Accumulation of Tc99m-DMSA-3 in the spleen in a case of multiple myeloma with associated amyloidosis.

We describe a case of a 58-year-old male with longstanding hypertension and Type 2 diabetes mellitus who developed sudden onset renal impairment. The first clue to the possible presence of amyloidosis in this case was provided by the radionuclide renal cortical scan performed with trivalent dimercapto succinic acid (Tc99m-DMSA-3), which revealed intense tracer uptake in the spleen suggesting amyloid deposit. Further workup to ascertain the cause of amyloidosis led to the diagnosis of multiple myeloma. We conclude that in cases of extra-renal or splenic accumulation of Tc99m-DMSA-3, a diagnosis of amyloidosis should be considered, in an appropriate clinical setting.

Use of atropine in patients with recent myocardial infarction during exercise myocardial perfusion study. Use of atropine during exercise myocardial perfusion SPECT.

BACKGROUND: Patients with recent myocardial infarction frequently require a myocardial perfusion study for risk stratification. However a conclusive study cannot be accomplished in many due to non-attainment of target heart rate. AIM OF THE STUDY: To evaluate the effect of pre-stress administration of atropine in exercise performance of patients with recent myocardial infarction. MATERIAL AND METHODS: Study included 43 test and 43 control patients and were matched for their age, sex, status of pretest exercise tolerance, area of infarction and for interval between infarction and stress thallium test. Atropine (0.01 mg/kg) was administered intravenously 3 min prior to treadmill stress in all the 43 test patients and no atropine was administered to control patients. RESULTS: Target heart rate was attained in 95.3% patients receiving atropine compared to in 67.4% of control patients. There was no significant difference between mean ages (p>0.33), basal BP (p>0.47), peak BP (p>0.18) of both groups. There was significant difference between the increment in exercise-induced heart rate (p<0.004), peak heart rate (p<0.001) and double product (p<0.001) attained between both groups. No significant adverse effect was noted in patients who received atropine. CONCLUSION: Pre-stress administration of atropine in patients with recent myocardial infarction is safe and results in a significantly better exercise performance, which might be useful in decreasing the number of equivocal myocardial perfusion studies.

Do healthy potential kidney donors in india have an average glomerular filtration rate of 81.4 ml/min?

BACKGROUND: Until now, a normal reference range for glomerular filtration rate (GFR) in adult Indian potential kidney donors has not been determined and values from a western population are being used as reference. AIM: To determine the reference range of GFR in healthy adult Indian potential kidney donors. BASIC PROCEDURES: GFR was measured in 610 (250 male, 360 female, average age 35.16 years) healthy potential kidney donors using the 99mTc-DTPA (diethylenetriamine pentaacetic acid) two-plasma sample method of Russell. RESULTS: The mean body surface area (BSA)-normalized GFR value of a young healthy Indian adult potential kidney donor was calculated as 81.4 +/- 19.4 ml/min/1.73 m2 BSA--for males it was 82.3 +/- 21.3 ml/min/1.73 m2 BSA and for females 80.8 +/- 18.1 ml/min/1.73 m2 BSA. There was no significant difference between derived mean GFR values in males and females with a p value of 0.37. CONCLUSIONS: The normal GFR value for the healthy Indian adult potential kidney donor appears to be much lower than the accepted value for a western population. The mean GFR value of a young healthy Indian adult potential kidney donor is 81.4 +/- 19.4 ml/min/1.73 m2 BSA, which is significantly different from the normal value of 109-125 ml/min derived from a western population. These findings might be useful in deciding on a suitable kidney donor in an Indian context.

Evaluation of Tc99m-glucoheptonate for SPECT functional imaging of medulloblastoma.

OBJECTIVES: Functional imaging of medulloblastoma using SPECT has been a difficult problem as this tumour does not concentrate conventional brain tumour imaging radiopharmaceuticals. This study aimed to evaluate Tc99m-glucoheptonate as a "brain tumour-seeking" radiopharmaceutical for functional imaging of medulloblastoma. METHODS: Tc99m-glucoheptonate brain SPECT was performed in 27 patients with medulloblastoma after radiation therapy and with clinical suspicion of tumour recurrence. Histological verification was obtained within 7 days in patients with a SPECT diagnosis of tumour recurrence. Patients with a SPECT diagnosis of post-radiation gliosis were clinically observed for a minimum period of one year after the SPECT study. RESULTS: Fourteen patients had increased radiotracer uptake in the primary tumour bed, suggesting tumour recurrence. Histopathology confirmed viable medulloblastoma in all cases. Thirteen patients had no increased tracer uptake in the primary tumour bed, suggesting post-radiation gliosis. They all had a clinical course consistent with post-radiation gliosis. CONCLUSION: Tc99m-glucoheptonate is an ideal SPECT tracer for functional evaluation of medulloblastoma. SPECT utilising Tc99m-glucoheptonate is a reliable diagnostic modality to differentiate tumour recurrence from post-radiation gliosis in patients with medulloblastoma.

