Ashish Kumar Jha, Vinod Kendarla, Bhakti Shetye, M Sneha, M Priya, S Sneha, A Archi, V Rangarajan

Department of Nuclear Medicine and Molecular Imaging, Tata memorial Hospital, Mumbai, Maharashtra, India

Aim and Objective: Plasma sampling method is the gold standard technique available to calculate the glomerular filtration rate (GFR) in clinical practice. Cr-51-EDTA is an ideal tracer for GFR calculation by plasma sampling method, but Tc-99m-diethylenetriamine penta-acetic acid (Tc-99m-DTPA) is also used in clinical practice particularly in a developing country like ours. Despite higher percentage of plasma binding Tc-99m-DTPA is able to produce satisfactory result considering its cost and availability. Usually weighing method is used to estimate the injected count by standard dilution technique but gamma camera counting method can also be used. The aim of our study was to compare the GFR, calculated by counting and weighing method, to avoid the expenses incurred on precision balance, if counting method correlates well with weighting method.

Patients and Methods: The study was performed on 60 patients (42 male and 18 female; age range 26 to 65 years) who were referred to our department for GFR estimation. All the patients were well hydrated and 3 to 5 mCi Tc-99m-DTPA was injected intravenously and thereafter blood samples were taken at 2 and 4 h via the indwelling tube in contra lateral arm.

Standard and Patient Dose Preparation and Injection: Standard and patient syringe were labeled properly. 3 to 5 mCi 99mTc-DTPA is dispensed in standard and patient labeled syringe. The loaded standard and patient syringe were weighed on precision balance and also counted on gamma camera and readings were noted in the GFR sheet. Patients were being injected by using butterfly (scalp vein) needle on the gamma camera to calculate GFR by Gates’ gamma camera method. Standard is emptied in a 1000 ml-measuring flask and diluted by 1000 ml water. Emptied standard syringe and patient syringe was weighed on precision balance and counted on gamma camera. Injected weight and standard weight of activity were calculated by subtracting post injection empty syringe weight from loaded syringe weight. Injected count and standard count of activity were calculated by subtracting background and decay corrected post injection empty syringe count from loaded syringe count. 2 h and 4 h blood sample is collected from contra lateral arm, opposite to that of injection arm. Plasma is separated from blood by centrifuging the blood sample for 10 min at 1000 g. Two aliquot of 1 ml each of 2 h and 4 h sample and standard were pipetted in labeled test tube and counted in well counter and noted in the GFR sheet. Russells’ formula was used to calculate the GFR by both the methods separately. GFR calculated by both the methods was correlated to find the correlation coefficient.

Results: The maximum and minimum GFR calculated by counting method were 133.8 ml/min and 44.22 ml/min (average 97.20 ml/min) respectively and by weighting method were 131.6 ml/min and 41.73 ml/min (average 97.35 ml/min) respectively. There was an excellent correlation seen (r = 0.991) in GFR calculated by counting method, with the reference weighing method. The excellent correlation was found because the higher activity 3 to 5 mCi was used in our study and gamma camera imaging was able to produce precise counting in this activity range.

Conclusion: Our study indicates that the counting method was equally good in providing comparable result in comparison with weighing method in this range of activity. So gamma camera method can be used reliably instead of precision balance method.

Nusrat Aland, Shwetal Pawar, Gundu Hari Tilve,Ashmi Manglunia

Department of Nuclear Medicine, Seth G.S. Medical College and KEM Hospital, Mumbai, Maharashtra, India

Objective: To evaluate the role of ^99mTc-DTPA scan in evaluation of hepatorenal syndrome in cirrhotic patients with ascites and with normal serum creatinine levels due to Budd chiari syndrome and other causes of liver cirrhosis.

Materials and Methods: Out of 34 patients; 27 cases of Budd Chiari syndrome and 7 cases of liver cirrhosis due to other causes with normal serum creatinine levels and normal renal system morphology on ultrasound underwent Tc99m DTPA scan on Symbia Dual Head Gamma Camera. Liver function was analyzed using MELD score and renal function (GFR) was analyzed using Gates formula. GFR values of 10 healthy renal donors were taken as controls for normal GFR calculation by camera based method. GFR values of patients in the two categories were correlated with their liver function status.

Results: The mean GFR by Tc-99m DTPA scintigraphy in Budd Chiari syndrome patients was found to be 49.9 ml/min (SD: 17.82 ml/min. 12 out of 27 patients (44%) were found to have reduced GFR by scintigraphic method, despite normal serum Creatinine. Whereas the mean GFR in liver cirrhosis group due to other causes was found to be 33.1 ml/min (SD: 6.49 ml/min) and 5 out of 7 patients (71%) were found to have reduced GFR by scintigraphic method. The liver function status of the two groups was comparable.

