Merkel cell carcinoma - description of five cases.

Merkel cell carcinoma (MCC) is a rare but very aggressive skin cancer that derives from neuroendocrine cells of the skin. Merkel cell carcinoma morbidity has been continuously increasing for the last few years. Increasing reported incidence of MCC is probably connected with increasing occurrence of this kind of malignancy or with development of histological and immunohistochemical methods of sample examinations which have allowed for more precise diagnosis of skin tumor that might have previously not been accurately recognized.

Thermal and resonance neutrons generated by various electron and X-ray therapeutic beams from medical linacs installed in polish oncological centers.

Background: High-energy photon and electron therapeutic beams generated in medical linear accelerators can cause the electronuclear and photonuclear reactions in which neutrons with a broad energy spectrum are produced. A low-energy component of this neutron radiation induces simple capture reactions from which various radioisotopes originate and in which the radioactivity of a linac head and various objects in the treatment room appear.

Aim: The aim of this paper is to present the results of the thermal/resonance neutron fluence measurements during therapeutic beam emission and exemplary spectra of gamma radiation emitted by medical linac components activated in neutron reactions for four X-ray beams and for four electron beams generated by various manufacturers' accelerators installed in typical concrete bunkers in Polish oncological centers.

Dose distribution homogeneity in two TBI techniques-Analysis of 208 irradiated patients conducted in Stanislaw Leszczynski Memorial Hospital, Katowice.

Background: To analyze and compare dose distribution homogeneity in selected points (especially in the chest wall region) for patients irradiated with two different TBI techniques to achieve a uniform total dose (excluding lungs area) specified in the range of 11.4-14.0 Gy.

The influence of the bolus-surface distance on the dose distribution in the build-up region.

Aim: The aim of the paper is to examine the relation between the increase of the photon dose in water in the region of electronic disequilibrium - so-called build-up region - and the distance of the bolus from the water surface for the applied parameters of X-ray beams.

Materials And Methods: PDD measurements were carried out using the plane-parallel ionization chamber Markus in the automatic water phantom IBA BluePhantom with OmniPro-Accept V7 (IBA Dosimetry GmbH, Schwarzenbruck, Germany). All measurements were performed for different field sizes and for 6 MV and 15 MV X-ray beams, respectively.