A planning study of simultaneous integrated boost with forward IMRT for multiple brain metastases

摘要

The objective of this study was to evaluate the dose conformity and feasibility of whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in patients with 1 to 3 brain metastases. Forward intensity-modulated radiation therapy plans were generated for 10 patients with 1 to 3 brain metastases on Pinnacle 6.2 Treatment Planning System. The prescribed dose was 30Gy to the whole brain (planning target volume [PTV]wbrt) and 40Gy to individual brain metastases (PTVboost) simultaneously, and both doses were given in 10 fractions. The maximum diameters of individual brain metastases ranged from 1.6 to 6cm, and the summated PTVs per patient ranged from 1.62 to 69.81cm3. Conformity and feasibility were evaluated regarding conformation number and treatment delivery time. One hundred percent volume of the PTVboost received at least 95) of the prescribed dose in all cases. The maximum doses were less than 110% of the prescribed dose to the PTVboost, and all of the hot spots were within the PTVboost. The volume of the PTVwbrt that received at least 95% of the prescribed dose ranged from 99.2% to 100%. The mean values of conformation number were 0.682. The mean treatment delivery time was 2.79 minutes. Ten beams were used on an average in these plans. Whole-brain radiotherapy with a simultaneous integrated boost by forward intensity-modulated radiation therapy in 1 to 3 brain metastases is feasible, and treatment delivery time is short.