The role of radioactive iodine therapy in the treatment of insular thyroid carcinoma: A case report

This is a case of a 54-year-old male, diagnosed to have insular thyroid carcinoma. The histopathologic characteristic of this rare neoplasm arising from follicular epithelial cells has the potential to take up 1-131 As shown in his postoperative 1-131 imaging, there are iodine-avid lesions in the parietal bone, thyroidal beds, ribs and vertebrae. The presence of these lesions in a &agnostic radioactive iodine scan makes it possible to do radioactive iodine therapy. A follow-up diagnostic study with 1-131 shows interval resolution and regression of the metastatic lesions. Thus, radioactive iodine therapy has a role in the treatment of this rare and aggressive neoplasm.

Significance of post-therapy whole body imaging with I-131 in well-differentiated thyroid cancer

Post-therapy whole body imaging with I-131 is not routinely done in the Philippines. This added cast of this procedure limits its diagnostic value for those patients who cannot afford it. This study was undertaken to evaluate the diagnostic relevance of I-131 whole body scan following therapeutic doses and its implication in further treatment and follow-up. This study included 61 patients treated in our institutions during a three-year period. Comparison of their-pre- and post-therapy who body scans was done. There were 10 males (16%) and 51 (84%) females with a mean age of 45 years + 15 (range, 17-77). Thirty three patients (54%) have corresponding pre-therapy serum thyroglobulin determination, which also guided the clinicians in the administration of appropriate therapeutic doses. The post-therapy studies were performed prior to hospital discharge . The mean interval between administration of therapy dose and imaging was 4 days (range, 2-10 days). About 34 patients (56% did not have any significant change between their pre- and post-therapy whole body scans. In 27 cases (44%), additional findings indicative of local and/or distant thyroid cancer metastasis were noted. Unsuspected cervical nodes were appreciated in 15(24%) of these cases. Seven (7) cases (11%) presented with increased metastatic deposits in the affected area. New areas of metastases were evident in 5 cases (8%). Our present data suggests that the incorporation of post-therapy whole body scans in the clinical evaluation of patients with well-differentiated thyroid cancer may help in the optimum therapeutic management and future follow-up of patients.

Are PET and PET/CT useful in pediatrics?

The value of PET in the evaluation of various disease states, particularly in oncology, has been well documented. Compared with its widespread application in adults, clinical use of PET in pediatrics is limited. Concerns of radiation exposure to the child, as well as lack of studies evaluating the diagnostic benefit of PET/CT in children, are a contributing factor. This study was conducted to review the usefulness of PET and PET/CT in the evaluation of pediatric patients and to identify unique FDG physiologic distribution in the sample population. All pediatric patients referred for PET scan from March 2002 - September 2010 were included in the study. The indication for referral was predominantly oncology-related (93.5%). Of the 85 patients included, PET/CT was able to detect new sites of metastases in 5 patients and help resolve equivocal CT findings in 12 patients. Of six patients presenting with seizures, PET successfully localized hypometabolic areas in the brain in all cases, as probable seizures foci. Physiologic distribution of F18-fluorodeoxyglucose (FDG)was noted in the thymus, adenoids/tonsils, laryngeal area and supraclavicular brown fat. PET/CT is useful in selective pediatric cases. Its value in effectively evaluating pediatric malignancies allows for early initiation of appropriate treatment and discourages unnecessary diagnostics and treatments for benign lesions. Physiologic uptake unique to children should be considered to avoid misinterpretations, reduce unnecessary treatments and follow-ups as well as provide an overall improvement in patient care.

