Browsing by Author "Holness, Jen L."

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    The utility of PET-CT in the staging and management of advanced and recurrent malignant melanoma
    (Medpharm Publications, 2019) Twycross, S. H.; Burger, Henriette; Holness, Jen L.
    BACKGROUND: Accurate pre-operative staging and correct surgical selection of patients with malignant melanoma reduces unnecessary morbidity and mortality, improves distant control and may improve survival. 18F-fluorodeoxyglucose Positron Emission Tomography Computed Tomography (18F-FDG PET-CT) has been shown to be useful in exclusion of metastatic sites and aids in surgical planning in stage III and potentially resectable stage IV disease. The primary objective of the study was to determine whether the use of PET-CT alters the initial staging and management of patients with advanced and recurrent melanoma METHODS: Retrospective analysis of clinical records of patients with malignant melanoma referred for staging PET-CT over a three-year period at our institution was performed. Pre- and post-PET-CT stage was recorded and a descriptive analysis was done to determine whether PET-CT resulted in a change in stage grouping and whether this change effected a change in clinical management RESULTS: A change in stage grouping occurred in 21/39 (53.8%) of patients, 76.2% of which were up-staged and 23.8% down staged. On analysis of stage III/Iv and recurrent melanoma, a change in stage occurred in 90% of stage III, 50% of stage IV and 50% of recurrent melanoma patients. This effected a change in management in 86.7% of patients with stage III, IV and recurrent melanoma collectively CONCLUSION: PET-CT is a useful tool in the staging and subsequent management of melanoma. Its utility is pronounced in advanced and recurrent melanoma
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    Validation of equations to estimate glomerular filtration rate in South Africans of mixed ancestry
    (Health & Medical Publishing Group, 2020-02-26) Holness, Jen L.; Bezuidenhout, K.; Davids, M. R.; Warwick, J. M.
    Background. The Modification of Diet in Renal Disease (MDRD) and Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) equations are two commonly used formulae to estimate glomerular filtration rate (GFR) in adults. The CKD-EPI equation is recommended in current international and local guidelines for the diagnosis and management of chronic kidney disease (CKD), unless an alternative equation has been shown to have superior accuracy. Validation and comparison of the equations in local populations are therefore required. Previous studies have reported on the accuracy of these prediction equations in black South Africans and those of Indian ancestry. Objectives. To evaluate the MDRD and CKD-EPI equations in South African (SA) adults of mixed ancestry. Methods. In all participants, GFR was measured (mGFR) from plasma clearance of 99mTc-diethylenetetraaminepenta-acetic acid (99mTc-DTPA), using a standardised technique. Serum creatinine assays were isotope dilution mass spectrometry traceable. GFR was estimated (eGFR) using the MDRD and CKD-EPI equations, with and without the black ethnicity factor. The agreement, bias, precision and accuracy of each equation was determined. Results. Eighty adults were included (30 male, median age 39 years, median GFR 59 mL/min/1.73 m2). Sixty-eight had a diagnosis of CKD, 10 were potential kidney donors, and 2 were healthy volunteers. Both equations, without the black ethnicity factor, had good agreement with measured GFR. The equations tended to overestimate GFR, with bias of 1.6 and 7.9 mL/min/1.73 m2 for the MDRD and CKD-EPI equations, respectively. The interquartile ranges of the differences were 15.9 and 20.2 mL/min/1.73 m2, and as a measure of accuracy, the percentages of estimates that fell within 30% of the mGFR (P30) were 80% and 72.5% (p=0.18). For identification of individuals with a GFR <60 mL/min/1.73 m2, the sensitivity of MDRD eGFR was 97.3% and that of CKD-EPI eGFR was 97.1%. Conclusions. The MDRD and CKD-EPI equations have shown satisfactory and comparable performance in this SA mixed-ancestry adult population, with the MDRD equation marginally less biased than the CKD-EPI.