Thallium-201 versus Tc99m-glucoheptonate SPECT for evaluation of recurrent brain tumours: a within-subject comparison with pathological correlation.

BACKGROUND: Thallium-201 (Tl-201) is the most commonly used tracer for functional imaging of recurrent brain tumours. However, the physical properties of Tl-201 are not particularly suitable for this application, thus, a technetium-99 (Tc99m) labelled alternative with more favourable physical properties has been sought. The aim of this study was to compare the ability of Tl-201 and Tc99m-glucoheptonate single photon emission computed tomography (SPECT) to detect viable recurrent tumour and differentiate post-radiation gliosis. METHOD: Brain SPECT with Tl-201 and Tc99m-glucoheptonate was performed in 20 patients with malignant brain tumour in whom recurrent disease was suspected. Tracer uptake in the mass was defined as high, moderate or low and was correlated with histological verification of the lesion in all cases. RESULTS: Recurrent tumour was demonstrated in 17 patients by both Tl-201 and Tc99m-glucoheptonate SPECT and confirmed by surgical resection in all 17 patients. Three patients had no tracer uptake on either Tl-210 or Tc99m-glucoheptonate SPECT and surgical resection revealed only fibrotic tissue with areas of necrosis. Tc99m-glucoheptonate images were found to correlate more closely with the surgical findings with regard to the location of tumour margin, extent of tumour invasion and intratumoural necrosis. CONCLUSION: Tc99m-glucoheptonate brain SPECT is an accurate agent for SPECT imaging of recurrent brain tumours and may provide more information about the location of the tumour margin and its extent and intratumoural necrosis than Tl-201. Tc99m-glucoheptonate may be a viable replacement for Tl-201.

Evaluation of 99mTc-L-methionine brain SPECT for detection of recurrent brain tumor: a pilot study with radiological and pathological correlation.

PURPOSE: To evaluate technetium labeled L-methionine for imaging recurrent brain tumors. MATERIAL AND METHODS: Brain SPECT with 99mTc-L-methionine was performed to evaluate tumor viability in 42 patients with primary brain tumor. Findings of SPECT were correlated with radiological and histopathological findings as reference. RESULTS: 99mTc-L-methionine showed localized increased uptake in 40 patients with tumor recurrence, whereas 2 patients with post-radiation gliosis did not show tracer accumulation. A low differential uptake rate (DUR) 2.43 +/- 0.74 and methionine retention (MR) index 0.93 +/- 0.03 was seen in cases of post-radiation gliosis. A high DUR (36.20 +/- 10.31) and MR index (4.87 +/- 2.37) was seen in cases of recurrent tumor. Mean DUR in high-grade tumors (44.01 +/- 8.46) was significantly higher (P<0.001) than in low-grade tumors (30.42 +/- 7.38), and mean MR index in high-grade tumors (7.03 +/- 2.05) was significantly higher than in low-grade tumors (3.27 +/- 0.82) (P<0.001). CONCLUSION: 99mTc-L-methionine can be used as a SPECT tracer to differentiate tumor recurrence from post-radiation gliosis.

Does I-131-MIBG underestimate skeletal disease burden in neuroblastoma?

