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Parathyroid Hormone Resistance: An Uncommon Cause of Hypocalcaemia in an Adult Ghanaian Female. West Afr J Med 2023; 40:1131-1134. [PMID: 37906970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2023]
Abstract
BACKGROUND AND OBJECTIVE Parathyroid hormone (PTH) resistance, the main biochemical feature of a rare group of disorders known as Pseudohypoparathyroidism (PHP) is an uncommon cause of hypocalcaemia. In addition to the biochemical abnormalities, some individuals with PHP may have features of Albright Hereditary Osteodystrophy (AHO). Being a rare disorder with a significant level of variation and overlap in its clinical presentation, diagnosis of PHP may be challenging in some clinical settings. This case report highlights the diagnosis of this rare disorder. CASE REPORT A 20-year-old Ghanaian female who had been involved in a road traffic accident (RTA) was referred to the endocrine clinic after a computer tomography (CT) scan of her head revealed an incidental finding of multiple basal ganglia calcifications. Investigations revealed hypocalcaemia, hyperphosphatemia, and elevated intact PTH in the presence of normal levels of 25-hydroxyvitamin D and magnesium, and a normal kidney function. She also had phenotypic features of AHO. Findings suggested a diagnosis of PHP, however, the type could not be identified due to the unavailability of further testing. CONCLUSION This report of a Ghanaian female with PTH resistance and features of AHO diagnosed at the age of 20 years, is expected to add to the existing literature and assist in increasing the level of awareness and facilitate the diagnosis of this disorder in our setting.
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PO-1250 Exploring published acute esophagitis models to support improved clinical management in thoracic RT. Radiother Oncol 2022. [DOI: 10.1016/s0167-8140(22)03214-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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P27.02 Associating Cardiac Plaque Accumulation With Cardiac Toxicity and Overall Survival In Locally Advanced Non-Small Cell Lung Cancer. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.08.385] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Determinants of willingness to accept kidney transplantation among chronic kidney disease patients in Ghana. BMC Nephrol 2021; 22:129. [PMID: 33849488 PMCID: PMC8045236 DOI: 10.1186/s12882-021-02335-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2020] [Accepted: 04/04/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The burden of chronic kidney disease in Africa is three to four times higher compared to high-income countries and the cost of treatment is beyond the reach of most affected persons. The best treatment for end stage renal disease is kidney transplantation which is not available in most African countries. As kidney transplantation surgery is emerging in Ghana, this study assessed factors which could influence the willingness of patients with chronic kidney disease to accept it as a mode of treatment. METHODS This cross-sectional survey was carried out among patients with chronic kidney disease in Korle-Bu Teaching Hospital. A consecutive sampling method was used to recruit consenting patients. A structured questionnaire and standardized research instruments were used to obtain information on demographic, socio-economic characteristics, knowledge about transplantation, perception of transplantation, religiosity and spirituality. Logistic regression model was used to assess the determinants of willingness to accept a kidney transplant. RESULTS 342 CKD patients participated in the study of which 56.7% (n = 194) were male. The mean age of the participants was 50.24 ± 17.08 years. The proportion of participants who were willing to accept a kidney transplant was 67.3% (95%CI: 62.0-72.2%). The factors which influenced participants' willingness to accept this treatment included; willingness to attend a class on kidney transplantation (p < 0.016), willingness to donate a kidney if they had the chance (p < 0.005), perception that a living person could donate a kidney (p < 0.001) and perceived improvement in quality of life after transplantation (p < 0.005). The barriers for accepting kidney transplantation were anticipated complications of transplant surgery and financial constraints. CONCLUSION More than two-thirds of CKD patients were willing to accept a kidney transplant and this is influenced by multiple factors. Government health agencies must consider full or partial coverage of kidney transplantation through the existing national health insurance scheme. Further, efficient educational programmes are required to improve both patients' and physicians' knowledge on the importance of kidney transplantation in the management of end stage renal disease in Ghana.
