A preliminary report on the impact of ¹8F-FDG PET/CT in the management of paediatric head and neck cancer.

INTRODUCTION: Paediatric head and neck malignancy accounts for 5% of all paediatric cancers. The choice of treatment and prediction of prognosis depend on the histological type of tumour, initial staging, evaluating treatment response and detection of early recurrence. Conventional imaging modalities have many limitations. Positron emission tomography/computed tomography (PET/CT) is more accurate; however, so far, the literature lacks reports of large groups of paediatric patients. AIM: To report the role of PET/CT in factors affecting the choice of treatment at the newly established Children Cancer Hospital in Cairo, Egypt, which is one of the busiest dedicated paediatric oncology centres in the world. All findings were proven by histopathology, radiology and by clinical follow-up. PATIENT POPULATION: Thirty-six paediatric patients (30 boys and six girls) with various histologically proven head and neck cancers were included in this study. Their age ranged from 2 to 17 years. High-resolution diagnostic CT and/or MRI of the head and neck, and in relevant cases also of the chest and the abdomen, were performed in all patients at a mean interval of 1.6 weeks (range, 1-3 months) before the PET/CT study. Results of PET/CT were compared with the findings of these conventional imaging modalities. RESULTS: The sensitivity, specificity, accuracy, positive and negative predictive values of PET/CT against the conventional imaging were as follows: sensitivity 100 and, 53%, specificity 89.5 and 47%, accuracy 94.5 and 50%, positive predictive value 89.5 and 47% and negative predictive value 100 and 53% respectively. PET/CT changed patient management in 50% of the cases. CONCLUSION: PET/CT in paediatric head and neck carcinoma is more accurate than conventional imaging. Therefore, it also has a significant impact on further patient management. We recommend that it should be the first imaging modality for all purposes in initial staging, evaluating treatment response and follow-up in paediatric head and neck carcinoma.

Intrareader variability in mammographic diagnostic and perceptual performance amongst experienced radiologists in Australia.

INTRODUCTION: The purpose of this study was, for a group of experienced radiologists, to identify the magnitude of and statistical significance of intrareader variability in mammographic diagnostic performance or cancer diagnosis and mammographic perceptual performance or microcalcification detection. METHODS: Eight radiologist readers (8-30 years experience in radiology, five current BreastScreen readers) read a set of 100 digital mammograms on two separate reads with random case orders. Twenty-three of the 100 had proven malignancies, and 52 of the 100 had confirmed microcalcifications. The same mammograms were presented for both reads. The radiologists were requested to clear or call back cases and to indicate if any benign and malignant microcalcifications were present on the mammograms. Reading conditions were standardised. RESULTS: Intrareader variability in accuracy was demonstrated to be between 0% and 6% for the diagnostic task of breast cancer diagnosis and between 0% and 16% for the perceptual task of microcalcification detection. Intrareader agreement in the group of readers was high; between 75% and 93% (κ=0.36-0.72) for cancer diagnosis and between 77.5% and 93% (κ=0.17-0.77) for microcalcification detection. There was no correlation between reader's experience in radiology or being a BreastScreen reader and level of intrareader variability in cancer diagnosis and microcalcification detection. CONCLUSION: There exists intrareader variability in diagnostic and perceptual performance. Despite this variability, intrareader agreement remains high.