International journal of radiation oncology, biology, physics
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2010
Breath-hold target localization with simultaneous kilovoltage/megavoltage cone-beam computed tomography and fast reconstruction.
Hypofractionated high-dose radiotherapy for small lung tumors has typically been based on stereotaxy. Cone-beam computed tomography and breath-hold techniques have provided a noninvasive basis for precise cranial and extracranial patient positioning. The cone-beam computed tomography acquisition time of 60 s, however, is beyond the breath-hold capacity of patients, resulting in respiratory motion artifacts. By combining megavoltage (MV) and kilovoltage (kV) photon sources (mounted perpendicularly on the linear accelerator) and accelerating the gantry rotation to the allowed limit, the data acquisition time could be reduced to 15 s. ⋯ The present results have shown that fast breath-hold, on-line volume imaging with a linear accelerator using simultaneous kV-MV cone-beam computed tomography is promising and can potentially be used for image-guided radiotherapy for lung cancer patients in the near future.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2010
Comparative StudyA more efficient, radiation-free alternative to systematic chest x-ray for the detection of embolized seeds to the lung.
To evaluate the efficacy of a seed-migration detector and to compare its performance to fluoroscopy and postoperative chest radiographs. ⋯ The usual recommendation to perform chest radiographs at the first follow-up visit to scan lungs for embolized seeds should be revised because of the high false-negative rate. Scintillator-based gamma counter detector provides superior detection sensitivity and should be adopted as a standard of practice. Chest X-ray could be limited to documenting cases of positive migration.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2010
Late rectal toxicity on RTOG 94-06: analysis using a mixture Lyman model.
To estimate the parameters of the Lyman normal-tissue complication probability model using censored time-to-event data for Grade ≥2 late rectal toxicity among patients treated on Radiation Therapy Oncology Group 94-06, a dose-escalation trial designed to determine the maximum tolerated dose for three-dimensional conformal radiotherapy of prostate cancer. ⋯ These results, based on a large cohort of patients from a multi-institutional trial, are expected to be widely representative of the ability of the Lyman model to describe the long-term risk of Grade ≥2 late rectal toxicity after three-dimensional conformal radiotherapy of prostate cancer.
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Int. J. Radiat. Oncol. Biol. Phys. · Nov 2010
Intensity-modulated radiotherapy for cervical node squamous cell carcinoma metastases from unknown head-and-neck primary site: M. D. Anderson Cancer Center outcomes and patterns of failure.
Conventional therapy for cervical node squamous cell carcinoma metastases from an unknown primary can cause considerable toxicity owing to the volume of tissues to be irradiated. In the present study, hypothesizing that using intensity-modulated radiotherapy (IMRT) would provide effective treatment with minimal toxicity, we reviewed the outcomes and patterns of failure for head-and-neck unknown primary cancer at a single tertiary cancer center. ⋯ The results of our study have shown that IMRT can produce excellent outcomes for patients who present with cervical node squamous cell carcinoma metastases from an unknown head-and-neck primary tumor. Severe late complications were uncommon.