Marina Vlajkovic

Extracorporeal shock wave lithotripsy for cystine urolithiasis in children: outcome and complications.

The Siemens Lithostar Litotriptor was used to treat 6 children withcystine nephrolithiasis, previously treated by open surgery. Fivechildren had renal calculi (3 multiple caliceal, 2 pelvis) and one hadureteral calculus. Stone size ranged from 0.2–2.5 cm in diameter,and stone burden was from 0.24 to 10.81 cm3 per kidney. Fromone to 4 ESWL sessions per unit were applied, with a total of 1,800 to12,000 shock waves. The stone free rate at 3 months was 50%. Acomplete elimination was obtained with cystine stones in renal pelvisand ureter, however, up to 4 ESWL treatments failed in caliceal stones.Rather location of cystine calculi than previous surgery was associatedwith ESWL success rate. Two patients with positive urine cultures weresuccessfully treated with appropriate antibiotics before ESWL wasattempted. Perirenal hematoma was major complication demonstrated byradionuclide scintigraphy in one patient, and resolved spontaneously by3 months. In the combined treatment of cystine urolithiasis in childrenESWL, as auxillary procedure, was safe and effective in pelvis stone butfailed in caliceal stones. Medical dissolution for retained fragmentswas found effective.

Unexpected effect of furosemide on radioiodine urinary excretion in patients with differentiated thyroid carcinomas treated with iodine 131.

BACKGROUND In patients receiving (131)I for therapeutic purposes, diuretics are frequently used in an attempt to accelerate elimination of unbound radioiodine, reduce its adverse effects, and shorten the hospital stay. The aims of our study were to investigate the influence of furosemide therapy on urinary excretion of (131)I in patients with differentiated thyroid cancer (DTC), referred to radioiodine ablation after thyroidectomy, and to investigate whether diuretics are useful in daily practice in patients with DTC. METHODS Forty-three patients with DTC who had normal renal function and low (131)I uptake in cervical region (3.55 +/- 3.45%) were included in this study. The furosemide (20 mg) and potassium chloride (250 mg) were given orally to 23 patients 3 hours after the (131)I administration, and then q8h for 3 days. Twenty patients did not receive either furosemide or potassium chloride. After (131)I administration, the patients collected their urine for 3 days, and radioactivity of urine sample from each micturition was expressed as percentage of the administered dose. Radioactivity of blood samples was measured after 72 hours, and the values were corrected for decay of (131)I and expressed in relation to the administered dose. Initial whole-body measurement (immediately after (131)I administration) and the whole-body measurement after 72 hours were recorded for all patients. The 72-hour whole-body measurement was corrected for decay of (131)I, and expressed as a percentage of the initial whole-body measurement. RESULTS Urinary excretion of (131)I was significantly lower in the patients who were taking furosemide and potassium chloride compared with the control group. The whole-body measurements after 72 hours (13.22 +/- 6.55% vs. 8.24 +/- 3.39% of the initial; p < 0.01, respectively) and the blood radioactivity (34.66 +/- 24.84 vs. 11.64 +/- 8.32 cpm/mL per 1 MBq of administered (131)I, p < 0.01) were found to be unexpectedly higher in the patients who were taking furosemide and potassium chloride compared with the control group. CONCLUSION Our results demonstrated that furosemide given as an adjuvant medication in patients with DTC causes a significant decrease in urinary excretion of radioiodine and its higher blood concentration. Therefore, furosemide should not be recommended as an adjuvant therapy to radioiodine ablation in patients with DTC previously iodine depleted by low-iodine diet.

