Evaluation of the clinical usefulness for using verification images during frameless radiosurgery

Our previous studies showed that intrafraction motion needs to be corrected for in frameless radiosurgery. This study was designed to evaluate if verification images can correct for mechanical inaccuracy and intrafraction motion. With proper immobilization and verification images on a regular basis during treatment, mechanical (table-) inaccuracies and intrafraction motion can be corrected for and the absence of PTV-margins warranted.     

Determinants of shuttle run performance in the prediction of peak VO2 in wheelchair users

Purpose. The purpose of this study was to determine the impact of ergonomic and environmental variations on indoor shuttle run (SR) performance in wheelchair sportsmen.

Methods. Eleven experienced male wheelchair sportsmen performed three 25-m SRs in random order with varying turning capacity (TC) and mechanical resistance (MR): condition NN where participants used their sports wheelchair on a tartan surface, condition RN with increased MR, and condition RD with limited TC. Metabolic data were continuously recorded using a portable K4b² system.

Results. Friedman ANOVA with Wilcoxon a posteriori testing indicated similar VO_2peak values in all three tests. SR performance, however, was significantly different across the three test conditions (NN: 536.18 ± 119.09 s; RN: 488.82 ± 119.84 s; RD: 404.91 ± 88.41 s). SR performance contributed for 28% of the explained variance of the measured VO_2peak. The addition of TC or MR or both increased the explained variance to 32, 38 and 41%, respectively.

Conclusions. These findings demonstrate a significant impact of variations in floor surface and wheelchair-user interface on SR performance. The findings also suggest that strong reservations have to be made regarding the validity of a SR test, as predictor of VO_2peak in a wheelchair user population.     

Clostridium difficile in neonates: serogrouping and epidemiology

A typing scheme for clostridium difficile based on serogrouping, toxigenicity and sorbitol fermentation was applied to 270 strains isolated in one neonatal ward during a 6-month prospecitive study. Two hundred and twenty-three strains were isolated from 377 faecal samples of 114 neonates and 47 from 92 environmental specimens. The isolates were distributed among five different types; 87% of the faecal and 85% of the environmental isolates belonged to two of these types (toxigenic, sorbitol negative, serogroup F and nontoxigenic, sorbitol positive, serogroup A). Nosocomial spread was clearly demonstrated and the environment appeared to be the main source of contamination: most of the neonates were colonized after admission by strains found in their environment; clusters of colonization with unusual isolates were observed following referral of patients from the intensive care unit or from other hospitals. No relation was found between the acquisition or the carriage of C. difficile and any intestinal symptoms. All the strains belonged to types different from those usually found in cases of antibiotic associated colitis (AAC) suggesting differences of pathogenicity among the different types.Abbreviations PMC pseudomembranous colitis - AAC antibiotic associated colitis - AAD antibiotic associated diarrhoea - TCCFA taurocholate cycloserin cefotaxim fructose agar - ICU intensive care unit - SDS-PAGE sodium dodecyl sulphate-polyacrylamide gel electrophoresis     

Deletion of the long arm of chromosome 18, primary hypothyroidism, Biermer's anemia and IgM hypogammaglobulinemia

We report the case of an adolescent girl who presents with the 18q-syndrome, primary hypothyroidism, pernicious anemia and IgM hypogammaglobulinemia. Her karyotype was performed during infancy because of malformations and showed deletion of the long arm of chromosome 18. The patient had been treated with levothyroxine (Elthyrone) since age 13 when primary hypothyroidism was documented. A close hematological follow-up was then undertaken due to the presence of anti-parietal cell antibodies. A megaloblastic anemia of sudden offset led to the diagnosis of pernicious anemia by age 16, which was confirmed by a positive Shilling's test. Recently, the patient was found to have antimicrosome antibodies and moderate IgM hypogammaglobulinemia.     

Evaluation of dose calculation algorithms for dynamic arc treatments of head and neck tumors.

