background: best dose distribution in target volume and control of organ at risk (oar) dose are the two main goals in brachytherapy. materials and methods: in this study in vivo dosimetry in 4 rectal points was performed by transillumination dosimeter (tld) s and the measured doses were compared in different patients. one point was reported to have the maximum dose in each patient and the very ...

BACKGROUND The dose distribution to the rectum, delineated as solid organ, rectal wall and rectal surface, in 3D conformal (3D-CRT) and intensity-modulated radiotherapy treatment (IMRT) planning for localized prostate cancer was evaluated. MATERIALS AND METHODS In a retrospective planning study 3-field, 4-field and IMRT treatment plans were analyzed for ten patients with localized prostate ca...

Rectal balloons are used in external beam prostate radiotherapy to provide reproducible anatomy and rectal dose reductions. This is an investigation into the combination of a MOSFET radiation detector with a rectal balloon for realtime in vivo rectal wall dosimetry. The MOSFET used in the study is a radiation detector that provides a water equivalent depth of measurement of 70 microm. Two MOSFE...

The purpose of this study was to evaluate the feasibility of assessing bladder and rectal point doses, using orthogonal radiographs without treatment planning, for vaginal cylinder applicator (VC), high-dose-rate (HDR) vaginal cuff brachytherapy (BT) after hysterectomy. Thirty-three VC HDR BT treatment plans from 31 postop- erative endometrial cancer patients were retrospectively analyzed. Sing...

PURPOSE To compare the fits of normal-tissue complication probability (NTCP) models based on rectal dose-wall histograms (DWHs) vs. dose-volume histograms (DVHs) when the two are used to analyze a common set of late rectal toxicity data. METHODS AND MATERIALS Data were analyzed from 128 prostate cancer patients treated with 3-dimensional conformal radiotherapy (3D-CRT) at The University of Te...

PURPOSE To evaluate association between equivalent dose in 2 Gy (EQD2) to rectal point dose and gastrointestinal toxicity from whole pelvic radiotherapy (WPRT) and intracavitary brachytherapy (ICBT) in cervical cancer patients who were evaluated by rectosigmoidoscopy in Faculty of Medicine, Chiang Mai University. MATERIALS AND METHODS Retrospective study was designed for the patients with loc...

PURPOSE Hydrogel prostate-rectum spacers, biomaterials placed between the prostate and rectum, continue to gain interest as a method to reduce or limit rectal dose during dose escalated prostate cancer radiation therapy. Because the spacer is initially injected into the perirectal space as a liquid, the final distribution can vary. The purpose of this study was to evaluate hydrogel spacer (Spac...

BACKGROUND To identify predictors of acute and late rectal toxicity following prostate cancer radiotherapy (RT), while integrating the potential impact of RT technique, dose escalation, and moderate hypofractionation, thus enabling us to generate a nomogram for individual prediction. METHODS In total, 972 patients underwent RT for localized prostate cancer, to a total dose of 70 Gy or 80 Gy, ...

This Phase 1, randomized, two-site (United States), double-blind, placebo-controlled study enrolled 18 sexually abstinent men and women. All received a single 300-mg dose of oral tenofovir disoproxil fumarate (TDF) and were then randomized 2:1 to receive single and then seven daily rectal exposures of vaginally-formulated tenofovir (TFV) 1% gel or a hydroxyethyl cellulose (HEC) placebo gel. Blo...

The use of rectal balloon in radiotherapy of prostate cancer is shown to be effective in reducing prostate motion and minimizing rectal volume, thus reducing rectal toxicity. Air-filled rectal balloon has been used most commonly, but creates dose perturbation at the air-tissue interface. In this study, we evaluate the effects of rectal balloon-filling materials on the dose distribution to the t...