BACKGROUND: Controversy persists as to the need for both MIBG and bone scanning in routine evaluation of neuroblastoma. AIM: To compare the efficacy of I-131- metaiodobenzylguanidine (MIBG) scan against that of conventional Tc99m- methylene diphosphonate (MDP) bone scan for the detection of skeletal deposition of neuroblastoma. METHODS AND MATERIAL: The study included 57 patients (36 boys, 21 girls: age range 1-14 years) of neuroblastoma who underwent both bone scan with Tc99m-MDP and I-131-MIBG scan within 15 days of each other at presentation and during follow-up. RESULTS: At presentation 11(19.2%) patients had evidence of skeletal metastases on MDP scan against 7 patients who showed bony secondaries on MIBG scan. Of the 7 patients, with positive MIBG and MDP scans, MDP scan detected 11 sites whereas MIBG scan detected 7 sites. On follow-up study, 3 patients with initial abnormal MDP scan but normal MIBG scan, developed skeletal metastases detectable on MIBG scan, whereas 3 of the 46 patients who had normal MDP and MIBG scan at presentation; developed skeletal metastases detectable on MDP scan. MIBG scan was concordant in 2 of them but was normal in the third patient. CONCLUSION: I-131-MIBG underestimates skeletal disease burden in neuroblastoma. Therefore, Tc99m-MDP bone scan should remain a part of routine assessment of patients with neuroblastoma.

Role of skeletal scintigraphy in soft tissue sarcoma: Improving the diagnostic yield.

BACKGROUND: The presence of skeletal metastases significantly influences the therapeutic strategy adopted for soft tissue sarcoma. However, literature on the prevalence of skeletal metastases in soft tissue sarcoma is limited and none of the available data is based on the Indian patient population. AIM: To determine the prevalence of skeletal metastases at presentation in patients of soft tissue sarcoma and to rationalise the use of preoperative skeletal scintigraphy in such patients. METHODS AND MATERIAL: Preoperative bone scans were evaluated in 122 patients with soft tissue sarcoma (median age, 34 years; range, 4-83). The scans were classified into 3 grades: Grade 1: metastases very likely; Grade 2: equivocal; Grade 3: normal or benign lesion. In all the patients studied, the ability of the patient to localize the site or sites of pain was recorded and that was correlated with the site of metastases in scintigraphy. RESULT: Seventeen (13.9%) patients had Grade 1 scan; 16 of them had bony pain that was not readily explainable by trauma or other local factors. Ten ( 8.1%) patients had Grade 2 scan, five of them had bony pain which was not readily explainable by trauma or other local factors. Ninety-five patients (77.8%) had Grade 3 scan. Of these, 9 had localised bone pain which could be definitely associated with trauma or joint degeneration. CONCLUSION: The prevalence of skeletal metastases at presentation in patients with soft tissue sarcoma is low (13.9%). The low rates of skeletal metastases in bone pain-free patients (0.9%) versus the high rate in symptomatic patients (76.1%) supports the use of bone scanning in symptomatic patients only.

Role of Tc-glucoheptonic acid brain single photon emission computed tomography in differentiation of recurrent brain tumour and post-radiation gliosis.

Blood-brain barrier imaging of brain tumours is fast attracting interest now that it has been demonstrated that disruption of the blood-brain barrier is essential for uptake of all tumour-seeking agents. The aim of the present study was to differentiate recurrent tumour from post-radiation gliosis using (99m)technetium-glucoheptonate ((99m)Tc-GHA) as a tumour-seeking agent. Brain single photon emission computed tomography (SPECT) with (99m)Tc-GHA was performed in 73 patients with primary malignant brain tumours after radiotherapy, and the results were correlated with the clinical behaviour of the disease on follow up. The SPECT was suggestive of recurrent tumour in 55 patients. The clinical course was consistent with recurrence in 51 of the 55 patients. The clinical course was consistent with radiation necrosis in the remaining 21 patients, which included 17 patients with a negative SPECT and four patients with a positive SPECT study. Mean GHA index in recurrent tumour and post-radiation gliosis was 7.04 +/- 4.35 and 1.88 +/- 1.70, respectively (P = 0.0001). Mean GHA index in high-grade and low-grade glioma was 7.78 +/- 4.73 and 3.15 +/- 2.44, respectively (P = 0.001). (99m)Technetium-glucoheptonate brain SPECT is a sensitive and reliable diagnostic modality to differentiate recurrent tumour from post-radiation gliosis.

Imaging using Tc99m-tetrofosmin for the detection of the recurrence of brain tumour: a comparative study with Tc99m-glucoheptonate.