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MA06.08 A Safety Study of Avelumab plus SBRT in Malignant Mesothelioma. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.01.178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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FP04.01 Heart Dose is a Dosimetric Predictor of Overall Survival in Patients with NSCLC Undergoing Post-Operative Radiation Therapy. J Thorac Oncol 2021. [DOI: 10.1016/j.jtho.2021.01.088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Willingness to pay for kidney transplantation among chronic kidney disease patients in Ghana. PLoS One 2020; 15:e0244437. [PMID: 33378327 PMCID: PMC7773273 DOI: 10.1371/journal.pone.0244437] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 12/09/2020] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Kidney transplantation is the preferred treatment for patients with end stage renal disease. However, it is largely unavailable in many sub-Sahara African countries including Ghana. In Ghana, treatment for end stage renal disease including transplantation, is usually financed out-of-pocket. As efforts continue to be made to expand the kidney transplantation programme in Ghana, it remains unclear whether patients with Chronic Kidney Disease (CKD) would be willing to pay for a kidney transplant. AIM The aim of the study was to assess CKD patients' willingness to pay for kidney transplantation as a treatment option for end stage renal disease in Ghana. METHODS A facility based cross-sectional study conducted at the Renal Outpatient clinic and Dialysis Unit of Korle-Bu Teaching Hospital among 342 CKD patients 18 years and above including those receiving haemodialysis. A consecutive sampling approach was used to recruit patients. Structured questionnaires were administered to obtain information on demographic, socio-economic, knowledge about transplant, perception of transplantation and willingness to pay for transplant. In addition, the INSPIRIT questionnaire was used to assess patients' level of religiosity and spirituality. Contingent valuation method (CVM) method was used to assess willingness to pay (WTP) for kidney transplantation. Logistic regression model was used to determine the significant predictors of WTP. RESULTS The average age of respondents was 50.2 ± 17.1 years with most (56.7% (194/342) being male. Overall, 90 out of the 342 study participants (26.3%, 95%CI: 21.7-31.3%) were willing to pay for a kidney transplant at the current going price (≥ $ 17,550) or more. The median amount participants were willing to pay below the current price was $986 (IQR: $197 -$1972). Among those willing to accept (67.3%, 230/342), 29.1% (67/230) were willing to pay for kidney transplant at the prevailing price. Wealth quintile, social support in terms of number of family friends one could talk to about personal issues and number of family members one can call on for help were the only factors identified to be significantly predictive of willingness to pay (p-value < 0.05). CONCLUSION The overall willingness to pay for kidney transplant is low among chronic kidney disease patients attending Korle-Bu Teaching Hospital. Patients with higher socio-economic status and those with more family members one can call on for help were more likely to pay for kidney transplantation. The study's findings give policy makers an understanding of CKD patients circumstances regarding affordability of the medical management of CKD including kidney transplantation. This can help develop pricing models to attain an ideal poise between a cost effective but sustainable kidney transplant programme and improve patient access to this ultimate treatment option.
