ESTRO 2020 Abstract book

S361 ESTRO 2020

Proffered Papers: Proffered papers 32: Innovations in RTT practice and complex decision making

Table 1 demonstrates the mean +/- standard deviation and the DICE values for the delineated GTV and CTV.

OC-0588 The role of the Consultant Neuro-Oncology Radiographer in the peer review session for brain tumours A. Williamson 1 , S. Nowicki 1 , A. James 1 , A. Chalmers 2 , R. Carruthers 2 , A. Duffton 1 1 Beatson West of Scotland Cancer Centre, Radiotherapy, Glasgow, United Kingdom ; 2 Institute of Sciences- University of Glasgow, Clinical Oncology, Glasgow, United Kingdom Purpose or Objective Accurate definition of gross target volumes (GTV) and clinical target volumes (CTV) is one of the most important steps in the delivery of high precision radiotherapy. Peer review of delineated radiotherapy target volumes ensures that every volume undergoes a systematic review ensuring transparency, standardisation, quality and safety, and promotes knowledge sharing within multi-disciplinary teams. Following the appropriate training and competency programme, Advanced Practice (AP) RTTs working in specialist roles can undertake the delineation of target volumes. This study aims to quantify volume difference and report agreement in GTV and CTV defined by a specialist RTT compared to final volumes agreed within a peer review session (PRS) Material and Methods The AP RTT creates the primary delineation of the GTV and CTV for high (HGG) and low grade gliomas (LGG) and brain metastases (BM). Once the AP RTT has completed the primary target delineation, the GTVp and CTVp volumes are saved and volumes are recorded. At the peer review session (PRS), which includes 2-4 clinical oncologists (CO), physicist and RTT, clinical information, pre-treatment imaging and pathology for each patient are discussed. All delineated target volumes were assessed by the MDT to ensure that the size and extent of each volume is appropriate. Modifications were made through consensus recommendations, and approved by CO in the presence of the MDT. The clinically approved GTVf and CTVf volumes were recorded. Results The study was conducted during September 2018- September 2019, 85 patients were included in the analysis. 57 % patients had high grade glioma, 16% low grade glioma and 27% brain metastases.

Mean CTVp +/- St Dev 365.5 3 cc 3 +/- 184.3 8 363.3 2 cc 3 +/- 168.4 9

Mean GTVf +/- St Dev

Mean CTVf +/- St Dev

DICE GTV p

DICE GTV f

Tumo ur Type

Mean GTVp +/- St Dev

35.47 cc 3 +/- 26.4

35.81cc 3 +/- 26.5

369.18 cc 3 +/- 178.96

69.1 8

91.8 3

HGG

363.35 cc 3 +/- 172.07

112.65 cc 3 +/- 61.64

114.41 cc 3 +/- 61.47

79.1 8

82.1 3

LGG

2.86 cc 3 +/- 2.53

1.65 cc 3 +/- 1.70

1.67 cc 3 +/- 1.72

2.89 cc 3 +/- 2.54

81.2 3

75.1 2

BM

Conclusion Good agreement was shown between RTT and the final volumes approved by the CO at the PRS. This study provides evidence demonstrating how AP RTT’s can lead target delineation of GTV and CTV contouring within the PRS. Such a transition in work practices has the potential to both broaden the role and skills of radiation therapists and increase departmental workload efficiencies. OC-0589 Concordance of Advanced Practitioner RT and Radiation Oncologists in reviewing NPC patients Y. Sin Sze 1 , X. Lin 1 , K. Sommat 1 , M.L.K. Chua 1 , Y.L. Soong 1 1 National Cancer Centre Singapore, Radiation Oncology, Singapore, Singapore Purpose or Objective Weekly toxicity assessments for patients undergoing head and neck (HN) radiotherapy (RT) are essential so that patients’ acute RT side effects are well managed in order for them to complete their treatment in a safe and timely manner. The role expansion of HN Advanced Practitioner Radiation Therapist APRT) at our department includes weekly treatment reviews to reduce the workload of the Radiation Oncologists (ROs). The concordance of toxicity assessment between HN APRT and ROs in patients with nasopharyngeal carcinoma (NPC) is reported here. Material and Methods 27 NPC patients under the care of 3 ROs were recruited from June to December 2018; weekly assessments were independently performed by HN APRT and ROs. The HN APRT’s assessment was graded according to the Common Terminology Criteria for Advanced Events (CTCAE) v4.0. ROs’ chart documentation was translated to CTCAE form for comparison. The concordance rate and agreement level were interpreted by Cohen’s Kappa statistic, with the ROs’ assessments deemed as the ‘gold standard’. Results Overall, HN APRT achieved 80.1% concordance with the ROs for all the graded toxicities. Xerostomia, dysgeusia,