Comparison of Lutetium-177 tin colloid and Rhenium-188 tin colloid radiosynovectomy in chronic knee arthritis.

OBJECTIVE: To assess the role of Lutetium-177(Lu-177) tin colloid for radiosynovectomy and compare it with Rhenium-188 (Re-188) tin colloid radiosynovectomy for alleviation of pain in patients with chronic inflammatory arthritis of knee. METHODS: Patients of chronic inflammatory arthritis of the knee underwent pretherapeutic evaluation in a form of knee ultrasonogram, bone scan and clinical evaluation. Fifty-seven recruited patients were allocated at random to receive either intraarticular injections of Lu-177 tin colloid or Re-188 tin colloid. Eventually, 27 patients received Re-188 tin colloid and 30 patients received Lu-177 tin colloid. The joint was then immobilized for 2 days. Response evaluation was done using knee ultrasound, bone scan and clinical findings. RESULT: Of 30, 20 patients responded to radiosynovectomy in the Lu-177 tin colloid group compared to 21/27 patients in the Re-188 tin colloid group. CONCLUSION: Lu-177 tin colloid is an effective alternative to Re-188 tin colloid for radiosynovectomy in patients with chronic inflammatory knee arthritis.

Right Ventricle Metastasis from Carcinoma Rectum: Findings on 18F-Fluorodeoxyglucose Positron Emission Tomography-Computed Tomography.

Rectal adenocarcinoma metastasizes most commonly to the lungs and liver. Metastasis to heart, although described in literature, is a very rare phenomenon. We describe the 18F-fluorodeoxyglucose positron emission tomography-computed tomography (18F-FDG PET-CT) findings of a 45-year-old male who was a biopsy-proven case of adenocarcinoma rectum. Apart from metastatic disease involving liver, lungs, bone marrow, and lymph nodes, metastasis to right ventricle was also seen on PET-CT scan.

Ileal Neuroendocrine Tumor With Bilateral Breast and Ovarian Metastases: Findings on 68Ga-DOTANOC PET/CT Scan.

Metastasis to the breast is a rare occurrence and constitutes less than 2% of all breast tumors. Similarly, ovarian metastases from neuroendocrine tumors are also uncommon, and if the adnexal masses are bilateral, then the chances of it being metastatic rather than being primary range from 88% to 94%. We present a case of 61-year-old woman who in the course of workup for abdominal pain and diarrhea was eventually diagnosed as ileal neuroendocrine tumor with breast, ovarian, and lymph nodal metastases on Ga-DOTANOC PET/CT scan.

Lutetium-177 tin colloid radiosynovectomy in patients with inflammatory knee joint conditions intractable to prevailing therapy.

OBJECTIVE: To evaluate the treatment response of lutetium-177 tin colloid radiosynovectomy (Lu-RSV) in patients with inflammatory knee joint conditions refractory to conventional treatment. PATIENTS AND METHODS: Overall, 29 knee joints in 29 patients with chronic synovitis caused by various inflammatory knee joint diseases refractory to conventional therapy were included in this prospective study. All patients were assessed clinically for pain, tenderness, joint swelling, mobility, analgesic intake, and blood pool activity on bone scan. Different scores were assigned to all these parameters. RSV of knee joint was done using intra-articular injection of Lu tin colloid. Response was assessed at 3 months using various clinical parameter scores and blood pool bone scan as mentioned before and categorized as responders and nonresponders on the basis of change in percentage of cumulative scores. RESULTS: Of the 29 joints, 21 were responders and eight were nonresponders at 3 months after RSV. There was a statistically significant reduction in clinical parameters cumulative scores at follow-up when compared with baseline (P<0.0001). Blood pool scintigraphy also showed decrease in blood pool activity compared with the baseline. There was statistically significant association between the responder group and absence of radiological abnormality. CONCLUSION: Lu tin colloid synovectomy is a useful treatment modality in patients with chronic inflammatory knee joint conditions refractory to conventional treatment. Patients with shorter duration of disease and normal or minor radiographic findings are better candidates for RSV.

Formulation and characterization of lutetium-177-labeled stannous (tin) colloid for radiosynovectomy.

OBJECTIVE: Easy large-scale production, easy availability, cost-effectiveness, long half-life, and favorable radiation characteristics have made lutetium-177 (Lu) a preferred radionuclide for use in therapy. Lutetium-177-labeled stannous (Lu-Sn) colloid particles were formulated for application in radiosynovectomy, followed by in-vitro and in-vivo characterization. METHODS: Stannous chloride (SnCl2) solution and Lu were heated together, the pH was adjusted, and the particles were recovered by centrifugation. The heating time and amount of SnCl2 were varied to optimize the labeling protocol. The labeling efficiency (LE) and radiochemical purity (RCP) of the product were determined. The size and shape of the particles were determined by means of electron microscopy. In-vitro stability was tested in PBS and synovial fluid, and in-vivo stability was tested in humans. RESULTS: LE and RCP were greater than 95% and ∼99% (Rf=0-0.1), respectively. Aggregated colloidal particles were spherical (mean size: 241±47 nm). The product was stable in vitro for up to 7 days in PBS as well as in synovial fluid. Injection of the product into the infected knee joint of a patient resulted in its homogenous distribution in the intra-articular space, as seen on the scan. No leakage of activity was seen outside the knee joint even 7 days after injection, indicating good tracer binding and in-vivo stability. CONCLUSION: Lu-Sn colloid was successfully prepared with a high LE (>95%) and high RCP (99%) under optimized reaction conditions. Because of the numerous benefits of Lu and the ease of preparation of tin colloid particles, Lu-Sn colloid particles are significantly superior to its currently available counterparts for use in radiosynovectomy.

Mammillary Body: Chronic Refractory Epilepsy Seizure Focus Detected by 18F-FDG PET-CT.

Epilepsy is one of the most common neurological conditions, which affect nearly 1% of the entire population. We present F-FDG PET-CT findings of a mammillary body epileptic focus in a 50-year-old woman with a 5-year history of seizure and behavior disturbance and memory problems for the past 4 years.