Radiolabeled somatostatin analog scintigraphy in differentiated thyroid carcinoma

After intravenous administration of a radiolabeled somatostatin analog (octreotide), an image of the thyroid gland is frequently observed; few data are available, however, on somatostatin receptors in epithelial thyroid cells assessed in vitro and on images of differentiated thyroid carcinoma (DTC) with pentetreotide scintigraphy. METHODS: In four patients with metastatic thyroid carcinoma, whole-body scintigraphy was performed 4 to 48 hr after injection of 110 MBq of 111In-pentetreotide. The results were compared to data obtained with other imaging modalities, including scintigraphy performed after administration of a therapeutic dose of 131I. RESULTS: There were positive foci in distant metastases on 111In-pentetreotide scintigraphy. Pentetreotide scintigraphy was positive in two patients with an "insular" form of DTC, one of whom had a positive (faintly) 131I scan. Of the other two patients with papillary DTC without radioiodine uptake, only one exhibited a certain degree of pentetreotide scintigraphy positivity in distant metastases. CONCLUSION: These results show promise for exploration of insular thyroid carcinoma and suggest that these carcinomas may possess functional differentiation features, including somatostatin receptors.     

Ga-67 scan as a prognostic indicator in primary lung carcinoma

GA-67 scintigraphy was performed on 74 patients with a variety of histologic types of untreated primary lung carcinoma. Ga-67 uptake was determined, allowing for differences in tumor size. Ga-67 uptake was compared with the response to the incidence of metastases, and to host survival in the 74 patients. From these results, it is suggested that the greater the Ga-67 accumulation in the tumor, the higher the incidence of metastases and the shorter the host survival. Ga-67 scintigraphy appears to be a valuable tool in indicating the prognosis following radiation therapy in patients with primary lung carcinoma.     

Inhalation scintigraphy with radioaerosols in bronchogenic carcinoma

Radioaerosol inhalation lung scintigraphy is discussed and its interpretation based on the segmental anatomy of the lung is presented. Correlation between bronchography and inhalation scintigraphy in 26 cases of bronchogenic carcinoma showed that partial obstruction of a major bronchus produces a clear "hot spot" with peripheral decrease of aerosol deposition, while partial or complete obstruction of the segmental bronchi causes segmentally decreased deposition distal to the site of obstruction. Even at an early stage, bronchogenic carcinoma may be detected by aerosol inhalation scintigraphy whenever the tumors are large enough to produce visible abnormalities of aerosol deposition.     

Thyroid scintigraphy in patients with thyroid tumors using 99mTc-hexakis 2-methoxy isobutyl isonitrile

Early and delayed thyroid scintigraphy with 99mTc-hexakis 2-methoxy isobutyl isonitrile (99mTc-MIBI) was performed in 18 patients with thyroid tumor, including 8 with papillary carcinoma, 1 each with follicular carcinoma, anaplastic carcinoma, and malignant lymphoma, and 7 with thyroid adenoma. Scintigrams obtained were compared with those taken with other radionuclides. In all 11 patients with malignant tumors, increased 99mTc-MIBI uptake was noted in the tumors on early images, although anaplastic carcinoma and malignant lymphoma had mild uptake. On delayed images, 99mTc-MIBI washout was noted in 45.4% (5/11). In one patient with extensive cervical lymph node metastasis, 99mTc-MIBI concentration was evident in the metastatic foci. In the 4 where, the thyroid adenoma consisted mainly of cystic degeneration, a focal defect was noted, but two of the three patients whose thyroid adenoma consisted mainly of a solid component had an intense tracer uptake in the tumors on early and delayed images. In conclusion, there were increased 99mTc-MIBI accumulations in all of the 14 solid thyroid tumors. The quality of 99mTc-MIBI scintigraphic images of thyroid tumors was equal or slightly superior to that taken with 201Tl scintigraphy. 99mTc-MIBI thyroid scintigraphy may be useful in detecting a solid thyroid tumor and its metastasis, although it cannot be used to differentiate between benign and malignant tumors.     

