PURPOSE To calculate the normal tissue complication probability (NTCP) of late radiation effects on the rectum and bladder from repetitive CT scans during fractionated high-dose-rate brachytherapy (HDRB) and external beam radiotherapy (EBRT) of the uterine cervix and compare the NTCP with the clinical frequency of late effects. METHODS AND MATERIALS Fourteen patients with cancer of the uterin...

PURPOSE Association between body mass index (BMI) and doses in organs at risk during postoperative vaginal cuff brachytherapy (VCB) treatment has not been evaluated. The aim of this study was to analyse the impact of BMI on the dose delivered to bladder and rectum during high-dose-rate VCB using computed tomography (CT) scans at every fraction. MATERIALS AND METHODS A retrospective analysis o...

Background: In the treatment of prostate cancer, radiotherapy is the potential to increase second primary cancers such as bladder and rectal cancers. The reasons for this potential are more monitor units (MUs), therefore a larger total body dose because of leakage radiation, a bigger volume of normal tissue is exposed to lower radiation doses. This study was designed to compare the integral dos...

PURPOSE Overlapping volume histogram (OVH) and distance-to-target histogram (DTH) calculations rely on the assumption that dose gradients are symmetric with respect to primary target volume (PTV) expansion and minimum distance to PTV surface, respectively. It is desirable to lift this assumption and instead account for achievable modality-specific dose gradients (MSDG) for a given PTV shape. ...

Treatment plans for prostate cancer patients undergoing stereotactic body radiation therapy (SBRT) are often challenging due to the proximity of organs at risk. Today, there are no objective criteria to determine whether an optimal treatment plan has been achieved, and physicians rely on their personal experience to evaluate the plan's quality. In this study, we propose a method for determining...

Uterus, bladder and rectum are the maximally exposed organs during cervical cancer radiotherapy and are at high risk of radiation exposure. Estimation of dose accumulation in these organs across multiple fractions of external beam radiotherapy (EBRT) and brachytherapy (BT) is extremely challenging due to structural mis-correspondences and complex anatomical deformations between the EBRT and BT ...

The primary application of Image Guided Radiotherapy (IGRT) in the treatment of localized prostate cancer has been to assist precise dose delivery to the tumor. With the ability to use in-room Computed Tomography (CT) imaging modalities, the prostate, bladder and rectum can be imaged before each treatment and the actual doses delivered to these organs can be tracked using anatomy of the day. Th...

OBJECTIVE The aim of this study was to investigate the effect of 6 and 15-MV photon energies on intensity-modulated radiation therapy (IMRT) prostate cancer treatment plan outcome and to compare the theoretical risks of secondary induced malignancies. METHODS Separate prostate cancer IMRT plans were prepared for 6 and 15-MV beams. Organ-equivalent doses were obtained through thermoluminescent...

PURPOSE Hypofractionated radiotherapy can reduce treatment durations and produce effects identical to those of conventionally fractionated radiotherapy for treating prostate cancer. Volumetric arc radiotherapy (VMAT) can decrease the treatment machine monitor units (MUs). Previous studies have shown that VMAT with multileaf collimator (MLC) rotation exhibits better target dose distribution. Thu...

background: in radiation therapy, peripheral dose or the dose outside the radiotherapy field, is important when anatomical structures with very low dose tolerances are involved. one of these critical organs in pelvic irradiation is testis. the amount of radiation delivered to the testes in radiotherapy must be kept as small as possible, consistent with the limit dose of this organ. the threshol...