THE PREDICTIVE VALUE OF 131I-HIPPURATE CLEARANCE IN THE PROGNOSIS OF ACUTE RENAL FAILURE

The aim of this investigation was to study the validity ofthe radionuclide methods in the estimation of kidney function, for prognosisand follow-up of acute renal failure (ARF). In thirty-one ARF patients, theevaluation of glomerular filtration rate (GFR) by 99mTc-DTPAclearance and effective renal plasma flow (ERPF) by 131I-ortoiodohippurate(131I-OIH) clearance was performed within 7 daysand after 6 months from ARF onset. All patients were divided in three groupsaccording to 131I-OIH clearance values obtainedwithin 7 days: group 1, under 150 mL/min; group 2, 150–250 mL/min; andgroup 3, over 250 mL/min. Seven days clearance values of both radiopharmaceuticalswere found to be very low, however, GFR was found more severely impaired thanERPF. Clearance values obtained after 6 months demonstrated no recovery ofrenal function in the first group, partial recovery in the second and almostcomplete recovery in the third group. Patients with the lowest 131I-OIHclearance values at the ARF onset had no recovery of renal function, whilein the other two groups recovery corresponded to initial 131I-OIHclearance values. In patients with ARF both, 99mTc-DTPAand 131I-OIH clearances were shown suitable forthe follow up of renal function, however, only 131I-OIHclearance had a strong predictive prognostic value for renal function recoveryin ARF.

Radionuclide Staging of Renal Function in Type 1 Diabetes Mellitus

Aim. The aim of this study was to assess renal function in different stages of type 1 diabetes mellitus by radionuclide methods. Additionally, glomerular and tubular functions were correlated with urinary albumin (UAER) and N-acetyl-β-D-glucosaminidase (NAGA) excretion rates. Patients and methods. Fifty-three patients with diabetes mellitus were classified into four groups: normoalbuminuric (NA, 18 patients), microalbuminuric (MiA, 12 patients), macroalbuminuric (MaA, 13 patients), and chronic renal failure group (CRF, 10 patients). Glomerular filtration rate (GFR) was estimated by diethylenetriamine pentaacetic acid-technetium 99m (99mTc-DTPA) clearance rate while tubular function was calculated as a percentage of net injected activity fixed in both kidneys, 4 h after intravenous injection of dimercaptosuccinate acid-technetium 99m (99mTc-DMSA). Additionally, 99mTc-DTPA clearance was correlated with estimated GFR (eGFR) by using modified Modification of Diet in Renal Disease (MDRD) Study Group formula. Results. 99mTc-DTPA clearance and 99mTc-DMSA fixation were found significantly higher in normoalbuminuric group (p < 0.05 and p < 0.02, respectively), unchanged in microalbuminuric group (p > 0.05, p > 0.05), and decreased in both macroalbuminuric (p < 0.0001, p < 0.00001) and chronic renal failure group (p < 0.0001, p < 0.00001). Renal function was denoted as normal, increased (hyperfunction), or decreased (hypofunction). It was found normal in a high percentage of patients with normalbuminuria (filtration 44.4%, fixation 72.2% pts) and microalbuminuria (66.7% and 66.7%). Renal hyperfunction was not only found frequent in normalbuminuric group (55.6% and 27.8%), but was also recorded in microalbuminuric group (8.3% and 8.3%). Renal hypofunction was present in all macroalbuminuric patients and in one-quarter of those with microalbuminuria as well. Such distribution of renal function conditions indicated normalbuminuric and microalbuminiric groups functionally heterogeneous. Regression analysis showed a significant correlation between 99mTc-DTPA clearance and eGFR in MaA and CRF groups only. Although urinary NAGA excretion rate was shown as a less sensitive staging parameter, being significantly increased when compared to control group only in MaA and CRF groups (p < 0.05), it significantly correlated with 99mTc-DTPA clearance rate (r = −0.485, p = 0.0004) and 99mTc-DMSA tubular fixation (r = −0.526, p = 0.0002). Conclusions. The results of this study favor the performance of radionuclide studies together with the determination of urinary albumin excretion rate in patients with type 1 diabetes mellitus in order to achieve more reliable staging of diabetic kidney disease. The demonstration of glomerular hyperfiltration and tubular hyperfunction by radiopharmaceuticals contributes to the early detection of diabetic kidney disease, while the quantification of renal function enables the follow-up of the progressive function loss in the later course of the disease.

