P-0100 - A retrospective study of liver stereotactic ablative radiotherapy: 21 months of follow-up
|Date||28 June 2014|
|Event||World GI 2014|
|Topics|| Hepatobiliary Cancers
Surgery and/or Radiotherapy of Cancer
|Citation||Annals of Oncology (2014) 25 (suppl_2): ii14-ii104. 10.1093/annonc/mdu165|
S. Palumbo, S. Deheneffe, S. Bougas, L. Donnay, C. Clermont, S. Bernard, V. Remouchamps
To retrospectively review metastatic liver cancer (MLC) patients and primary hepatocellular carcinoma (HCC) patients treated with Stereotactic Ablative Body Radiotherapy (SABR) in our institution in the context of a multicentric collaboration.
Fourteen MLC patients and six primitive HCC patients with contraindication to surgery were treated between Augustus 2010 and January 2014. The median age was 61 years old (range 36-88). The Gross Tumor Volume (GTV, macroscopic tumor) delineation was done on fused images between Computed Tomography scanner (CT) included contrast enhancing disease (portal phase for MLC, arterial phase for HCC) and liver Magnetic Resonance Image. The 2 main liver radiotherapy uncertainties can be described as patient positioning and internal liver motion due to patient breathing. A thermoplastic abdominal compression device is used to both ensure patient immobilization and reduce liver breathing motion. Additionally, an Internal Target Volume (ITV, sum of all GTV positions during breathing cycles) was built with a 4D-CT scan (including 10 breathing phases). The dose is optimized on The Planning Target Volume (PTV) which is an expansion of the ITV (a margin of at least 5 mm is used to include systematic errors). 14 patients received 3fractions of 15 Gy. Six patients were treated with 4 fractions of 10 Gy due to higher risk of severe complication. All patients were treated on Varian Novalis Tx accelerator (calculation of 6 MV photon beams with AAA algorithm). Daily Image-guided Radiation Therapy (IGRT) with on board CT imaging was performed to control the treatment reproducibility.
The treatment was well tolerated by all patients except nausea (grade1) for few of them. At a median follow up of 21 months (range 1-42), local control, overall survival and progression free survival is 85%, 75% and 35% respectively for all patients, 83.3%, 50% and 50% respectively for primary HCC patients and finally 85.7%, 85.7% and 28.5% respectively for MLC patients. At 3 months, complete response was observed for all patients. At 12 months, overall survival rate was 72.2%. To date (February 2014), 13 patients had developed recurrences (3 local and distant metastasis; 10 only metastasis). Updated results will be presented at the meeting.
SABR has been developed in the last few years because of its excellent results in terms of local control rates with low morbidity. Our results are similar to the literature. This technique is safe and effective to treat inoperable MLC or HCC patients. It is however possible to propose SABR treatment to operable patients too, because control rates are comparable to surgical results. However, there is only little data available considering direct comparison between SBRT and surgery. In a near future it should be interesting to compare the 3 local treatments for MLC and HCC: surgery, SABR and radiofrequency ablation in a prospective randomized study.