Department of Medical Imaging and Clinical Oncology

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99mTc-MIBI stress-rest myocardial perfusion scintigraphy in patients with complete left bundle branch block
(2001) Ellmann, A.; Van Heerden, P. D. R.; Van Heerden, B. B.; Klopper, J. F.
Background. Patients with complete left bundle branch block (LBBB) often show a false-positive ischaemic pattern in the interventricular septum on thallium-201 (201Tl) stress-rest myocardial perfusion scintigraphy. Equivocal results have been reported with technetium-99m labelled hexakis-methoxyisobutyl isonitrile (99mTc-MIBI) in such patients. The aim of this retrospective study was to determine the effect of LBBB on the septal uptake of 99mTc-MIBI during stress-rest single photon emission computed tomography (SPECT) scintigraphy. Methods. We studied 75 consecutive patients with LBBB, referred for 99mTc-MIBI stress-rest SPECT. Studies were evaluated by visual analysis using a semi-quantitative grading technique. In all patients with abnormal septal segments, the presence or absence of ischaemic heart disease was confirmed either clinically or by means of angiographical examination. Results. Forty-three patients (57.3%) had completely normal studies. Only 15 (20%) had septal abnormalities (11 with reversible and 4 with fixed defects), while 17 patients (22.7%) had abnormal segments in areas other than the interventricular septum. Except for 1 patient lost to follow-up, ischaemic heart disease was confirmed in all the patients with septal changes. Conclusion. We conclude that 99mTc-MIBI is more specific than 201Tl for identifying ischaemic heart disease in the presence of LBBB.
Accuracy of "red-dot" after-hour trauma-radiograph triage by radiographers in a South African regional hospital
(Stellenbosch University, 2013) Hlongwane, S. T.; Pitcher, R. D.
BACKGROUND: The global demand for diagnostic imaging exceeds the supply of radiologists and is of particular significance in poorly resourced healthcare environments where many radiographs are unreported. Delayed or absent reporting may negatively impact patient management. In well-resourced countries there is recognition that extending the role of radiographers to radiological reporting tasks helps meet service demands. AIM: To determine the accuracy of acute fracture detection by South African radiographers working in an after-hour setting. METHOD: We performed a retrospective study of radiographers at a Western Cape Regional Hospital over 2 months in 2011. The sensitivity and specificity of radiographers' fracture detection were compared with that of a consultant radiologist. Differences were evaluated using the McNemar chi-squared test, with p<0.05 regarded as significant. RESULTS: A total of 369 radiographs were analysed. The overall accuracy of reporting by radiographers was 93.7%, with 74.4% sensitivity for fracture detection. Experienced radiographers performed better than inexperienced radiographers; adult fractures were more consistently identified than paediatric fractures, and appendicular fractures were better visualised than axial fractures. In all instances there was a significant difference between fracture detection by radiographers and the radiologist. Experienced radiographers evaluating appendicular fractures in adults achieved the highest sensitivity (89.9%), which was not significantly different from that of a consultant radiologist (p=0.88). CONCLUSION: The performance of experienced radiographers in our study is comparable with that of experienced radiographers internationally, who have no specific training in trauma radiograph reporting. However, additional training is required if role extension is to be considered.
The accuracy of after-hour registrar Computed Tomography (CT) reporting in a tertiary South African teaching hospital
(AOSIS Publishing, 2014-05-16) De Witt, Juruan F.; Griffith-Richards, Stephanie; Pitcher, Richard D.
Background: The Division of Radiodiagnosis at Tygerberg Academic Hospital, a 1384-bed tertiary training institution in Cape Town, South Africa provides a comprehensive 24-hour clinical radiology service, and has a duty registrar on-site at all times. The demand for computed tomography (CT) imaging is increasing and plays a pivotal role in patient management. Objectives: The purpose of this study was to determine the accuracy of after-hour registrar CT reporting, to identify possible factors that may affect the error rate, and to assess whether or not errors had any clinical impact. Method: A set of senior registrar reports (provisional reports) issued during a 28-day period was compared with the corresponding consultant reports (final reports). Discrepancies were identified and quantified, based on their impact on patient management. Results: The overall discrepancy rate was 8% (18 out of 225) and the overall accuracy rate was 92% (207 out of 225). The major error rate was 4% (9 out of 225) and the minor error rate was also 4% (9 out of 225). Conclusion: We observed that the accuracy of after-hour CT reporting by senior registrars at the Division of Radiodiagnosis at Tygerberg Hospital was on par with international standards. We investigated three factors which may have affected discrepancy rates, and only found one factor, namely the time of day, to be significant. Steps can be taken to create awareness of this fact amongst registrars, which hopefully would result in improved patient care and management.