Pediatric nuclear medicine and pediatric radiology

To improve clinical practice is our daily duty as specialists in radiology and in nuclear medicine. When a clinician asks us to perform an imaging examination, we have to advise that clinician about the best test or imaging strategy to study the clinical problem. Risk-to-benefit ratio and the ALARA principle have to be weighed, as well as modality and cost. Hybrid imaging is now the standard in nuclear medicine. The use of multimodality cameras such as SPECT/CT, PET/CT and PET/MR has been revolutionary [1–4]. The key is finding the exact location of functional or metabolic lesions. But adding CT increases the dosimetry [5–7], requires more detailed knowledge of imaging anatomy and depends on collaboration between radiologists and nuclear medicine specialists. The level of expertise among imaging specialists (at least in pediatric nuclear medicine) varies too much. In some countries nuclear medicine is an independent specialty, and in other countries radiologists are in charge of nuclear medicine tests. Physicians-in-training in radiology and in nuclear medicine have to receive multimodality training [8–12]. And continuing education in both specialties is vital to ensure that senior specialists are well-versed in the latest techniques. In any case, imaging specialists must be able to discuss the options with referring clinicians and to advise them on the appropriate technique for each clinical situation. Pediatric nuclear medicine can be performed in general nuclear medicine facilities or in dedicated pediatric nuclear medicine departments. The quality of the images has to be diagnostically excellent in pediatric nuclear medicine but superfluous scans must be avoided and doses must be as low as reasonably achievable and adjusted to each child according to international recommendations [7, 13–16]. These goals can be more easily reached in dedicated pediatric facilities. Dose reduction remains important. Contrary to general opinion the radiation dose of most nuclear medicine scans is lower than that of many comparable radiologic studies. The most typical example is abdominal CT, which has a higher dose than the most frequent nuclear medicine studies. Another example is that two-thirds of the radiation dose from PET/CT is from the CT component [12–14]. In the latter case it is possible to perform a diagnostic CT scan during the PET/CT examination rather than a separate diagnostic CT scan. Or a lower-dose CT scan could be performed in a patient who has recently undergone a diagnostic CT scan. The best option for the future in pediatric oncology, however, is PET/MR. In bone scintigraphy or an MIBG scan, performance of an SPECT/CT scan significantly increases the radiation dose [15–17]. A possibility is to use a lower-dose nondiagnostic CT scan in these cases. And the best practice is to report together with the radiologist, comparing the SPECT and the CT or MR images frame-by-frame. In many papers, correlative analysis of PET/CT images in children has been reported to be superior to separate analysis of CT and FDG/PET images. The term “correlative imaging” is the joint interpretation of different imaging modalities – CT, MR, US and scintigraphy [18]. This is the best example yet of why collaboration between radiologists and nuclear medicine physicians is so important.

Evaluation of neuroendocrine tumors with 99mTc-EDDA/HYNIC TOC.

BACKGROUND This paper is the short review of our preliminary results obtained with 99mTc-EDDA/HYNIC-TOC. MATERIAL AND METHODS The total of 495 patients with different neuroendocrine tumors were investigated during last few years. RESULTS There have been 334 true positive (TP), 73 true negative (TN), 6 false positive (FP) and 82 false negative findings (FN). Diagnosis was made according to SPECT findings in 122 patients (25%). The mean T/NT ratio for TP cases was significantly higher (p < 0.01) on SPECT (3.12 ± 1.13) than on whole body scan (2.2 ± 0.75). According to our results, overall sensitivity of the method is 80%, specificity 92%, positive predictive value 98%, negative predictive value 47% and accuracy 82%. Fifteen TP patients underwent therapy with 90Y-DOTATATE. CONCLUSION Scintigraphy of neuroendocrine tumors with 99mTc-Tektrotyd is a useful method for diagnosis, staging and follow up of the patients suspected to have neuroendocrine tumors. SPECT had important role in diagnosis. It is also helpful in the appropriate choice of the therapy, including the peptide receptor radionuclide therapy. In the absence of 68Ga-labeled peptides and PET/CT, the special emphasize should be given to application of SPECT/CT as well as to the radioguided surgery.

Evaluation of autosomal dominant polycystic kidney disease by DTPA renal scintigraphy

Sixty patients with previously documented autosomal dominant polycystic kidney disease (ADPKD) were investigated using dynamic kidney scintigraphy with99mTc-diethylenetriaminepentaacetic acid (DTPA). Patients were subdivided in respect of glomerular filtration rate (GFR) as follows: PKD I group (normal GFR), PKD II group (moderately reduced GFR), and PKD III (severely reduced GFR). Seintigraphic features, time activity curves, excretion parameters, global and individual kidney functions were analyzed. Because of GFR dependent sensitivity, in advanced renal failure being only 0.1, and low reproducibility (11% intraobserver, 22% interobserver),99mTc-DTPA dynamic kidney scintigraphy cannot be generally recommended for the diagnosis of ADPKD, but has to become a routine method for functional evaluation of both global and individual renal functions, as well as degree of excretion disturbances in ADPKD patients.

