Room: AAPM ePoster Library
Purpose : To compare Stereotactic Radiosurgery (SRS) planning by UAB (University of Alabama, Birmingham, USA) method and HyperArc technique (HA) for non-malignant intracranial lesions.
Methods : Fifty consecutive patients with non-malignant intracranial lesions were selected and replanned with UAB (with two coplanar arc) and HA (automated non-coplanar arc) techniques. Plans were generated for each patient. Dose prescriptions ranged from 10Gy-18Gy. PTV volumes ranged from 0.8cc-23.53cc. Dosimetric data of the plans were compared accordingly. The RTOG Conformity index (CI), Paddick gradient index (PGI), Homogeneity index (HI), volume of the normal brain receiving V12Gy ,V10Gy was calculated for each target. Critical organ doses were also calculated for each plan.
Results: Plans for both techniques achieved acceptable PTV coverage for all patients. The difference in values for various indices were CI(1.058Vs1.108) UAB and HA P<0.010 , PGI were (1.613 Vs 2.943 ) UAB and HA P<0.00001 HI were ( 1.272 Vs 0.314 ) P<0.00001,V12Gy were (6.73 Vs 3.78 cc) UAB and HA P<0.019, V10Gy were (11.22 Vs 7.0 cc) UAB and HA P<0.01167. The percentage reduction of mean difference in doses to critical organs like brainstem, optic chiasm, left optic nerve and right optic nerve were 8.93%, 25.8%, 52.6%, 47.1% respectively for HA plans.
Conclusion: This study revealed significant differences in CI, PGI ,V12Gy, V10Gy and critical organ doses in favour of HyperArc plans.
Not Applicable / None Entered.