The role of iodine-131 and thallium-201 imaging and serum thyroglobulin in the management of differentiated thyroid carcinoma

BACKGROUND: A prospective study was conducted to evaluate the use of iodine-131 sodium scintigraphy, thallium-201 chloride scintigraphy, and quantitative serum thyroglobulin estimation in the detection of differentiated thyroid carcinoma after thyroidectomy and iodine-131 sodium ablative therapy. METHODS: Thirty-one patients with a median age of 45.6 years (range, 20-73 years) were included in the study. After optimal endogenous thyroid-stimulating hormone stimulation (> 50 mU/ml), 53 pairs of iodine-131 and thallium-201 scans were performed. Concomitant serum thyroglobulin levels were available for 32 pairs of scans. The presence or absence of thyroid cancer was established by clinical, radiologic, and/or biopsy findings. RESULTS: The concordance between iodine-131 and thallium-201 scan findings in the presence of disease (25 scan sets) was 36%. The concordance in the absence of disease (28 scan sets) was 82%. Iodine-131 scanning was found to be significantly better (P < 0.05) than thallium-201 scanning, in terms of sensitivity (0.8 versus 0.6), specificity (0.96 versus 0.82), accuracy (0.89 versus 0.72), and the predictive value of a positive test (0.95 versus 0.75). The measurement of serum thyroglobulin had a low sensitivity (0.3) in the study but had a specificity of 1.0. CONCLUSION: It was concluded that iodine-131 sodium scintigraphy is superior to thallium-201 scintigraphy and serum thyroglobulin estimation for the detection of residual or metastatic differentiated thyroid carcinoma. However, the use of combined modalities provides a higher diagnostic yield. Thallium-201 scintigraphy was especially useful in cases in which iodine-131 scintigraphy was negative and quantitative thyroglobulin levels were elevated.     

Fetal oxygen saturation and uterine contractions during labor

In the majority of cases, carcinoma of the thyroid presents as a cold nodule by radioiodine and Tc-99m sodium pertechnetate scintigraphy. Whereas the presence of a hot nodule usually implies a benign entity, it does not provide complete assurance against thyroid malignancy. Presented is a rare case of metastatic pure papillary thyroid carcinoma appearing as a hot nodule on Tc-99m sodium pertechnetate and I-123 sodium iodide scintigraphy. The implications of such a case, its management, and review of the pertinent literature are discussed.     

Thallium-201 scintigraphy to predict therapeutic outcome of iodine-131 therapy of metastatic thyroid carcinoma

We studied the relationship between 201Tl uptake and the efficacy of radioiodine therapy in thyroid carcinoma. METHODS: Forty-four patients with metastases of well-differentiated thyroid carcinoma received 201Tl scintigraphy within the 2 mo before their initial 131I therapy. Patients were classified into two groups according to the tumor-to-background (T/B) ratio on the late 201Tl scan: high 201Tl uptake (T/B > or = 2.1) and low 201Tl uptake (T/B < 2.1). The therapeutic outcome was judged by the percent reduction in the tumor diameter at 6 mo after the treatment. The treatment was defined as effective when the tumor showed more than 50% reduction in the tumor diameter. The patients in whom radioiodine was ineffective were followed up to determine if the tumor showed further growth. RESULTS: Of the 44 patients, 25 had high 201Tl uptake and 19 had low 201Tl uptake. The therapy was effective in 15 patients and was ineffective in 29. All the patients in whom radioiodine was effective had low 201Tl uptake. On the other hand, 25 of 29 patients in whom radioiodine was ineffective had high 201Tl uptake. Eight patients, in whom radioiodine was ineffective despite good 131I uptake, had high 201Tl uptake. There were no significant differences in the positive predictive value and the negative predictive value for effective treatment between 201Tl scintigraphy and therapeutic dose 131I scintigraphy. Among the 25 patients in whom radioiodine was ineffective and who had high 201Tl uptake, the tumor diameter increased in 7 (28%). However, none of the tumors with low 201Tl uptake increased in size during the follow-up period. CONCLUSION: Thallium-201 scintigraphy has a high predictive value for the efficacy of radioiodine therapy in metastatic thyroid carcinoma. Thus, it is helpful in determining the indication for radioiodine therapy and it seems to be an adjunct to tracer dose 131I scintigraphy.     

