Iranian Journal of Nuclear Medicine
Volume:22 Issue: 1, Winter-Spring 2014

Rheumatoid arthritis (RA) is the most common autoimmune disease, leading to the destruction of the joints and causing pain, disability, and immobility in the patients. Radiosynovectomy (RSV) has been applied as an effective treatment for the patients with resistant synovitis after failure of long-term pharmacotherapy and intra-articular steroid injection for more than 50 years. Several radiopharmaceuticals have been developed for RSV so far, but still development of new radiophamaceuticals is of crucial interest. In this research, the 177Lu-chitosan complex (177Lu-CHITO) was introduced as a new agent for RSV. 177Lu was produced by irradiation of a natural Lu2O3 target at a thermal neutron flux of approximately 4 × 1013 n/cm2·s. 177Lu-CHITO was prepared in the diluted acetic acid solution. The radiochemical yield was checked by ITLC method. The biodistribution of the complex was investigated by intra-articular injection to rabbits’ and rats’ knee joints. The leakage of injected dose from the injection site in the rabbit organs was investigated using SPECT imaging up to 48 hours. 177Lu was prepared with a specific activity of 2.6-3 GBq.mg-1 and radionuclide purity of 99.98%. 177Lu-CHITO was prepared successfully with high radiochemical purity (95%) and specific activity of 888 TBq/mmol. Both the biodistribution data in rats and SPECT imaging of the rabbit showed that there was no significant leakage of the injected activity even after 192 h. Considering all of the excellent features of the complex, this radiopharmaceutical can be used for effective management of synovial inflammation.

Appendicitis is one of the most common surgical emergencies. In spite of the relatively high rate of negative appendectomy, as a result of miss diagnosis, uncertainty of diagnosis still continues to challenge physicians. The objective of this prospective study was to investigate the role of 99mTc-Ubiquicidin (UBI) scintigraphy in the diagnosis of acute appendicitis and to compare 99mTc-UBI scintigraphy with 99mTc-IgG scintigraphy. Twelve patients with right lower quadrant pain and suspicious of acute appendicitis were referred to the nuclear medicine imaging center. Radionuclide imaging was performed with 99mTc-UBI in 8 and 99mTc-IgG in 4 patients. Ultrasonography, Alvarado scoring and histopathological examinations were also performed as additional diagnostic tests. Reports from 99mTc-IgG and 99mTc-UBI scintigraphies of all patients were negative. This study may conclude that 99mTc-IgG scintigraphy and 99mTc-UBI scintigraphy in the detection of appendicitis do not have adequate efficacy. However, in order to better evaluate 99mTc-IgG and 99mTc-UBI scintigraphy, a comprehensive study on a large number of patients with clinical suspicious of acute appendicitis would be more helpful.

To measure radiation exposures rate in low-risk patients having stress-only and stress-rest myocardial perfusion imaging. This was a prospective study conducted from January 2012 till November 2012 upon patients with low pre-test probability for coronary artery disease (CAD). A stress MPI (stress-only if MPI is normal and no resting study) followed by a resting MPI study (same day) if stress study was positive or equivocal. Exposure rates (in milli-Roentgen/hour, mR/hr) from injected patients at 1 meter distance were measured at 10 minutes, 1 hour and at time of releasing patients in both groups. Total 369 patients were included and 104 (28%) patients had stress-only and 265 (72%) had stress-resting studies. Mean administered 99mTc-MIBI dose in Stress-only and Stress-rest groups was 8 ±1 mCi and 24 ±03 mCi respectively (p<0.05). Exposure rates(in mR/hr) within 10 min, 1 hour and at release time in Stress-only and stress-rest groups were 0.394, 0.294, 0.194and 1.540, 1.431, 1.207 respectively (p<0.05). Mean stay of patients in laboratory was 90 ±39 minute in Stress-only and 156 ±53 minute in Stress-Rest group (p <0.0001). There was a significantly widening gap between exposure rates from patients with Stress-only and stress-rest protocols as 26:74%, 21:79% and 16:84% at 10 min, 1 hour and at time of release respectively. We conclude that adopting a Stress-only MPI protocol in low risk patients ensures significantly lower radiation doses to patients and technologists. A worldwide paradigm shift in nuclear cardiology practice would safe mankind from unjustified radiation exposure.