Transarterial 188 rhenium-HDD-lipiodol conjugate in the treatment of inoperable hepatocellular carcinoma

This is a descriptive study to assess the safety and efficacy of 188 Rhenium-HDD-Lipiodol conjugate in treating patients with unresectable hepatocellular carcinoma. Eight patients with inoperable hepatocellular carcinoma with liver lesions ranging from 1.8 x 2.0 cm to 12.7 x 70 cm participated in the study. 188 Rhenium-HDD-Lipiodol conjugate was administered to the patients via femoral catheter based on the radioactivity that was eluted from the generator. Corresponding whole body scintigraphic images, which showed significant tracer uptake in the liver lesions, were obtained at 24, 48 and 72 hours after 188 Rhenium-HDD-lipiodol administration. Follow-up CT scans in six patients showed progressive disease in three patients and stable disease in three patients. Two patients had re-treatment due to progression of liver lesions. Follow-up scintigraphy after re-treatment showed decrease in tracer uptake in liver lesions on one patient, while the other showed diffuse tracer uptake. Post-ttherapy symptoms were minimal: mild to moderate epigastric pain in two, nausea and vomiting in one, while the rest are asymptomatic. Karnofsky performance status of patients three months after the therapy ranged from 20-90%. Two of the eight patients are still living at the time this paper was written. Radionuclide therapy aided in the prolongation of life and improvement of its quality for some patients. 188 Rhenium-HDD-Lipiodol radio conjugate provides promising results in treating inoperable hepatocellular carcinoma.

Right-to-left shunting secondary to microvascular pulmonary arteriovenous malformation demonstrated by lung perfusion scintigraphy

Right-to-left shunting is usually associated with congenital conditions involving the heart, lungs, and the blood vessels that connect both organs. It is demonstrated by echocardiography, transesophageal ultrasound, CT scan, MRI and more definitively by conventional angiography. In this paper, we present a 16-year old female who manifested with progressive dyspnea, persistent cyanosis and decreased arterial oxygen saturation. Clinical assessment and arterial blood gas parameters suggested the presence of significant shunting. However, cardiac evaluation showed no intracardiac defects. High resolution CT scan of the chest with CT angiography of the pulmonary artery also showed no evidence of pulmonary vascular malformation or shunt anomaly. Lung perfusion scintigraphy performed after intravenous administration Tc99m-MAA showed tracer uptake in the brain, spleen and kidneys signifying the presence of a right-to-left shunt in the lungs. Cardiac catheterization later demonstrated the presence of primary pulmonary telangiectasia.

Metastatic thyroid carcinoma in the kidney

Thyroid carcinoma, particularly papillary thyroid carcinoma, may present with a wide range of clinical course--from an indolent to an aggressive form of poorly differentiated thyroid carcinoma. About 10% of patients with papillary thyroid cancer develop distant metastasis to the lymph nodes, lungs, mediastinum, or bone. Several cases of unusual metastasis to the kidney have been reported previously. A rare case of renal metastasis from papillary thyroid carcinoma and the roles of PET and SPECT-CT in its detection are presented here.

I131 MIBG imaging in the diagnosis of pheochromocytoma: Philippine setting

The clinical diagnosis of pheochromocytoma is easy, considering that it manifests as labile hypertension, attacks of palpitations, headache, sweating, pallor or flushing. Urinary VMA or metanephrines seem to be the first investigative step as well as a CT scan to localize it as 85-90 percent arise from the adrenal medulla. Ten percent of these tumors are bilateral but non-adrenal tumors may arise from the sympathetic ganglia, usually alongside the aorta or its branches and in the wall of the urinary bladder. One percent is found outside the abdominal cavity. Meta-iodobenzyl guanidine (MIBG) is an excellent scanning agent that is taken up by most benign and malignant pheochromocytoma tissues. While this procedure is quite costly and underutilized in the Philippines, this paper was done to review its indications and how helpful it can be. From 2001 -2005, I131 MIBG scintigraphy was done only in 17 patients in two medical centers to confirm the diagnosis of pheochromocytoma. The clinicians must be informed that this is not a screening procedure but it is particularly helpful in surveying the entire body for adrenal and extra-adrenal metastatic lesions. It is also diagnostic of intra-adrenal paragangliomas, neuroblastoma, carcinoids, and medullary thyroid carcinoma. This study was, likewise, done with the thought that MIBG may be utilized in the future for therapy as it has shown to be effective in pheochromocytoma and neuroblastoma.