ESTRO 38 Abstract book

S369 ESTRO 38

This study reflects the current patterns of care for local recurrent NPC in Hong Kong. Early detection of local recurrence is of paramount importance as surgery for resectable tumours is associated with the most favourable outcomes. Re-RT could be considered in selected patients with unresectable disease but favourable prognostic features. PO-0719 head and neck contour peer review improves quality of radiotherapy targets L. MCGEE 1 , J. Rwigema 1 , M. Halyard 1 , T. DeWees 1 , J. Gagneur 1 , S. Patel 1 1 Mayo Clinic Arizona, Radiation Oncology, Phoenix, USA Purpose or Objective Head and neck (HN) radiotherapy contour quality can directly impact local control and survival. However, few departments peer review (PR) contours prior to radiotherapy planning (RP). In an effort to further improve radiotherapy quality at our institution, we implemented a formal HN contour PR process. This series reports results of the first 7 months after initiation of this workflow. Material and Methods A formal HN contour PR process was implemented within our department. Contours were reviewed by radiation oncologists (RO) who specialize in HN cancer and revised prior to initiation of RP. A PR task item was built into the care path of the electronic medical record (EMR) to track the PR process. Dosimetry was not allowed to initiate RP until the PR task in the care path had been completed by the RO HN team. RO participated in a weekly meeting to review contours. Together, the RO evaluated factors pertinent to individual patient contours including pretreatment imaging, physical examination photographs, recorded flexible scope examination, operative notes and surgical pathology. Contours were assessed by the RO HN team, and feedback was provided to the treating physician if contour revision was recommended. Contour revisions were graded by the RO present as follows: R0 (no change), R1 (minor revision, not deemed high risk) or R2 (major revision, deemed to have potential to negatively impact patient outcomes). The PR task was completed and grading of contours recorded in the EMR. The Cochran-armitage trend test was performed to determine if contour grade trend was significant over time. Results From February to August 2018, 110 HN cancer patients had the contour PR task completed in the EMR; 88 (80%) had grade recorded for contour revision. Four RO participated in the first 3 months; 3 RO participated all 7 months. Contours were graded as follows: R0 (N=50), R1 (N=20) and R2 (N=18). Over time the number of major revisions (R2) decreased (p=0.0001); month 1 (N=7) month 2 (N=3), month 3 (N=5) month 4 (N=2) and months 5-7 (N=0). Each individual RO who participated the entire time demonstrated reduction in R2 revisions; Oncologist A: month 1 (N=2), month 2 (N=1), month 3 (N=2), month 4 (N=1) and month 5-7 (N=0). Oncologist B: month 1 (N=2), months 2-4 (N=1) and months 5-7 (N=0). Oncologist C: month 1 and 3 (N=1) and months 2, 4-7 (N=0). The total number of R0 revisions improved over time (p=0.0203); month 1 (N=5), months 2-3 (N=9), month 4 (N=5) month 5 (N=8), month 6 (N=12) and month 7 (N=3). Conclusion HN contour PR can be implemented into routine clinical workflow. The collective experience of multiple high volume RO led to improved contour quality over time for each RO. This improvement in contour quality may result in improved plan quality which in turn could lead to improved disease control and toxicity in patients treated after implementation of this process.

≥3°dysphagia which were also not significantly different between the treatments. Conclusion The addition of chemotherapy to hyperfractionated RT schedules in definitive treatment of advanced HN-cancers improves all studied endpoints without a significant increase in the investigated high-grade acute and late toxicities. PO-0718 Patterns of care for local recurrence of NPC after definite IMRT – a study by the HKNPCSG W.T. Ng 1 , E.C. Wong 1 , L.L. Chan 1 , A.K. Cheung 2 , J.C. Chow 3 , D.M. Poon 4 , J.W. Lai 5 , C.L. Chiang 6 , K.H. Au 3 , A.W. Lee 7 1 Pamela Youde Nethersole Eastern Hospital, Clinical Oncology, Hong Kong, Hong Kong SAR China ; 2 Tuen Mun Hospital, Clinical Oncology, Hong Kong, Hong Kong SAR China ; 3 Queen Elizabeth Hospital, Clinical Oncology, Hong Kong, Hong Kong SAR China ; 4 Prince of Wales Hospital, Clinical Oncology, Hong Kong, Hong Kong SAR China ; 5 Princess Margaret Hospital, Clinical Oncology, Hong Kong, Hong Kong SAR China ; 6 Queen Mary Hospital, Clinical Oncology, Hong Kong, Hong Kong SAR China ; 7 The University of Hong Kong and The University of Hong Kong-Shenzhen Hospital, Departments of Clinical Oncology, Hong Kong, Hong Kong SAR China Purpose or Objective This retrospective study evaluated the patterns of care for patients with local recurrence of nasopharyngeal carcinoma (NPC) after intensity modulated radiotherapy (IMRT) treated in all public hospitals in Hong Kong from 2001 to 2010. Material and Methods Eligible patients were identified through the Hong Kong Cancer Registry data base. Patients with biopsy proven/ radiologically documented local recurrence without concomitant distant metastasis were included. All patients received IMRT as the primary course of treatment. Patient demographics, tumour characteristics and treatment details were retrieved and verified. Survival outcomes after local recurrence were analysed. Results 272 patients were identified. The median follow-up time was 31.5 months. Median time from primary diagnosis to local relapse was 29.6 months. The rT stage distribution was rT1: 30.5%, rT2: 9.6%, rT3: 25.4% and rT4: 34.6%. 74.3% had rN0 disease. Thirty one percent of patients received surgery, 35.7% received re-irradiation (RT), 23.2% received palliative chemotherapy alone and 10.3% had no active treatment. Early local recurrence was mostly treated with surgery (82.3% of Stage I, 38.1% of Stage II), while late recurrence was commonly treated non-surgically (52.1% of Stage III managed with re-RT; 42.3% of Stage IVA managed with chemotherapy alone). Adjuvant RT was commonly given in case of involved resection margin after radical resection (65.4%). Surgery was associated with 2.4% perioperative mortality, while re-RT was associated with 16.7% grade 5 late complications. The 5-year overall survival (OS) for the whole group was 30.2%. Older age and advanced rT stage were adverse prognostic factors, while the use of surgery as primary treatment (mainly in early local recurrence) was associated with favourable outcome. The 5-year OS rates for patients who received surgery, re-RT, chemotherapy and no active treatment were 56.3%, 21.8%, 15.0% and 11.1% respectively. For the surgery group, resection margin status was the most important prognostic factor. Adjuvant RT did not improve local control and OS when compared with surgery alone and was associated with 28.5% of grade 4 toxicities or above. For the re-RT group, OS were adversely affected by older age and larger gross tumour volume. Conclusion