Evaluasi Dosis Organ Kritis pada Perlakuan Gamma Knife Stereotactic Radiosurgery (GKSRS) Menggunakan Film Gafchromic Xr-Qa2 dan Thermoluminescent Dosimeter (TLD) = Dose Evaluation at Organs at Risk During Treatment Gamma Knife Stereotactic Radiosurgery (GKSRS) using GafChromic XR-QA2 Film and Thermoluminescent Dosimeter (TLD).