Target volume size effect on comparison of dynamic arc treatment plans computed using flattened and unflattened 6MV beams.

Introduction/background: In conventional linear accelerators, to obtain flat profiles leading to uniform dose distribution in homogeneous medium, the flattening filter is usually applied on the beam path. In recent years, to obtain higher dose rates, there have been the options of flattening filter free (FFF) beams and it has been noticed that these have many advantages. The aim of this study was to clearly underline the advantages and the drawbacks of flattened filter free (FFF) beams in comparison with the flattening filter (FF) beams for different clinical contexts (planning target volumes locations).

Light and shadows of a new technique: is photon total-skin irradiation using helical IMRT feasible, less complex and as toxic as the electrons one?

Background: Radiotherapy is one of the standard treatments for cutaneous lymphoma and Total Skin Electrons Beam Irradiation (TSEBI) is generally used to treat diffuse cutaneous lymphoma and some cases of localized disease. Helical IMRT (HI) allows to treat complex target with optimal dose distribution and organ at risk sparing, so helical tomotherapy has been proposed as alternative technique to TSEBI but only one preliminary report has been published.

Methods: Three patients treated (from May 2013 to December 2014) with Helical IMRT, with a total dose between 24 and 30 Gy, were retrospectively evaluated.