ESTRO 36 Abstract Book

S741 ESTRO 36 2017 _______________________________________________________________________________________________

EP-1402 Impact of SBRT on pain and local control for bone metastases: a systematic review and meta-analysis J.M. Van der Velden 1 , A.S. Gerlich 1 , E. Wong 2 , E. Chow 2 , M. Intven 1 , N. Kasperts 1 , W.S.C. Eppinga 1 , E. Seravalli 1 , M. Van Vulpen 1 , H.M. Verkooijen 1 1 UMC Utrecht, Department of Radiation Oncology, Utrecht, The Netherlands 2 Sunnybrook Odette Cancer Center, Radiation Oncology, Toronto, Canada Purpose or Objective Pain due to bone metastases is the most common cancer- related pain syndrome. Besides analgesics, conventional radiotherapy has been the cornerstone in the management of bone metastases. However, control of pain after conventional radiotherapy is modest, approximately 60%. Advances in radiotherapy technique enable the delivery of potentially ablative radiation doses, while respecting healthy tissue constraints under the heading of stereotactic body radiotherapy (SBRT). We conducted a systematic review and meta-analysis to quantify pain response and local control after SBRT for bone metastases. Material and Methods Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guideline, Embase, PubMed and Cochrane Libraries were searched with the (synonym) terms ‘bone metastases’ and ‘stereotactic body radiotherapy’. Studies delivering SBRT in 1 – 6 fractions to patients with or without previous radiotherapy or surgery were included. Information from studies reported in more than one publication was collated, and the most complete or recent article was cited. Study variables, including pain response and local control rates, were extracted from the selected articles. Pain response was defined as a complete or partial (i.e., at least 2 points decrease in pain score) response. To qualify for inclusion in the meta-analysis, outcomes had to be reported on an individual patient or lesion level, follow up had to be recorded at least 45% of the study population, and the size of the study population had to be 10 or more. Pooled estimates using random- effects models were calculated for pain response and local control rates. Results After screening of 2619 unique articles, 54 articles (3359 patients) were included in the systematic review. Twenty- six articles (1627 patients/lesions) were included in the meta-analysis for pain response, and 36 articles (2875 lesions) in the meta-analysis for local control. After SBRT, pain response rate ranged from 62% to 98% (see forest plot), and local control rate ranged between 25% and 97% (see forest plot). Excluding the study with the lowest local control rate, which included patients with spinal lesions from hepatocellular carcinoma, the local control rates varied between 74% and 97%. Pooled pain response rate was 80% (95% confidence interval [CI] 72% – 87%) with high heterogeneity (I 2 = 77%). Pooled local control rate was 87% (95% CI 84% – 90%) with high heterogeneity (I 2 = 76%).

Conclusion SBRT for bone metastases results in high pain control and high local control rates. This observation needs to be further confirmed within large randomized controlled trials. EP-1403 A comparison between 3D and volumetric technique in lumbar vertebral palliative irradiation N. Ricottone 1 , N. Cavalli 2 , E. Bonanno 2 , C. Marino 2 , G. Pisasale 1 , A. D'Agostino 1 , A. Girlando 1 1 HUMANITAS CCO, Radiation Oncology, Catania, Italy 2 HUMANITAS CCO, Medical Physics, Catania, Italy Purpose or Objective Lumbar rachis radiation treatment requires to take into account dose to kidneys. Aim of this paper is to evaluate if volumetric techniques can give an advantage when irradiating young patients, patient with a long life expectancy or patients with renal dysfunction. The clinical advantage is to preserve renal function and to not interfere with previous or further medical treatments that make use of renal toxic drugs, as for instance: cisplatin, A comparison between four plans were performed: a two fields three dimensional (3D) anterior-posterior plan (3D- 2F); a three fields (0°-150°-210°) 3D plan (3D-3F); a VMAT plan and a second VMAT plan spine sparing (VMAT-SS). Dose prescription was 30 Gy in 10 fractions. All plans were calculated with Eclipse 13.6 using AAA algorithm. 3D plans were calculated using MLC shielding and different weighted fields; regarding VMAT plans dose constraints according to QUANTEC were used. Results Even if dose delivered to kidneys do not exceed QUANTEC dose constraints, VMAT plans achieve better results in term of dose reduction to OARs particularly for kidneys (as carboplatin, ifosfamide. Material and Methods