Evaluating dose coverage and conformity in stereotactic ablative body radiotherapy (SABR) plans.

Purpose: Accepted conformity metrics in stereotactic ablative body radiotherapy (SABR) have significant limitations. This work aimed to develop a spatial assessment methodology that improves and automates checks of dose prescription and dose gradient from planning target volume (PTV) edge.

Methods: A Python-based script was developed to determine linear distances from the PTV edge to specified isodose, every 15 degrees on all axial slices and along the central axis in the coronal plane.

A strategy to reduce fraction number in peripheral lung stereotactic ablative body radiotherapy.

Background And Purpose: Hypo-fractionated lung Stereotactic Ablative Body Radiotherapy (SABR) has often been avoided when tumours are close to the chest wall. Our strategic objective was the reduction of fraction number, while maintaining target biological effective dose coverage without increasing chest wall toxicity (CWT) predictors.

Materials And Methods: Twenty previously treated lung SABR patients were stratified into four cohorts according to distance from PTV to the chest wall, <1 cm, <0.

The influence of Acuros XB on dose volume histogram metrics and tumour control probability modelling in locally advanced non-small cell lung cancer.

Purpose: Radiation therapy plans are assessed using dose volume metrics derived from clinical toxicity and outcome data. In this study, plans for patients with locally advanced non-small cell lung cancer (LA-NSCLC) are examined in the context of the implementation of the Acuros XB (AXB) dose calculation algorithm focussing on the impact on common metrics.

Methods: Volumetric modulated arc therapy (VMAT) plans were generated for twenty patients, using the Analytical Anisotropic Algorithm (AAA) and recalculated with AXB for both dose to water (D) and dose to medium (D).

The potential for increased tumor control probability in non-small cell lung cancer with a hypofractionated integrated boost to the gross tumor volume.

Treatment outcomes in locally advanced non-small cell lung cancer (NSCLC) to date have been poor, with normal tissue toxicity often limiting the dose that can be delivered to the tumor. Treatment intensification in NSCLC via targeted dose escalation with modern delivery techniques may offer the potential for a significant increase in tumor control probability (TCP) without a clinically significant increase in organ-at-risk (OAR) toxicity. In this planning study, 20 patients were re-planned with a volumetric modulated arc therapy (VMAT) and an inhomogeneous dose distribution with iteratively escalated doses to the gross tumor volume (iGTV) (composite GTV across multiple 4-dimensional computed tomography [4DCT] phases) in a series of 20 fraction regimes.

Normal tissue considerations and dose-volume constraints in the moderately hypofractionated treatment of non-small cell lung cancer.

Hypofractionated radiation therapy (RT) regimes in non-small cell lung cancer (NSCLC) have become increasingly popular with a number of international trials currently underway. The majority of the dose-volume-constraints (DVCs) published in the literature refer to conventional 2Gy per fraction deliveries. Here relevant organs-at-risk (OARs) are identified and available dose-volume constraint data discussed and summarised for moderately hypofractionated NSCLC regimes.