Conclusion: ^99mTC-DTPA scan identifies hepatorenal dysfunction earlier than serum creatinine in cirrhotic patients. The renal dysfunction was found to be more prevalent in liver cirrhosis group as compared to the Budd Chiari group with comparable liver function status.

Sarita Sahoo, Anuja Anand, Shwetal Uday Pawar,Gundu Hari Tilve

Department of Nuclear Medicine, Seth G S Medical College and KEM hospital, Parel, Mumbai, Maharashtra, India

Objective: The purpose of this study is to assess the usefulness of Indirect radionuclide cystogram (IRC), which is a continuation of renogram (EC) for diagnosis of urinary bladder dysfunction as a screening procedure in children.

Materials and Methods: Thirty neurologically intact and toilet trained children, 24 boys and 6 girls aged between 3 and 12 years enrolled in the study IRC using Technetium-99m EC as first study, followed by uroflowmetry study within a period of less than 3 days. 23 were cases and 7 children were control for the study.

Results: Vesicoureteral reflux, residual volume and curve pattern were the parameters used for evaluation. Among 23 patients, 6 patients had reflux (26%); 4/6 patients had obstructed curve pattern on uroflowmetry. 3 patients had inconclusive results because of megaureter and 2/3 had obstructed pattern on uroflowmetery. 6 patients had increased time of voiding (>35 s) and increased residual volume (>35 ml). Average residual volume of control patients were 31 ml. The range was between 12 and 52 ml. Percentage of patients with more residual volume was 26%. IRC curve pattern was smooth in 20 patients 4 (17%) patients had abnormal curve pattern (step ladder pattern).

Conclusion: Among three parameters of IRC reflux, residual volume were found to be reliable parameters to diagnose bladder dysfunction. The curve pattern is a weak parameter on IRC study. In comparison with uroflowmetry study, IRC study gives one additional parameter i.e. residual volume. Therefore IRC can be used with renal dynamic scan for screening of patient suspected with VUR as a non-invasive screening tool.

T Rosenara Beegum, Amit Abhyankar, Basant L Malpani, Sandip Basu

Radiation Medicine Centre, Bhabha Atomic Research Centre, Tata Memorial Centre Annexe, Jerbai Wadia Road, Parel, Mumbai, Maharashtra, India

Objective: To assess the renal functional parameters and compare them before and after various cycles of ¹⁷⁷Lu-DOTA-peptide therapy.

Materials and Methods: 32 patients were treated with ¹⁷⁷Lu-DOTA-peptide from February 2012 to April 2013. The standard institutional protocol of renal evaluation was carried out prior to each cycle of ¹⁷⁷Lu-DOTA-peptide therapy and 3 months after each cycle - ^99mTc-DTPA renogram for GFR assessment (timed blood sampling also done), ^99mTc-EC renogram for renal tubular function assessment and serum creatinine. Patients also underwent protein load GFR estimation and Creatinine clearance calculation using Cockroft-Gault (CG) formula. Renal functional reserve (difference between protein load and baseline GFR) was calculated by camera method and blood sampling GFR). The difference in GFR, renal functional reserve, creatinine clearance and ^99mTc-EC clearance between subsequent cycles of therapy were calculated by grouping patients based on the number of cycles received: Group 1 - treatment naïve patients, Group 2 - patients already received 1 cycle, Groups 3 and 4 - treatment naïve patients and already treated patients followed-up for 2 consecutive cycles respectively.

Results: None of the patients showed significant change in pre- and post-treatment GFR values. Blood sample method showed fall in renal functional reserve in 5/10 patients in first, 7/9 patients in second and only in 2/6 patients in the sequential treatment group. No consistent sequential change in RFR was noted in Group 3; whereas a sequential reduction was noted in 2 patients in Group 4. 8/11 in first and 9/11 patients in second group showed a reduction in ERPF All patients in Groups 3 and 4 showed a reduction in ERPF by ^99mTc-EC clearance. All routine renal function tests were normal on all these occasions.

Conclusion: Our data demonstrates that PRRT with ¹⁷⁷Lu-DOTA-peptide does not lead to a significant decline in GFR on short term follow up. The reduction in renal functional reserve noted in the study population, long term follow up study with more patients and comparison with normal control population is needed for ascertaining the significance of this finding. There was a progressive decline in ERPF measurement in most patients. This requires further follow-up to make definitive conclusions.