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PO-1545: Dose-volume factors predicting esophageal after SBRT for ultra-central lung tumors. Radiother Oncol 2020. [DOI: 10.1016/s0167-8140(21)01563-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Radiation-induced Lumbosacral Plexopathy after Spine Stereotactic Body Radiotherapy - Should the Lumbosacral Plexi be Contoured? Clin Oncol (R Coll Radiol) 2020; 32:884-886. [PMID: 33082091 DOI: 10.1016/j.clon.2020.10.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2020] [Accepted: 10/01/2020] [Indexed: 11/19/2022]
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Use of a carbonated beverage to disintegrate a phytobezoar obstructing the intrathoracic portion of the oesophagus of a horse. EQUINE VET EDUC 2020. [DOI: 10.1111/eve.13082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Toward personalized dose-prescription in locally advanced non-small cell lung cancer: Validation of published normal tissue complication probability models. Radiother Oncol 2019; 138:45-51. [PMID: 31146070 DOI: 10.1016/j.radonc.2019.05.011] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2018] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 12/23/2022]
Abstract
PURPOSE To identify published normal tissue complication probability (NTCP) models suitable for patient-specific dose-prescription in locally advanced non-small cell lung cancer (LA-NSCLC) through in-house validation. MATERIAL AND METHODS From eight previously published candidate NTCP models (≥grade 2 acute esophagitis and radiation pneumonitis; AE2, RP2), patient-specific dose-responses were calculated using model variables and fractionation-corrected doses for 241 LA-NSCLC patients treated with chemo-IMRT to 50-80 Gy@1.8-2.0 Gy between 2004 and 2014 (AE2/RP2 rate: 50%/12%). A model was judged final if it significantly predicted AE2 or RP2 (p ≤ 0.05), was discriminative and well calibrated (AUC > 0.60; Hosmer-Lemeshow test pHL > 0.05), which were assessed as the median over 1000 bootstrap samples. RESULTS Models for AE2 had superior discrimination to RP2 models (AUC = 0.63-0.65 vs. 0.51-0.65). The final AE2 model included mean esophageal dose and concurrent chemotherapy (AUC = 0.65; p < 0.0001). The final RP2 model was a slightly adjusted version of the RP2 model with the best discrimination, and included age, mean lung dose, and pulmonary comorbidity (AUC = 0.73; p < 0.0001). CONCLUSION Of the eight investigated and published NTCP models, one model successfully described AE2 and one slightly adjusted model successfully described RP2 in the independent cohort. Estimates from these two NTCP models will, therefore, be considered internally when prescribing patient-specific doses in LA-NSCLC patients.
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MA01.10 Toxicity and Local Control in “Ultra-Central” Lung Tumors Treated With SBRT or High-Dose Hypofractionated RT. J Thorac Oncol 2018. [DOI: 10.1016/j.jtho.2018.08.320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Radiotherapeutic implications of the updated ICRP thresholds for tissue reactions related to cataracts and circulatory diseases. Ann ICRP 2018; 47:196-213. [PMID: 29741403 DOI: 10.1177/0146645318759622] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Radiation therapy of cancer patients involves a trade-off between a sufficient tumour dose for a high probability of local control and dose to organs at risk that is low enough to lead to a clinically acceptable probability of toxicity. The International Commission on Radiological Protection (ICRP) reviewed epidemiological evidence and provided updated estimates of 'practical' threshold doses for tissue injury, as defined at the level of 1% incidence, in ICRP Publication 118. Particular attention was paid to cataracts and circulatory diseases. ICRP recommended nominal absorbed dose threshold for these outcomes as low as 0.5 Gy. Threshold doses for tissue reactions can be reached in some patients during radiation therapy. Modern treatment planning systems do not account for such low doses accurately, and doses to therapy patients from associated imaging procedures are not generally accounted for. While local control is paramount, the observations of ICRP Publication 118 suggest that radiation therapy plans and processes should be examined with particular care. The research needs are discussed in this paper.
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SP-0112: Dose to cardiac substructures predicts survival in non-small cell lung cancer chemo-radiotherapy. Radiother Oncol 2018. [DOI: 10.1016/s0167-8140(18)30422-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Predictors and outcome of systemic lupus erythematosus (SLE) admission rates in a large teaching hospital in sub-Saharan Africa. Lupus 2017; 27:336-342. [PMID: 29173007 DOI: 10.1177/0961203317742710] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Although it was previously believed that systemic lupus erythematosus was uncommon among Africans, it has become increasingly apparent that the incidence is higher, and socioeconomic challenges such as physician shortages, poor medical facility access, and poor health literacy may worsen prognosis. This retrospective study examines characteristics and outcomes of hospitalized systemic lupus erythematosus patients over a two-year period and serves as a baseline for comparison for future studies to examine the outcomes with the provision of more dedicated care. There were 51 patient admissions over a two-year period, with a mean duration from start of illness to admission of approximately two years. Duration of admission ranged from one to 140 days with a mean period of 26.12 days (SD ± 26.6). There were 22 deaths (43.1% of admissions), which were mainly due to infections and renal complications. Factors associated with risk of death in regression analysis were: infections, fever, disease flare, musculoskeletal involvement, amenorrhea, depression, a clinical finding of hepatomegaly, and chest infection. Understanding the effect and outcome of systemic lupus erythematosus across different countries can elucidate the role of genetic, environmental, and other causative factors in the progression of the disease.
