BACKGROUND The aim of this study is to evaluate the radiobiological impact of Acuros XB (AXB) vs. Anisotropic Analytic Algorithm (AAA) dose calculation algorithms in combined dose-volume and biological optimized IMRT plans of SBRT treatments for non-small-cell lung cancer (NSCLC) patients. METHODS Twenty eight patients with NSCLC previously treated SBRT were re-planned using Varian Eclipse (V...

A generalization of the well known critical volume NTCP model is proposed to take into account dependence of the functional subunits of irradiated organ (or tissue). A new statistical version of the CLT is established to analyze the corresponding random fields. AMS classification: 60F05, 62E20, 62G15, 62P10.

OBJECTIVE The effect of multileaf collimator (MLC) margin on target and normal tissue dose-volume metrics for intracranial stereotactic radiosurgery (SRS) was assessed. METHODS 118 intracranial lesions of 83 SRS patients formed the basis of this study. For each planning target volume (PTV), five separate treatment plans were generated with MLC margins of -1, 0, 1, 2 and 3 mm, respectively. Id...

UNLABELLED The 50% normal-tissue complication probability (NTCP) after lobar irradiation of the liver results in highly variable biologic effective doses depending on the modality used: a biologic effective dose for 50% (BED50) of 115, 93, and 250 Gy for external-beam radiotherapy, resin microsphere radioembolization, and glass microsphere radioembolization, respectively. This misunderstood pro...

PURPOSE The relationship between spatial aspects of the dose distribution and incidence of acute radiation esophagitis for non-small-cell lung cancer (NSCLC) patients is not well understood. Specifically, the location of dose along the superior-inferior (SI) axis of the esophagus has not been previously considered. We introduce the concept of mean regional dose (MRD) calculated for esophageal s...

PURPOSE Intensity-modulated radiation therapy (IMRT) is the most common treatment technique for nasopharyngeal carcinoma (NPC). Physical quantities such as dose/dose-volume parameters are used conventionally for IMRT optimization. The use of biological related models has been proposed and can be a new trend. This work was to assess the performance of the biologically based IMRT optimization mod...

AIM To model acute rectal toxicity in Intensity Modulated Radiation Therapy (IMRT) for prostate cancer using dosimetry and patient specific characteristics. METHODS A database of 79 prostate cancer patients treated with image guided IMRT was used to fit parameters of Lyman-Kutcher-Burman (LKB) and logistic regression Normal Tissue Complications Probability (NTCP) models to acute grade ≥ 2 rec...

BACKGROUND Linear Accelerator-based Intensity Modulated Radiation Therapy (IMRT), either as step-and shoot (SS) or in dynamic mode, is now considered routine in the definitive management of head and neck squamous cell carcinoma (HNSCC). Helical TomoTherapy (HT) is a new platform to deliver IMRT. This study aims to compare step-and-shoot Intensity Modulated Radiation Therapy (SS IMRT) with dynam...

BACKGROUND To make a radiobiological comparison, for high risk prostate cancer (T3a, PSA > 20 ng/ml or Gleason > 7) of two radiotherapy treatment techniques. One technique consists of a treatment in three phases of the pelvic nodes, vesicles and prostate using a conventional fractionation scheme of 2 Gy/fraction (SIMRT). The other technique consists of a treatment in two phases that gives simul...

BACKGROUND To evaluate the risk of rectal, bladder and small bowel toxicity in intensity modulated radiation therapy (IMRT) of the prostate only compared to additional irradiation of the pelvic lymphatic region. METHODS For ten patients with localized prostate cancer, IMRT plans with a simultaneous integrated boost (SIB) were generated for treatment of the prostate only (plan-PO) and for addi...