Monitoring of anatomical changes during adaptive brain radiotherapy in glioma patients

Purpose: We investigated the extent of changes in the anatomical position, shape and volume of lateral ventricles (LVs) and subventricular zones (SVZs). We included other critical organs at risk (OARs) to examine their contribution to the dose delivered to these regions. Additionally, the correlation between the SVZ radiation dose and clinical outcome was analyzed using the median SVZ dose as a cut-off value for both of the structures defined on the first planning CT and the data on the changed ipsi- and contralateral SVZs on the repeated CT during the course of irradiation. Methods: We examined changes in the ipsilateral/contralateral LV and SVZ, as well as in the relevant OARs. We evaluated the volumetric and dosimetric changes on both planning CT scans (primary CT1 and secondary CT2). The survival of the GBM patients was analyzed using the Kaplan–Meier method; the multivariate Cox regression was also performed. Results: LV and SVZ structures exhibited significant volumetric changes on CT2, resulting in an increase of dose coverage. At a cut-off point of 58 Gy, a significant correlation was detected between the iSVZ2 mean dose and OS (27.8 vs 15.6 months, p=0.048). In a multivariate analysis, glioblastoma multiforme (GBM) patients with a shorter time to postoperative chemoradiotherapy (<3.8 weeks), with good performance status (≥70%) and higher mean dose (≥58 Gy) to the iSVZ2 had significantly better overall survival (OS). We observed that the average of all investigated dose parameters to other OARs was lower at each volume dose level than on CT1 and replanning caused significant differences on most of them. Conclusions: Significant anatomical and dose distribution changes to the brain structures were observed, which have a relevant impact on the dose-effect relationship for GBM; therefore, involving the iSVZ in the target volume should be considered and adapted to the changes

Modern Radiotherapy Era in Breast Cancer

Radiation therapy (RT) is one of the major treatment modalities that are used in breast cancer treatment, and depending on the chest-wall anatomy, RT fields have to be customized. Techniques used in planning have been evolving since last two decades from two dimensional (2D) to three-dimensional (3D), while intensity modulated radiotherapy (IMRT), volumetric modulated arc therapy (VMAT) and even proton therapy have been an option in daily approach. In addition, technological hardware and software advances in delivery and planning systems, total treatment duration of breast RT have been shortened in last decades along with recent hypofractionated radiotherapy schemes or emerging partial-breast irradiation protocols. The other attractive approach—accelerated partial breast irradiation (APBI) could be a reasonable option for highly selected subpopulation of early-stage breast cancer patients out of a clinical trial. Long-term follow-up results have emerged heart and coronary sparing with maximum safety and efficacy. The most important advance could be named as cardiac sparing—deep breath-hold approach—in all the modern technique improvement. Although most advanced techniques in management of breast cancer have not been verified to increase survival, we suggest recommending resource stratified advanced in order to provide best technical and clinical care in this long-term survivor candidates