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TU-D-201-02: Medical Physics Practices for Plan and Chart Review: Results of AAPM Task Group 275 Survey. Med Phys 2016. [DOI: 10.1118/1.4957468] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-F-J-07: Evaluating the Adequacy of Biopsy Specimens for Genetic Signature Assessment by Measuring the Metabolic Activity in Specimens Obtained Under 18F-FDG PET/CT Guidance. Med Phys 2016. [DOI: 10.1118/1.4955915] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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TH-EF-BRC-04: Quality Management Program. Med Phys 2016. [DOI: 10.1118/1.4958239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-F-T-253: Volumetric Comparison Between 4D CT Amplitude and Phase Binning Mode. Med Phys 2016. [DOI: 10.1118/1.4956393] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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WE-DE-BRC-05: Risk-Based QA/QM Programs. Med Phys 2016. [DOI: 10.1118/1.4957827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-G-JeP4-05: Effects of Irregular Respiratory Motion On the Positioning Accuracy of Moving Target with Free Breathing Cone-Beam Computerized Tomography. Med Phys 2016. [DOI: 10.1118/1.4957115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-C-202-04: Adapting Biologically Optimized Dose Escalation Based On Mid-Treatment PET/CT for Non-Small-Cell Lung Cancer. Med Phys 2016. [DOI: 10.1118/1.4955572] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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OC-0097: Radiation dose-volume effects for liver SBRT. Radiother Oncol 2016. [DOI: 10.1016/s0167-8140(16)31346-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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SU-E-P-22: AAPM Task Group 263 Tackling Standardization of Nomenclature for Radiation Therapy. Med Phys 2015. [DOI: 10.1118/1.4923956] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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WE-F-304-01: Overview of the Working Group On Stereotactic Body Radiation Therapy (WGSBRT). Med Phys 2015. [DOI: 10.1118/1.4926037] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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WE-AB-BRA-04: Evaluation of the Tumor Registration Error in Biopsy Procedures Performed Under Real Time PET/CT Guidance. Med Phys 2015. [DOI: 10.1118/1.4925857] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SP-0171: Pediatric Normal Tissue Effects in the Clinic (PENTEC): An international collaboration. Radiother Oncol 2015. [DOI: 10.1016/s0167-8140(15)40169-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Setting Action Levels for Abdominal Stereotactic Body Radiation Therapy Monitored With Frequent kV Imaging Surveillance. Int J Radiat Oncol Biol Phys 2014. [DOI: 10.1016/j.ijrobp.2014.05.2383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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TH-E-19A-01: Quality and Safety in Radiation Therapy. Med Phys 2014. [DOI: 10.1118/1.4889650] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-T-341: Use of Patient Geometry and Multiple Linear Regression to Predict Prescription Dose for Pleurectomy/decortication Cases in Malignant Pleural Mesothelioma. Med Phys 2014. [DOI: 10.1118/1.4888674] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-F-BRD-15: The Impact of Dose Calculation Algorithm and Hounsfield Units Conversion Tables On Plan Dosimetry for Lung SBRT. Med Phys 2014. [DOI: 10.1118/1.4889069] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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WE-G-BRD-02: Dynamic Contrast Enhanced (DCE) MRI for Response Assessment of Inoperable Lung Tumors for Patients Undergoing SBRT Treatment. Med Phys 2014. [DOI: 10.1118/1.4889486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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TH-E-17A-08: Estimation of Image Quality of 4-Dimensional Computed Tomography (4DCT) Via Fourier Analysis of Corresponding 1D Breathing Surrogate. Med Phys 2014. [DOI: 10.1118/1.4889683] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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WE-G-BRD-01: Diffusion Weighted MRI for Response Assessment of Inoperable Lung Tumors for Patients Undergoing SBRT Treatment. Med Phys 2014. [DOI: 10.1118/1.4889485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-T-496: A Study of Two Commercial Dose Calculation Algorithms in Low Density Phantom. Med Phys 2014. [DOI: 10.1118/1.4888829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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MO-G-17A-09: Quantitative Autoradiography of Biopsy Specimens Extracted Under PET/CT Guidance. Med Phys 2014. [DOI: 10.1118/1.4889211] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-J-226: Propagation of Pancreas Target Contours On Respiratory Correlated CT Images Using Deformable Image Registration. Med Phys 2014. [DOI: 