BackgroundPET/CT scans acquired in the radiotherapy treatment position are typically performed without compensating for respiratory motion. The purpose of this study was to investigate geographic miss of lung tumours due to respiratory motion for target volumes defined on a standard 3D-PET/CT.Methods29 patients staged for pulmonary malignancy who completed both a 3D-PET/CT and 4D-PET/CT were included. A 3D-Gross Tumour Volume (GTV) was defined on the standard whole body PET/CT scan. Subsequently a 4D-GTV was defined on a 4D-PET/CT MIP. A 5 mm, 10 mm, 15 mm symmetrical and 15×10 mm asymmetrical Planning Target Volume (PTV) was created by expanding the 3D-GTV and 4D-GTV’s. A 3D conformal plan was generated and calculated to cover the 3D-PTV. The 3D plan was transferred to the 4D-PTV and analysed for geographic miss. Three types of miss were measured. Type 1: any part of the 4D-GTV outside the 3D-PTV. Type 2: any part of the 4D-PTV outside the 3D-PTV. Type 3: any part of the 4D-PTV receiving less than 95% of the prescribed dose. The lesion motion was measured to look at the association between lesion motion and geographic miss.ResultsWhen a standard 15 mm or asymmetrical PTV margin was used there were 1/29 (3%) Type 1 misses. This increased 7/29 (24%) for the 10 mm margin and 23/29 (79%) for a 5 mm margin. All patients for all margins had a Type 2 geographic miss. There was a Type 3 miss in 25 out of 29 cases in the 5, 10, and 15 mm PTV margin groups. The asymmetrical margin had one additional Type 3 miss. Pearson analysis showed a correlation (p < 0.01) between lesion motion and the severity of the different types of geographic miss.ConclusionWithout any form of motion suppression, the current standard of a 3D- PET/CT and 15 mm PTV margin employed for lung lesions has an increasing risk of significant geographic miss when tumour motion increases. Use of smaller asymmetric margins in the cranio-caudal direction does not comprise tumour coverage. Reducing PTV margins for volumes defined on 3D-PET/CT will greatly increase the chance and severity of a geometric miss due to respiratory motion. 4D-imaging reduces the risk of geographic miss across the population of tumour sizes and magnitude of motion investigated in the study.
Background Virtual simulations are used throughout healthcare training programs to enable development of clinical skills, however the potential for virtual simulation to enhance cognitive and affective skills is less well understood. This study explored pre-clinical optometry students’ perceptions of the impact of virtual simulation on the development of core competency skills including patient-centred care, communication, scientific literacy, and evidence-based practice. Methods A mixed methods study was conducted using pre-existing anonymized data from an electronic survey distributed to pre-clinical optometry students enrolled in the double degree Bachelor of Vision Science/Master of Optometry at Deakin University, Australia. The data were interpreted using descriptive statistics and qualitative analysis using constant comparison for thematic analysis. Results A total of 51 responses were analyzed. Students reported that virtual simulation motivated them to become an optometrist (93%) and to learn beyond the course material (77%). Students reported that after participating in the virtual simulation, their core competency skills improved: patient-centered care (100%) evidence-based practice (93%) and clinical reasoning (93%). The themes identified through qualitative analysis were: enablers to cognitive experience in virtual simulation in optometry education, realism of the virtual simulation design, dimensions of fidelity in virtual simulations design replicated the complexity of the optometric environment, virtual simulation as an enabler for learning and assessment in optometry education, a place to develop cognitive and affective skills and application of learning in the virtual simulation developed an appreciation of future roles and professional identity. Conclusion Optometry students perceived virtual simulation in optometric education as a valuable training and assessment strategy enabled by qualities that generate contextual, cognitive, functional, task and psychological fidelity. The data provide insight to inform how optometry educators can incorporate simulation into the curriculum.