Accuracy of patients' self-reporting of pregnancy and awareness of risks to the fetus from x-ray radiation
(Health and Medical Publishing Group (HMPG), 2008) Vadachia, Yousuf; Els, Hein; Andronikou, Savvas
[No abstract available]
The accuracy of radiology speech recognition reports in a multilingual South African teaching hospital
(BioMed Central, 2015-03) Du Toit, Jacqueline; Hattingh, Retha; Pitcher, Richard
Background: Speech recognition (SR) technology, the process whereby spoken words are converted to digital text, has been used in radiology reporting since 1981. It was initially anticipated that SR would dominate radiology reporting, with claims of up to 99% accuracy, reduced turnaround times and significant cost savings. However, expectations have not yet been realised. The limited data available suggest SR reports have significantly higher levels of inaccuracy than traditional dictation transcription (DT) reports, as well as incurring greater aggregate costs. There has been little work on the clinical significance of such errors, however, and little is known of the impact of reporter seniority on the generation of errors, or the influence of system familiarity on reducing error rates. Furthermore, there have been conflicting findings on the accuracy of SR amongst users with English as first- and second-language respectively. Methods: The aim of the study was to compare the accuracy of SR and DT reports in a resource-limited setting. The first 300 SR and the first 300 DT reports generated during March 2010 were retrieved from the hospital’s PACS, and reviewed by a single observer. Text errors were identified, and then classified as either clinically significant or insignificant based on their potential impact on patient management. In addition, a follow-up analysis was conducted exactly 4 years later. Results: Of the original 300 SR reports analysed, 25.6% contained errors, with 9.6% being clinically significant. Only 9.3% of the DT reports contained errors, 2.3% having potential clinical impact. Both the overall difference in SR and DT error rates, and the difference in ‘clinically significant’ error rates (9.6% vs. 2.3%) were statistically significant. In the follow-up study, the overall SR error rate was strikingly similar at 24.3%, 6% being clinically significant. Radiologists with second-language English were more likely to generate reports containing errors, but level of seniority had no bearing. Conclusion: SR technology consistently increased inaccuracies in Tygerberg Hospital (TBH) radiology reports, thereby potentially compromising patient care. Awareness of increased error rates in SR reports, particularly amongst those transcribing in a second-language, is important for effective implementation of SR in a multilingual healthcare environment.
The accuracy of radiology speech recognition reports in a multilingual South African teaching hospital
(Springer Verlag, 2015-03) Du Toit, Jacqueline; Hattingh, Retha; Pitcher, Richard; Medical Imaging and Clinical Oncology: Radiodiagnosis
Background Speech recognition (SR) technology, the process whereby spoken words are converted to digital text, has been used in radiology reporting since 1981. It was initially anticipated that SR would dominate radiology reporting, with claims of up to 99% accuracy, reduced turnaround times and significant cost savings. However, expectations have not yet been realised. The limited data available suggest SR reports have significantly higher levels of inaccuracy than traditional dictation transcription (DT) reports, as well as incurring greater aggregate costs. There has been little work on the clinical significance of such errorshowever, and little is known of the impact of reporter seniority on the generation of errors, or the influence of system familiarity on reducing error rates. Furthermore, there have been conflicting findings on the accuracy of SR amongst users with English as first- and second-language respectively. Methods The aim of the study was to compare the accuracy of SR and DT reports in a resource-limited setting. The first 300 SR and the first 300 DT reports generated during March 2010 were retrieved from the hospital’s PACS, and reviewed by a single observer. Text errors were identified, and then classified as either clinically significant or insignificant based on their potential impact on patient management. In addition, a follow-up analysis was conducted exactly 4 years later. Results Of the original 300 SR reports analysed, 25.6% contained errors, with 9.6% being clinically significant. Only 9.3% of the DT reports contained errors, 2.3% having potential clinical impact. Both the overall difference in SR and DT error rates, and the difference in ‘clinically significant’ error rates (9.6% vs. 2.3%) were statistically significant. In the follow-up study, the overall SR error rate was strikingly similar at 24.3%, 6% being clinically significant. Radiologists with second-language English were more likely to generate reports containing errors, but level of seniority had no bearing. Conclusion SR technology consistently increased inaccuracies in Tygerberg Hospital (TBH) radiology reports, thereby potentially compromising patient care. Awareness of increased error rates in SR reports, particularly amongst those transcribing in a second-language, is important for effective implementation of SR in a multilingual healthcare environment.
