Magnetic resonance imaging organ at risk delineation for nasopharyngeal radiotherapy: Measuring the effectiveness of an educational intervention

• Published in: Journal of medical radiation sciences 2023-04, Vol.70 (S2), p.59-69
• Main Authors: Ryan, Olivia, Dundas, Kylie, Surjan, Yolanda, Elwadia, Doaa, Nguyen, Kimberley, Cardoso, Michael, Kumar, Shivani
• Format: Article
• Language: English
• Subjects: Cancer; Datasets; Didacticism; Education; Humans; Intervention; inter‐observer variability; Likert scale; Magnetic Resonance Imaging; Medical imaging; MRI; nasopharyngeal carcinoma; Neck; OAR delineation; Observer Variation; Organs at Risk; Original; Planning; Radiation Oncology; Radiation therapy; Radiotherapy Planning, Computer-Assisted - methods; Retrospective Studies; Software; Throat cancer; Workshops
• ISSN: 2051-3895; 2051-3909
• DOI: 10.1002/jmrs.651

Introduction Magnetic resonance imaging (MRI) demonstrates superior soft tissue contrast and is increasingly being used in radiotherapy planning. This study evaluated the impact of an education workshop in minimising inter‐observer variation (IOV) for nasopharyngeal organs at risk (OAR) delineation on MRI. Methods Ten observers delineated 14 OARs on 4 retrospective nasopharyngeal MRI data sets. Standard contouring guidelines were provided pre‐workshop. Following an education workshop on MRI OAR delineation, observers blinded to their original contours repeated the 14 OAR delineations. For comparison, reference volumes were delineated by two head and neck radiation oncologists. IOV was evaluated using dice similarity coefficient (DSC), Hausdorff distance (HD) and relative volume. Location of largest deviations was evaluated with centroid values. Observer confidence pre‐ and post‐workshop was also recorded using a 6‐point Likert scale. The workshop was deemed beneficial for an OAR if ≥50% of observers mean scores improved in any metric and ≥50% of observers' confidence improved. Results All OARs had ≥50% of observers improve in at least one metric. Base of tongue, larynx, spinal cord and right temporal lobe were the only OARs achieving a mean DSC score of ≥0.7. Base of tongue, left and right lacrimal glands, larynx, left optic nerve and right parotid gland all exhibited statistically significant HD improvements post‐workshop (P