Video surface image guidance for external beam partial breast irradiation.

Objective: Accelerated partial breast irradiation is an emerging treatment option for early stage breast cancer. With accelerated partial breast irradiation, patient setup, and target registration accuracy is vital. The current study compared various methods for isocenter placement accuracy.

Long term outcome with post-operative radiation therapy for spinal canal ependymoma.

Purpose: A retrospective study was performed to evaluate the long term efficacy and safety of post-operative radiation therapy in the management of spinal canal ependymoma at our institution.

Methods And Materials: Between 1954 and 1997, 22 patients with spinal canal ependymoma were treated with post-operative radiotherapy at our institution. The median age at diagnosis was 34.

A prospective study of differences in duodenum compared to remaining small bowel motion between radiation treatments: implications for radiation dose escalation in carcinoma of the pancreas.

Purpose: As a foundation for a dose escalation trial, we sought to characterize duodenal and non-duodenal small bowel organ motion between fractions of pancreatic radiation therapy.

Patients And Methods: Nine patients (4 women, 5 men) undergoing radiation therapy were enrolled in this prospective study. The patients had up to four weekly CT scans performed during their course of radiation therapy.

Novel breathing motion model for radiotherapy.

Purpose: An accurate model of breathing motion under quiet respiration is desirable to obtain the most accurate and conformal dose distributions for mobile lung cancer lesions. On the basis of recent lung motion measurements and the physiologic functioning of the lungs, we have determined that the motion of lung and lung tumor tissues can be modeled as a function of five degrees of freedom, the position of the tissues at a user-specified reference breathing phase, tidal volume and its temporal derivative airflow (tidal volume phase space). Time is an implicit variable in this model.

Comparison of spirometry and abdominal height as four-dimensional computed tomography metrics in lung.

An important consideration in four-dimensional CT scanning is the selection of a breathing metric for sorting the CT data and modeling internal motion. This study compared two noninvasive breathing metrics, spirometry and abdominal height, against internal air content, used as a surrogate for internal motion. Both metrics were shown to be accurate, but the spirometry showed a stronger and more reproducible relationship than the abdominal height in the lung.

Comparison of spirometry and abdominal height as four-dimensional computed tomography metrics in lung.

An important consideration in four-dimensional CT scanning is the selection of a breathing metric for sorting the CT data and modeling internal motion. This study compared two noninvasive breathing metrics, spirometry and abdominal height, against internal air content, used as a surrogate for internal motion. Both metrics were shown to be accurate, but the spirometry showed a stronger and more reproducible relationship than the abdominal height in the lung.

Quantitation of the reconstruction quality of a four-dimensional computed tomography process for lung cancer patients.

We have developed a four-dimensional computed tomography (4D CT) technique for mapping breathing motion in radiotherapy treatment planning. A multislice CT scanner (1.5 mm slices) operated in ciné mode was used to acquire 12 contiguous slices in each couch position for 15 consecutive scans (0.

Postoperative radiation therapy for grade II and III intracranial ependymoma.

Purpose: To retrospectively determine the long-term outcome of intracranial ependymoma patients treated with surgery and postoperative radiation therapy.

Methods And Materials: Sixty patients were treated at our institution between 1964 and 2000. Forty patients had World Health Organization Grade II ependymoma, and 20 patients had Grade III ependymoma.

A treatment planning study comparing HDR and AGIMRT for cervical cancer.

The customization of brachytherapy dose distributions for gynecologic malignancies is limited by the spatial positioning of the applicators. We tested the hypothesis that applicator-guided intensity modulated radiation therapy (AGIMRT) has the potential to deliver highly conformal dose distributions to cervical tumors, representing improvement over distributions obtained with intracavitary brachytherapy. A commercial three-dimensional (3-D) treatment planning system was used to create plans for ten cervical cancer patients treated at our institution.

A method for the reconstruction of four-dimensional synchronized CT scans acquired during free breathing.

Breathing motion is a significant source of error in radiotherapy treatment planning for the thorax and upper abdomen. Accounting for breathing motion has a profound effect on the size of conformal radiation portals employed in these sites. Breathing motion also causes artifacts and distortions in treatment planning computed tomography (CT) scans acquired during free breathing and also causes a breakdown of the assumption of the superposition of radiation portals in intensity-modulated radiation therapy, possibly leading to significant dose delivery errors.