The added value of SPECT/CT in complicated osteomyelitis
(Stellenbosch : Stellenbosch University, 2013-12) Tag, Naima; Korowlay, Nisaar A.
ENGLISH ABSTRACT: Background: The detection of bone infection can be very difficult especially in bone with altered structure due to prior trauma or surgical procedures. Complicated osteomyelitis (COM) is becoming a public health problem especially with the difficult choice between, high cost surgery and prolonged courses of intravenous or oral antibiotic therapy, as well as the social and psychological effect of longterm disease and disability of the patient. The correct localisation of especially bone infection is still a challenge for the clinician. The single photon emission computed tomography/low dose computed tomography (SPECT/CT), by fusing the functional information with the anatomical parts, is a wellestablished tool used in many nuclear medicine studies. This improves the overall quality of the study with more clear answers. The aim of the study was to determine the added value of SPECT/CT in the management of complicated osteomyelitis (COM) in patients with endo-prosthesis, post traumatic osteomyelitis with and without metal implants and diabetic foot. Methods: This was a prospective study, between February 2010 and February 2012. Patients with suspected COM who fulfilled the selection and inclusion criteria were included. All had abnormal three phase bone scan followed by infection imaging with 99mTc labelled white blood cells and 99mTc -colloid if the99mTc labelled white blood cell study was abnormal. 67Ga citrate was used in vertebral involvement. Planar and SPECT/CT images were reviewed for presence of abnormal uptake and for its localization in bone and soft tissue. Scan results were defined as positive or negative. Both planar and SPECT/CT images were compared regarding diagnosis and precise localization of infection. The final diagnosis was obtained from surgical specimen or microbiological culture as well as clinical follow-up of all patients. Results: There were 72 patients, 29 male and 43 female with mean age of 57 yrs [range 27-88].There were 24 patients with prosthesis, 16 with hip prosthesis (PH=16), and 8 with knee prosthesis (PK=8). There were 44 patients with post traumatic osteomyelitis, 26 with metal implants (TOM=26) and 18 without metal implants (TOWM= 18). Four patients had diabetic foot (DF= 4). Infection was diagnosed in 19/72 patients on planar images and in 21/72 on SPECT/CT. Infection was diagnosed in 4 patients with prosthesis, 16 patients with post traumatic injury and one diabetic foot patient. The four patients with prosthesis, SPECT /CT added diagnostic value by excluding osteomyelitis in 3 patients and by defining the exact extent and localizing soft tissue and bone infection (STI/OM) in one patient. In 16 patients with post traumatic OM on planar images, SPECT /CT added diagnostic value, by excluding OM in 4 patients and confirming only STI, better localisation of the uptake in bone and soft tissue in 5 patients, of them 2 patient was negative on planar, and in 7 patients, confirmed and defined the exact extent of both OM and STI. One diabetic foot was positive for STI on the planar, the SPECT/CT added diagnostic value by defining the extent of the infection. In summary the added value of SPECT/CT was: a. Overall infection: 1. Exclusion of osteomyelitis by confirming only soft tissue involvement: 7 patients (10%) 2. Better localization in bone and soft tissue: 6 patients (8%) 3. Better delineation of extent of infection: 9 patients (12%) 4. None: 50 patients (70%) b. In positive cases only: 1. Exclusion of osteomyelitis by confirming only soft tissue involvement: 7 patients (33%) 2. Better localization in bone and soft tissue: 5 patients (24%) 3. Better delineation of extent of infection: 9 patients (43%) 4. None: 0 patients The overall sensitivity, specificity, positive predictive value, negative predictive value and accuracy for infection, on planar was 90%, 100%, 100%, 97%, 97%, respectively and for SPECT/CT 100%, 100%, 100%, 100%, 100%. For OM on planar, the sensitivity, specificity , positive predictive value, negative predictive value and accuracy was 100%, 89%, 53%, 100%, 90%, respectively and for SPECT/CT 100%, 100%, 100%, 100%, 100%. Conclusion: In complicated osteomyelitis, SPECT/CT is useful in localizing, defining the exact extent of infection where the planar images are abnormal, with no added value if the planar images are negative. We recommend in clinical practice the routine use of hybrid SPECT/CT imaging in complicated osteomyelitis when planar images are abnormal.
