Derfel ap Dafydd

Dr. Derfel ap Dafydd

orcid

Research Focus & Metrics

Academic Career Length

11Years (2016-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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1 February 2017 in Urology
Verified
Journal Article
Closed access
DDDerfel ap Dafydd
Derfel ap Dafydd
CMChristina Messiou
Christina Messiou
KTKhin Thway
Khin Thway
DSDirk C. Strauss
Dirk C. Strauss
DNDavid L. Nicol
David L. Nicol
EMEleanor Moskovic
Eleanor Moskovic

22 January 2016 in European Radiology
Verified
Journal Article
Closed access
PDF file
DDDerfel ap Dafydd
Derfel ap Dafydd
SDSujal R. Desai
Sujal R. Desai
FGFabiana Gordon
Fabiana Gordon
SCSusan J. Copley
Susan J. Copley

15 February 2021 in British Journal of Radiology
Verified
Journal Article
Closed access
JKJie-Ying Kowa
Jie-Ying Kowa
NSNeil Soneji
Neil Soneji
SSS Aslam Sohaib
S Aslam Sohaib
EMErik Mayer
Erik Mayer
SHStephen Hazell
Stephen Hazell
DDDerfel ap Dafydd
Derfel ap Dafydd
Objective: We determined the sensitivity and specificity of multiparametric magnetic resonance imaging (MP-MRI) in detection of locally recurrent prostate cancer and extra prostatic extension in the post-radical radiotherapy setting. Histopathological reference standard was whole-mount prostatectomy specimens. We also assessed for any added value of the dynamic contrast enhancement (DCE) sequence in detection and staging of local recurrence. Methods: This was a single centre retrospective study. Participants were selected from a database of males treated with salvage prostatectomy for locally recurrent prostate cancer following radiotherapy. All underwent pre-operative prostate-specific antigen assay, positron emission tomography CT, MP-MRI and transperineal template prostate mapping biopsy prior to salvage prostatectomy. MP-MRI performance was assessed using both Prostate Imaging-Reporting and Data System v. 2 and a modified scoring system for the post-treatment setting. Results: 24 patients were enrolled. Using Prostate Imaging-Reporting and Data System v. 2, sensitivity, specificity, positive predictive value and negative predictive value was 64%, 94%, 98% and 36%. MP-MRI under staged recurrent cancer in 63%. A modified scoring system in which DCE was used as a co-dominant sequence resulted in improved diagnostic sensitivity (61%–76%) following subgroup analysis. Conclusion: Our results show MP-MRI has moderate sensitivity (64%) and high specificity (94%) in detecting radio-recurrent intraprostatic disease, though disease tends to be under quantified and under staged. Greater emphasis on dynamic contrast images in overall scoring can improve diagnostic sensitivity. Advances in knowledge: MP-MRI tends to under quantify and under stage radio-recurrent prostate cancer. DCE has a potentially augmented role in detecting recurrent tumour compared with the de novo setting. This has relevance in the event of any future modified MP-MRI scoring system for the irradiated gland.

26 November 2020 in British Journal of Radiology
Verified
Journal Article
Open access
DDDerfel ap Dafydd
Derfel ap Dafydd
MOMichelle O’mAhony
Michelle O’mAhony
SJShaman Jhanji
Shaman Jhanji
ADAnand Devaraj
Anand Devaraj
WAWilliam Allum
William Allum
ARAngela M Riddell
Angela M Riddell
Objectives: In accordance with initial guidance from the Royal College of Surgeons and Royal College of Radiologists, we evaluated the utility of CT of the chest in the exclusion of asymptomatic COVID-19 infection prior to elective cancer surgery on self-isolating patients during the pandemic. Methods: All surgical referrals without symptoms of COVID-19 infection in April and May 2020 were included. Patient records were retrospectively reviewed. Screening included CT chest for major thoracic and abdominal surgery. CTs were reported according to British Society of Thoracic Imaging guidelines and correlated with reverse transcriptase polymerase chain reaction (RT-PCR) and surgical outcomes. Results: The prevalence of RT-PCR confirmed COVID-19 infection in our screened population was 0.7% (5/681). 240 pre-operative CTs were performed. 3.8% (9/240) of CTs were reported as abnormal, only one of which was RT-PCR positive. 2% (5/240) of cases had surgery postponed based on CT results. All nine patients with CTs reported as abnormal have had surgery, all without complication. Conclusion: The prevalence of asymptomatic COVID-19 infection in our screened population was low. The pre-test probability of CT chest in asymptomatic, self-isolating patients is consequently low. CT can produce false positives in this setting, introducing unnecessary delay in surgery for a small proportion of cases. Advances in knowledge: Self-isolation, clinical assessment and RT-PCR are effective at minimising COVID-19 related surgical risk. The addition of CT chest is unhelpful. Our data have particular relevance during the second wave of infection and in the recovery phase.


25 October 2024 in Cancer Imaging
Verified
Journal Article
Open access
PDF file
GBGeorge Gabriel Bitar
George Gabriel Bitar
MPMelissa Persad
Melissa Persad
ADAlina Dragan
Alina Dragan
AAAdebayo Alade
Adebayo Alade
PJPablo Jiménez-Labaig
Pablo Jiménez-Labaig
DDDerfel ap Dafydd
Derfel ap Dafydd
Background: Directly-injected therapies (DIT) include a broad range of agents within a developing research field in cancer immunotherapy, with encouraging clinical trial results in various tumour subtypes. Currently, the majority of such therapies are only available within clinical trials; however, more recently, talimogene laherparepvec (T-VEC, Imlygic) has been approved as the first oncolytic virus therapy in the USA and Europe. Our institution contributes to multiple different trials exploring the efficacy of DIT, the majority of which are performed by oncologists in clinic. However, specific, challenging cases – mainly neck tumours – require image-guided administration. Main body: This review article addresses the technical and logistical factors relevant to the incorporation of image-guided DIT into an established ultrasound service. Image-guidance (usually with ultrasound) is frequently needed for certain targets that cannot be palpated or are in high-risk locations, e.g. adjacent to blood vessels. A multi-disciplinary approach is essential to facilitate a safe and efficient service, including careful case-selection. Certain protocols and guidance need to be followed when incorporating such a service into an established ultrasound practice to enhance efficiency and optimise safety. Key learning points are drawn from the literature and from our early experience at a tertiary cancer centre following image guided DIT for an initial cohort of 22 patients (including 11 with a neck mass), addressing trial protocols, pre-procedure work-up, organisation, planning, consent, technical aspects, procedure tolerability, technical success, and post-procedure considerations. Conclusion: With appropriate planning and coordination, and application of the learning points discussed herein, image-guided administration of DIT can be safely and efficiently incorporated into an established procedural ultrasound list. This has relevance to cancer centres, radiology departments, individual radiologists, and other team members with a future role in meeting the emerging need for these procedures. This paper provides advice on developing such an imaging service, and offers certain insights into the evolving remit of radiologists within cancer care in the near future.