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To investigate, with dynamic magnetic resonance imaging (dMRI) and a fiducial marker, the influence of different breathing maneuvers on internal organ and external chest wall motion.Lung and chest wall motion of 16 healthy subjects (13 male, 3 female) were examined with real-time trueFISP (true fast imaging with steady-state precession) dMRI and a small inductively coupled marker coil on either the abdomen or thorax. Three different breathing maneuvers were performed (predominantly "abdominal breathing," "thoracic breathing," and unspecific "normal breathing"). The craniocaudal (CC), anteroposterior (AP), and mediolateral (ML) lung distances were correlated (linear regression coefficient) with marker coil position during forced and quiet breathing.Differences of the CC distance between maximum forced inspiration and expiration were significant between abdominal and thoracic breathing (p0.05). The correlation between CC distance and coil position was best for forced abdominal breathing and a marker coil in the abdominal position (r = 0.89 +/- 0.04); for AP and ML distance, forced thoracic breathing and a coil in the thoracic position was best (r = 0.84 +/- 0.03 and 0.82 +/- 0.03, respectively). In quiet breathing, a lower correlation was found.A fiducial marker coil external to the thorax in combination with dMRI is a new technique to yield quantitative information on the correlation of internal organ and external chest wall motion. Correlations are highly dependent on the breathing maneuver.

To investigate the feasibility of raster scanned heavy charged particle therapy in the treatment of prostate cancer (PCa,) with special regard to the influence of internal organ motion on the dose distribution.The CT data of 8 patients with PCa who underwent three-dimensional conformal radiotherapy (RT) were chosen. In addition to the routine treatment planning scan, three to five additional positioning control CT scans were performed. The organs at risk and the target volumes were defined on all CT scans. Primary and boost carbon ion plans were calculated to deliver 66 Gy to the clinical target volume/planning target volume, with an additional 10 Gy to the gross tumor volume (GTV). To estimate the influence of internal organ motion on plan quality, the dose was recalculated on the basis of the control CT scans. The comparative analysis was based on the dose-volume histogram-derived physical parameters.The average 90% target coverage was 99.1% for the GTV. The maximal dose to the rectum was 71.8 Gy. The average rectal mean dose was 19 Gy. The volume of the rectum receiving 70 and 68 Gy was 0.1 and 0.3 cm3. The average difference in the 90% coverage for the GTV on control CT cubes was 3.6%. The maximal rectal dose increased to 76.2 Gy. The deviation in the mean rectal dose was1 Gy on average. The rectal volume receiving 70 and 68 Gy increased to 2.5 and 3.3 cm3.The investigation demonstrated the feasibility of raster scanned carbon ions for PCa RT. Excellent coverage of the target volume and optimal sparing of the rectum were acquired. The combination of photon intensity-modulated RT and a carbon ion boost to the GTV is the most rational solution for the gain of clinical experience in heavy ion RT for PCa patients.

To evaluate outcome after fractionated stereotactic radiotherapy (RT) of patients with World Health Organization Grade 2 astrocytoma in terms of progression-free survival, overall survival, toxicity, quality of life, and prognostic factors.Between 1984 and 2000, 143 patients with histologically proven Grade 2 astrocytoma were treated with fractionated stereotactic RT at our institution. The evaluation of the quality of life and toxicity was based on neurologic examinations and the Karnofsky performance score. Univariate analysis was performed on seven potential prognosticators and multivariate analysis on four prognosticators.The median follow-up was 44 months. The actuarial overall survival and progression-free survival was 58% and 39% at 5 years, respectively. Out-of-field recurrences occurred in 1 patient (1.2%). We did not observe a dose-response relationship. Overall survival and progression-free survival were significantly correlated with the absence of contrast media enhancement before RT (p0.01). Toxicity was mild and included severe side effects of European Organization for Research and Treatment of Cancer/Radiation Therapy Oncology Group Grade 3 in only 4 patients (2.8%). The Karnofsky performance score improved in most patients.Fractionated stereotactic RT is effective and has low toxicity in the treatment of Grade 2 gliomas. The rate of field border recurrences was not increased compared with after conventional RT. Exceeding the tumor dose did not improve the tumor control rate but did enhance toxicity. Pretherapeutic contrast media enhancement should be interpreted as a sign of higher grade tumor elements.