The added value of SPECT/CT in the evaluation of equivocal skeletal lesions in patients with known malignant disease
(Stellenbosch : University of Stellenbosch, 2010-03) Ndlovu, Xolani; Warwick, James M.; University of Stellenbosch. Faculty of Health Sciences. Dept. of Medical Imaging and Clinical Oncology. Nuclear Medicine.
ENGLISH SUMMARY: Introduction: Bone scintigraphy is used extensively in evaluating metastatic disease. There are currently no clear recommendations for the use of SPECT/CT in metastatic bone disease. Existing procedural guidelines from the Society of Nuclear Medicine (SNM) for SPECT/CT do not provide specific indications for use of SPECT/CT in bone scintigraphy, and there are currently no other guidelines for the use of SPECT/CT in bone scintigraphy that the author is aware of. The aim of this study was to investigate the additional value of SPECT/CT, and to identify the clinical indications for which SPECT/CT is most useful in patients with suspected bone metastases. Subjects and Methods: Forty-two patients with equivocal lesions on planar scintigraphy were prospectively recruited and planar imaging, SPECT, and SPECT/CT done on all patients. On reading of SPECT and then SPECT/CT, patients and individual lesions were classified as malignant, benign or equivocal. Radiological studies and available clinical information were also used during reading of scans. Review of clinical information, radiological studies and/or follow-up bone scans were used as gold standard. The results of the SPECT and SPECT/CT were compared in terms of proportion of equivocal findings and accuracy. Results: Forty-two patients with 189 skeletal lesions were examined. There was a diverse variety of primary tumours, although the majority had breast (n=22) or prostate cancer (n=8). Overall, SPECT/CT resulted in a significant reduction in the proportion of equivocal findings on both a patient-wise (p=0.0015) and lesion-wise basis (p<0.0001). The overall accuracy of SPECT/CT was significantly higher than that of SPECT on both a patient-wise (p=0.0026) and lesion-wise basis (p<0.0001). Generally SPECT/CT decreased the proportion of equivocal findings and increased the accuracy independent of the presence of bone pain, type of primary tumour, or skeletal region involved. SPECT/CT did not significantly improve the diagnostic confidence of readers in equivocal lumbar lesions although accuracy was significantly improved in this region. Conclusion: SPECT/CT performs significantly better than SPECT alone for the interpretation of equivocal planar lesions. There is no evidence that the benefit of SPECT/CT is dependent on the type of primary tumour or the presence of bone pain. Where resources are limited, SPECT/CT is indicated only in those patients in whom correct classification of the lesions in question is expected to alter the patient’s management. SPECT/CT images should be interpreted with the aid of a diagnostic radiologist or nuclear medicine physicians should acquire sufficient experience in Computed Tomographic image interpretation in order to optimise diagnostic benefit from SPECT/CT.
Advanced osteitis fibrosa cystica in the absence of phalangeal subperiosteal resorption : a case report and review of the literature
(Health & Medical Publishing Group, 1985) Wagener, G. W. W.; Sandler, M.; Hough, F. S.
A case of primary hyperparathyroidism with advanced osteitis fibrosa cystica but without any subperiosteal phalangeal bone resorption is described. A review of this unusual rdiological feature is presented. High-detail magnification radiography (microradiography) is advocated for the early diagnosis of bony defects in hyperparathyroidism.
Advanced radiological investigations and findings amongst community assault victims admitted to a tertiary South African hospital
(Health and Medical Publishing Group, 2019) Du Toit, F.; Griffith-Richards, S. B.; Van Zyl, B. C.; Pitcher, Richard D.