BACKGROUND: In the past "blood-brain barrier" agents such as Tc99m-glucoheptonate were routinely used for the diagnosis of brain tumours. Of late, agents used for studying myocardial perfusion namely, Tc99m-tetrofosmin, Thallium-201, and Tc99m-sestamibi have replaced the "blood-brain barrier agents " when imaging is undertaken for the detection of the recurrence of brain tumours. However, the incremental diagnostic information provided by Tc99m-tetrofosmin when compared with a blood brain barrier agent in the diagnosis of recurrent brain tumour has not been evaluated till date. AIMS: The study was carried out to substantiate whether Tc99m-tetrofosmin provides any incremental diagnostic information not provided by the blood brain barrier agent Tc99m-glucoheptonate. MATERIAL AND METHODS: Brain SPECT scans were performed using Tc99m-tetrofosmin and Tc99m-glucoheptonate in 126 patients of recurrent brain tumour. Bio-distribution and uptake properties of both the tracers were analysed by measuring relative uptake of both the tracers in tumour compared to background (T/B ratio), nasopharynx (T/N ratio) and scalp (T/S ratio). STATISTICAL ANALYSIS: Descriptive statistics were calculated for each variable. Pearson's correlation coefficient was applied to see agreement of the continuous variables. Paired t test was used to evaluate the difference between two means. RESULTS: Uptake properties of both the tracers were analysed in 105 patients in whom both Tc99m-tetrofosmin and Tc99m-glucoheptonate showed concentration. The remaining 21 patients in whom the tumour mass did not show Tc99m-tetrofosmin concentration were excluded from the study. Mean T/B ratio, T/N ratio and T/S ratio was 5.83 + 2.09 and 5.99 + 2.26, 0.53 + 0.21 and 0.55 + 0.22 and 1.11 + 0.60 and 1.26 + 0.52 for Tc99m-tetrofosmin and Tc99m-glucoheptonate respectively. No statistically significant difference between T/B ratio and T/N ratio of Tc99m-tetrofosmin and Tc99m-glucoheptonate was found; p values were 0.25 and 0.83 respectively. However there was significant difference (P=0.006) between the T/S ratio of Tc99m-tetrofosmin and that of Tc99m-glucoheptonate. CONCLUSION: Tc99m-tetrofosmin does not provide any incremental diagnostic information not provided by the blood brain barrier agent Tc99m-glucoheptonate.

Cerebellar medulloblastoma presenting with skeletal metastasis.

Medulloblastomas are highly malignant brain tumours, but only rarely produce skeletal metastases. No case of medulloblastoma has been documented to have produced skeletal metastases prior to craniotomy or shunt surgery. A 21-year-old male presented with pain in the hip and lower back with difficulty in walking of 3 months' duration. Signs of cerebellar dysfunction were present hence a diagnosis of cerebellar neoplasm or skeletal tuberculosis with cerebellar abscess formation was considered. MRI of brain revealed a lesion in the cerebellum suggestive of medulloblastoma. Bone scan revealed multiple sites of skeletal metastases excluding the lumbar vertebrae. MRI of lumbar spine and hip revealed metastases to all lumbar vertebrae and both hips. Computed tomography-guided biopsy was obtained from the L3 vertebra, which revealed metastatic deposits from medulloblastoma. Cerebrospinal fluid cytology showed the presence of medulloblastoma cells. A final diagnosis of cerebellar medulloblastoma with skeletal metastases was made. He underwent craniotomy and histopathology confirmed medulloblastoma.

Role of skeletal scintigraphy in advanced retinoblastomas.

PURPOSE: To document the incidence of skeletal metastases exclusively in advanced cases of retinoblastoma and to rationalize the use of preoperative skeletal scintigraphy in such patients. MATERIAL AND METHODS: Preoperative bone scans of 36 consecutive patients with advanced retinoblastoma who underwent skeletal scintigraphy during 1998 to 2003 were analyzed retrospectively. Bone scans were classified as: Grade 1 (high probability scan for skeletal metastases), Grade 2 (equivocal malignant or benign abnormalities), or Grade 3 (normal or certainly benign lesions). RESULTS: Grade 1 scan was found in 3 (8.33%) patients; bone metastases were confirmed by additional investigations. Grade 2 scan was found in 5 (13.88%) patients; bone metastases were excluded in all by additional investigations. Grade 3 scan was found in the remaining 28 (77.77%) patients. Extraorbital extension of disease was demonstrated by fine needle aspiration of lymph nodes in five patients, which included all three patients with Grade 1 scan. In addition to lymph node metastases, two patients had intracranial extension of the disease; demonstrated by contrast-enhanced magnetic resonance imaging of the head. One patient had liver metastases detected on abdominal ultrasound. None of the patients had skeletal metastases only. CONCLUSION: Routine preoperative bone scan is not justified in patients with locally advanced retinoblastoma. Bone scan should only be performed in patients with documented extraocular metastatic disease.

