The need to update NCRP 151 data for 10 MV linear accelerator bunker shielding based on new measurements and Monte Carlo simulations

Linear accelerator bunker shielding protocols such as NCRP 151 have previously been tested against a large sample of measured data from real bunkers and machines but differences in per-energy concrete penetration (TVLs) for 10 MV has not yet been resolved. These differences are likely due to historical beam data and can potentially result in over-exposure of radiation workers and the public. This study examines a cohort of clinical linac bunker survey measurements and compares them to popular shielding protocols. Differences were investigated using contemporary beam data for both Monte Carlo simulation and in analytical equations. For primary barriers, NCRP 151 underestimates the dose rate through concrete by on average a factor of 2 with secondary barriers and maze entrance doses having much better agreement. Use of contemporary beam data in Monte Carlo simulation and an analytical equation yielded TVL values much closer to the measured values compared to NCRP 151. The TVL data in NCRP 151 is outdated and needs to be updated based upon the energy spectra of modern linear accelerators. Until then, physicists should use the TVL values shown in this study instead.

Coagulation and fibrinolysis in inflammatory bowel disease and in giant cell arteritis

BACKGROUND

In inflammatory bowel disease (IBD), gut microvascular thrombosis as well as thromboembolic complications have repeatedly been observed. We examined the long-term course of markers of coagulation and fibrinolysis in relation to clinical disease activity.

MATERIALS AND METHODS

In a prospective study, prothrombin fragment 1 and 2 (F1.2), thrombin-antithrombin complex (TAT), antithrombin, D-dimer, plasmin-alpha(2)-antiplasmin complex (PAP) and plasminogen activator inhibitor-1 (PAI-1) were measured in 20 patients with Crohn's disease (CD), 18 with ulcerative colitis (UC), and 19 with giant cell arteritis during active and inactive disease, as well as in 51 controls without inflammation.

RESULTS

Levels of F1.2, TAT, D-dimer, PAP and PAI-1 were significantly higher in active versus inactive CD and UC. However, even after 12 months of follow-up, in CD and UC the mean levels of F1.2, D-dimer and PAP were significantly higher than the levels of the controls.

CONCLUSIONS

Levels of F1.2, D-dimer and PAP were markedly raised for a long time in clinically inactive IBD, underlining a chronic state of hypercoagulation and enhanced fibrinolysis.

Platelet factor 4 and beta-thromboglobulin in inflammatory bowel disease and giant cell arteritis

BACKGROUND

As platelet factors are important in the inflammatory response, we examined the course of platelet factor 4 and beta-thromboglobulin in relation to disease activity in inflammatory bowel disease and in giant cell arteritis.

PATIENTS AND METHODS

In a prospective study, the platelet count, platelet factor 4 and beta-thromboglobulin were measured in 20 patients with Crohn's disease, 18 with ulcerative colitis and 19 with giant cell arteritis, during active and inactive disease, as well as in 51 controls without inflammation.

RESULTS

Platelet counts were significantly higher in active vs. inactive Crohn's disease, ulcerative colitis and giant cell arteritis. Levels of platelet factor 4 and beta-thromboglobulin were significantly higher in active inflammatory bowel disease and giant cell arteritis, as well as in inactive inflammatory bowel disease and giant cell arteritis, than in the non-inflammatory controls. A positive correlation was found between the Crohn's disease activity index and the platelet count, platelet factor 4 and beta-thromboglobulin. Also, a positive correlation was found between the ulcerative colitis activity index and beta-thromboglobulin. However, even after 12 months of follow-up, in Crohn's disease and ulcerative colitis the mean levels of platelet factor 4 and beta-thromboglobulin were significantly higher than the levels of the controls.

CONCLUSION

Platelet factors were correlated with inflammatory bowel disease activity. Levels of platelet factor 4 and beta-thromboglobulin, however, were markedly raised for a long time in clinically inactive inflammatory bowel disease, which might point to a pre-thrombotic state of disease.

Differential behavior of coagulation factor XIII in patients with inflammatory bowel disease and in patients with giant cell arteritis

The aim of this prospective study was to examine the role of coagulation factor XIII (FXIII) in relation to disease activity in inflammatory bowel disease (IBD) and in giant cell arteritis. Plasma FXIII activity was studied during active and inactive disease in newly diagnosed patients with Crohn's disease (CD; n = 20), ulcerative colitis (UC; n = 18) and giant cell arteritis (GCA; n = 19), in 3-month intervals (median follow-up 12 months). FXIII was also measured in two noninflammatory control groups, age and sex matched for IBD (n = 25) and GCA (n = 26). FXIII activity was significantly lower in active CD or UC than in active GCA or the noninflammatory controls. Both in CD and UC, FXIII activity correlated inversely with indices of clinical disease activity, the erythrocyte sedimentation rate, fibrinogen and C-reactive protein levels. Low FXIII activity is a characteristic feature of active IBD, and serial measurements may be useful to assess IBD activity.