Community assault (CA) has been increasing in certain Cape Town suburbs over the past decade. There are limited CA-related imaging data. The aim of this study was to review CA-related advanced radiological investigations and findings at a Level 1 South African Trauma Centre. METHODS: A retrospective study at Tygerberg Hospital, Cape Town, from 1 January through 30 June 2013. All advanced radiological investigations performed on CA victims at the time of admission were retrieved and analysed by patient demographics, imaging investigations and radiological findings. RESULTS: Sixty-two patients (n=62) with a median age of 25 years were included; CT brain was acquired in 90% (n=56) and was abnormal in 68% (n=42). Craniofacial fractures were demonstrated in 60% (n=37), with involvement of the paranasal sinuses in 32% (n=20) and the base of skull in 19% (n=12). Almost half (n=28/62; 45%) had intracranial haemorrhage, which was intra-axial in 36% (n=22/62), extra-axial in 34% (n=21/62) and both intra- and extra-axial in 23% (n=14/62). Cerebral oedema was present in 29% (n=18/62), with herniation in 10% (n=6/62). Non-cranial CT was acquired in 52% (n=32/62), of whom 19 (n=19/32; 59%) also underwent CT brain. CT abdomen was acquired in approximately a quarter of the cohort (n=16/62, 26%), demonstrating abnormalities in 15 (24%). Fifteen cervical spine CTs were performed (n=15/62; 24%) demonstrating no acute bony injury. CONCLUSION: We recommend a high index of suspicion for severe intracranial injury in CA victims and urgent tertiary referral of those with a depressed level of consciousness. Prospective work is required to determine the long-term outlook for survivors.
The anatomical extent of the pyloric sphincteric cylinder, the pyloric mucosal zone and the pyloric antrum
(Health & Medical Publishing Group, 1982-8) Keet, A. D.
The anatomy of the pyloric sphincteric cylinder is discussed. The pyloric ring is not a separate anatomical structure, but is an inherent part of the cylinder. Contraction of the cylinder narrows the diameter of the pyloric ring, and thus of the pyloric aperture. The extent of the sphincteric cylinder is determined on radiographs. It is seen to be 3-5 cm in length when fully contracted. Anatomical features of the pyloric mucosal zone are reviewed. On the aboral side both the cylinder and the mucosal zone end at the ring. The entire cylinder is lined by pyloric mucosa, but the mucosal zone extends orally beyond the confines of the cylinder. In gastric ulcer it may extend much further up the stomach. In contrast to the cylinder, the greatest length of the mucosal zone is on the lesser curvature. The sphincteric cylinder and the pyloric mucosal zone are clearly defined anatomically. The term 'pyloric antrum', in contrast, has been used in many different senses.
An anatomico physiological principle governing the direction of the gastro intestinal mucosal folds during life
(HMPG, 1974-03) Keet A. D.
The mucosa, being the innermost layer of the gastro intestinal tract, is intimately concerned with digestion and absorption, and, presumably, also with the transport of intestinal contents. In anatomical, physiological and motility studies, possible movements of the mucosa and its folds are neither considered nor investigated. Dogmatic statements about the direction of the folds are often made. Radiologists have long been aware of mucosal movements, but after the fundamental work of Forssell, no further views have been put forward. Radiological procedures have been used to investigate the normal, macroscopic, physiological movements of mucosal folds. A general rule follows. Normally, when the intestine is filled, but inactive, the folds are circular; when the walls contract, the folds change in direction, to become longitudinal. This phenomenon is confirmed by in vivo baboon studies and elucidated by wire spirals. It is seen to be an inherent characteristic of 'peristaltic' and 'segmental' contractions. In this manner longitudinal mucosal furrows are formed simultaneously with the contraction wave of the walls, thus facilitating transit. Were this not so, peristalsis would be an ineffective mechanism, with contraction waves acting against the resistance of circular folds.
The anatomy and movements of the pyloric sphincteric cylinder
(1982) Keet, A. D.; Heydenrych, J. J.
Disagreement about various aspects of the structure and function of the pylorus persists. Morbid anatomical, living anatomical, manometric and radiographic studies were done in an attempt to clarify some problems. It is shown that the pyloric ring (sphincteric ring) is not a separate anatomical structure, but that it constitutes the aboral end of the pyloric sphincteric cylinder, a muscular tube several centimeters in length. The ring does not function independently and conventional peristaltic waves do not proceed as far as the ring. Consequently the ring does not relax reciprocally with an oncoming peristaltic wave in the sense that a wave travels up to the ring, which relaxes upon its arrival. Each peristaltic wave stops on arrival at the oral end of the cylinder, simultaneously initiating a concentric or systolic contraction of the entire cylinder, including the ring. The cylinder, including the ring, is open at rest.
The application of a deep convolution neural network for the automated delineation of the target and organs at risk in High Dose Rate Cervical Brachytherapy
(Stellenbosch : Stellenbosch University, 2022-12) Duprez, Didier Raphael Roger; Trauernicht, Christoph Jan; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medical Imaging and Clinical Oncology. Medical Physics.