BACKGROUND AND PURPOSE: To investigate if the Pencil Beam (PB) algorithm takes the disturbance of the dose distribution due to tissue inhomogeneities sufficiently into account in dynamic field shaping rotation therapy (called the dynamic arc treatment modality) for fractionated stereotactic radiation therapy of head and neck tumors. MATERIAL AND METHODS: A treatment plan using the dynamic arc treatment modality of an oropharynx lesion on a humanoid phantom was evaluated. The same plan was calculated with three different calculation algorithms: the Clarkson and the PB algorithm (both available on the planning system of the Novalis system used for dynamic arc treatments), and the Collapsed Cone Convolution Superposition (CC) algorithm (used by the Pinnacle planning system). The three resulting plans are compared using isodose distributions and cumulative dose volume histograms (CDVHs). An intercomparison of the results of the three algorithms was performed to investigate how accurately each of them takes the influence of tissue inhomogeneities into account such as bony structures and air cavities often appearing in the head and neck region. Additionally, the resulting plans were compared with absolute and relative dosimetric measurements of the treatment plan on the humanoid phantom with thermoluminescent detectors and radiographic film, respectively. RESULTS: All calculated dose distributions show a good agreement with the measured distribution except in the planning target volume (PTV) in and at the border of the air cavity. All three algorithms overestimate the dose in the PTV at the boundary with the low-density tissue, with 12, 10 and 7% for the Clarkson, the PB and the CC algorithm, respectively. The correspondence between the calculated dose distributions is reflected in the graphs of the CDVHs. They show similar curves for the PTV and the structures except for the left parotic gland and the myelum. CONCLUSIONS: The PB algorithm of the Novalis system calculates a treatment plan for the dynamic arc treatment modality adequately for fractionated stereotactic radiation therapy of head and neck tumors, except in the PTV in and at the border of the air cavity where the actual dose is overestimated. Care needs to be taken in clinical cases where it is critical to irradiate the air-tissue boundary to a sufficient dose.     

X-linked Alport syndrome: natural history in 195 families and genotype- phenotype correlations in males

Alport syndrome (AS) is a type IV collagen hereditary disease characterized by the association of progressive hematuric nephritis, hearing loss, and, frequently, ocular changes. Mutations in the COL4A5 collagen gene are responsible for the more common X-linked dominant form of the disease. Considerable allelic heterogeneity has been observed. A "European Community Alport Syndrome Concerted Action" has been established to delineate accurately the AS phenotype and to determine genotype-phenotype correlations in a large number of families. Data concerning 329 families, 250 of them with an X-linked transmission, were collected. Characteristics of the 401 male patients belonging to the 195 families with COL4A5 mutation are presented. All male patients were hematuric, and the rate of progression to end-stage renal failure and deafness was mutation-dependent. Large deletions, non-sense mutations, or small mutations changing the reading frame conferred to affected male patients a 90% probability of developing end-stage renal failure before 30 yr of age, whereas the same risk was of 50 and 70%, respectively, in patients with missense or splice site mutation. The risk of developing hearing loss before 30 yr of age was approximately 60% in patients with missense mutations, contrary to 90% for the other types of mutations. The natural history of X-linked AS and correlations with COL4A5 mutations have been established in a large cohort of male patients. These data could be used for further evaluation of therapeutic approaches.     

Surgical necrotizing enterocolitis: are intestinal lesions more severe in infants with low birth weight?

Purpose: This study examines whether the intestinal lesions of necrotizing enterocolitis (NEC) in infants undergoing surgery are more severe in patients with extremely low birth weight (BW). Methods: Between 1980 and 2000, 128 infants underwent laparotomy for NEC: 90 in the acute phase, and 38 for secondary stenosis. Resections were limited to areas of transparietal bowel necrosis and to secondary stenoses. The authors studied the extent of initial bowel lesions at initial laparotomy, and, in the survivors, the extent of bowel resections and the existence of digestive sequelae, with a median follow-up of 24 (range, 1 to 247) months. Children with BW [le ]1,000 g (group 1, 22 patients) and greater than 1,000 g (group 2, 103 patients) were compared by using [chi ]² and t test. Results: Patients' survival rate was 87%: 68% and 91% in the groups 1 and 2, respectively (P = .01). No significant difference between the 2 groups was seen: (1) for the rate of patients with panintestinal lesions at initial surgery (12%); (2) in the survivors, the ratio of remaining to total length of jejuno-ileum (mean 88%), the number of colonic segments resected (mean 1.2), the rate of survivors without distal ileum (34%), ileo-caecal valve (39%), or right colon (29%); and (3) for the existence of digestive symptoms, even minor, at last follow-up (25%). Conclusions: Although the prognosis of surgical NEC was worse in infants with extremely low birth weight, the intestinal lesions were not found more severe in these patients. J Pediatr Surg 38:167-172.     

