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17 result(s) for "Chander, Sarat"
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Impact of repeated simulation on learning curve characteristics of residents exposed to rare life threatening situations
BackgroundLittle is known about the learning curve characteristics of residents undertaking simulation-based education. It is important to understand the time for acquisition and decay of knowledge and skills needed to manage rare and difficult clinical situations.MethodTen anaesthesiology residents underwent simulation-based education to manage a cannot intubate cannot ventilate scenario during general anaesthesia for caesarean section. Their performance was measured using an assessment tool and debriefed by two experienced anaesthesiologists. The parameters against which the performance was judged were grouped into preoperative assessment, preoperative patient care, equipment availability, induction sequence, communication and adherence to airway algorithm protocol. The scenario was repeated at 6 and 12 months thereafter. The residents’ acquisition of knowledge, technical and non-technical skills were assessed and compared at baseline, 6 months and end of 12 months.ResultThe skills of preoperative assessment, preoperative care and communication quickly improved but the specific skill of managing a difficult airway as measured by adherence to an airway algorithm required more than 6 months (CI at 6 vs 12 months: −3.4 to –0.81, p=0.016). The skills of preoperative assessment and preoperative care improved to a higher level quickly and were retained at this improved level. Communication (CI at 0 vs 6 months: −3.78 to −0.22, p=0.045 and at 6 vs 12 months : −3.39 to −1.49, p=0.007) and difficult airway management skill were slower to improve but continued to do so over the 12 months. The compliance to machine check was more gradual and showed an improvement at 12 months.ConclusionOur study is unique in analysing the learning curve characteristics of different components of a failed obstetric airway management skill. Repeated simulations over a longer period of time help in better reinforcement, retention of knowledge, recapitulation and implementation of technical and non-technical skills.
Diffusion weighted and dynamic contrast enhanced MRI as an imaging biomarker for stereotactic ablative body radiotherapy (SABR) of primary renal cell carcinoma
To explore the utility of diffusion and perfusion changes in primary renal cell carcinoma (RCC) after stereotactic ablative body radiotherapy (SABR) as an early biomarker of treatment response, using diffusion weighted (DWI) and dynamic contrast enhanced (DCE) MRI. Patients enrolled in a prospective pilot clinical trial received SABR for primary RCC, and had DWI and DCE MRI scheduled at baseline, 14 days and 70 days after SABR. Tumours <5cm diameter received a single fraction of 26 Gy and larger tumours received three fractions of 14 Gy. Apparent diffusion coefficient (ADC) maps were computed from DWI data and parametric and pharmacokinetic maps were fitted to the DCE data. Tumour volumes were contoured and statistics extracted. Spearman's rank correlation coefficients were computed between MRI parameter changes versus the percentage tumour volume change from CT at 6, 12 and 24 months and the last follow-up relative to baseline CT. Twelve patients were eligible for DWI analysis, and a subset of ten patients for DCE MRI analysis. DCE MRI from the second follow-up MRI scan showed correlations between the change in percentage voxels with washout contrast enhancement behaviour and the change in tumour volume (ρ = 0.84, p = 0.004 at 12 month CT, ρ = 0.81, p = 0.02 at 24 month CT, and ρ = 0.89, p = 0.001 at last follow-up CT). The change in mean initial rate of enhancement and mean Ktrans at the second follow-up MRI scan were positively correlated with percent tumour volume change at the 12 month CT onwards (ρ = 0.65, p = 0.05 and ρ = 0.66, p = 0.04 at 12 month CT respectively). Changes in ADC kurtosis from histogram analysis at the first follow-up MRI scan also showed positive correlations with the percentage tumour volume change (ρ = 0.66, p = 0.02 at 12 month CT, ρ = 0.69, p = 0.02 at last follow-up CT), but these results are possibly confounded by inflammation. DWI and DCE MRI parameters show potential as early response biomarkers after SABR for primary RCC. Further prospective validation using larger patient cohorts is warranted.