Metastasis of hepatocellular carcinoma to the colon demonstrated by Tc-99m PMT scintigraphy

A 57-year-old man was found to have a tumor in the ascending colon after hepatic segmentectomy for ruptured hepatocellular carcinoma. Colonoscopy was performed, and metastasis of the hepatocellular carcinoma to the ascending colon was suspected based on the biopsy specimens obtained from the tumor. On hepatobiliary scintigraphy using Tc-99m PMT performed to confirm this diagnosis, Tc-99m PMT was clearly observed to accumulate in the tumor. Thus, the tumor was diagnosed as metastasis of hepatocellular carcinoma.     

Spasskyellina mandi n. sp. (Proteocephalidea:Monticelliidae), parasite of Pimelodus ornatus Kner, 1857 (Pisces:Pimelodidae) of the Paraná River, Paraná, Brazil

Indium-111 pentetreotide scintigraphy was performed in two patients for the localization of recurrent medullary thyroid carcinoma treated by surgery and external radiotherapy 1 and 10 years earlier. A marked uptake of the radiopharmaceutical was demonstrated in the lung areas that had been irradiated. These cases strongly suggest that this uptake is related to pulmonary fibrosis, a well-known complication of radiotherapy, even long after the irradiation. Therefore, attention must be paid to the avoidance of false-positive interpretation of somatostatin receptor scintigraphy in patients previously treated by radiotherapy.     

Fluorine-18-fluorodeoxyglucose PET identification of cardiac metastasis arising from uterine cervical carcinoma

Cardiac metastasis of uterine cervical carcinoma is rare. We describe a patient with a past history of uterine cervical carcinoma who presented with metastasis to the heart, lungs and distant lymph nodes 3 yr after surgery and chemotherapy. Since the patient complained of chest pain and demonstrated electrocardiogram abnormalities, we performed echocardiography, electron beam CT and MRI, which revealed a tumor in the right ventricular wall. The tumor was assessed by 67Ga scintigraphy and 18F-fluorodeoxyglucose (FDG) PET scanning. The mean differential 18F-FDG uptake ratio of the tumor was 7.9, suggesting malignancy, which was later confirmed by myocardial biopsy. Information about the extent of the tumor and partial necrosis within it was provided by 18F-FDG PET. Although both radionuclide imaging techniques also detected metastatic lesions in the lungs and lymph nodes, 18F-FDG PET scanning detected small lesions more sensitively than 67Ga scintigraphy.     

Post-therapy iodine-131 localization in unsuspected large renal cyst: possible mechanisms

Sensitive and specific, whole-body 131I scintigraphy remains an important technique for diagnosing metastases from differentiated papillary or follicular thyroid carcinoma. False-positive 131I localization is well recognized and can occur in a variety of conditions. We present a case of intense 131I localization in a previously unsuspected large renal cyst; the lesion was not visualized on routine preablation diagnostic 131I scintigraphy but was obvious on post-therapeutic whole-body imaging, underscoring the value of post-therapy imaging in detecting abnormalities not apparent on diagnostic studies. Radioiodine within the urinary bladder or, at times, the renal collecting system is expected, because 131I excretion is primarily by glomerular filtration. In the case presented here, 131I activity within the renal cyst supports the concept that iodide is subject to an active secretory process by the renal tubule.     

The utility of a somatostatin-type receptor binding peptide radiopharmaceutical (P829) in the evaluation of solitary pulmonary nodules

