the follow-up of patients with high serum Tg levels and negative I-131 WBS results, and it can help clinicians in making the decision to treat these patients.     

Concentration of Tc-99m MDP in ovarian carcinoma and its soft tissue metastases

A patient with ovarian carcinoma was evaluated for skeletal metastasis with a routine whole body bone scan. Although no bone metastases were visualized, there was dramatic accumulation of tracer in the soft tissues of the abdomen. CT revealed calcifying soft tissue metastases on the liver surface, the bowel serosa, and in the pelvis corresponding to the abnormal areas of Tc-99m MDP uptake. Tumor necrosis and ongoing calcification within the metastatic sites are possible explanations for this unusual soft tissue concentration of the bone-seeking radiopharmaceutical. In patients with metastatic ovarian carcinoma, careful review of extraosseous regions on bone scan images may provide valuable diagnostic information.     

Tc-99m PMT hepatobiliary scintigraphy in the differential diagnosis of extrahepatic metastases and hepatocellular carcinoma

PURPOSE: The authors evaluated the utility of hepatobiliary scintigraphy for tissue characterization of extrahepatic metastases from hepatocellular carcinoma (HCC) using Tc-99m N-pyrydoxyl-5-methyltriptophane (Tc-99m PMT). METHODS: We examined 13 patients with HCC (29 extrahepatic metastases and 3 benign bone lesions) and 5 patients with other cancers (15 extrahepatic metastases). Thirty minutes to 6 hours after intravenous administration of Tc-99m PMT, planar (all 47 lesions) and SPECT (42 lesions) images were obtained. Accumulation of Tc-99m PMT in the lesion was evaluated visually by comparing bone scintigraphy, computed tomography, magnetic resonance imaging, or all of these. RESULTS: Findings were positive in 12 of 13 patients with HCC and extrahepatic metastases (16 of 29 on planar imaging and 21 of 26 on SPECT). Findings in all three benign bone lesions and 15 metastatic lesions from non-HCC primary lesions were negative (0 of 18 on planar imaging, 0 of 16 on SPECT). There were no false-positive findings in these lesions. Lesion-by-lesion sensitivity, specificity, accuracy, and positive and negative predictive values were 55%, 100%, 72%, 100%, and 58% by planar imaging and 81%, 100%, 88%, 100%, and 76% by SPECT, respectively. CONCLUSIONS: Because of the high specificity and reasonable sensitivity, Tc-99m PMT appears to be useful for the differential diagnosis of extrahepatic metastases from HCC. SPECT improves the detectability of small or faint accumulation in metastases from HCC.     

Scintigraphic findings in infantile hemangioendothelioma

The scintigraphic findings on sulfur colloid liver-spleen imaging, Tc-99m labeled RBC blood pool imaging, and Tc-99m MDP bone imaging in four patients with infantile hemangioendothelioma are described. Thirteen radionuclide studies were performed, with serial sulfur colloid images obtained in three patients, allowing interval assessment of liver size and tumor involvement. Findings of Tc-99m MDP uptake in the livers of two patients with hemangioendothelioma and diffuse increase in hepatic RBC labeled blood pool activity in one patient also are reported.     

Massive splenic metastases with localization of a skeletal imaging agent

A 70 year old man with squamous cell carcinoma of the lung underwent Tc-99m sulfur colloid liver-spleen scintigraphy and abdominal CT studies; both studies showed multiple large lesions in the massively enlarged spleen, with a cystic appearance being noted on the CT examination. Two consecutive Tc-99m HMDP bone scintigrams demonstrated mild, diffuse radioactivity in the region of the spleen, indicating extraosseous localization of the bone imaging agent in the spleen and suggesting solid tumor masses rather than cysts. At autopsy, the huge spleen weighing 2,200 gm contained multiple, large, metastatic masses. Some of the masses were undergoing necrosis/liquification which would explain the cystic appearance on CT. While bone scintigraphy plays an important role in the detection of skeletal metastatic lesions, extraosseous localization of the imaging agent can provide additional diagnostic information.     

