Clinical evaluation of simultaneous integrated boost in brain metastasis patients with helical intensity modulated radiotherapy

Background: This study was performed to assess patient survival and treatment toxicity after helical tomotherapy (HT) with simultaneous integrated boost (SIB) radiotherapy (RT) for cancer patients with one to eight brain metastases (BM) who have been treated with or without surgery. Materials and Methods: A total of 48 brain metastasis (BM) patients were included in this retrospective study between April 2015 and December 2016,. The patients were treated with image-guided intensity modulated radiation therapy (IMRT) on the helical tomotherapy (HT) machine. Whole brain HT as 25 Gy and SIB to metastasis sites as 35 Gy was delivered in 10 fractions. The patient were aged between 50 to 80 years old, volume of the BM was between 6 to 75 cc and the number of brain metastasis was between 1 to 8, Karnofsky Performance Score (KPS) ranged between 50-90 and RPA I-III. Surgery was performed to two patients before RT. The maximum patient follow-up time was 20 months.  Results: The primary neurotoxicity observed in patients was grade I- II brain edema related headache and lethargy. In patients who had survived 3- 12 months, KPS improved median score of 20 points and RPA was grade I after six months. Twelve patients had passed away at the end of a 20- month follow-up. Conclusion: HT utilizing SIB treatment for 1- 8 BM was achieved successfully with no significant toxicity. An improvement of performance status indicators of patients following RT was observed.