Appropriate indications for positron emission tomography/computed tomography, 2015

These recommendations are intended to serve an important and relevant role in advising referring physicians on the appropriate use of 18F-fluorodeoxyglucose (18F-FDG) and non-18F-FDG positron emission tomography/computed tomography (PET/CT), which can be a powerful tool in patient management in oncology, cardiology, neurology and infection/inflammation. PET is a non-invasive molecular imaging tool that provides tomographic images and quantitative parameters of perfusion, cell viability, proliferation and/or metabolic activity of tissues. These images result from the use of different substances of biological interest (sugars, amino acids, metabolic precursors, hormones) labelled with positron-emitting radionuclides (PET radiopharmaceuticals). Fusion of the aforementioned important functional information with the morphological detail provided by CT as PET/CT provides clinicians with a sensitive and accurate one-step whole-body diagnostic and prognostic tool, which directs and changes patient management. Hence PET/CT is currently the most widely used molecular imaging technology for a patient-tailored treatment approach. In these recommendations we outline which oncological and non-oncological indications are appropriate for PET/CT. Once each combination of pathology and clinical indication is defined, a recommendation is given as: 1. Recommended; 2. Recommended in select cases; 3. May be considered; or 4. Not recommended

Appropriate indications for positron emission tomography/computed tomography, 2015

These recommendations are intended to serve an important and relevant role in advising referring physicians on the appropriate use of 18F-fluorodeoxyglucose (18F-FDG) and non-18F-FDG positron emission tomography/computed tomography (PET/CT), which can be a powerful tool in patient management in oncology, cardiology, neurology and infection/inflammation. PET is a non-invasive molecular imaging tool that provides tomographic images and quantitative parameters of perfusion, cell viability, proliferation and/or metabolic activity of tissues. These images result from the use of different substances of biological interest (sugars, amino acids, metabolic precursors, hormones) labelled with positron-emitting radionuclides (PET radiopharmaceuticals). Fusion of the aforementioned important functional information with the morphological detail provided by CT as PET/CT provides clinicians with a sensitive and accurate one-step whole-body diagnostic and prognostic tool, which directs and changes patient management. Hence PET/CT is currently the most widely used molecular imaging technology for a patient-tailored treatment approach. In these recommendations we outline which oncological and non-oncological indications are appropriate for PET/CT. Once each combination of pathology and clinical indication is defined, a recommendation is given as: 1. Recommended; 2. Recommended in select cases; 3. May be considered; or 4. Not recommended.

Asymmetric response of forest and grassy biomes to climate variability across the African Humid Period : influenced by anthropogenic disturbance?

A comprehensive understanding of the relationship between land cover, climate change and disturbance dynamics is needed to inform scenarios of vegetation change on the African continent. Although significant advances have been made, large uncertainties exist in projections of future biodiversity and ecosystem change for the world's largest tropical landmass. To better illustrate the effects of climate–disturbance–ecosystem interactions on continental‐scale vegetation change, we apply a novel statistical multivariate envelope approach to subfossil pollen data and climate model outputs (TraCE‐21ka). We target paleoenvironmental records across continental Africa, from the African Humid Period (AHP: ca 14 700–5500 yr BP) – an interval of spatially and temporally variable hydroclimatic conditions – until recent times, to improve our understanding of overarching vegetation trends and to compare changes between forest and grassy biomes (savanna and grassland). Our results suggest that although climate variability was the dominant driver of change, forest and grassy biomes responded asymmetrically: 1) the climatic envelope of grassy biomes expanded, or persisted in increasingly diverse climatic conditions, during the second half of the AHP whilst that of forest did not; 2) forest retreat occurred much more slowly during the mid to late Holocene compared to the early AHP forest expansion; and 3) as forest and grassy biomes diverged during the second half of the AHP, their ecological relationship (envelope overlap) fundamentally changed. Based on these asymmetries and associated changes in human land use, we propose and discuss three hypotheses about the influence of anthropogenic disturbance on continental‐scale vegetation change

Interpretation of late Holocene pollen in channel fills in the eastern Free State, South Africa, in terms of local conditions and sediment reworking

Channel deposits of two cut and fill cycles in swampy deposits from the eastern Free State contain organic layers and some of these include pollen. Radiocarbon dating of the basal organic layers in the two channels gives indications of a late Holocene age but they provide an inverted chronological sequence. This discrepancy is interpreted as possible re-deposition of organic material from older up-stream deposits. This problem suggests that narrow channel fills are not ideal for environmental reconstruction and should be avoided in favour of wide low energy valley fills, which can be found in the eastern highlands. The pollen contents of the two sequences nevertheless, suggest marked variation that indicates climate variability during the Holocene in the area. The general pollen contents in the channel deposits appear typical of the regional grassland (Scott 1989) except for relatively high proportions of Asteraceae and smooth trilete fern spores. A possible explanation for the prominent Asteraceae may be found in relatively dry, sandy conditions on the north facing slope where the site is situated, while the trilete spores are possibly derived from upslope vegetation of rocky outcrops

The College of Nuclear Physicians of South Africa practice guidelines on peptide receptor radionuclide therapy in neuroendocrine tumours

CITATION: Lawal, I., et al. 2018. The College of Nuclear Physicians of South Africa Practice Guidelines on peptide receptor radionuclide therapy in neuroendocrine tumours. South African Journal of Surgery, 56(3):55-64, doi:10.17159/2078-5151/2018/v56n3a2775.The original publication is available at http://www.scielo.org.zaBackground: Peptide receptor radionuclide therapy (PRRT) for metastatic or inoperable neuroendocrine tumours (NETs) is a systemic therapy which targets somatostatin receptors overexpressed by differentiated NETs for endoradiotherapy. This guideline has been compiled by the College of Nuclear Physicians of the Colleges of Medicine of South Africa, with endorsement by the South African Society of Nuclear Medicine and the Association of Nuclear Physicians to guide Nuclear Medicine Physicians in its application during the management of these patients. Recommendations: Patients with well- to moderately-differentiated NETs should be comprehensively worked-up to determine their suitability for PRRT. Treatment should be administered by a Nuclear Medicine Physician in a licensed, appropriately equipped and fully staffed facility. Patient monitoring is mandatory during and after each therapy cycle to identify and treat therapy-related adverse events. Patients should also be followed-up after completion of therapy cycles for monitoring of long-term toxicities and response assessment. Conclusion: PRRT is a safe and effective therapy option in patients with differentiated NETs. Its use in appropriate patients is associated with a survival benefit.http://www.scielo.org.za/scielo.php?script=sci_abstract&pid=S0038-23612018000300011&lng=en&nrm=isoPublishers versio

Peptide receptor radionuclide therapy of neuroendocrine tumors : how important is internal dosimetry?

CITATION: Lawal, I., et al. 2019. Peptide receptor radionuclide therapy of neuroendocrine tumors : how important is internal dosimetry?. South African Journal of Surgery, 57(1):58-59.No abstract availablehttp://www.scielo.org.za/scielo.php?script=sci_arttext&pid=S0038-23612019000100016Publishers versio