Neurotensin (NT) is a tridecapeptide that binds specifically to neurotensin receptors. Several forms of cancer, including small cell lung cancer, colon, pancreatic and prostate carcinomas especially exocrine pancreatic carcinomas express receptors for neurotensin peptide. Radiolabeled neurotensin derivatives with a high affinity for these receptors might be used for scintigraphy. The aim of this work was to prepare a freeze-dried kit formulation for routine preparation of 99mTc labeled neurotensin in nuclear medicine center. A freeze dried kit containing reducing agent, coligands and HYNIC-Neurotensin derivative for labeling with 99mTc was prepared. Labeling was performed at 95°C for 15 min and radiochemical analysis involved ITLC and HPLC methods. The stability of radiopeptide was checked in the presence of human serum at 37°C up to 24 h. The receptor bound internalization rate was studied in neurotensin receptor expressing HT-29 cells. Biodistribution of radiopeptide was studied in mice. Labeling yield of >95% was obtained corresponding to a specific activity of 80 MBq/nmol. Prepared radioconjugate was stable in human serum and more than 12% of activity was specifically internalized into HT-29 cells up to 4 h. Biodistribution study showed a rapid blood clearance, with renal excretion and specific binding towards NT receptor-positive tissues such as intestines (0.99 ± 0.16% ID/g at 1 h). The favorable characteristics of our new designed labeled peptide formulation make it as a promising candidate for diagnosis of malignant tumors.

We intended to assess the accuracy of re-expressed Modification of Diet for Renal Disease (MDRD) and Cockcroft-Gault (CG) equations to estimate glomerular filtration rate (GFR) in chronic kidney disease in two different etiologies of acute renal failure (ARF): acute tubular necrosis (ATN) and acute glomerulonephritis (AGN). Patients admitted for ARF or the patients complicated with ARF during the course of their hospitalization were enrolled to the study (n=21; 14 females and 7 males; 11 ATN and 12 AGN). When the plasma creatinine reached a steady state (DPSM) using 99mTc-DTPA. GFR was also estimated by MDRD (GFRMDRD) and CG (GFRCG) equations. The patients aged 44.8±19.5 years and weighted 67.8±10.7kg. GFRDPSM (32.9±14.7 ml/min) was statistically different from the GFRMDRD (11.6±8.2 ml/min; pCG was lower than GFRDPSM in patients with either ATN (16.5±12.5ml/min and pDPSM and GFRMDRD (r=0.34; p=0.13) but GFRDPSM and GFRCG values were correlated (r=0.48; p=0.03). Out of subjects with GFRDPSM >30, 92.3% had GFRMDRDCG Our results indicate that MDRD and CG equations were substantially inaccurate in patients with ARF. More precise methods of GFR evaluation is recommended in these patients.

Chronic recurrent multifocal osteomyelitis (CRMO) is an inflammatory bone disease usually affecting children. A 9-year old boy presented with recurrent lower extremities pain and discomfort lasting for two years. In every time, symptoms vanished after several weeks. The patient received antibiotics only in one period of bone pain. In other occasions the patient didn’t received any antibiotics. In last episode of bone pain, symptoms disappeared by use of naproxen. In patient’s X-rays, there were multifocal areas of sclerosis with a wide transitional zone accompanied by a fine periosteal reaction. Regarding his history and MRI, bone scan findings were more in favor of active inflammatory process in the involved regions. In needle biopsy and bone curetting of left & right tibiae, osteonecrosis, mild inflammatory fibrosis, and scattered chronic inflammatory cells consistent with chronic osteomyelitis were noticed. No malignant neoplastic tissue was identified. In 2-year follow-up, diagnosis of CRMO was confirmed by serial laboratory tests, three-phase bone scan, CT and MRI findings. This diagnosis was proved by pathology evaluation following needle bone biopsy.

Vulvar cancer is a rare gynecological malignancy with mainly lymphatic spread. Sentinel node mapping plays an important role in the management of this gynecological malignancy. In the current study, we reported our experience in sentinel node mapping of vulvar cancer and review the literature accordingly. Since the introduction of sentinel node mapping to the surgical oncology community of our university in 2004, we had two operable vulvar cancer patients who were candidate for sentinel node mapping for inguinal lymph node staging. In the current study, we reported these two cases in details and a brief review of literature on sentinel node mapping in vulvar cancer was done. We specifically discussed the overall accuracy, importance of blue dye injection, learning curve effect, frozen section, excisional biopsy and location of the tumors. Overall sentinel node mapping is a safe and effective method for inguinal lymph node staging in vulvar cancers. In order to perform sentinel node mapping efficiently, paying attention to the details is of utmost importance.