Low rate of severe-end-stage kidney disease after SABR for localised primary kidney cancer
Background Stereotactic ablative body radiotherapy (SABR) is an emerging treatment for patients with primary renal cell carcinoma (RCC). However, its impact on renal function is unclear. This study aimed to evaluate incidence and clinical factors predictive of severe to end-stage chronic kidney disease (CKD) after SABR for RCC. Methods and materials This was a Single institutional retrospective analysis of patients with diagnosed primary RCC receiving SABR between 2012–2020. Adult patients with no metastatic disease, baseline estimated glomerular filtration rate (eGFR) of ≥ 30 ml/min/1.73 m 2 , and at least one post-SABR eGFR at six months or later were included in this analysis. Patients with upper tract urothelial carcinoma were excluded. Primary outcome was freedom from severe to end-stage CKD, determined using the Kaplan–Meier estimator. The impact of baseline CKD, age, hypertension, diabetes, tumor size and fractionation schedule were assessed by Cox proportional hazard models. Results Seventy-eight consecutive patients were included, with median age of 77.8 years (IQR 70–83), tumor size of 4.5 cm (IQR 3.9–5.8) and follow-up of 42.2 months (IQR 23–60). Baseline median eGFR was 58 mls/min; 55% (n = 43) of patients had baseline CKD stage 3 and the remainder stage 1–2. By last follow-up, 1/35 (2.8%) of baseline CKD 1–2, 7/27 (25.9%) CKD 3a and 11/16 (68.8%) CKD 3b had developed CKD stage 4–5. The estimated probability of freedom from CKD stage 4–5 at 1 and 5 years was 89.6% (CI 83.0–97.6) and 65% (CI 51.4–81.7) respectively. On univariable analysis, worse baseline CKD ( p  < 0.0001) and multi-fraction SABR ( p  = 0.005) were predictive for development of stage 4–5 CKD though only the former remained significant in multivariable model. Conclusion In this elderly cohort with pre-existing renal dysfunction, SABR achieved satisfactory nephron sparing with acceptable rates of severe to end-stage CKD. It can be an attractive option in patients who are medically inoperable.
Outcomes of unplanned sarcoma excision: impact of residual disease
This study aimed to compare the oncological results between unplanned excision (UE) and planned excision (PE) of malignant soft tissue tumor and to examine the impact of residual tumor (ReT) after UE. Nonmetastatic soft tissue sarcomas surgically treated in 1996–2012 were included in this study. Disease‐specific survival (DSS), metastasis‐free survival (MFS), and local‐recurrence‐free survival (LRFS) were stratified according to the tumor location and American Joint Committee on Cancer Classification 7th edition stage. Independent prognostic parameters were identified by Cox proportional hazard models. Two‐hundred and ninety PEs and 161 UEs were identified. Significant difference in oncological outcome was observed only for LRFS probability of retroperitoneal sarcomas (5‐year LRFS: 33.0% [UE] vs. 71.0% [PE], P = 0.018). Among the 142 UEs of extremity and trunk, ReT in re‐excision specimen were found in 75 cases (53%). UEs with ReT had significantly lower survival probabilities and a higher amputation rate than UEs without ReT (5‐year DSS: 68.8% vs. 92%, P < 0.001; MFS: 56.1% vs. 90.9%, P < 0.001; LRFS: 75.8% vs. 98.4%, P = <0.001; amputation rate 18.5% vs. 1.8%, P = 0.003). The presence of ReT was an independent poor prognostic predictor for DSS, MFS, and LRFS with hazard ratios of 2.02 (95% confidence interval (CI), 1.25–3.26), 1.62 (95% CI, 1.05–2.51) and 1.94 (95% CI, 1.05–3.59), respectively. Soft tissue sarcomas should be treated in specialized centers and UE should be avoided because of its detrimental effect especially when ReT remains after UE. Residual disease in unplanned excision of soft tissue sarcoma was a poor prognostic predictor for all oncological outcomes. Soft tissue sarcomas should be treated in specialized centers and unplanned excision should be avoided because of its detrimental effect especially when residual disease remains after unplanned excision.
Trends in Practice Patterns and Clinical Outcomes for Desmoid Tumors: A Large Single‐Institutional Australian Cohort
ABSTRACT Background Desmoid tumors (DT) are rare, locally aggressive neoplasms that affect a young population and have a tendency for recurrence. There is sparse contemporary real‐world data to guide practice for DT. Here, we report on a large cohort of DT patients, describing patterns of care and clinical outcomes. Methods Data on DT patients first seen between 2010 and 2021 were extracted from a prospective database and supplemented with a retrospective review of hospital records. Trends in treatment use were analyzed using the Cochran‐Armitage test. Time‐to‐next intervention (TTNI) was estimated with the Kaplan–Meier method. Imaging response was categorized using the RECIST v1.1 criteria. Results A total of 135 patients, 265 treatment episodes were analyzed. Median follow‐up was 4.3 years. The common tumor sites were abdominal wall (27%), upper limb (20%), lower limb (16%), and intra‐abdominal (15%). Over time, the proportion of patients receiving no upfront treatment was stable (2010–2013: 31%, 2014–2017: 35%, 2018–2021: 29%; p = 0.5), but there was increasing first‐line use of NSAID/tamoxifen (7%, 41%, 47%; p < 0.001), and decreasing first‐line use of radiotherapy (35%, 14%, 4%; p < 0.001) and surgery (28%, 8%, 18%; p < 0.05). At 5 years, the proportion not requiring treatment switch was highest following surgery (72%), radiotherapy (66%), and no upfront therapy (52%). 12% and 5% of patients without treatment achieved partial and complete imaging responses at 2 years. Conclusion We highlight the heterogeneity and trends in DT management over a 12‐year period, affirming the role of active surveillance, radiotherapy, and surgery in selected patients. Medical therapies are evolving and may significantly influence the DT management paradigm.
