The Urological Dyna-CT: ex vivo feasibility study of interventional cross-sectional imaging in the endourological operation room.

BACKGROUND: Imaging of the urinary tract and its surrounding tissue still remains challenging, since standard imaging in the urological operation room consists of fluoroscopy and plain X-rays. The combination of a ceiling-mounted X-ray system and a new urological intervention table now allows cross-sectional imaging and 3D reconstruction to be performed in the endourological operation room (Urological Dyna-CT). MATERIALS AND METHODS: The imaging quality of the Artis Zee Ceiling (Siemens Medical Solutions, Erlangen, Germany) was assessed using slice images of an ex vivo pig kidney model prepared with artificial stones (plaster of Paris). We compared the image quality of three different examination protocols with this model. 3D reconstruction quality was illustrated by means of retrograde filling of one pig`s urinary tract with a diluted contrast medium. RESULTS: Interventional stone detection and localization is possible with a 5 s low-dose Urological Dyna-CT. Detailed imaging of the collecting system by retrograde pyelography is possible with a high image quality. CONCLUSION: The combination of an Artis Zee(®) Ceiling (Siemens Medical Solutions, Erlangen, Germany) with our newly developed urological intervention table we call the Urological Dyna-CT. In addition to such standard procedures as fluoroscopy or plain X-rays, cross-sectional imaging and 3D reconstruction of the urinary tract are possible and provide fast and excellent urological imaging.

Adjuvant IMRT/XELOX radiochemotherapy improves long-term overall- and disease-free survival in advanced gastric cancer.

PURPOSE: In a retrospective analysis, adjuvant intensity-modulated radiation therapy (IMRT) combined with modern chemotherapy improved advanced gastric cancer survival rates compared to a combination of three-dimensional conformal radiation therapy (3D-CRT) and conventional chemotherapy. We report on the long-term outcomes of two consecutive patient cohorts that were treated with either IMRT and intensive chemotherapy, or 3D-CRT and conventional chemotherapy. PATIENTS AND METHODS: Between 2001 and 2008, 65 consecutive gastric cancer patients received either 3D-CRT (n = 27) or IMRT (n = 38) following tumor resection. Chemotherapy comprised predominantly 5-fluorouracil/folinic acid (5-FU/FA) in the earlier cohort and capecitabine plus oxaliplatin (XELOX) in the latter. The primary endpoints were overall survival (OS) and disease-free survival (DFS). RESULTS: Median OS times were 18 and 43 months in the 3D-CRT and IMRT groups, respectively (p = 0.0602). Actuarial 5-year OS rates were 26 and 47 %, respectively. Within the IMRT group, XELOX gave better results than 5-FU/FA in terms of OS, but this difference was not statistically significant. The primary cause of death in both groups was distant metastasis. Median DFS times were 14 and 35 months in the 3D-CRT and IMRT groups, respectively (p = 0.0693). Actuarial 5-year DFS rates were 22 and 44 %, respectively. Among patients receiving 5-FU/FA, DFS tended to be better in the IMRT group, but this was not statistically significant. A similar analysis for the XELOX group was not possible as 3D-CRT was almost never used to treat these patients. No late toxicity exceeding grade 3 or secondary tumors were observed. CONCLUSION: After a median follow-up period of over 5 years, OS and DFS were improved in the IMRT/XELOX treated patients compared to the 3D-CRT/5-FU/FA group. Long-term observation revealed no clinical indications of therapy-induced secondary tumors or renal toxicity.

Assessment of renal function after conformal radiotherapy and intensity-modulated radiotherapy by functional 1H-MRI and 23Na-MRI.

PURPOSE: Adjuvant radiochemotherapy (RCHT) improves survival of patients with locally advanced gastric cancer. Conventional three-dimensional conformal radiotherapy (3D-CRT) results in ablative doses to a significant amount of the left kidney, while image-guided intensity-modulated radiotherapy (IG-IMRT) provides excellent target coverage with improved kidney sparing. Few long-term results on IMRT for gastric cancer, however, have been published. Functional magnetic resonance imaging (fMRI) at 3.0 T including blood oxygenation-level dependent (BOLD) imaging, diffusion-weighted imaging (DWI) and, for the first time, (23)Na imaging was used to evaluate renal status after radiotherapy with 3D-CRT or IG-IMRT. PATIENTS AND METHODS: Four disease-free patients (2 after 3D-CRT and 2 after IMRT; FU for all patients > 5 years) were included in this feasibility study. Morphological sequences, axial DWI images, 2D-gradient echo (GRE)-BOLD images, and (23)Na images were acquired. Mean values/standard deviations for ((23)Na), the apparent diffusion coefficient (ADC), and R2* values were calculated for the upper/middle/lower parts of both kidneys. Corticomedullary (23)Na-concentration gradients were determined. RESULTS: Surprisingly, IG-IMRT patients showed no morphological alterations and no statistically significant differences of ADC and R2* values in all renal parts. Values for mean corticomedullary (23)Na-concentration matched those for healthy volunteers. Results were similar in 3D-CRT patients, except for the cranial part of the left kidney. This was atrophic and presented significantly reduced functional parameters (p = 0.001-p = 0.033). Reduced ADC values indicated reduced cell density and reduced extracellular space. Cortical and medullary R2* values of the left cranial kidney in the 3D-CRT group were higher, indicating more deoxygenated hemoglobin due to reduced blood flow/oxygenation. ((23)Na) of the renal cranial parts in the 3D-CRT group was significantly reduced, while the expected corticomedullary (23)Na-concentration gradient was partially conserved. CONCLUSIONS: Functional MRI can assess postradiotherapeutic renal changes. As expected, marked morphological/functional effects were observed in high-dose areas (3D-CRT), while, unexpectedly, no alteration in kidney function was observed in IG-IMRT patients, supporting the hypothesis that reducing total/fractional dose to the renal parenchyma by IMRT is clinically beneficial.

