Complimentary role of FDG-PET imaging and skeletal scintigraphy in the evaluation of patients of prostate carcinoma.

Prostate cancer is one of the most common malignancies of elderly males. Management depends on the accurate estimation of disease both at initial diagnosis and in its subsequent course. In the present study, we evaluated the diagnostic utility of positron emission tomography with 18 F-fluorodeoxyglucose (FDG-PET) in patients having prostate cancer. The findings were compared with the results of bone scan (BS) for the detection of bone metastases. Sixteen patients (age range, 55-83 years) with confirmed diagnosis of prostate cancer were included in the prospective study. Three patients had undergone bilateral orchidectomy, 1 had hormonal therapy, 9 had undergone both, and 3 had no therapy. All the patients underwent wholebody BS and FDG-PET within 1 week. Interpretation of BS and FDG-PET were performed qualitatively. Osseous abnormalities detected by both methods were compared. Involvement of the disease in other sites as seen on FDG-PET was also noted. BS detected 197 osseous lesions, whereas FDG-PET could detect 97 (49%) bone lesions. However, in 3 patients without any prior therapeutic intervention, FDG-PET results were superior or equivalent to that of BS. FDG-PET also detected extensive involvement of the disease in the bone marrow in 4 patients, lymph node metastases at various sites in 8, liver metastases in 2, and lung metastases in 1 patient. FDG-PET could demonstrate less number of osseous metastases in comparison with BSs, but the results have to be interpreted in the background of prior treatment administered and the tumor biology of the lesion. It is evident that FDG-PET could detect the unknown soft tissue involvement of the disease with good sensitivity, which might play an important role in the management of prostate cancer. Overall, in the absence of novel PET tracers, both skeletal scintigraphy and FDG-PET imaging can play a complimentary role in the management of prostate cancer.

Thoracic duct cyst presenting as a left supraclavicular mass.

Thoracic duct cysts may occur either in the mediastinum or in the neck. The majority of such lesions occurring in the neck consist of chylous fistulae and are secondary to surgery on the neck. Fewer than five cases have been reported in the literature of primary thoracic duct cysts occurring in the neck (1).

Gastro-intestinal effects of Indian spice mixture (Garam Masala).

Spices are a part of diet all over the world but the variety and quantity consumed in tropical countries is particularly significant. The intestinal transit time of Indians is shorter, and their stool weight larger than that of Europeans on a comparable fibre intake. Ingestion of chilli is associated with a faster whole gut transit time. There is hardly any human work on the effects of spices on intestinal transit or gastric emptying. To explore the effects of spices on gastro intestinal transit this study was conducted on 18 well nourished healthy human adult volunteers using Radiolabelled Idli with or without Garam Masala. On gastric scintigraphy the gastric emptying time was much faster in subjects when spicy meal was given. The t1/2 of the spicy meal, 40.09 +/- (p < 0.05) thus implying a faster transit through the stomach. In 17 out of the 18 subjects t1/2 of the spicy meal was consistently lower than that of spicefree meal. The lag phase of gastric emptying showed no significant difference. There was a tendency towards slower gastrocolic transit with Spicefree meal but more subjects need to be done to confirm this.

Urinary continence following posterior urethral valves treatment.

This retrospective study discusses the incidence of symptomatic voiding dysfunction, the etiological factors and the changes with age and with increasing duration of follow up in 67 boys treated for posterior urethral valves and followed up for a period ranging from 1-21 years. Twenty three of the 67 patients (34.3%) had symptomatic voiding dysfunction; the commonest symptom being nocturnal enuresis with diurnal urgency and frequency. Data in this study suggests a definite decrease in the incidence of urinary incontinence as the patient grows older or as the duration of follow up after valve fulguration increases. A Tc-99m DRCG based uroflowmetry was available in 31 of the 67 patients at the time of this review and evidence of detrusor dysfunction was identified in 9 of the 31 patients on the basis of uroflowmetry. Of significance was the detection of detrusor dysfunction on uroflowmetry in 3 patients with a history of normal urinary control and urinary stream with persistent post treatment hydroureteronephrosis eventually culminating into renal failure. Imipramine therapy was given to 10 of the 17 patients with symptoms of urinary frequency, urgency and nocturnal enuresis with a significantly symptomatic improvement in 9 of these patients. Urinary incontinence, detrusor dysfunction and its effect on the upper tracts and renal function is a significant determinant of the long term outcome of the boys treated for posterior urethral valves and this paper emphasises on the need to carefully evaluate and treat this aspect of all valve patients.

Reduction-mediated 99mTc-labeling of antitumor monoclonal antibodies: effect of increasing specific activity on antibody binding kinetics.

Reduction-mediated 99mTc-labeling of antibodies has gained widespread acceptance in preparation of tumor imaging agents. Increased specific activity to enhance detection signals has raised the question of whether such an attempt would cause change in antibody binding kinetics. To answer this question, two antitumor monoclonal antibodies, i.e. IOR-CEA (IgG1) and EMD (IgG2a) were labeled with 99mTc to yield specific activities ranging from 549-4414 MBq/mg. Regression analysis of the binding data revealed that the binding kinetics of IOR-CEA were shifted from monovalent to bivalent binding upon increasing the specific activities. This phenomenon of affinity enhancement was confirmed by the dissociation study where we found soluble CEA had greater difficulty in extracting the cell-bound IOR-CEA labeled at higher specific activity. The bivalent bindings was further supported by the finding that IOR-CEA with higher specific activities delivered less than expected radioactivity to tumor targets despite their immunoreactivities being well preserved. For EMD, the kinetics seemed to be shifted from bivalent to monovalent interaction. At higher specific activities, adverse changes in immunoreactivity were recognized. Breakage of EMD into 99mTc-Fab fragments was likely to occur and was supported by the observation that EMD delivered more than expected radioactivities to target cells upon increasing specific activity. Precaution should be taken when one deals with high specific activity labeling since this might alter the antibody binding kinetics either favorably or unfavorably.

Significance of transplant perfusion index in the diagnosis of acute rejection in live related renal allograft recipients.

The study was undertaken to assess the usefulness of transplant perfusion index (TPI) in the differential diagnosis of renal allograft dysfunction with special reference to acute rejection. It was observed that the TPI has a sensitivity of 100 per cent and specificity of 98.1 per cent in the diagnosis of acute rejection. It was also observed that the serial values of TPI provided valuable clues and guide in the management of transplant dysfunction and helped in the immediate and long term follow-up of patients with renal allografts.