ENGLISH SUMMARY: Low/middle income countries suffer from large deficits in experienced Radiation Oncologists, Medical Physicists and Radiation Therapists. Due to these deficits, the bottlenecks experienced in the High-dose rate (HDR) cervical brachytherapy treatment planning workflow are amplified. Image-guided HDR cervical brachytherapy is a complex, labour intensive, manual, time-consuming and expertise driven process. Automation in radiotherapy treatment planning, especially in brachytherapy, has the potential to substantially reduce the overall planning time however most of these algorithms require high level of expertise to develop. The aim of this study is to implement the out of the box self-configuring deep neural network package, known as No New U-Net (nnU-Net), for the task of automatically delineating the organs at risk (OARs) and high-risk clinical target volume (HR CTV) for HDR cervical brachytherapy. The computed tomography (CT) scans of 100 previously treated patients were used to train and test three different nnU-Net configurations (2D, 3DFR and 3DCasc). The performance of the models was evaluated by calculating the Sørensen-Dice similarity coefficient, Hausdorff distance (HD), 95th percentile Hausdorff distance, mean surface distance (MSD) and precision score for 20 test patients. The dosimetric accuracy between the manual and predicted contours was assessed by looking at the various dose volume histogram (DVH) parameters and volume differences. Three different radiation oncologists (ROs) scored the predicted bladder, rectum and HR CTV contours generated by the best performing model. The manual contouring, prediction and editing times were recorded. The mean DSC, HD, HD95, MSD and precision scores for our best performing model (3DFR) were 0.92/7.5 mm/3.0 mm/ 0.8 mm/0.91 for the bladder, 0.84/13.8 mm/5.2 mm/1.4 mm/0.84 for the rectum and 0.81/8.5 mm/6.0 mm/2.2 mm/0.80 for the HR CTV. Mean dose differences (D2cc/90%) and volume differences were 0.08 Gy/1.3 cm3 for the bladder, 0.02 Gy/0.7 cm3 for the rectum and 0.33 Gy/1.5 cm3 for the HR CTV. On average, 65 % of the generated contours were clinically acceptable, 33 % requiring minor edits, 2 % required major edits and no contours were rejected. Average manual contouring time was 14.0 minutes, while the average prediction and editing times were 1.6 and 2.1 minutes respectively. Our best performing model (3DFR) provided fast accurate auto generated OARs and HR CTV contours with a large clinical acceptance rate. Future work should focus on including larger datasets to eliminate inconsistencies, as well as focus on automating the generation of treatment plans.
Application of gradient dose segmented analysis as a treatment quality indicator for patients undergoing volumetric modulated arc radiotherapy
(Stellenbosch : Stellenbosch University, 2022-12) van Reenen, Christoffel Jacobus; Trauernicht, Christoph Jan; Stellenbosch University. Faculty of Medicine and Health Sciences. Dept. of Medical Imaging and Clinical Oncology. Medical Physics.
ENGLISH SUMMARY: The gamma analysis metric is a commonly used metric for volumetric modulated arc radiotherapy (VMAT) plan evaluation. The major drawback of this metric is the lack of correlation between gamma passing rates and dose-volume histogram (DVH) values for planning target volumes (PTV). The novel gradient dose segmented analysis (GDSA) metric was developed by Steers et al. to quantify changes in the PTV mean dose (Dmean) for patients undergoing VMAT. In this study, the GDSA metric was applied to 115 head-and-neck cancer patients treated on the Varian Halcyon v2.0 linear accelerator between August 2019 and July 2020 in the Division of Radiation Oncology. The GDSA indicated that a total of 13 patients had received at least one treatment fraction where the PTV Dmean exceeded 3% compared to the first treatment fraction. The kilovoltage cone-beam computed tomography (kV CBCT) images of these patients were analysed to determine the cause. The maximum predicted change in the PTV Dmean was 4.83%. Measurable changes in anterior-posterior and lateral separations were observed for 8 out the 13 patients (62%) where the change in PTV Dmean exceeded 3%. The maximum calculated effective separation change diameter was calculated as 3.86 cm. In cases where the change in PTV Dmean was less than 3%, no measurable separation changes were observed. The pitch-, roll- and yaw-rotational errors were quantified as the Halcyon treatment couch does not allow for online rotational corrections. The maximum pitch, roll and yaw rotational errors were 3.91º ± 0.89º, 3.07º ± 0.51º and 2.62º ± 0.40º, respectively. The mean errors were 0.9º, 0.45º, and 0.43º, for pitch, roll and yaw, respectively. The obtained results demonstrated that large deviations in PTV Dmean (>3%) were more likely due to change in effective diameter, whereas small deviations in PTV Dmean combined with separation changes less than 1 cm, were more likely caused by errors in pitch for long treatment fields. Weight loss during radiotherapy is well documented and proven to be the highest among head-and-neck cancer patients. The GDSA easily be implemented to identify setup/immobilization errors, as well as aid the department in scheduling new CT scans for patients experiencing continuous weight loss before significant differences in dose delivery occur.
