Poster - Thur Eve - 35: Characterization of performance of two deformable registration software.

PURPOSE: To evaluate the performance of two deformable registration softwares (a commercial and an open source software) using cone-beam computed tomography (CBCT) images. METHODS: We used a set of 34 lung patients with generally large tumors each having between 1 and 20 CBCT scans. A radiation oncologist resident contoured GTVs on each CBCTs using planning CT contours as reference. Deformable registrations were performed on CT scans to adapt it to the first CBCT of each patient independently with both software. Then each CBCT was registered to the next CBCT. Contour structures have been deformed in the process for the commercial software and for the open source software contours have been drawn manually on deformed images. RESULTS: Mean remaining volume (±SD) for manual GTV contours was 59 ± 32 %. GTVs obtained with the open source software were closer to the manual GTV in size than the commercial software. Mean relative errors on volume were 45 ± 60 % for the commercial system (33 patients) and 9 ± 2 % for the open source software (6 patients). Relative errors for the commercial software increased exponentially with the volume reduction but were constant over all CBCT for the open source software. Mean Jaccard and Dice's index were 0.57 and 0.71 for the commercial software (24 patients) and 0.80 and 0.88 for the open source software (6 patients). CONCLUSION: Open source software shown tendency to give better results than commercial software but was slower than the commercial software.

Insulin-induced lipoatrophy in type I diabetes. A possible tumor necrosis factor-alpha-mediated dedifferentiation of adipocytes.

OBJECTIVE: To test the hypothesis that tumor necrosis factor (TNF)-alpha may mediate the loss and the dedifferentiation of subcutaneous fat tissue in the insulin-induced lipoatrophies of a diabetic patient who presented extensive lesions. RESEARCH DESIGN AND METHODS: An in vitro exploration of cytokine production by peripheral blood mononuclear cells (PBMC) from the reported case was performed and compared with the same explorations of PBMC from three nondiabetic subjects and three diabetic patients without lipoatrophic lesions. A proliferation test and an evaluation of TNF-alpha and interleukin (IL)-6 production from PBMC in presence of insulin were studied. RESULTS: The production of TNF-alpha and IL-6 by the macrophages of the patient in presence of insulin were dramatically increased in comparison with control subjects. This process needed cooperation with other lymphoid cells and was abrogated by dexamethasone. CONCLUSIONS: In our reported case, a local hyperproduction of TNF-alpha from macrophages that was induced by the injected insulin could explain the dedifferentiation of the adipocytes of the subcutaneous tissue and the reversion that was induced by the local injection of dexamethasone.

[Acute, reversible, interstitial pneumopathy induced by melphalan]. / Pneumopathie interstitielle, aiguë, réversible, induite par le melphalan.

A case of acute interstitial pneumonia with hypoxaemia is described; this occurred after the cessation of cortico steroids in a patient suffering from myeloma treated with melphalan. The absence of any microbes and the lymphocytosis in the bronchoalveolar lavage and the rapid and favourable improvement on cortico steroids led to a diagnosis of melphalan induced pneumonia. This acute form is probably due to a hypersensitivity mechanism and should be distinguished from the majority of cases of sub-acute fibrosing pneumonitis due to melphalan which have been published before. Urgent treatment with glucocorticoids is justified as well as the immediate and final cessation of the medication responsible, because it is this which will affect prognosis.

Prevention of urinary catheter incrustations by acetohydroxamic acid.

Acetohydroxamic acid was administered in 5 patients to determine its effect in reducing urinary catheter incrustations. All patients had chronic indwelling catheters that required frequent changes because of severe incrustations and catheter occlusion. Incrustations were analyzed chemically for calcium, magnesium, ammonia nitrogen and phosphorus. The degree of incrustation before and during acetohydroxamic acid therapy was compared in each patient and was decreased significantly (average 81 per cent) during therapy (p less than 0.05). Catheter changes were required less frequently during therapy in all patients. Acetohydroxamic acid is effective in preventing catheter incrustations and should be considered in patients with this problem.

Dissolution kinetics of uric acid calculi.

Dissolution of uric acid calculi was studied in vitro. Calculated rate constants were then applied to an in vivo situation. The time required for complete dissolution of a uric acid calculus in a patient on oral alkali therapy can be estimated. Sodium bicarbonate, acetylcysteine, [tris(hydroxymethyl)aminomethane] and [tris(hydroxymethyl)aminomethane]-E were tested for relative effectiveness in dissolving uric acid calculi in vitro. In patients who require irrigation for dissolution of uric acid calculi [tris(hydroxymethyl)-aminomethane] is the preferred agent.