No abstract

No abstract

Concomitant use of radioembolization plus irinotecan did not reach a maximum-tolerated dose. The recommended dose of irinotecan in this setting is 100 mg/m(2) on days 1 and 8 of a 3-week cycle.

Dimercaptosuccinic acid (DMSA) studies were performed in 113 infants less than 1 year old at risk of renal scarring. Of these patients 86 presented with urinary tract infection and 27 were asymptomatic. A voiding cystourethrogram was performed in all cases and excretory urography (IVP) was done in 99. More abnormalities were detected by DMSA study when compared to scars on IVP. When both studies were abnormal there was an excellent correlation on a site by site basis. Fever or systemic disorder was not a reliable sign to determine whether there was upper tract involvement with infection. The incidence of DMSA abnormalities in infants increased with high grade vesicoureteral reflux and decreased with low grade reflux. There was no significant difference in the incidence of abnormal kidneys between the infected and noninfected groups, suggesting that renal scarring may occur with sterile reflux.

Positron emission tomography (PET) is a minimally invasive technique which has been well validated for the diagnosis, staging, monitoring of response to therapy, and disease surveillance of adult oncology patients. Traditionally the value of PET and PET/computed tomography (CT) hybrid imaging has been less clearly defined for paediatric oncology. However recent evidence has emerged regarding the diagnostic utility of these modalities, and they are becoming increasingly important tools in the evaluation and monitoring of children with known or suspected malignant disease. Important indications for 2-deoxy-2-((18)F)fluoro-D-glucose (FDG) PET in paediatric oncology include lymphoma, brain tumours, sarcoma, neuroblastoma, Langerhans cell histiocytosis, urogenital tumours and neurofibromatosis type I. This article aims to review current evidence for the use of FDG PET and PET/CT in these indications. Attention will also be given to technical and logistical issues, the description of common imaging pitfalls, and dosimetric concerns as they relate to paediatric oncology.

Background: Malignant gastrointestinal stromal tumours (GISTs) are a rare subset of aggressive mesenchymal tumours specific to the gastrointestinal system. They are both locally aggressive and can metastasize. The aim of this analysis was to report on our experience of the utility of coincidence positron emission tomography (co-PET) based on an ¹⁸F-FDG gamma camera in assessing treatment response to imatinib using CT as the comparator and the final clinical outcome as the end point. Methods: We compared the results of CT and PET scans as predictors of outcome in a consecutive series of patients treated at the Prince of Wales hospital. All patients had biopsy-proven malignant GIST and were on treatment with the targeted pharmacotherapeutic agent imatinib. The majority of the patients were receiving treatment as part of the randomized trial of the European Organization for Research and Treatment of Cancer, the Australian Gastrointestinal Trials Group and the Italian Sarcoma Group, comparing 400 with 800 mg (400 mg b.i.d.). The monitoring of tumour response was achieved by serial CT measurements according to the RECIST criteria. Concurrent ¹⁸F-FDG co-PET studies were performed within a mean of 2.8 days from the CT scan and were interpreted by a consensus panel of 2 nuclear medicine physicians. Results: A total of 18 patients were recruited into the study, with a total of 74 lesions. There were 47 liver lesions, 31 of which were identified on the initial ¹⁸F-FDG co-PET scans (63%). There were 10 primary lesions (4 stomach, 4 duodenal, 2 small bowel), 9 of which were demonstrated on initial ¹⁸F-FDG co-PET examinations (90%). There were 17 extrahepatic metastatic sites, 15 of which were visualized on the initial ¹⁸F-FDG study (88%). Of the 18 patients, 8 showed concordant improvement on both CT and ¹⁸F-FDG co-PET criteria. One patient showed concordant worsening and 1 was not FDG avid. Eight patients initially showed discordance. ¹⁸F-FDG co-PET studies demonstrated changes preceding CT findings in all 8 patients with subsequent concordant improvement. Conclusion:¹⁸F-FDG co-PET is a useful modality to monitor treatment response to imatinib in patients with malignant GIST. Although there is a relatively reduced sensitivity when compared with CT for the detection of lesions especially in the liver, co-PET changes in several instances precede the changes on CT scanning. This modality has the potential to influence clinical decision making and should be considered as part of the standard care of patients on imatinib.

Abnormal left ventricular diastolic function is being increasingly recognised in patients with clinical heart failure and normal systolic function. A simple routine radionuclide measure of diastolic function would therefore be useful. To establish this, the relationship of peak diastolic filling rate (normalized for either end diastolic volume, stroke volume, or peak systolic emptying rate), and heart rate, age, and left ventricular ejection fraction was studied in 64 subjects with normal cardiovascular systems using routine gated heart pool studies. The peak filling rate, when normalized to end diastolic volume, correlated significantly with heart rate, age and left ventricular ejection fraction, whereas normalization to stroke volume correlated significantly to heart rate and age but not to left ventricular ejection fraction. Peak filling rate normalized for peak systolic emptying rate correlated with age only. Multiple regression equations were determined for each of the normalized peak filling rates in order to establish normal ranges for each parameter. When using peak filling rate normalized for end diastolic volume or stroke volume, appropriate allowance must be made for heart rate, age and ejection fraction. Peak filling rate normalized to peak ejection rate is a heart rate independent parameter which allows the performance of the patient's ventricle in diastole to be compared with its systolic function. It may be used in patients with normal systolic function to serially follow diastolic function or if age corrected, to screen for diastolic dysfunction.

No abstract