Appropriate indications for positron emission tomography/computed tomography : College of Nuclear Physicians of the Colleges of Medicine of South Africa
(Health & Medical Publishing Group, 2016) Sathekge, Mike; Warwick, James M.; Doruyter, Alex; Vorster, Mariza
Individualised patient treatment approaches demand precise determination of initial disease extent combined with early, accurate assessment of response to treatment, which is made possible by positron emission tomography/computed tomography (PET/CT). PET is a non-invasive tool that provides tomographic images and quantitative parameters of perfusion, cell viability, and proliferation and/or metabolic activity of tissues. Fusion of the functional information with the morphological detail provided by CT as PET/CT can provide clinicians with a sensitive and accurate one-step whole-body diagnostic and prognostic tool, which directs and changes patient management. Three large-scale national studies published by the National Oncologic PET Registry in the USA have shown that imaging with PET changes the intended patient management strategy in 36.5% to 49% of cases, with consistent results across all cancer types. The proven clinical effectiveness and growing importance of PET/CT have prompted the College of Nuclear Physicians of South Africa, in collaboration with university hospitals, to develop a list of recommendations on the appropriate use of fluorine-18-fluorodeoxyglucose (18F-FDG) and non-18F-FDG PET/CT in oncology, cardiology, neurology and infection/inflammation. It is expected that other clinical situations will be added to these recommendations, provided that they are based upon solid clinical evidence. These recommendations are intended to offer advice regarding contemporary applications of PET/CT, as well as indicating novel developments and potential future indications. The CNP believes that these recommendations will serve an important and relevant role in advising referring physicians on the appropriate use of 18F-FDG and non-18F-FDG PET/CT. More promising clinical applications will be possible in the future, as newer PET tracers become more readily available.
An audit of elective outpatient magnetic resonance imaging in a tertiary South African public-sector hospital
(AOSIS Publishing, 2014-12-09) Van Schouwenburg, Francois; Ackermann, Christelle; Pitcher, Richard
Background: Increasing demand for magnetic resonance imaging (MRI) has resulted in longer waiting times for elective MRI, particularly in resource-limited healthcare environments.However, inappropriate imaging requests may also contribute to prolonged MRI waiting times. At the time of the present study, the waiting time for elective MRI studies at Tygerberg Hospital (TBH), a tertiary-level public-sector healthcare facility in Cape Town (South Africa),was 24 weeks. Objectives: To document the nature and clinical appropriateness of scheduled TBH outpatient MRI examinations. Method: A retrospective analysis of the referral forms of all elective outpatient MRIexaminations scheduled at TBH from 01 June to 30 November 2011 was conducted. Patient age, gender, clinical details, provisional diagnosis, examination requested and referring clinician were recorded on a customised data sheet. Two radiologists independently evaluated the appropriateness of each request by comparing the clinical details and the provisional diagnosis provided with the 2012 American College of Radiology (ACR) guidelines for the appropriate use of MRI. Results: Four hundred and sixty-six patients (median age 42 years; interquartile range 19–55) who had 561 examinations were scheduled in the review period; 70 (15%) were children less than 6 years old. Neurosurgery (n = 164; 35%), orthopaedic (n = 144; 31%),neurology (n = 53; 11%) and paediatric (n = 27; 6%) outpatients accounted for the majority(81%) of referrals; 464 (99.6%) were from specialist clinics. MRIs of the spine (n = 314; 56%),brain (n = 152; 27%) and musculoskeletal system (n = 70, 13%) accounted for more than 95%of the investigations. In 455 cases (98%), the referral was congruent with published ACR guidelines for appropriate MRI utilisation. Conclusion: Scheduled outpatient MRI examinations at TBH reflect optimal clinical use of a limited resource. MRI utilisation is largely confined to traditional neuro-imaging. Any initiative to decrease the elective MRI waiting time should focus on service expansion.