10.1118/1.4888279] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Incorporating the Prediction of Residual Tumor Location Into Prospective Dose Painting for Locally-Advanced Non-Small Cell Lung Cancer. Int J Radiat Oncol Biol Phys 2013. [DOI: 10.1016/j.ijrobp.2013.06.1853] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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TU-G-141-02: Evaluation of Respiration Motion-Corrected Cone-Beam CT: Prospective Study in Lung. Med Phys 2013. [DOI: 10.1118/1.4815462] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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MO-F-WAB-02: Constancy of Time Lag Relationship Between External and Internal Signal in Abdominal Tumor Sites. Med Phys 2013. [DOI: 10.1118/1.4815291] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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MO-A-137-09: Reduced Order Prioritized Optimization for IMRT Planning. Med Phys 2013. [DOI: 10.1118/1.4815212] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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MO-D-105-01: Safety Profile Assessment: A Tool for Improving Safety and Quality in Radiotherapy. Med Phys 2013. [DOI: 10.1118/1.4815227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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A study of respiration-correlated cone-beam CT scans to correct target positioning errors in radiotherapy of thoracic cancer. Med Phys 2012; 39:5825-34. [PMID: 23039621 DOI: 10.1118/1.4748503] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
PURPOSE There is increasingly widespread usage of cone-beam CT (CBCT) for guiding radiation treatment in advanced-stage lung tumors, but difficulties associated with daily CBCT in conventionally fractionated treatments include imaging dose to the patient, increased workload and longer treatment times. Respiration-correlated cone-beam CT (RC-CBCT) can improve localization accuracy in mobile lung tumors, but further increases the time and workload for conventionally fractionated treatments. This study investigates whether RC-CBCT-guided correction of systematic tumor deviations in standard fractionated lung tumor radiation treatments is more effective than 2D image-based correction of skeletal deviations alone. A second study goal compares respiration-correlated vs respiration-averaged images for determining tumor deviations. METHODS Eleven stage II-IV nonsmall cell lung cancer patients are enrolled in an IRB-approved prospective off-line protocol using RC-CBCT guidance to correct for systematic errors in GTV position. Patients receive a respiration-correlated planning CT (RCCT) at simulation, daily kilovoltage RC-CBCT scans during the first week of treatment and weekly scans thereafter. Four types of correction methods are compared: (1) systematic error in gross tumor volume (GTV) position, (2) systematic error in skeletal anatomy, (3) daily skeletal corrections, and (4) weekly skeletal corrections. The comparison is in terms of weighted average of the residual GTV deviations measured from the RC-CBCT scans and representing the estimated residual deviation over the treatment course. In the second study goal, GTV deviations computed from matching RCCT and RC-CBCT are compared to deviations computed from matching respiration-averaged images consisting of a CBCT reconstructed using all projections and an average-intensity-projection CT computed from the RCCT. RESULTS Of the eleven patients in the GTV-based systematic correction protocol, two required no correction, seven required a single correction, one required two corrections, and one required three corrections. Mean residual GTV deviation (3D distance) following GTV-based systematic correction (mean ± 1 standard deviation 4.8 ± 1.5 mm) is significantly lower than for systematic skeletal-based (6.5 ± 2.9 mm, p = 0.015), and weekly skeletal-based correction (7.2 ± 3.0 mm, p = 0.001), but is not significantly lower than daily skeletal-based correction (5.4 ± 2.6 mm, p = 0.34). In two cases, first-day CBCT images reveal tumor changes-one showing tumor growth, the other showing large tumor displacement-that are not readily observed in radiographs. Differences in computed GTV deviations between respiration-correlated and respiration-averaged images are 0.2 ± 1.8 mm in the superior-inferior direction and are of similar magnitude in the other directions. CONCLUSIONS An off-line protocol to correct GTV-based systematic error in locally advanced lung tumor cases can be effective at reducing tumor deviations, although the findings need confirmation with larger patient statistics. In some cases, a single cone-beam CT can be useful for assessing tumor changes early in treatment, if more than a few days elapse between simulation and the start of treatment. Tumor deviations measured with respiration-averaged CT and CBCT images are consistent with those measured with respiration-correlated images; the respiration-averaged method is more easily implemented in the clinic.