Acute toxicity in prostate cancer patients treated with and without image-guided radiotherapy
Background Image-guided radiotherapy (IGRT) increases the accuracy of treatment delivery through daily target localisation. We report on toxicity symptoms experienced during radiotherapy treatment, with and without IGRT in prostate cancer patients treated radically. Methods Between 2006 and 2009, acute toxicity data for ten symptoms were collected prospectively onto standardized assessment forms. Toxicity was scored during radiotherapy, according to the Common Terminology Criteria Adverse Events V3.0, for 275 prostate cancer patients before and after the implementation of a fiducial marker IGRT program and dose escalation from 74Gy in 37 fractions, to 78Gy in 39 fractions. Margins and planning constraints were maintained the same during the study period. The symptoms scored were urinary frequency, cystitis, bladder spasm, urinary incontinence, urinary retention, diarrhoea, haemorrhoids, proctitis, anal skin discomfort and fatigue. Analysis was conducted for the maximum grade of toxicity and the median number of days from the onset of that toxicity to the end of treatment. Results In the IGRT group, 14228 toxicity scores were analysed from 249 patients. In the non-IGRT group, 1893 toxicity scores were analysed from 26 patients. Urinary frequency ≥G3 affected 23% and 7% in the non-IGRT and IGRT group respectively (p = 0.0188). Diarrhoea ≥G2 affected 15% and 3% of patients in the non-IGRT and IGRT groups (p = 0.0174). Fatigue ≥G2 affected 23% and 8% of patients in the non-IGRT and IGRT groups (p = 0.0271). The median number of days with a toxicity was higher for ≥G2 (p = 0.0179) and ≥G3 frequency (p = 0.0027), ≥G2 diarrhoea (p = 0.0033) and ≥G2 fatigue (p = 0.0088) in the non-IGRT group compared to the IGRT group. Other toxicities were not of significant statistical difference. Conclusions In this study, prostate cancer patients treated radically with IGRT had less severe urinary frequency, diarrhoea and fatigue during treatment compared to patients treated with non-IGRT. Onset of these symptoms was earlier in the non-IGRT group. IGRT results in less acute toxicity during radiotherapy in prostate cancer.
NaF PET/CT for response assessment of prostate cancer bone metastases treated with single fraction stereotactic ablative body radiotherapy
Introduction In prostate cancer patients, imaging of bone metastases is enhanced through the use of sodium fluoride positron emission tomography ( 18 F-NaF PET/CT). This imaging technique shows areas of enhanced osteoblastic activity and blood flow. In this work, 18 F-NaF PET/CT was investigated for response assessment to single fraction stereotactic ablative body radiotherapy (SABR) to bone metastases in prostate cancer patients. Methods Patients with bone metastases in a prospective trial treated with single fraction SABR received a 18 F-NaF PET/CT scan prior to and 6 months post-SABR. The SUV max in the tumour was determined and the difference between before and after SABR determined. The change in uptake in the non-tumour bone was also measured as a function of the received SABR dose. Results Reduction in SUV max was observed in 29 of 33 lesions 6 months after SABR (mean absolute decrease in SUV max 17.7, 95% CI 25.8 to − 9.4, p  = 0.0001). Of the three lesions with increased SUV max post-SABR, two were from the same patient and located in the vertebral column. Both were determined to be local progression in addition to one fracture. The third lesion (in a rib) was shown to be controlled locally but suffered from a fracture at 24 months. Progression adjacent to the treated volume was observed in two patients. The non-tumour bone irradiated showed increased loss in uptake with increasing dose, with a median loss in uptake of 23.3% for bone receiving 24 Gy. Conclusion 18 F-NaF PET/CT for response assessment of bone metastases to single fraction SABR indicates high rates of reduction of osteoblastic activity in the tumour and non-tumour bone receiving high doses. The occurrence of marginal recurrence indicates use of larger clinical target volumes may be warranted in treatment of bone metastases. Trial registration POPSTAR, ‘Pilot Study of patients with Oligometastases from Prostate cancer treated with STereotactic Ablative Radiotherapy’, Universal Trial Number U1111-1140-7563 , Registered 17th April 2013.