An audit of licensed Zimbabwean radiology equipment resources as a measure of healthcare access and equity
(Pan African Medical Journal, 2019-10-01) Maboreke, Tashinga; Banhwa, Josephat; Pitcher, Richard D.
Introduction: approximately two-thirds of the world's population has no access to diagnostic imaging. Basic radiological services should be integral to universal health coverage. The World Health Organization postulates that one basic X-ray and ultrasound unit for every 50000 people will meet 90% of global imaging needs. However, there are limited country-level data on radiological resources, and little appreciation of how such data reflect access and equity within a healthcare system. The aim of this study was a detailed analysis of licensed Zimbabwean radiological equipment resources. Methods: the equipment database of the Radiation Protection Authority of Zimbabwe was interrogated. Resources were quantified as units/million people and compared by imaging modality, geographical region and healthcare sector. Zimbabwean resources were compared with published South African and Tanzanian data. Results: public-sector access to X-ray units (11/106 people) is approximately half the WHO recommendation (20/106 people), and there exists a 5-fold disparity between the least- and best-resourced regions. Private-sector exceeds public-sector access by 16-fold. More than half Zimbabwe's radiology equipment (215/380 units, 57%) is in two cities, serving one-fifth of the population. Almost two-thirds of all units (243/380, 64%) are in the private sector, routinely accessible by approximately 10% of the population. Southern African country-level public-sector imaging resources broadly reflect national per capita healthcare expenditure. Conclusion: there exists an overall shortfall in basic radiological equipment resources in Zimbabwe, and inequitable distribution of existing resources. The national radiology equipment register can reflect access and equity in a healthcare system, while providing medium-term radiological planning data.
Audits of oncology units – an effective and pragmatic approach
(Health and Medical Publishing Group, 2017) Abratt, R. P.; Eedes, D.; Bailey, B.; Salmon, C.; Govender, Y.; Oelofse, I.; Burger, H.
Background. Audits of oncology units are part of all quality-assurance programmes. However, they do not always come across as pragmatic and helpful to staff. Objective. To report on the results of an online survey on the usefulness and impact of an audit process for oncology units. Methods. Staff in oncology units who were part of the audit process completed the audit self-assessment form for the unit. This was followed by a visit to each unit by an assessor, and then subsequent personal contact, usually via telephone. The audit self-assessment document listed quality-assurance measures or items in the physical and functional areas of the oncology unit. There were a total of 153 items included in the audit. The online survey took place in October 2016. The invitation to participate was sent to 59 oncology units at which staff members had completed the audit process. Results. The online survey was completed by 54 (41%) of the 132 potential respondents. The online survey found that the audit was very or extremely useful in maintaining personal professional standards in 89% of responses. The audit process and feedback was rated as very or extremely satisfactory in 80% and 81%, respectively. The self-assessment audit document was scored by survey respondents as very or extremely practical in 63% of responses. The feedback on the audit was that it was very or extremely helpful in formulating improvement plans in oncology units in 82% of responses. Major and minor changes that occurred as a result of the audit process were reported as 8% and 88%, respectively. Conclusion. The survey findings show that the audit process and its self- assessment document meet the aims of being helpful and pragmatic.
Automated radiation treatment planning for cervical cancer
(Elsevier, 2020-10) Rhee, Dong Joo; Jhingran, Anuja; Kisling, Kelly; Cardenas, Carlos; Simonds, Hannah; Court, Laurence
The radiation treatment-planning process includes contouring, planning, and reviewing the final plan, and each component requires substantial time and effort from multiple experts. Automation of treatment planning can save time and reduce the cost of radiation treatment, and potentially provides more consistent and better quality plans. With the recent breakthroughs in computer hardware and artificial intelligence technology, automation methods for radiation treatment planning have achieved a clinically acceptable level of performance in general. At the same time, the automation process should be developed and evaluated independently for different disease sites and treatment techniques as they are unique from each other. In this article, we will discuss the current status of automated radiation treatment planning for cervical cancer for simple and complex plans and corresponding automated quality assurance methods. Furthermore, we will introduce Radiation Planning Assistant, a web-based system designed to fully automate treatment planning for cervical cancer and other treatment sites.

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