Diffuse hepatic and splenic uptake of Tc-99m methylene diphosphonate on bone scintigraphy after intravenous administration of gadolinium-containing MRI contrast

Three patients with known lung cancer came on different days to our department to have a bone scan to evaluate possible osseous metastatic disease. The bone scan images showed increased Tc-99m methylene diphosphonate (Tc-99m MDP) activity in the liver and to a lesser degree in the spleen, whereas bone scan images from other patients on the same days showed no abnormal activity in the liver or spleen. On the same day, shortly before the bone scan, all 3 patients had a magnetic resonance imaging scan with an intravenous injection of Magnevist (Gadolinium-DTPA), which was not previously known to cause an altered Tc-99m MDP distribution. In the follow-up bone scans performed within 1 week of the initial bone scintigraphy, images from none of these 3 patients showed abnormal liver or spleen activity. The findings indicated that the increased Tc-99m MDP activity in the liver and spleen in the early studies was indeed an effect of Gadolinium-containing magnetic resonance imaging contrast. This effect was further confirmed by an animal experiment.     

Utility of Tc-99m GSA whole-body scintigraphy in detecting bone metastases from hepatocellular carcinoma

Recent advances in the treatment of hepatocellular carcinoma (HCC) have prolonged patient survival. However, the number of patients with bone metastases identified during follow-up examinations has increased. Tc-99m Sn-N-pyridoxy-5-methyltryptophan (Tc-99m PMT) has been reported to accumulate at a high rate in HCC lesions and bone metastases. In the patient described here, whole-body scintigraphy showed accumulation of DTPA galactosyl human serum albumin (Tc-99m GSA) and Tc-99m PMT in bone metastases from HCC. The authors suggest that asialoglycoprotein receptors may be present in bone metastases from well-differentiated HCC. Tc-99m GSA whole-body imaging can be used to detect bone metastases from HCC and to evaluate hepatic reserve.     

Medullary thyroid carcinoma with radioiodide transport. Effects of iodine-131 therapy and lithium administration

A 37-year-old woman presented with a neck mass that proved to be medullary thyroid carcinoma by histologic and immunoperoxidase examinations. Serum calcitonin values were greatly elevated (over 100,000 pg/ml). There were widespread metastases in bone and liver. As the peripheral lesions showed only slight response to chemotherapy and local radiation therapy, potential use of radioiodine was studied. The bone lesions showed uptake of both Tc-99m MDP and radioiodide (I-131). Metastatic lesions were similar to the primary tumor in terms of histology, presence of calcitonin, and absence of thyroglobulin. Hence, the patient had a medullary thyroid carcinoma that took up radioiodide in its metastases. Two large oral doses of radioiodide (over 100 mCi each) did not significantly alter the serum calcitonin values, although there was a slight response in the activity of bone lesions. The whole body turnover of radioiodide was rapid (T 1/2 = 0.7 days). Upon oral administration of lithium carbonate, whole-body radioiodide turnover slowed slightly (T 1/2 = 1 day). If this effect were reflected in greater tumor retention of radioiodide (slower release), then agents that block radioiodide egress might have a role to play in therapy.     

Testicular lymphoma with bone/bone marrow metastases illustrated by scrotal sonography, spinal MRI, and total body Tc-99m HMDP and Tc-99m MIBI imagines

An 83-year-old man with testicular lymphoma demonstrated progressive scrotal enlargement with non-homogeneity sonographically and abnormally increased uptake in the scrotum of Tc-99m HMDP and Tc-99m MIBI scintigraphically. Extensive bone/bone marrow metastases were exhibited by Tc-99m MIBI and Tc-99m HMDP scintigraphies and MRI of the spine. In addition, focal/tubular activity of the femoral bone marrow on Tc-99m MIBI imaging was consistent with skeletal scintigraphic findings. It is emphasized that Tc-99m MIBI total body imaging enabled the demonstration of testicular lymphoma as increased uptake and the illustration of skeletal/bone marrow metastases as diffuse and/or focal increased uptake, especially focal/tubular MIBI activity of the femoral marrow.     

