Total body irradiation using helical tomotherapy: Set-up experience and in-vivo dosimetric evaluation.

PURPOSE: Helical Tomotherapy (HT) appears as a valuable technique for total body irradiation (TBI) to create highly homogeneous and conformal dose distributions with more precise repositioning than conventional TBI techniques. The aim of this work is to describe the technique implementation, including treatment preparation, planning and dosimetric monitoring of TBI delivered in our institution from October 2016 to March 2019. MATERIAL AND METHOD: Prior to patient care, irradiation protocol was set up using physical phantoms. Gafchromic films were used to assess dose distribution homogeneity and evaluate imprecise patient positioning impact. Sixteen patients' irradiations with a prescribed dose of 12Gy were delivered in 6 fractions of 2Gy over 3 days. Pre-treatment quality assurance (QA) was performed for the verification of dose distributions at selected positions. In addition, in-vivo dosimetry was carried out using optically stimulated luminescence dosimeters (OSLD). RESULTS: Planning evaluation, as well as results of pre-treatment verifications, are presented. In-vivo dosimetry showed the strong consistency of OSLD measured doses. OSLD mean relative dose differences between measurement and calculation were respectively +0,96% and -2% for armpit and hands locations, suggesting better reliability for armpit OSLD positioning. Repercussion of both longitudinal and transversal positioning inaccuracies on phantoms is depicted up to 2cm shifts. CONCLUSION: The full methodology to set up TBI protocol, as well as dosimetric evaluation and pre-treatment QA, were presented. Our investigations reveal strong correspondence between planned and delivered doses shedding light on the dose reliability of OSLD for HT based TBI in-vivo dosimetry.

[Use of a Tenckhoff catheter implanted in the superior vena cava in hemodialysis]. / Utilisation du cathéter de Tenckhoff implanté dans la veine cave supérieure en hémodialyse.

For some patients in hemodialysis, repeated failure of conventional access routes requires consideration of unusual forms of access. For others, peritonitis or other problems may temporarily restrict the use of peritoneal route. We report our experience with Tenckhoff peritoneal dialysis catheter implanted into the superior vena cava through a venotomy in the right external jugular vein. The catheter was used for hemodialysis in five patients and we had no serious problems. Recirculation rate and removal rates of BUN and creatinine showed a satisfactory dialysis efficiency. While we do not recommend the procedure for routine permanent access, we believe that this technique provides a significant new choice in patients in whom conventional access methods have failed.

[Aneurysm of the abdominal aorta, retroperitoneal fibrosis and extramembranous glomerulitis]. / Anévrisme de l'aorte abdominale, fibrose rétro-péritonéale et glomérulite extra-membraneuse.

The authors report a case of a 58 year old male presenting with bilateral ureteral compression by peri-aneurysmal retroperitoneal fibrosis. A ureterolysis and prosthetic replacement of the abdominal aorta gave good results. Eighteen months postoperatively, proteinuria and an edema of the lower limbs revealed an extramembranous glomerulitis, for which no cause could be found. Was this rare association fortuitous, or does it result from the action of some unknown antigen?

[Presence of the bacterial kidney disease in salmonid fish in Quebec (author's transl)]. / Présence de la maladie bactérienne du rein chez les salmonidés Québec.

Presence of the bacterial kidney disease in salmonid fish in Quebec During the summers of 1979 and 1980, wild and hatchery fish were analysed for the presence of the bacterial kidney disease (BKD) agent in salmonid fish in Quebec by the indirect immunofluorescence technique. The causative agent of BKD was detected in all hatcheries tested. Ten to 25% of the fish were positive. The presence of this agent was independent of age and species. We were unable to detect the BKD in fish from the rivers in the northern part of Quebec (over the 50th parallel). The first detection of BKD in Quebec was made in the spring of 1979 in a hatchery. A high mortality occurred in fish over a year old. The majority of the fish were positive by immunofluorescence and the bacteriun was isolated from some fish. Three weeks before the disease appeared, six ponds received fish from this hatchery. No mortality was observed in those ponds and in the middle of the summer the percentage of carrier fish by immunofluorescence was approximately 20%.