ESTRO 38 Abstract book

S385 ESTRO 38

Purpose or Objective Brain metastases (BM) occurs in 10-30 % in adult cancer patients, and it is an important factor affecting patient survival rate and quality of life. In recent years, neutrophil lymphocyte ratio (NLR) and platelet lymphocyte ratio (PLR) have been reported to correlate with overall survival (OS) in various cancers. However, few reports have verified the NLR and PLR in patients with BM. The purpose of this study is to evaluate whether NLR and PLR is a prognostic factor for OS, using in Japanese BM patients our hospital. Material and Methods We retrospectively compiled the NLR and PLR in patients who received radiotherapy in our hospital from March 2011 to December 2017. Neutrophils, platelet and lymphocytes were calculated based on absolute values and analyzed with the OS. The absolute values of neutrophils, platelet and lymphocytes were obtained at the time of diagnoses of primary cancer and BM. For the data of BM, we didn’t exclude patients who underwent chemotherapy or molecular targeted drugs for primary The number of patients is 256, and primary sites were 150 lung, 66 breast, 15 gastrointestinal, 7 urological, and 18 others. The median age of the patient cohort at diagnosis of primary cancer was 65 years (range: 20-87 years), and BM was 66 years (range: 24–87 years). The patient group contained 136 males and 120 females, median KPS of BM detection was 70 (range: 10-100). Radiation therapy was 227 patients of whole brain irradiation (20-40 Gy) and 29 patients of stereotactic radiotherapy (15-32 Gy). The median follow up period was 19 months (mo.) from cancer diagnosis (range: 1–236 mo.), and 5 mo. from BM detection (range: 1–83 mo.). The median survival time (MST) from cancer diagnosis was 33 mo. and MST from BM detection was 9 mo. Patients with NLR <4.0 at the diagnosis of primary cancer had better MST compared with patients with NLR ≥4.0 (24 mo. vs. 12 mo.; P =0.0116). Patients with PLR <150 at the diagnosis of primary cancer had better MST compared with patients with PLR ≥150 (33 mo. vs. 13 mo.; P =0.0012). Patients with NLR <4.0 at the time of BM detection had better MST compared with patients with NLR ≥4.0 (12 mo. vs. 4 mo.; P <0.001). Patients with PLR <150 at the time of BM detection had better MST compared with patients with PLR ≥150, but there was no significant difference (15 mo. vs. 7 mo.; P =0.0538). Utilizing Multivariate analysis, age ≥65 and PLR ≥150 at the diagnosis of primary cancer were significantly correlated with survival (HR2.30; P =0.0008, HR2.17; P =0.0043). KPS and NLR ≥4 at the time of BM detection were significantly correlated with survival (HR1.53; P =0.0201, HR2.28; P <0.001). tumor. Results

Conclusion NLR and PLR at the diagnosis of primary cancer might be prognostic factors. Furthermore, this tendency was also showed at the time of BM detection. To our knowledge, our study was the first report about NLR and PLR with BM patients who underwent radiation therapy. We are planning a prospective study to validate the results. PO-0752 Hypofractionated stereotactic radiotherapy for inoperable arteriovenous malformations T. Takahashi 1 , T. Yamano 2 , K. Nishimura 1 , S. Ueno 2 , K. Washizu 1 , R. Soda 1 , S. Kondo 1 , N. Utsumi 1 , M. Shimbo 1 , S. Hatanaka 1 , M. Hariu 1 1 Saitama Medical Center- Saitama Medical University, Radiation Oncology, Kawagoe, Japan ; 2 Saitama Medical Center- Saitama Medical University, Radiation Oncology- , Kawagoe, Japan Purpose or Objective In our institute, we performed hypofractionated stereotactic radiotherapy (HSRT) for inoperable arteriovenous malformations (AVM) whose Spetzler-Martin grade was mainly more than grade III. In this time, we investigated therapeutic efficacy and obliteration rate of our HSRT from the view point of prescription doses and dose fractionations, retrospectively. Material and Methods We examined 23 patients of inoperable AVM who underwent HSRT at our institute between 2003 and 2014. Spetzler-Martin grade III was 90 % in patients. Mean nidus volume was 7.95 ml. At the beginning of HSRT, patients’ median age was 30.5 years old (4 - 68 years old). Median observation periods were 56 months (4 – 117 months). A median dose was 33.8 Gy (20 – 40 Gy). Median fractionations were 6.8 fractions (4 – 13 fractions). Results The occlusion rate at 2 years after HSRT was 57.1%, and 4 years 87.5 %, respectively. There is no evidence of obvious late adverse events of more than 3 grade. No significant difference in the occlusion rate of nidus volume was found between more than 14 ml and less than 14 ml. There was no significant difference in the occlusion rate between patients who received more than 7 Gy and less than 7 Gy, in a fractional dose. On the other hand, significant difference of obliteration rate of the nidus was found between patients who received more than 100 Gy and less than 100 Gy, in biological effective doses (BED) with α/β=3. Patients who received more than 100 Gy in BED 3 resulted in favourable outcome (p=0.02). Conclusion In the past, stereotactic radiosurgery (SRS) has been mainly reported about radiotherapy for inoperable AVM. Although the therapeutic results of SRS is favorable, there is a tendency to reducing prescription doses for the patients who have large nidus volume, in consideration of adverse events. Our results suggest that HSRT also have been performed favorably and safely for patients whose nidus volumes were larger than 14 ml. Recently, some studies about HSRT occur in various reports, however suitable doses remain a subject of future investigation.