[Image-guided radiation therapy]. / Bildgeführte Strahlentherapie.

Radiotherapy technology has improved rapidly over the past two decades. New imaging modalities, such as positron emission (computed) tomography (PET, PET-CT) and high-resolution morphological and functional magnetic resonance imaging (MRI) have been introduced into the treatment planning process. Image-guided radiation therapy (IGRT) with 3D soft tissue depiction directly imaging target and normal structures, is currently replacing patient positioning based on patient surface markers, frame-based intracranial and extracranial stereotactic treatment and partially also 2D field verification methods. On-line 3D soft tissue-based position correction unlocked the full potential of new delivery techniques, such as intensity-modulated radiotherapy, by safely delivering highly conformal dose distributions that facilitate dose escalation and hypofractionation. These strategies have already resulted in better clinical outcomes, e.g. in prostate and lung cancer and are expected to further improve radiotherapy results.

Dosimetric consequences of a translational isocenter correction based on image guidance for intensity modulated radiotherapy (IMRT) of the prostate.

Interfractional prostate motion during radiotherapy can have deleterious clinical consequences. It has become clinical practice to re-position the patient according to ultrasound or other imaging techniques. We investigated the dosimetric consequences of the linear translational position correction (isocenter correction) when a conformal IMRT technique with nine fields was used. Treatment plans of seven patients with empty and distended rectums were analyzed. The reference plans were calculated on the CT with an empty rectum. The treatment plans were transferred to a second CT with a distended rectum for an uncorrected setup of the patient referenced to bony anatomy and a corrected setup after translational position correction of the isocenter. The dosimetric consequences (with and without correction) were analyzed. For single treatment fractions, organ motion decreased the volume of the prostate encompassed by the 95% isodose (V95%) by up to -24%-p (percentage points). The mean rectum dose increased by up to 41%-p. Linear translational correction increased V95% of the prostate by up to 17%-p while the mean rectum dose was reduced by up to -23%-p compared to the uncorrected setup. Linear translational correction can improve radiation treatment accuracy for prostate cancer if geometrical changes are within certain limits.

Cortisol responses in adults who stutter: coping preferences and apprehension about communication.

This study evaluated the moderating effects of individuals' coping styles for physiological reactivity to a stressor in the laboratory in 11 persons who stuttered and 11 persons who did not stutter. Reactivity was defined as changes in levels of salivary cortisol after a stressor. Subjects were grouped according to scores on apprehension about communication. Individuals scoring high on Communication Apprehension showed significantly elevated cortisol levels compared to those scoring low on Communication Apprehension. Stuttering subjects who scored high on Communication Apprehension and used emotion-based coping strategies showed the largest elevations in cortisol levels.

The effects of life stressors and daily stressors on stuttering.

This study systemically documented the effect of perceived daily stress on subjective and objective measures of disfluencies in 12 adults who stuttered and 12 adults who did not stutter. Subjects participated in a prospective research study for 22 consecutive days. Measures of life stress, daily stress, and self-ratings of fluency were obtained. Subjects were trained in rating their fluency levels (self-ratings of fluency) and perceived daily stress levels (frequency and perceived impact of daily stressors). Results revealed a significantly higher number of daily stressors endorsed by subjects who stutter. Subjects who stuttered also displayed a significantly greater number of disfluencies and higher self-ratings of disfluencies on "high-stress" days. No significant differences were found between the mean total scores for life stress or impact scores for daily stress for the two groups. These data suggest that day-to-day variations in stuttering could be related to multiple, minor, daily stressors in some persons who stutter. Implications for treatments involving cognitive restructuring and desensitization are discussed.