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Predictive Treatment Management: Incorporating a Predictive Tumor Response Model Into Robust Prospective Treatment Planning for Non-small Cell Lung Cancer. Int J Radiat Oncol Biol Phys 2012. [DOI: 10.1016/j.ijrobp.2012.07.2038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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SU-E-T-595: Comparison of Volumetric Modulated Arc Therapy (VMAT) and Static Intensity Modulated Radiotherapy (IMRT) for Malignant Pleural Mesothelioma in Patients with Intact Lungs/Post Pleurectomy. Med Phys 2012; 39:3842. [PMID: 28517082 DOI: 10.1118/1.4735684] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
PURPOSE This planning study compares VMAT and static gantry, sliding window IMRT for malignant pleural mesothelioma for post pleurectomy. METHODS We compared plans for a left sided (L) and a right sided case (R). Plans used clinically approved planning target volumes (PTVs) and critical organ contours. IMRT plans employed 7-8 6 MV photon beam directions over a 215° range centered on the ipsilateral lung. VMAT plans used 4 partial arcs within the same range and energy. Prescription dose per fraction was 1.8 Gy; case L went to 50.4 Gy, case R to 46.8 Gy. Planning objectives were: Lyman model NTCP for both lungs < 25%; contralateral lung, mean dose < 8 Gy; heart, V30 Gy < 50%, mean < 30 Gy; Each Kidney, V18 Gy < 33%; liver_not_GTV, mean < 30 Gy, V30 Gy < 50%; stomach not PTV, mean < 30 Gy; cord maximum < 45 Gy; bowel maximum < 55 Gy, D05 < 45 Gy; PTV D95 = 94%, V95 = 94%, D05 = 115%. Dose calculation was done with the AAA algorithm. RESULTS VMAT and IMRT both met the dosimetric constraints. The VMAT MU were 887 (L)_and 896 (R) and for IMRT were 1691 (L) and 2409 (R). IMRT required 14-16 fields (wide-field splitting). The delivery times were 8 minutes (VMAT) and 20 minutes (IMRT). For coverage and plan homogeneity parameters within 1.5% - 2%, VMAT better spared organs at risk. CONCLUSIONS Both VMAT and IMRT are feasible techniques for the treatment of malignant pleural mesothelioma with intact lungs, with less MU and a shorter delivery time for VMAT. Additional cases must be planned to test generality of our preliminary results.
