Iranian Journal of Nuclear Medicine
Volume:8 Issue: 1, 2000

Differentiated thyroid carcinomas usually show good uptake and response to I-131 ablative treatment. In this study, 90 patients following near total thyroidectomy who were referred to our institute for I-131 therapy are retrospectively studied. The patients are divided in two groups. Group 1 revealed complete ablation after one dose of I-131. Group 2 needed more than one dose of I-131 for ablation. 26 patients (28.9%) were Categorized in group 1 and 64 patients (71.1%) in group 2 patients. Comparison between the two groups revealed the highest success rate (Ablation with one dose of I-131) in male patients between 30-50 years of age, with mixed type of differentiated thyroid carcinoma without any evidence of local or distant metastasis.

In this report, the clinical course and treatment response of 210 patients with Grawes’ disease referred to the research institute for nuclear medicine were studied. The disease was more common in 3rd and 4th decades and more frequent in women (F/M=4). Treatment response with antithyroid drugs was about 50%, whereas 80% of the patients treated by I-131 showed positive response. There was no meaningful relation between treatment response and thyroid size or the dose of I-131.

A 49 year old man with previous history of colectomy for colon cancer was referred to our department for further evaluation of suspicious hepatic lesions noticed during an abdominal CT scan. 99mTc-RBC scan revealed multiple hot spots in the region of the liver, correlating to the CT and liver-spleen scan. Further follow-ups of the patient revealed no remarkable change in the size or number of the hepatic lesions. The diagnosis of multiple hemangiomas with high probability was made. The usefulness of RBC scan in differential diagnosis of hepatic lesions is reviewed.

To minimize renal radiation in abdomical radiotherapy, shielding of the kidneys is essential. IVP-simulator is used as an standard method. In this study, we used 99mTc-DMSA to localize and shield the Kidneys and we compared this method with IVP-simulator. The size of the kidneys was proven to be larger as compared with IVP method. The mean of the overlap percentage was 81.88 in right and 82.89 in left kidney. The confidence interval between two methods ranged from 20 to 80 percent. It is concluded that this is a useful method and can be recommended for localization and shielding of the kidneys in patients with abdominal radiotherapy.

In recent years, several radiopharmaceuticals have been developed for imaging regional cerebral blood flow (rCBF) such as 75Se labelled PIPSE and MOSE, ²º¹TI labelled DDC and 99mTc labelled HMPAO. HMPAO with two asymmetric carbon atoms (At the 3 and 9 positions), produces d,1 and meso isomers, only one of which is retained in the brain. Rapid intracellular conversion of 99mTc-d,1-HMPAO to hydrophilic 99mTC species causes the complex becoming fixed in the brain. In this report we synthesized and characterized d,1-HMPAO. Kit formulations have been done and biological characteristics of 99mTc-d,1-HMPAO have been examined.

There is no organometalic compound of Indium known to exist naturally in the human body. However, a number of compounds prepared with ¹¹¹In have been evaluated for localization studies. The useful radioactive decay characteristics and the suitable chemical properties of the metal ion have drawn attention of many investigators resulting in the preparation of numerous ¹¹¹In labeled compounds for potential medical applications. One of them is ¹¹¹In-DTPA complex that is used for cerebro spinal fluid studies. In the present study, DTPA has been chelated with ¹¹¹In by employing various methods and then tested for its stability in vitro during storage and in human plasma. Three methods for the preparation of ¹¹¹In-DTPA were used. In every method, labeling efficiency and radiochemical purity were determined by chromatography systems.

Radiodine therapy (RIT) for hyperthyroidism is increasingly used as a therapy of choice in most of the patients. Effect of multiple factors on the result of therapy was noted. This study tries to analyze the effect of multiple factors on success rate of RIT. Methods and patients: One hundred and sixty four hyperthyroid patients referred for RIT therapy from 1996-99, were studied. Thyroid examination and 24 hrs RAIU were performed in all patients and 150-255 μCi/gr of ¹³¹I was administered. Follow up of the patients, including thyroid examination and thyroid values measurements were done at 2-6 months after treatment. The patients were divided in two groups: those who responded to radioiodine (group 1) and those who did not (group 2). Two to six months after RIT, seventy one percent of the patients were in group 1 and 29% in group 2. No difference was noted in the mean age [45.7 yrs vs 47.2 yrs] (P=0.42), total Iodine dose [15.4 mCi vs 17.2] (P=0.2), Iodine dose per gram of thyroid weight [189.3 μCi/gr vs 192.6 μCi/gr] (P=0.06) and female/male ratio [65/21 vs 30/5] (P=0.32) between two groups. The mean thyroid weight was 59.1 gr in group 1 and 55.2 gr in group 2. Using logistic regression, the only significant effective factor in success of therapy was thyroid weight (R=0.172, P=0.03). With inceasing thyroid weight, success rate of Iodine therapy was decreased. With high dose (>150 μCi/gr) RIT, only thyroid weight negatively affects the result of the therapy and the other factors have no significant role.

Treatment of bone metastases comprises over 10% of the workload of a radiation-oncology center. Bone metastases produce severe pain and immobility, necessitate narcotic use, and reduce the quality of life. A good palliative treatment must be complete, free from side effects and fast; Thus we decided to evaluate Strontium-89 (89Sr) effectivity for palliation of breast and prostate cancer bone metastases in relation to above factors. The use of 89Sr radionuclide therapy started on 1992 in radiation-oncology department of Cancer Institute. Until early 1999, 91 patients with bone metstases have been treated for pain relief in our department with 4 mCi of 89Sr. Of these, 80 were breast and prostate metastatic cancers. 35 patients came back for follow-up and were completely evaluated. Response was seen in 65% of patients (Complete response in 40% and partial response in 25%). Side effects were negligible, and quality of life of the responding patients significantly increased. There was no significant relationship between the type of primary cancer or patient age and response. In conclusion, treatment of metastatic bone cancer from prostate and breast primaries in our department was effective, with a relatively high rate of response and no serious side effects.

A 64-year-old woman, with amyloid related kidney failure (On renal dialysis) had a bone scan because of pain in the right upper femur. The 99m Tc-MDP images revealed marked hepatic uptake. In addition, there was right proximal femoral concentration of radiotracer, which corresponded to a fracture site. As an added finding, the same femor demonstrated circumferential uptake at the lower pole. This region fractured on next day. A biopsy of the fracture site revealed amyloid staining. The plasma aluminum level was elevated, consistent with long-term dialysis. Hepatic uptake of bone imaging agent might be related to amyloid deposition or the elevated aluminum concentration.