OBJECTIVE: Many neoplasms including small cell cancers more densely express somatostatin-type receptors or more avidly bind somatostatin than granulomatous and other nonmalignant processes. While non-small cell neoplasms of the lung have not yet been shown to demonstrate this receptor expression, previous studies have documented non-small cell lung cancer detection with somatostatin analog scintigraphy. This phenomenon can be conceivably exploited utilizing technetium Tc-99m P829 (P829), a unique low molecular weight somatostatin-type receptor binding polypeptide radiopharmaceutical. The objective of this study was to determine the ability of P829 scintigraphy to noninvasively differentiate malignant and nonmalignant solitary pulmonary nodules (SPNs). METHODS: The radiopharmaceutical technetium 99mTc-P829 was utilized for scintigraphy including single photon emission computed tomography. Thirty individuals with indeterminate SPNs of > or = 1 cm and significant risk factors for primary lung cancer were identified and underwent P829 scintigraphy. Tissue diagnosis was then established by transthoracic needle biopsy specimens. RESULTS: Fourteen subjects demonstrated abnormal P829 scans in the region of the radiographic abnormality. Twelve of this group had biopsy specimens revealing neoplasia. Two subjects with necrotizing granuloma on biopsy specimen had abnormal P829 scans in the region of the nodule. Sixteen subjects had no abnormal P829 tracer uptake in the region of the nodule. Fourteen subjects had benign diagnoses on biopsy specimens. One member of this group with a non-diagnostic biopsy specimen refused thoracotomy and remains radiographically stable at 24 months of follow-up. One subject with a squamous cell carcinoma demonstrated no P829 activity in the region of the nodule. The specificity of P829 scintigraphy based on transthoracic needle biopsy specimen was 88%. The sensitivity was 93%. P829 scintigraphy correctly identified or excluded malignancy in 27 of 30 subjects. CONCLUSIONS: P829 scintigraphy reliably identified or excluded malignancy in radiographically indeterminate solitary pulmonary nodules. The sensitivity and specificity compared favorably with the reported results of F-18 fluorodeoxyglucose positron emission tomographic imaging.     

Somatostatin receptor subtypes, octreotide scintigraphy, and clinical response to octreotide treatment in patients with neuroendocrine tumors

Several types of neuroendocrine tumor express high numbers of somatostatin receptors (sstr). We have compared the expression of sstr subtypes with the outcome of octreotide scintigraphy in patients with carcinoids and medullary thyroid carcinoma (MTC) in comparison with Hürthle cell tumors. The effect of sstr activation (octreotide treatment) on tumor markers was also studied in patients with disseminated carcinoid tumors. Six patients with carcinoid tumors (four midgut and two foregut), and three patients with thyroid tumors (one MTC, one Hürthle cell carcinoma, and one Hürthle cell adenoma) were studied. Octreotide scintigraphy visualized tumor sites in all nine patients. Macroscopic tumor was verified at these sites at subsequent surgical exploration. Using Northern blotting and subtype-specific riboprobes, sstr could be detected in all tumors examined. All five sstr subtypes were detected in most of the carcinoid tumors. All six carcinoids expressed sstr2. This was in contrast to the findings for the thyroid tumors analyzed, which also expressed several sstr subtypes but in some cases lacked expression of sstr2. This was also the case for normal thyroid tissue. Clinically, octreotide treatment of the patients with midgut carcinoid tumors resulted in palliation of hormonal symptoms accompanied by a significant reduction of urinary 5-HIAA levels (28-71%). These results indicate that carcinoid tumors frequently express all five sstr subtypes. The thyroid tumors also expressed multiple sstr but could lack expression of sstr2. Nevertheless, these tumors were visualized by octreotide scintigraphy, indicating that sstr2 expression is not a prerequisite for tumor imaging.     

Technetium-99m tetrofosmin and technetium-99m sestamibi imaging of multiple metastases from differentiated thyroid carcinoma

A 79-year-old male with follicular thyroid carcinoma metastasizing to the lung, bone and lymph nodes was subjected to whole-body scintigraphy using technetium-99m tetrofosmin and 99mTc-sestamibi. Both agents delineated the metastatic lesions and the two image qualities were comparable. We believe that 99mTc-tetrofosmin and 99mTc-sestamibi images may be helpful in localizing metastatic foci and substitute for thallium-201 in the follow-up of patients with differentiated thyroid carcinoma.     

Observation of live, attenuated hepatitis A vaccines in humans

In a patient with metastatic Hurthle cell carcinoma of the thyroid, a subgroup of follicular carcinoma, scintigraphy with pentavalent 99mTc-labeled dimercaptosuccinic acid (V)DMSA showed a significant uptake of the radiopharmaceutical in all tumor sites. We suggest that the accumulation of 99mTc-(V)DMSA within metastases of Hurthle cell thyroid tumor may have a useful role in the staging of these patients, especially when radioiodine fails to concentrate.     