Are Interferential Electrical Stimulation and Diaphragmatic Breathing Exercises Beneficial in Children With Bladder and Bowel Dysfunction

OBJECTIVE To evaluate the effects of interferential current (IC) stimulation and diaphragmatic breathing exercises (DBEs) in children with bladder and bowel dysfunction. PATIENTS AND METHODS Seventy-nine children with dysfunctional voiding and chronic constipation who were failures of primary care interventions were included in the prospective clinical study. All the children were checked for their medical history regarding lower urinary tract symptoms and bowel habits. Physical examination, including abdominal and anorectal digital examination, was performed. Children kept a bladder and bowel diary, and underwent urinalyses and urine culture, ultrasound examination of bladder and kidneys, and uroflowmetry with pelvic floor electromyography. Eligible children were divided into 3 groups (A, B, and C). All groups were assigned education and behavioral modifications. Additionally, group A underwent DBEs and IC stimulation, whereas group B received only DBEs. The treatment was conducted for 2 weeks in the clinic in all 3 groups,. The behavioral modifications and DBEs were continued at home for 1 month. Clinical manifestations, uroflowmetry parameters, and postvoided residual urine were analyzed before and after 6 weeks of therapy. RESULTS After the treatment, significant improvement in defecation frequency and fecal incontinence was noticed only in group A (P < .001 and P < .05, respectively). These children demonstrated significant improvement in lower urinary tract symptoms and postvoided residual urine (P < .001 and P < .05, respectively). Bell-shaped uroflowmetry curve was observed in 73.3% of group A patients (P < .001). CONCLUSION IC stimulation and DBEs are beneficial in chronically constipated dysfunctional voiders. Further trials are needed to define the long-term effects of this program.

Scintigraphy evaluation of the types of functional constipation in children with bowel bladder dysfunction

PURPOSE To evaluate the types of constipation according to colonic transit time in chronically constipated children with dysfunctional voiding (bowel bladder dysfunction, BBD group) and to compare the results with transit type in children with chronic functional constipation without urinary symptoms (constipation group) and children with normal bowel habits, but with lower urinary tract symptoms (control group). PATIENTS AND METHODS One-hundred and one children were included and their medical histories were obtained. The BBD group kept a voiding diary, and underwent urinalyses and urine culture, ultrasound examination of bladder and kidneys and uroflowmetry with pelvic floor electromyography. Radionuclear transit scintigraphy was performed in all children according to a standardized protocol. Patients were categorized as having either slow-transit (ST), functional fecal retention (FFR) or normal transit. RESULTS FFR was diagnosed in 31 out of 38 children with BBD, and 34 out of 43 children in the constipation group. ST was found in seven children with BBD, compared with nine children in the constipation group. The control group children demonstrated normal colonic transit. Urgency, daily urinary incontinence and nocturnal enuresis were noted only in children with FFR. Both children with ST constipation and FFR complained of difficulties during voiding, voiding postponement and urinary tract infections. CONCLUSIONS FFR is the most common form of constipation in children with dysfunctional voiding. However, some children might suffer from ST constipation. Differentiation between these two types of constipation is clinically significant because they require different treatment. Future studies with larger numbers of patients are needed to confirm the noted differences in urological symptoms in these two groups of constipated children..

Solitary congenital pelvic kidney: An extremely rare developmental aberration

&NA; An ectopic pelvic kidney contralateral to an agenetic one is an extremely rare congenital malformation that is usually discovered incidentally on abdominal ultrasound or computed tomography. The authors describe a 40‐yearold woman with right renal agenesis and a contralateral pelvic kidney who had a history of symptomatic recurrent urinary tract infections. She underwent Tc‐99m DTPA dynamic scintigraphy and clearance measurement to assess renal function and the patency of the urinary tract. She had bacteruria and proteinuria at the time of the study but normal blood urea (4.6 mmol/l) and serum creatinine (91 μmol/l) levels. An ultrasound scan did not show renal pelvis dilatation. Dynamic scintigraphy and the clearance value of Tc‐99m DTPA showed a compensatory elevated glomerular filtration rate and normal urine outflow despite the presence of a urinary tract infection and short ureter, which is commonly associated with an ectopic kidney.