BACKGROUND To evaluate the impact of image-guided radiation therapy (IGRT) versus non-image-guided radiation therapy (non-IGRT) on the dose to the clinical target volume (CTV) and the cervical spinal cord during fractionated intensity-modulated radiation therapy (IMRT) for head-and-neck cancer (HNC) patients. MATERIAL AND METHODS For detailed investigation, 4 exemplary patients with daily con...

OBJECTIVE The efficacy of stereotactic radiosurgery (SRS) using Gamma Knife (GK) (Elekta, Tokyo) is well known. Recently, Automatic Brain Metastases Planning (ABMP) Element (BrainLAB, Tokyo) for a LINAC-based radiation system was commercially released. It covers multiple off-isocenter targets simultaneously inside a multi-leaf collimator field and enables SRS / stereotactic radiotherapy (SRT) w...

BACKGROUND Large tumor motion often leads to larger treatment volumes, especially the lung tumor located in lower lobe and adhered to chest wall or diaphragm. The purpose of this work is to investigate the impacts of planning target volume (PTV) margin on Stereotactic Body Radiotherapy (SBRT) in non-small cell lung cancer (NSCLC). METHODS Subjects include 20 patients with the lung tumor locat...

The purpose of this study is to use the same diagnostic-quality verification and planning CTs to validate planning margin account for residual interfractional variations with image-guided soft tissue alignment of the prostate. For nine pros-tate cancer patients treated with IMRT to 78 Gy in 39 fractions, daily verification CT-on-rails images of the first seven and last seven fractions (n = 126)...

PURPOSE The purpose of this study is to determine dose delivery errors that could result from random and systematic setup errors for head-and-neck patients treated using the simultaneous integrated boost (SIB)-intensity-modulated radiation therapy (IMRT) technique. METHODS AND MATERIALS Twenty-four patients who participated in an intramural Phase I/II parotid-sparing IMRT dose-escalation prot...

We investigated the effect of different set-up error corrections on dose-volume metrics in intensity-modulated radiotherapy (IMRT) for prostate cancer under different planning target volume (PTV) margin settings using cone-beam computed tomography (CBCT) images. A total of 30 consecutive patients who underwent IMRT for prostate cancer were retrospectively analysed, and 7-14 CBCT datasets were a...

A comprehensive quality assurance (QA) device cum program was developed for the commissioning and routine testing of the 6D IGRT systems. In this article, both the new QA system and the BrainLAB IGRT system which was added onto a Varian Clinac were evaluated. A novel compound 6D-offset simulating phantom was designed and fabricated in the Prince of Wales Hospital (PWH), Hong Kong. The QA progra...

A 67-year old man with a history of papillary thyroid cancer (PTC) presented with metastatic disease to the left colon in the form of a 6.1x1.0 cm bleeding, ulcerated mass. Radiopaque surgical clips were used as fiducial markers to localize the gross tumor volume (GTV) as well as the corresponding clinical target volume (CTV) and planning target volume (PTV). Daily cone beam computed tomography...

BACKGROUND The advent of IMRT and image-guided radiotherapy (IGRT) in combination with involved-field radiotherapy (IF-RT) in inoperable non-small-cell lung cancer results in a decreased incidental dose deposition in elective nodal stations. While incidental nodal irradiation is considered a relevant by-product of 3D-CRT to control microscopic disease this planning study analyzed the impact of ...