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SU-E-T-532: Comparison of Dose Distributions Calculated Using Different Planning Systems with Radiochromic Film Measurements in an Inhomogeneous Phantom. Med Phys 2012; 39:3828. [PMID: 28518481 DOI: 10.1118/1.4735621] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE Accurate modeling of the dose distribution in a lung tumor is challenging for traditional dose calculation algorithms. We compare the dose distributions of four commercial dose calculation Methods: Raysearch (Raysearch Laboratories) and Pinnacle (Philips Healthcare) collapsed cone, and Eclipse AAA and Eclipse Acuros,(Varian Medical Systems) with measurements using radiochromic film in a lung tumor phantomMethods: A simple lung tumor phantom was constructed using a thermoplastic cylinder 29 mm diameter and 40mm in length (density 1.3 gm/cc) imbedded in cork phantom 25 × 25 × 20 cm of density 0.32 gm/cc. Nine film layers normal to the axis of the cylinder where placed between layers of cork, above, below and through the cylindrical inhomogeneity. The phantom was irradiated with a single asymmetric 10×10 cm 6 MV field with the central axis collinear with the cylinder axis. Thirteen film exposures at 5 cm depth taken with doses 0-10 Gy were used to calibrate the film. The phantom was CT scanned and the DICOM study loaded into each of the treatment planning systems to calculate the dose distribution in the phantom. RESULTS Away from cork-poly interfaces, agreement between the four algorithms was within 3% of the film measurements. For Acuros, the dose at the edge of the cylinder was found to be up to 2% lower than that at the center of the cylinder possibly because of the loss of lateral electron equilibrium. CONCLUSIONS All four algorithms achieved remarkable agreement with the radiochromic film measurement. The Acuros algorithm appeared to more accurately model the peripheral dose deficit in the tumor, although a more detailed study is required for confirmation.
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TU-C-213CD-04: Tracking Implanted Fiducials Using Kilovoltage (kV) Projection Images: A Feasibility Study. Med Phys 2012. [DOI: 10.1118/1.4735931] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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TU-C-213CD-08: Investigation of Gated Cone-Beam CT to Reduce Respiratory Motion Blurring in Images of Thorax and Abdomen. Med Phys 2012. [DOI: 10.1118/1.4735935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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SU-E-J-67: A Potential New Technique to Measure Respiratory Tidal Volume Using Optical Surface Imaging: A Geometric and Deformable Phantom Study. Med Phys 2012; 39:3667-3668. [PMID: 28519779 DOI: 10.1118/1.4734902] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE To develop a new method for accurate measurement of dynamic respiratory tidal volume, we investigate the feasibility of measuring torso volume change using optical surface imaging (OSI). METHODS Based on a validated volume conservation theory, the tidal volume is equal to the volume change of the torso during quiet respiration (Li et al, PMB, 54:1693, 2009). A clinical OSI system was employed to acquire surface images of seven geometric phantoms and two 'deformable' torso phantoms. The mesh surface images were converted into contours for volume calculation using a treatment planning system. For geometric phantoms, their volumes under the incomplete surface images were calculated with aid of their symmetry. The results were compared with theoretical calculation and water containment experiments. For deformable torso phantoms, we created volume-controlled deformation stages by placing deformable PlayDoh (DPD) materials on top of rigid Rando/Thorax phantoms, mimicking respiration-induced torso surface elevation and volume change. The volume difference under the surfaces with and without the DPD padding was calculated with aid of a common posterior line to enclose the region of interest. Three different volumes of DPD padding (>500cc) were mounted on the torso phantoms and CT scanned for volume measurements. RESULTS For geometric phantoms, the OSI measured volume had accuracy (±1s) of 0.0%±1.6% (vs. geometric volume calculation) and 0.6%±3.8% (vs. water containment experiment). For deformable torso phantoms, the volume change was measured using OSI with an accuracy of 1.5%±2.5% against the measured volume using CT imaging. Linear regression showed a one-to-one relationship between the OSI volumes and CT volumes with a slope of 1.003 (r2=0.999). CONCLUSIONS The optical surface imaging system can accurately measure the volume of geometric phantoms and the volume change of deformable torso phantoms. The accuracy is about 3% against standard volume measurement methods. Further study on human subjects is under investigation. Memorial Sloan-Kettering Cancer Center has a reserach agreement with Vision RT, Inc.
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