Accumulation of Tc-99m methylene diphosphonate in calcified metastatic lesions of the liver from colonic carcinoma. Comparison with calcification on X-ray computed tomogram

Abnormal accumulation of Tc-99m MDP in two metastatic lesions of the liver was observed in a patient with resected colon carcinoma. Single-photon emission computed tomography (SPECT) revealed characteristic marginal accumulation of Tc-99m MDP in both of those metastatic lesions. X-ray CT showed the corresponding marginal calcification in one of the metastases, but no apparent calcification was observed in the other lesion. Two months later, however, the latter also became calcified on x-ray CT. These findings suggest that the accumulation of Tc-99m MDP in the present case is strongly related to the calcium deposition and that Tc-99m MDP may accumulate in a calcified metastatic lesion before the calcification appears on x-ray CT.     

Parathyroid adenomas and hyperplasia. Dual radionuclide scintigraphy and bone densitometry studies

Dual radionuclide imaging of the neck (Tc-99m pertechnetate and TI-201 thallous chloride) was performed in 22 patients with chemical evidence of hyperparathyroidism (elevated blood calcium and parathormone [PTH] levels). Of these, 19 of 22 had localization of a TI-201 "excess" area on radiothallium-radiotechnetium subtraction images. In 13 patients who have had operative confirmation at this writing, the dual radionuclide imaging was positive in 12 (12/13 = 92.3%). One patient had two parathyroid adenomas, both of which were seen on the images; thus, overall detection was 13 out of 14 or 92.8%. The parathyroid adenomas visualized weighed from 0.06 to 3.0 g; the one not detected weighed 0.25 g. In three patients with parathyroid hyperplasia secondary to renal disease, the subtraction imaging detected eight of 12 glands (66.7%). The forearm bone mineral content and bone density were determined in eight patients with parathyroid adenomas; results were abnormally low in five of these eight. One of the three patients with secondary hyperparathyroidism had an abnormally low radial bone mass. The combination of dual radionuclide imaging and radial bone mass determination may present a useful approach in both localizing abnormal parathyroid tissue and in examining its functional consequences.     

Comparison of In-111 octreotide and Tc-99m (V) DMSA scintigraphy in the detection of medullary thyroid tumor foci in patients with elevated levels of tumor markers after surgery.

PURPOSE: In this retrospective study, the authors evaluated the utility of In-111 octreotide (OctreoScan) and Tc-99m (V) DMSA scintigraphy for the localization of recurrent metastatic tumor foci in patients with medullary thyroid cancer (MTC) and compared the findings with those of conventional radiologic imaging methods. METHODS: The scintigraphic images were compared with computed tomography (CT) and magnetic resonance imaging (MRI) and ultrasonography (US) in 14 patients (8 men, 6 women; age range, 22 to 74 years) with elevated calcitonin and carcinoembryonic antigen levels after total thyroidectomy. All scintigraphic image findings were evaluated qualitatively as mild uptake (+) and moderate to marked uptake (++). RESULTS: In-111 octreotide may be superior to Tc-99m (V) DMSA for the detection of tumor foci of patients with MTC on a patient basis (78.5% versus 57.1%) and on a lesion basis (44.1% versus 30.2%). The sensitivity rate for In-111 octreotide (78.5%) was also similar to that of CT and MRI on a patient basis. Conversely, the combined use of Tc-99m (V) DMSA and In-111 octreotide revealed the best sensitivity rate (85.7%) on a patient basis, whereas the combined use of CT and MRI showed the best sensitivity rate (81.3%) on a lesion basis. CONCLUSIONS: These findings suggest that In-111 octreotide is superior to Tc-99m (V) DMSA and has a similar sensitivity rate to CT and MRI for the diagnosis of recurrent or metastatic MTC. Although the combined use of In-111 octreotide and Tc-99m (V) DMSA was most sensitive, the combined use of CT and MRI with radionuclide imaging methods may better detect more metastatic tumor foci.