The purpose of this study was to compare positional and volumetric differences of planning target volumes (PTVs) defined on axial three dimensional CT (3D CT) and four dimensional CT (4D CT) for liver cancer. Fourteen patients with liver cancer underwent 3D CT and 4D CT simulation scans during free breathing. The tumor motion was measured by 4D CT. Three internal target volumes (ITVs) were prod...

BACKGROUND The impact of primary tumor volume (pTV) on local control after definitive radiotherapy (RT) for head and neck squamous cell carcinoma (HNSCC) is unclear. METHODS Pertinent literature was reviewed to address the impact of pTV on local control after definitive RT for HNSCC. RESULTS Reproducibility of pTV calculations is probably influenced by interobserver variability and may be r...

BACKGROUND Primary tumor volume (PTV) is known to be a significant prognostic factor in malignant tumor. There have been several studies of nasopharyngeal carcinoma (NPC) relating tumor volume to treatment outcome. Our study was designed to evaluate the effect of PTV on treatment outcomes in NPC treated with radiotherapy (RT)/concurrent chemoradiotherapy (CCRT) or CCRT with adjuvant chemotherap...

We investigated the dosimetric differences among volumetric-modulated arc radiotherapy (RapidArc, RA) plans designed for various target volumes in hepatocellular carcinoma (HCC). Ten HCC patients underwent 3D-CT scanning at free breathing (FB), 3D-CT at end inspiration hold (EIH) assisted by an Active Breathing Coordinator (ABC), and 4D-CT scanning. Gross tumor volumes (GTVs) were manually cont...

There is a considerable underdosage (11%-13%) of PTV due to anisotropy of a stationary source in breast balloon brachytherapy. We improved the PTV coverage by varying multiple dwell positions and weights. We assumed that the diameter of spherical balloons varied from 4.0 cm to 5.0 cm, that the PTV was a 1-cm thick spherical shell over the balloon (reduced by the small portion occupied by the ca...

PURPOSE During stereotactic body radiation therapy (SBRT) for the treatment of prostate cancer, an inflatable endorectal balloon (ERB) may be used to reduce motion of the target and reduce the dose to the posterior rectal wall. This work assessed the dosimetric impact of manual interventions on ERB position in patients receiving prostate SBRT and investigated the impact of ERB interventions on ...

BACKGROUND In a previous report, we compared the conformity of robust intensity-modulated proton therapy (IMPT) plans with that of helical tomotherapy plans for re-irradiations of head and neck carcinomas using a fixed set-up error of 2 mm. Here, we varied the maximum set-up errors between 0 and 5 mm and compared the robust IMPT-plans with planning target volume (PTV) based intensity-modulated ...