Extracorporeal Irradiation and Reimplantation with Total Hip Arthroplasty for Periacetabular Pelvic Resections: A Review of 9 Cases
We report the early results of nine patients with periacetabular malignancies treated with Enneking and Dunham type 2 resection and reconstruction using extracorporeally irradiated (ECI) tumour bone combined with total hip arthroplasty (THA). Diagnosis was chondrosarcoma in six patients, osteosarcoma in two patients, and metastatic renal cell carcinoma in one patient. All patients underwent surgical resection and the resected specimen was irradiated with 50 Gy in a single fraction before being prepared for reimplantation as a composite autograft. The mean follow-up was 21 months (range, 3–59). All patients were alive at latest follow-up. No local recurrence was observed. One patient serially developed three pulmonary metastases, all of which were resected. One experienced hip dislocation due to incorrect seating of an acetabular liner. This was successfully treated with revision of the liner with no further episodes of instability. There were no cases of deep infection or loss of graft. The average Musculoskeletal Tumor Society (MSTS) score was 75% (range, 57–87%). Type 2 pelvic reconstruction with ECI and THA has shown excellent early oncological and functional results in our series. Preservation of the gluteus maximus and hip abductors is important for joint stability and prevention of infection.
The Impact of Uterine Radiation on Subsequent Fertility and Pregnancy Outcomes
Future fertility is of paramount importance to younger cancer survivors. Advances in assisted reproductive technology mean that young women treated with radiation involving the uterus may require clinical guidance regarding whether to attempt a pregnancy themselves. We performed a review of the literature regarding radiation involving uterus (total body irradiation (TBI) and pelvic radiation), fertility, and pregnancy outcomes to come up with a recommendation for our patients. Limited evidence suggests lower fecundity and an increased incidence of pregnancy complications after uterine radiation. Higher radiation doses and direct uterine radiation both significantly increase the risk of an adverse pregnancy outcome. Uterine radiation doses of <4 Gy do not appear to impair uterine function. Adult TBI data (usually 12 Gy) suggest pregnancy is possible but with lower fecundity and more complications. Although there is no clear data indicating the dose of radiation to the uterus, above which a pregnancy would not be sustainable, we suggest patients receiving >45 Gy during adulthood and >25 Gy in childhood be counselled to avoid attempting pregnancy. There is preliminary evidence that menopausal hormone therapy and a combination of pentoxifylline and tocopherol may improve uterine function following irradiation.
Diffusion weighted and dynamic contrast enhanced MRI as an imaging biomarker for stereotactic ablative body radiotherapy
To explore the utility of diffusion and perfusion changes in primary renal cell carcinoma (RCC) after stereotactic ablative body radiotherapy (SABR) as an early biomarker of treatment response, using diffusion weighted (DWI) and dynamic contrast enhanced (DCE) MRI. Twelve patients were eligible for DWI analysis, and a subset of ten patients for DCE MRI analysis. DCE MRI from the second follow-up MRI scan showed correlations between the change in percentage voxels with washout contrast enhancement behaviour and the change in tumour volume ([rho] = 0.84, p = 0.004 at 12 month CT, [rho] = 0.81, p = 0.02 at 24 month CT, and [rho] = 0.89, p = 0.001 at last follow-up CT). The change in mean initial rate of enhancement and mean Ktrans at the second follow-up MRI scan were positively correlated with percent tumour volume change at the 12 month CT onwards ([rho] = 0.65, p = 0.05 and [rho] = 0.66, p = 0.04 at 12 month CT respectively). Changes in ADC kurtosis from histogram analysis at the first follow-up MRI scan also showed positive correlations with the percentage tumour volume change ([rho] = 0.66, p = 0.02 at 12 month CT, [rho] = 0.69, p = 0.02 at last follow-up CT), but these results are possibly confounded by inflammation. DWI and DCE MRI parameters show potential as early response biomarkers after SABR for primary RCC. Further prospective validation using larger patient cohorts is warranted.