Abstract book - ESTRO meets Asia

S61 ESTRO meets Asia 2018

Results At 18 months, the estimated overall survival was 89.3% for 2 phase IMRT and 91.4 % in the SIB IMRT (p = 0.13). Disease- free survival was 82 and 79% respectively (p = 0.27). There were no significant differences in local, regional or distant recurrence-free survival. There was no significant difference in weight loss (p = 0.291). No difference in nasogastric tube dependence (p = 0.465). Rates of acute grade 3 or 4 dysphagia (82% vs 70%) and dermatitis (68% vs 58%) were significantly higher in the SIB IMRT group (p < 0.005 and p = 0.023 respectively). Both the cohorts completed planned dose of radiation without any interruptions. Conclusion We found no differences in disease related outcomes between the two treatment delivery methodology A higher rate of acute grade 3 and 4 radiation dermatitis and dysphagia were observed in the SIB group. We still need a longer follow up to further evaluate the acute toxicity differences and confirm if this is being carried over to late treatment related toxicities. PO-154 Treatment Outcomes and Patterns of Failure in in Major Salivary Gland Salivary Duct Carcinomas D.S. Lee 1 , M.K. Kang 2 , K.M. Kang 3 , K.C. Keum 4 , Y.S. Kim 1 , J.H. Kim 5 , J.H. Kim 6 , S.H. Moon 7 , Y.T. Oh 8 , H.G. Wu 5 , C.G. Lee 4 , K.H. Cho 7 1 College of Medicine- The Catholic University of Korea, Department of Radiation Oncology, Seoul, Korea Republic of 2 Kyungpook National University School of Medicine, Department of Radiation Oncology, Daegu, Korea Republic of 3 Gyeongsang National University School of Medicine and Gyeongsang National University Changwon Hospital, Department of Radiation Oncology, Jinju, Korea Republic of 4 Yonsei University College of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of 5 Seoul National University College of Medicine, Department of Radiation Oncology, Seoul, Korea Republic of 6 Dongsan Medical Center- Keimyung University School of Medicine, Department of Radiation Oncology, Daegu, Korea Republic of 7 Research Institute and Hospital- National Cancer Center , Proton Therapy Center, Goyang, Korea Republic of 8 Ajou University School of Medicine, Department of Radiation Oncology, Suwon, Korea Republic of Purpose or Objective This retrospective study was launched to analyze the treatment outcomes and patterns of failure in relation to radiotherapy (RT) field in Salivary duct carcinoma. Material and Methods Between 1999 and 2008, a total of 27 SDC patients were recruited. All of enrolled patients were diagnosed with major salivary gland SDC and had received surgical resection of primary site (with or without neck dissection) followed by postoperative RT. The primary sites were parotid gland in 21 (77.8%) and submandibular gland in six (22.2%) patients, respectively. Pathological T- and N- stages were as follows: pT1 in four (14.8%), pT2 in seven (25.9%), pT3 in seven (25.9%), pT4a in eight (29.6%) and pT4b in one (3.7%); pN0 in four (14.8%), pN1 in two (7.4%), pN2b in 14 (51.9%), N3 in two (7.4%) and unknown in five (18.5%), respectively. Results The median age of study population was 61 (range, 23-78) years and 22 (81.5%) patients were male. The median follow-up duration was 57 (range, 4-141) months. The 5- year overall survival rates, disease-free survival rates,

local control rates, regional control rates and distant control rates were 63.4%, 47.4%, 72.7%, 96.3% and 68%, respectively. During follow-up periods, 13 (48.1%) patients had experienced recurrences and 13 (48.1%) patients died. Among 13 dead patients, 12 patients had undergone disease relapses. The patterns of failure were local in four (14.8%), regional in one (3.7%), local and distant in one (3.7%), and distant in seven (25.9%). Three (11.1%) local and one (3.7%) regional recurrence occurred within the RT field (infield recurrence). Accordingly, the outfield loco- regional recurrence rates were as follows: two (7.4%) local and 0 (0%) regional. The median elapsed time to distant metastasis was six (range, 3-23) months. Conclusion Surgery and postoperative radiotherapy was effective in loco-regional control of SDC. Distant recurrences were common and the major patterns of failure. The disease prognosis after any recurrence was extremely poor with 92.3% of death among patients who relapsed. PO-155 Planning Risk Volume PRV quantification of spinal cord and canal doses in head&neck cancer radiation A. Waheed1 1Aga khan university hospital, radiation oncology, Karachi, Pakistan Purpose or Objective To report the maximum, minimum, mean and 1% of the total dose that is delivered to the spinal cord and spinal canal in definitive treatment of patients of Head and Neck Squamous cell carcinoma Material and Methods A retrospective study is being conducted on Radiation treatment plans of Head and Neck cancer patients treated between period of 2008 to 2017. A total number of 90 patients plans were reviewed who were treated with radical intent concurrent chemo radiation. Total radical doses delivered were in the range of 66-74 Gray. As a part of treatment planning Organ At Risks (OAR) like spinal cord and spinal canal are contoured. The range of spinal cord and spinal canal doses were analyzed using data extracted from approved plans using Dose Volume Histogram(DVH). Maximum, mean and 1% of total dose delivered to spinal cord and spinal canal during the entire treatment was analyzed. In order to comply with the concepts of PRV (Planning Risk Volume) we have adopted to mark the spinal canal along with spinal cord for planning purposes. As a matter of extra precaution another percentage level was introduced, as 1% dose level, which was also documented and analyzed. Dose Volume Histogram were studied and documented. Results The ranges of maximum, mean and 1% of spinal canal doses were found to be (49.99Gy to 43.08Gy) , (41.66Gy to 13.11Gy) and (39.73Gy to 49.75Gy) respectively. The maximum, mean and 1% doses of all 90 patients was 46.53Gy, 27.38Gy and 44.74Gy. Conclusion A Radical course of RT can be easily delivered in Head and Neck cancer keeping spinal cord doses within acceptable tolerance level. PO-156 Results of surgery for early tongue cancer and effects of adjuvant RT in patients with risk features C. Hao-Shen 1 , L. Jin-Ching 1 , L. Shih-An 2 1 Taichung Veterans General Hospital- Taiwan, Departments of Radiation Oncology, Taichung, Taiwan 2 Taichung Veterans General Hospital- Taiwan, Departments of Otorhinolaryngology, Taichung, Taiwan Purpose or Objective To investigate 1) long-term outcome and prognostic factors in patients with early tongue cancer treated by