[Dosimetric analysis of LINAC based stereotactic irradiation of brain tumours in CIRS SHANE phantom].

The aim of the study was to compare the different stereotactic treatment plans and dose calculation algorithms for small targets with film dosimetry in anthropomorphic phantom. Treatment plans were prepared for multiple targets with single setup isocenter. Plans for three different irradiation techniques were generated using conformal arc with four non-coplanar arcs, RapidArc with two coplanar full arcs and RapidArc with four non-coplanar arcs in the Varian Eclipse v13.

[Early experience with CyberKnife treatment in case of intra-, suprasellar hypernephroma metastasis].

Among tumours found in the suprasellar region metastases are very rare and the most frequent primary tumours are lung and breast cancer. Data of a patient with clear cell renal carcinoma with intra-suprasellar metastasis will be discussed. As in most of the tumours in the sellar region, the first symptom was visual deterioration with visual field defect.

[Stereotactic body radiation therapy with CyberKnife accelerator for low- and intermediate risk prostate cancer].

We report implementation of stereotactic body radiotherapy (SBRT) for the treatment of early, localized prostate cancer patients, and acute side effects caused by radiation therapy. Between February 2018 and July 2018, 36 prostate cancer patients were treated with SBRT. Treatments were performed with "CyberKnife M6" linear accelerator.

[Measurement of peak correction factor of Farmer chamber for calibration of flattening filter free (FFF) clinical photon beams].

Farmer-type ionization chambers are considered the most reliable detectors and for this reason they are most frequently used for the calibration of photon beams of medical linear accelerators. Flattening filter free (FFF) photon beams of linear accelerators have recently started to be used in radiotherapy. The dose profile of FFF beams is peaked in the center of the field and the dose distribution will be inhomogeneous along the axis of the 2.

[Improvement of the first cerebral stereotactic radiosurgery system of Hungary].

Objective: The first cerebral stereotactic radiosurgery system in Hungary was built in 1991. This system was based on a Leksell stereotactic head frame and a Neptun 10p linear accelerator. We performed 624 radiosurgery treatments with this system between 1991 and 2000.

[Lens-sparing external beam radiotherapy of periocular lymphomas].

Purpose: The presentation of techniques and results of lens-sparing external beam radiotherapy of patients with ophthalmologic lymphomas.

Material And Methods: From 1991 to 2001, at the Department of Radiotherapy of the National Institute of Oncology, Budapest, 92 patients with periocular lymphomas were treated by photon and/or electron beam irradiation depending on the localization. Mean age was 63 years (range: 26-89 years) and the male/female ratio was 1.

[Dosimetry of total skin electron irradiation].

Elaboration of such a simple technique for total skin electron irradiation which ensures good dose homogeneity and minimal x-ray background dose. MATERIALS AND METHODS: We started large electron field irradiations with the Neptun 10p linear accelerator in the National Institute of Oncology -Budapest in 1986. After the installation of the Siemens Mevatron KD linear accelerator it was possible to introduce the modified Stanford technique.