Principal component, Varimax rotation and cost analysis of volume effects in rectal bleeding in patients treated with 3D-CRT for prostate cancer.

We investigate the utility of principal component analysis as a tool for obtaining dose-volume combinations related to rectal bleeding after radiotherapy for prostate cancer. A direct implementation of principal component analysis reduces the number of degrees of freedom from the patient's dose-volume histograms that are associated with bleeding. However, when low-variance principal components are strongly correlated to outcome, their interpretation is problematic.

Intensity-modulated radiation treatment for head-and-neck squamous cell carcinoma--the University of Iowa experience.

Purpose: To review the University of Iowa experience with intensity-modulated radiotherapy (IMRT) in the treatment of head-and-neck squamous cell carcinoma.

Methods And Materials: From October 1999 to April 2004, 151 patients with head-and-neck squamous cell carcinoma were treated with IMRT for curative intent. One patient was lost to follow-up 2 months after treatment and therefore excluded from analysis.

Value of FDG PET in assessment of treatment response and surveillance in head-and-neck cancer patients after intensity modulated radiation treatment: a preliminary report.

Purpose: [(18)F] fluorodeoxyglucose positron emission tomography (FDG PET) imaging has been shown to be valuable in early detection of persistent and recurrent head-and-neck cancer after treatment. Previous studies have reported its use in patients treated with conventional radiation. Many patients are now treated with intensity-modulated radiation treatment (IMRT).

The role of post-radiation therapy FDG PET in prediction of necessity for post-radiation therapy neck dissection in locally advanced head-and-neck squamous cell carcinoma.

Purpose: The role of neck dissection after radiation therapy ([RT] with or without chemotherapy) for regionally advanced head and neck cancer is controversial. As much as 50% of residual lymphadenopathy after radiation has no viable tumor cells present on histopathologic analysis. [(18)F] fluorodeoxyglucose positron emission tomography (FDG PET) imaging can detect metabolically active cancer.

Does prone positioning reduce small bowel dose in pelvic radiation with intensity-modulated radiotherapy for gynecologic cancer?

Purpose: Intensity-modulated radiotherapy (IMRT) has been shown to reduce the radiation dose to small bowel in pelvic RT in gynecology patients. Prone positioning has also been used to decrease small bowel dose by displacement of small bowel from the RT field in these patients. The purpose of this study was to determine whether the combination of both IMRT and prone positioning on a belly board can reduce small bowel dose further in gynecologic cancer patients undergoing pelvic RT.