Experimentally induced nasal hypersecretion does not reduce the efficacy of intranasal levocabastine

Pulmonary tumor embolism is an often missed antemortem diagnosis in patients with cancer and respiratory failure. Although rare, this complication is an important cause of additional morbidity. Referred for radionuclide pulmonary perfusion and ventilation scintigraphy, a typical pattern of multiple subsegmental peripheral defects on perfusion lung scanning without matching ventilation defects, suggesting a high probability of pulmonary thromboembolism, often leads to false conclusions. We present a case of bilateral multiple subsegmental mismatched defects in lung ventilation perfusion scintigraphy, where autopsy confirmed the diagnosis of pulmonary tumor embolism, secondary to an undifferentiated ductal type adenocarcinoma of the pancreas. Pulmonary tumor embolism is an entity to keep in mind in patients treated for carcinoma presenting with (sub) acute dyspnea.     

Improvement of the merthiolate-iodine-formalin (MIF) fecal technique for hookworm, Trichuris trichiura, and Ascaris lumbricoides eggs

A patient with a history of total thyroidectomy for papillary carcinoma showed a solitary hot spot in the chest on post-therapy radioiodine imaging. Subsequent evaluation demonstrated that this lesion was a primary squamous-cell lung cancer. Our case illustrates a rare but important differential diagnosis from lung metastasis of thyroid cancer in 131I scintigraphy. Alternatively, this "aberrant uptake" might be a rather common phenomenon for lung neoplasms, although the underlying mechanism is not yet known. Future experimental studies might lead to a new application of radioiodine imaging in pulmonary oncology.     

Thyroglossal duct cyst with papillary carcinoma in an 11-year-old girl

A case of primary papillary carcinoma arising in a thyroglossal duct cyst is reported in a young girl. This is a rare finding, with only five pediatric cases in the total of 115 cases reported in the literature. Subsequent management is described, including the role of scintigraphy and radioiodine ablation.     

A painful inflammation of the thyroid

Four women aged 30, 29, 52 and 43 years presented with what appeared to be subacute thyroiditis (De Quervain's thyroiditis). This disease is characterized by fatigue, a painful thyroid gland and thyrotoxic manifestations. The diagnosis is further based on a high erythrocyte sedimentation rate and low tracer uptake during thyroid scintigraphy. Only the first patient showed a typical course. In the second and third ones the painful thyroid was associated with nodular enlargement. Fine needle aspiration cytology was at first consistent with subacute thyroiditis but a repeated aspiration showed papillary carcinoma in the second and anaplastic carcinoma in the third patient. In the fourth one, subacute thyroiditis was accompanied by normochromic anaemia, a low serum albumin concentration and liver function disorders. She made a full recovery without treatment. Thyroid malignancies can mimic subacute thyroiditis. Persistent nodular enlargement of the thyroid is suspicious and requires careful investigation.     

The relevance of somatostatin receptors in thyroid neoplasia

111In-octreotide scintigraphy in patients with persistent medullary thyroid carcinoma (MTC) visualized tumors in about half of the surgically explored sites. Tumor visualization correlated with rapid tumor growth and large tumor volume as judged from calcitonin levels. The 111In concentration ratio between tumor (T) and blood (B) in surgically excised lymph node metastases of MTC showed a large variation, with low values for microscopic and high values for macroscopic metastases in individual patients. Three cases of MTC, Hürthle cell adenoma and papillary thyroid cancer are reported with preoperative scintigraphy, T/B ratios and Northern analyses of the surgical biopsies. Visualization of tumors was possible in the absence of sstr2 (the high affinity receptor for octreotide) with the exception of microscopic tumor growth. T/B values in the patient with Hürthle cell adenoma were similar to those found in the contralateral thyroid lobe with goitre. The relatively high uptake of 111In in benign thyroid conditions probably limits the use of octreotide scintigraphy in the diagnosis of primary tumors. The technique has certain advantages over radioiodine scintigraphy after the surgical treatment of thyroid tumors: no need for withdrawal of thyroxin substitution; a possibility to diagnose metastases of tumors that do not concentrate radioiodine (MTC, Hürthle cell cancer); and complementary information about metastatic sites of non-medullary thyroid cancer (papillary and follicular tumors).