The potential for using entrustable professional activities in assessing optometric clinical competence.

Qualifications required to practise optometry seek to provide assurance that those completing them have the necessary competencies to be safe and effective clinicians. Often, this assurance is gained via high stakes assessments such as objective structured clinical examinations. This paper introduces entrustable professional activities (EPAs) as a potential alternative approach to assessing optometric clinical competence. Entrustable professional activities are defined in the context of optometric practice and the potential advantages and challenges of using them are outlined.

Joint radial trajectory correction for accelerated T2 * mapping on an MR-Linac.

BACKGROUND: T2 * mapping can characterize tumor hypoxia, which may be associated with resistance to therapy. Acquiring T2 * maps during MR-guided radiotherapy could inform treatment adaptation by, for example, escalating the dose to resistant sub-volumes. PURPOSE: The purpose of this work is to demonstrate the feasibility of the accelerated T2 * mapping technique using model-based image reconstruction with integrated trajectory auto-correction (TrACR) for MR-guided radiotherapy on an MR-Linear accelerator (MR-Linac). MATERIALS AND METHODS: The proposed method was validated in a numerical phantom, where two T2 * mapping approaches (sequential and joint) were compared for different noise levels (0,0.1,0.5,1) and gradient delays ([1, -1] and [1, -2] in units of dwell time for x- and y-axis, respectively). Fully sampled k-space was retrospectively undersampled using two different undersampling patterns. Root mean square errors (RMSEs) were calculated between reconstructed T2 * maps and ground truth. In vivo data was acquired twice weekly in one prostate and one head and neck cancer patient undergoing treatment on a 1.5 T MR-Linac. Data were retrospectively undersampled and T2 * maps reconstructed, with and without trajectory corrections were compared. RESULTS: Numerical simulations demonstrated that, for all noise levels, T2 * maps reconstructed with a joint approach demonstrated less error compared to an uncorrected and sequential approach. For a noise level of 0.1, uniform undersampling and gradient delay [1, -1] (in units of dwell time for x- and y-axis, respectively), RMSEs for sequential and joint approaches were 13.01 and 9.32 ms, respectively, which reduced to 10.92 and 5.89 ms for a gradient delay of [1, 2]. Similarly, for alternate undersampling and gradient delay [1, -1], RMSEs for sequential and joint approaches were 9.80 and 8.90 ms, respectively, which reduced to 9.10 and 5.40 ms for gradient delay [1, 2]. For in vivo data, T2 * maps reconstructed with our proposed approach resulted in less artifacts and improved visual appearance compared to the uncorrected approach. For both prostate and head and neck cancer patients, T2 * maps reconstructed from different treatment fractions showed changes within the planning target volume (PTV). CONCLUSION: Using the proposed approach, a retrospective data-driven gradient delay correction can be performed, which is particularly relevant for hybrid devices, where full information on the machine configuration is not available for image reconstruction. T2 * maps were acquired in under 5 min and can be integrated into MR-guided radiotherapy treatment workflows, which minimizes patient burden and leaves time for additional imaging for online adaptive radiotherapy on an MR-Linac.

Salvage of the failed implant-based breast reconstruction using the Deep Inferior Epigastric Perforator Flap: A single centre experience with tertiary breast reconstruction.

BACKGROUND: The longevity and durability of implant-based reconstruction is limited and many patients who develop complications seek alternative reconstruction. Recent studies have shown tertiary reconstruction with autologous tissue to be safe in the short term. But no study has looked in-depth at the motivation for seeking referral and its long-term outcome. METHODS: This was a retrospective study using patient case-notes and a prospectively-collated database. One hundred and fifteen patients underwent tertiary breast reconstruction with a Deep Inferior Epigastric Perforator (DIEP) flap between 1998 and 2016. RESULTS: Mean age was 49 (23-67). The predominant initial reconstruction was expander (71%). Twenty nine percent received a definitive reconstruction (implant with acellular dermal matrix or pedicled latissimus dorsi). The proportion of patients who received post-mastectomy radiotherapy (PMRT) to their implant was 72%. Thirty four percent underwent surgical salvage prior to referral for autologous tissue and this was significantly higher in the group that did not receive PMRT (29% vs 40, p = 0.04). Predominant motivation for autologous reconstruction was poor cosmesis (62%) and/or grade III/IV capsular contracture (27%). Mean time from implant to DIEP was 4 years 5 months. Ten percent had complications requiring re-operation. Flap loss was 0.7%. Fifty five percent required an additional ipsilateral procedure and 47% required symmetrization. Median follow-up was 20-months (6-months to 7-years). CONCLUSIONS: We present the largest UK series of tertiary breast reconstruction. Tertiary reconstruction is safe with a surgical outcome comparable to delayed autologous reconstruction. Patients with implant complications often had multiple failed attempts at salvage prior to referral. We advocate careful consideration of implants in the setting of PMRT and early referral for autologous tissue once complications become apparent.