Abstract book - ESTRO meets Asia

S65 ESTRO meets Asia 2018

Material and Methods Databases were systematically searched for eligible studies with dose escalation (BED >68-70 Gy) in the form of brachytherapy, EBRT or SRT boost for primary treatment of nasopharyngeal cancer after EBRT. Single- arm, non-English and studies published before 1990 were excluded. LRFS, OS, PFS, DFS, toxicities and relevant factors for the chosen studies were then pooled and analyzed. Results 2 RCTs and 7 retrospective cohort studies with a total of 2145 patients were included in the final analysis. 988 patients received dose escalation, mainly in the form of brachytherapy (90%). Patients were mostly male, from Southeast Asia, had T1-T2 disease (80%), underwent radiotherapy via 2D techniques (87%), but less than half received concurrent chemotherapy. From the 2 RCTs, 3- year LRFS (RR 1.04; 95% CI: 0.85 – 1.28, p=0.71), OS, PFS and DFS were not significantly improved with dose escalation. However, the subset of patients pooled from the retrospective studies who did not receive concurrent chemotherapy showed significant 3-year LRFS (RR 1.04; 95% CI: 1.01 – 1.07, p=0.003), PFS and DFS benefit with dose escalation. Toxicities were not significantly increased with dose escalation. Conclusion Radiotherapy dose escalation may be an option patients who are unable to undergo concurrent chemotherapy during definitive treatment of nasopharyngeal cancer. PO-162 Outcomes with Local Therapy for mNPC at Diagnosis: Experience from a Tertiary Center in a LMIC K.K. Yu 1 Purpose or Objective The role of local treatment is currently undefined in patients with metastatic nasopharyngeal carcinoma (NPC). We evaluated the oncologic outcomes after local radiotherapy in newly-diagnosed metastatic NPC patients at our center Material and Methods We retrospectively reviewedrecords of 17 patients with metastatic NPC at diagnosis from the period of 2006 to 2017. All patients were treated with primary local radiotherapy at our center. The median age of the cohort was 50 years old. Majority of the population had T3/T4 (65%) and/or N3 (64.7%) disease. Most of the patients were treated with conventional Modified Ho’s technique (70.6%) and received a total dose of 70Gy (76.5%). Twelve (70.6%) patients were given concurrent chemotherapy (triweekly cisplatin) and another 12 received induction chemotherapy (cisplatin + FU, 64.7%) Oncologic outcomes were calculated using the Kaplan Meier method. Clinical parameters and treatment modalities were compared using univariate analysis. Results The median follow-up for the entire cohort was 11 months (range, 1-93 months). One-year and 2-year overall survival were 69% and 36%, respectively with a median survival estimate of 24 months. Univariate analysis showed significantly improved survival for patients with higher performance status (p=0.001) and those who had concurrent chemotherapy (p=0.46). No significant difference in overall survival was seen between RT modalities, T and N stage, site of metastasis, and induction chemotherapy. Five patients developed grade 3 mucositis. No grade 4 toxicities were noted. Conclusion Local radiotherapy combined with systemic treatment may be associated with prolonged survival in newly diagnosed metastatic nasopharyngeal carcinoma patients 1 Benavides Cancer Institute- UST Hospital, Radiation Oncology, Manila, Philippines

Clinical CNS:

PO-163 Correlation of PFS with RANO criteria in primary GBM patients treated by chemoradiotherapy A. Mukherjee 1 , N. Kumar 1 , S. Dhunganama 2 1 Postgraduate Institute of Medical Education and Researc h, Radiation Oncology, Chandigarh, India 2 Postgraduate Institute of Medical Education and Researc h, Radiology, Chandigarh, India Purpose or Objective In clinical trials, Over-all response rates (ORRs) and Progression-free survival (PFS) are particularly important because they are not confounded by salvage therapies and other variables that may affect Over-all Survival(OS) and because they can be assessed relatively rapidly . For any response criteria to be used as surrogate end-points for clinical trials like PFS and ORR, it should have high reproducibility and should be easy to implement. Whether the ORR determined by RANO (Revised assessment in Neuro-oncology) criteria correlates with PFS in primary glioblastoma (GBM) treated by post-operative radiotherapy with concurrent and adjuvant temozolomide (TMZ) has not been studied yet, to the best of our knowledge. This prospective study aims to investigate any such possible correlation. Material and Methods 36 GBM patients were recruited in this study from December 2016 to March 2017. All of them were treated with standard post-operative radical radiotherapy (60Gy in conventional fractionation) with concurrent (75mg/m2) and adjuvant temozolomide (175mg/m2) . Target volumes of irradiation were based on MD Anderson contouring guidelines. The radiotherapy course was divided into primary(46Gy) and boost phases(14Gy). RANO defined ORR groups were CR(Complete Response), PR(Partial Response), SD (Stable disease) and PD (Progressive disease) based on features shown in the table.

Results The median age of our patients was 54 years (range 40-67 years) with a male: female ratio of 1.57:1. Majority of them (26, 72.2%) had undergone subtotal resection (STR), rest had gross tumour resection (GTR). Most of the patients had a ECOG performance status of 2 (15, 41.7%) and 1(14, 38.9%). Only 3 patients received a hypofractionated regime of 25 Gy in 5 fractions, rest (33, 91.6%) received 60Gy in 30 fractions over 1.5 months. 29 patients (80.5%) received concurrent (75mg/m2) and adjuvant TMZ (175mg/m2) with radiotherapy; rest were not fit to receive chemotherapy. Most of the patients had a ECOG performance status of 2 (15, 41.7%) and 1(14, 38.9%). The median number of adjuvant TMZ cycles received was 4.13. Response to treatment was assessed by RANO criteria at 3 months (RANO-3) and 6 months (RANO- 6) after radiotherapy completion. After a median follow- up of 15 months, the median PFS came out to be 9.2 months (95% confidence intervals ,7.23 -1.16 months, standard error 1.004) (Reference: Kaplan Meier plot). We