Clinical use of stereoscopic X-ray positioning of patients treated with conformal radiotherapy for prostate cancer

PURPOSE: To evaluate accuracy and time requirements of a stereoscopic X-ray-based positioning system in patients receiving conformal radiotherapy to the prostate. METHODS AND MATERIALS: Setup errors of the isocenter with regard to the bony pelvis were measured by means of orthogonal verification films and compared to conventional positioning (using skin drawings and lasers) and infrared marker (IR) based positioning in each of 261 treatments. In each direction, the random error represents the standard deviation and the systematic error the absolute value of the mean position. Time measurements were done in 75 treatments. RESULTS: Random errors with the X-ray positioning system in the anteroposterior (AP), lateral, and longitudinal direction were (average +/- 1 standard deviation) 2 +/- 0.6 mm, 1.7 +/- 0.6 mm, and 2.4 +/- 0.7 mm. The corresponding values of conventional as well as IR positioning were significantly higher (p < 0.01). Systematic errors for X-ray positioning were 1.1 +/- 1.2 mm AP, 0.6 +/- 0.5 mm laterally, and 1.5 +/- 1.6 mm longitudinally. Conventional and IR marker-based positioning showed significantly larger systematic errors AP and laterally, but longitudinally, the difference was not significant. Depending on the axis looked at, errors of >or=5 mm occurred in 2%-14% of treatments after X-ray positioning, 13%-29% using IR markers, and 28%-53% with conventional positioning. Total linac time for one treatment session was 14 min 51 s +/- 4 min 18 s, half of which was used for the X-ray-assisted positioning procedure. CONCLUSION: X-ray-assisted patient positioning significantly improves setup accuracy, at the cost of an increased treatment time.     

Prolonged release oxycodone and naloxone treatment counteracts opioid-induced constipation in patients with severe pain compared to previous analgesic treatment

Objective: Treatment with prolonged-release oxycodone/naloxone (PR OXN) has been shown to improve opioid induced constipation (OIC) in constipated patients. This publication reports on a real-life observational study investigating the efficacy of PR OXN with regard to bowel function in patients switching to PR OXN from WHO step 1, step 2 and step 3 opioids.

Methods: Patients with chronic pain experiencing insufficient pain relief and/or unacceptable side effects were switched to PR OXN and monitored in this observational study with respect to efficacy regarding bowel function and efficacy regarding pain relief in comparison with previous analgesic therapy. A patient was considered a responder with respect to efficacy if this assessment was “slightly better”, “better” or “much better” compared with previous therapy. Bowel function index, pain intensity, quality of life, laxative medication use, and safety analgesic were also evaluated.

Results: A total of 1338 patients (mean [SD] age 64.3 [14.9], 63% female) were observed for 43 [3–166] days (median [range]) during treatment with PR OXN. Overall response rate regarding bowel function efficacy was 82.5%. Patients with symptoms of constipation at study entry obtained a clinically relevant improvement of the bowel function index (BFI) within the first 2 weeks of PR OXN treatment. Non-constipated patients at study entry maintained normal bowel function despite switching to treatment with the opioid PR OXN.

Conclusion: In conclusion, treatment with PR OXN results in a significant and clinically relevant improvement of bowel function. During the observation of the treatment with PR OXN patients reported an improvement of quality of life (QoL). More interestingly, non-constipated patients maintained a normal bowel function, showing prevention of constipation despite the use of an opioid.