Prevalence of vesicoureteral reflux in patients with incidentally diagnosed adult hypertension.

OBJECTIVES: To evaluate the prevalence of vesicoureteral reflux (VUR) in hypertensive patients without any other evidence of renal involvement. Reflux nephropathy may be clinically latent and present in early adulthood as hypertension when superimposed confounding factors are added. METHODS: The medical records of 157 adult hypertensive patients with normal renal parameters and low-probability, captopril-enhanced renal dynamic scan findings who underwent direct radionuclide voiding cystoscintigraphy between June 1998 and May 2003 were retrospectively analyzed. RESULTS: VUR was documented in 30 patients (19.1%). In those 30 patients, VUR was mild in 8 (26.6%), moderate in 6 (20%), and severe in 16 (53.3%) patients. Bilateral VUR was seen in 7 patients, graded as severe in all cases. The prevalence by age was 20% in the 18 to 30-year-old group, 16.6% in the 31 to 45-year-old group, and 20% in the older than 45-year-old group. CONCLUSIONS: The results of this study have shown that VUR is present in a significantly large proportion of adult patients with hypertension without any apparent renal parenchymal or renovascular involvement.

Is brain SPECT a suitable modality for evaluation of postradiotherapy posterior fossa brain tumours? A comparative evaluation with contrast enhanced computed tomography.

Single photon emission computed tomography (SPECT) of the brain is exquisitely sensitive in detecting viable tumour tissue in the supratentorial region, but its efficacy has not been properly evaluated till date in case of infratentorial posterior fossa tumours. Twenty-four patients with primary posterior fossa brain tumour were included in this study. In each case brain SPECT with 99mTc-glucoheptonate (GHA) was performed for the evaluation of disease status. Contrast enhanced computerised tomography of brain was also performed in all the patients. Brain SPECT was positive in four patients with recurrence of tumour as compared to fifteen cases with computed tomography with a mean GHA retention index 5.26 +/- 1.64. Patients with postradiation gliosis (n=9) showed lower GHA retention index of 1.24 +/- 0.27. This study demonstrates that brain SPECT is not sensitive in detecting recurrence of tumour tissue in infratentorial region, as it is in the supratentorial region, with a sensitivity of 20%, accuracy of 45.83% and negative predictive value of 40% and the chance of any single study coming as false negative is about 80%.

Evaluation of single photon emission computerised tomography (SPECT) using Tc99m-tetrofosmin as a diagnostic modality for recurrent posterior fossa tumours.

BACKGROUND: Brain Single Photon Emission Computerised Tomography (SPECT) has been established as a potentially useful tool for the assessment of recurrent brain tumours. Though brain SPECT is exquisitely sensitive in detecting viable tumour tissue in the supratentorial region, its efficacy has not been evaluated till date in case of infratentorial posterior fossa tumours. AIM OF THE STUDY: To evaluate the diagnostic utility of brain SPECT in differentiating recurrence of tumour from post-radiation gliosis in the posterior fossa of the brain. SUBJECTS AND METHODS: Twenty-one patients with primary malignant posterior fossa brain tumour were evaluated by brain SPECT with Tc99m-Tetrofosmin as the tumour-seeking agent. Clinical behaviour of the tumour observed for a minimum period of one year after the SPECT study was taken as the gold standard. STATISTICAL ANALYSIS: The Chi-square test has been used to note the significance of the association between the clinical outcome and the SPECT finding. In addition, the sensitivity and specificity of brain SPECT were also calculated. RESULT: Brain SPECT in 4 patients revealed increased tracer concentration over the primary tumour bed, which was consistent with recurrent tumour. The clinical course was consistent with tumour recurrence in 13 of the 21 patients, which included 3 patients with positive SPECT study and 10 patients with negative SPECT study. Brain SPECT revealed recurrent tumour in 4 patients whereas clinical follow-up suggested recurrence in 13 patients. The clinical course was consistent with radiation necrosis in the remaining 8 patients. In 1 brain SPECT positive patient the clinical course was consistent with post-radiation gliosis. CONCLUSION: This study demonstrates that brain SPECT is not a sensitive diagnostic modality to differentiate recurrent tumour from post-radiation gliosis in the posterior fossa of the brain.