Duodenal diverticulitis

The case history of a 56-year-old woman with an acute abdomen is presented. Laboratory data, a plain abdominal X-ray and ultrasound examination provided no clues for a definite diagnosis. Surprisingly, a duodenal diverticulitis was found at operation. Some aspects and complications of duodenal diverticula are discussed.

Validation of the Dutch translation of the Inflammatory Bowel Disease Questionnaire (IBDQ): a health-related quality of life questionnaire in inflammatory bowel disease

Health-related quality of life assessment can benefit several groups involved with health care. The aim of our study was to assess construct validity, reliability, discriminant ability and sensitivity to change of the Dutch translation of the Inflammatory Bowel Disease Questionnaire (IBDQ), a disease-specific quality-of-life questionnaire. A group of 120 IBD patients completed the IBDQ and two Visual Analogue Scales concerning general well-being and bowel function twice. Fifty-two patients also completed the Short-Form 36 twice. Disease activity was assessed once. Correlations between the IBDQ scores and the global assessments were reasonably high and the IBDQ was shown to be discriminative. High intraclass correlation coefficients between both measurements of the IBDQ were observed in patients who reported no change in bowel complaints. In contrast, significant differences were found between both moments in patients who reported change. The Dutch IBDQ proved to be valid, discriminative and reliable.

A single session of intraluminal brachytherapy in palliation of oesophageal cancer

Between September 1987 and September 1993, 88 patients with oesophageal cancer were treated by a single session of intraluminal brachytherapy of 15 Gy prescribed at 1 cm distance from the central axis, using MDR137Cs (n = 51) during the first part of the study and HDR192Ir (n = 37) during the second part of the study. All patients were regarded as inoperable. Improvement of dysphagia, assessed 4-6 weeks after treatment, was noted in 50 of 75 (67%) evaluable patients, whereas swallowing ability was completely restored in 47% of them. Relapse of dysphagia occurred in 28 (37%) patients during follow-up. Additional palliative treatment consisted of endoprosthesis in 14 (19%), a second course of brachytherapy in 13 (17%), one or more dilatations only in 11 (15%) and laser treatment in four (5%) patients. One non-fatal haemorrhage and five fistulae occurred, all in the presence of tumour. Two severe ulcerations without evidence of tumour were noted, both managed by combined curative treatment. The median survival of the group investigated was 5.5 months. An exophytic, non-circular growth pattern was associated with a better response. In a multivariate analysis the presence of distant metastases (p = 0.0028), weight loss (p = 0.0051) and an exophytic growth pattern (p = 0.0199) were associated with a worse survival. The present data indicate that a single session of ILB is appropriate in the palliation of dysphagia in patients with inoperable oesophagal cancer showing bad prognostic signs. Up to now there has been no clear evidence for benefit of addition of ERT.

[Postinfectious tropical malabsorption and the differences from non-tropical sprue (celiac disease)]

The clinical course is described of a 69-year-old patient with a malabsorption syndrome since her stay in Indonesia. Besides chronic diarrhoea and weight loss she suffered from malnutrition and had partial villous atrophy. Coeliac disease was considered in the differential diagnosis but considering the endemic appearance of postinfectious tropical sprue (PTS) in Indonesia and the extreme vitamin B12 deficiency our patient experienced, PTS appeared more likely. A good response to the therapy prescribed for PTS confirmed the diagnosis.

Palliation in esophageal cancer with a single session of intraluminal irradiation

From September 1987 to December 1989, 36 patients with advanced esophageal cancer entered a study in order to determine the efficacy of palliation by a single session of intraluminal irradiation. A dose of 15 Gy was administered at 1 cm distance from the central axis of the applicator. In 22 of 32 patients alive at least 6 weeks after treatment dysphagia improved, in 14 this relief was complete. Re-obstruction occurred in 8 of the 22 responders, but a second treatment with intraluminal irradiation gave improvement in six. Intraesophageal prostheses were needed in only 6 of the 36 patients. Intraluminal irradiation is easy to administer and safe, it forms a useful addition to the therapeutic possibilities for the palliation of esophageal cancer.

Platelet count, platelet function, coagulation activity and fibrinolysis in the acute phase of inflammatory bowel disease

Twenty two patients with exacerbation of inflammatory bowel disease (19 with Crohn's disease, 3 with ulcerative colitis) and thrombocytosis were tested for possible activation of the coagulation and platelet system. Fifteen patients had abnormal platelet function i.e. unphysiologically high sensitivity in vitro towards ADP 2 mumol/l aggregation induction. In 81.8% of the patients we found enhanced fibrinogen concentrations. In 22.7% of the patients thrombin-antithrombin III values exceeded the upper limit of the reference range, and in 68.2% of the patients the D-Dimer concentration exceeded the upper reference limit as a result of reactive fibrinolysis. The altered platelet count and function, and the increased levels of fibrinogen and thrombin-antithrombin III with reactive fibrinolysis activation indicate the presence of prethrombotic factors in patients with exacerbation of inflammatory bowel disease. The presence of enhanced fibrinolysis in these patients might have consequences for the therapeutic treatment.