Background Inherent features in virtual simulation could be utilised to deliver collaborative global education that is inclusive, accessible, and valued by students and facilitators. The aim of this study was to evaluate the impact of the International Eyecare Community (IEC) platform’s virtual simulated international placements (VSIP) in optometric education. Methods An international, multi-center, cross-sectional mixed methods study with Deakin University, Australia, and the Elite School of Optometry, India, was used to evaluate the impact of VSIP in the IEC using pre-existing deidentified data collected from teaching and learning activities within the optometry course curriculum. Data on students and facilitators perceptions of the VSIP were collected through deidentified transcripts from focus group discussions. The data were interpreted using descriptive statistics and qualitative analysis using constant comparison for thematic analysis. Results A total of 64 out of 167 student participants completed survey responses (39%) and 46 out of 167 (28%) completed self-reflective inventories. Focus groups with 6 student participants and 6 facilitator participants were recorded and analysed. Student participants reported the IEC was relevant (98% agreement) and motivated them to apply theoretical knowledge to a clinical context (97% agreement). The themes identified through qualitative analysis were: factors inherent to the virtual simulation that enabled learning through VSIP, the VSIP supported cognitive apprenticeship, VSIP enabled clinical learning for optometric education, VSIP’ role in cross-cultural professional identity development in optometry students. Conclusion The study found that the VSIP platform helped to motivate students to learn and improve their clinical skills. The VSIP was considered a potential supplement to physical clinical placements and could revolutionize global optometric education by offering co-learning across cultures.
Background Diagnostic reasoning is an essential skill for optometry practice and a vital part of the curriculum for optometry trainees but there is limited understanding of how diagnostic reasoning is performed in optometry or how this skill is best developed. A validated and reliable self-reflective inventory for diagnostic reasoning in optometry, would enable trainees and registered practitioners to benchmark their diagnostic reasoning skills, identify areas of strength and areas for improvement. Methods A 41 item self-reflective inventory, the Diagnostic Thinking Inventory, used extensively in the medical field was adapted for use in optometry and called the Diagnostic Thinking Inventory for Optometry (DTI-O). The inventory measures two subdomains of diagnostic reasoning, flexibility in thinking and structured memory. Context based changes were made to the original inventory and assessed for face and content validity by a panel of experts. The inventory was administered to two groups, experienced (qualified) optometrists and second-year optometry students to establish validity and reliability of the self-reflective tool in optometry. Results Exploratory Factor Analysis uncovered 13 domain specific items were measuring a single construct, diagnostic reasoning. One misfitting item was removed following Rasch analysis. Two unidimensional subdomains were confirmed in the remaining 12 items: Flexibility in Thinking (χ2 = 12.98, P = 0.37) and Structured Memory (χ2 = 8.74, P = 0.72). The ‘Diagnostic Thinking Inventory for Optometry Short’ (DTI-OS) tool was formed from these items with the total and subdomain scores exhibiting strong internal reliability; Total score Cα = 0.92. External reliability was established by test-retest methodology (ICC 0.92, 95% CI 0.83–0.96, P < .001) and stacked Rasch analysis (one-way ANOVA, F = 0.07, P = 0.80). Qualified optometrists scored significantly higher (P < .001) than students, demonstrating construct validity. Conclusion This study showed that the DTI-O and DTI-OS are valid and reliable self-reflective inventories to quantify diagnostic reasoning ability in optometry. With no other validated tool to measure this metacognitive skill underpinning diagnostic reasoning a self-reflective inventory could support the development of diagnostic reasoning in practitioners and guide curriculum design in optometry education.
This case study discusses the use of superficial radiotherapy (SXRT) in the treatment of recurrent conjunctival squamous cell carcinoma (SCC). Conjunctival SCC is often an aggressive cancer, with surgery the current standard of care. There is currently limited literature on alternative treatment options to treat conjunctival SCC recurrences that enable ocular function preservation. Furthermore, the use of SXRT in this setting is not well‐reported. Technical feasibility, practical limitations and potential side effects of SXRT (in comparison to other treatment options) are discussed in this case study. This case describes a 62 years old male with limited treatment options following multiple recurrences of conjunctival SCC. He was prescribed a therapeutic SXRT dose of 48.4 Gy in 22 fractions (5 fractions/week). At 6‐month follow‐up, there was no evidence of residual or recurrent disease, or any significant objective or patient reported treatment induced side effects. This case study provides preliminary evidence for the potential application of SXRT for conjunctival SCC. The benefits reported in this case study warrant further investigation of the applicability of SXRT in a larger patient cohort, with the potential to provide patients with a less invasive treatment alternative for recurrent conjunctival SCC.
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