Topological methods for the comparison of structures using LDR-brachytherapy of the prostate as an example.

The dose coverage of low dose rate (LDR)-brachytherapy for localized prostate cancer is monitored 4-6 weeks after intervention by contouring the prostate on computed tomography and/or magnetic resonance imaging sets. Dose parameters for the prostate (V100, D90 and D80) provide information on the treatment quality. Those depend strongly on the delineation of the prostate contours. We therefore systematically investigated the contouring process for 21 patients with five examiners. The prostate structures were compared with one another using topological procedures based on Boolean algebra. The coincidence number C(V) measures the agreement between a set of structures. The mutual coincidence C(i, j) measures the agreement between two structures i and j, and the mean coincidence C(i) compares a selected structure i with the remaining structures in a set. All coincidence parameters have a value of 1 for complete coincidence of contouring and 0 for complete absence. The five patients with the lowest C(V) values were discussed, and rules for contouring the prostate have been formulated. The contouring and assessment were repeated after 3 months for the same five patients. All coincidence parameters have been improved after instruction. This shows objectively that training resulted in more consistent contouring across examiners.

[Autosomal dominant polycystic kidney disease. Case report of a 20 kg polycystic kidney]. / Autosomal-dominante polyzystische Nierenerkrankung. Ein Fallbericht von 20 kg schweren polyzystischen Nieren.

Polycystic kidneys can reach huge dimensions as a result of their continuous growth and thus lead to a "mechanical problem." We report on a 69-year-old patient with enormous polycystic kidneys having been treated for 4 years with standard hemodialysis. In the last 12 months, the patient was suffering from a deterioration of his condition and progressively developed cachexy. The preoperative status of the multi-morbid patient jeopardized operability. It was decided to perform bilateral nephrectomy with a Chevron incision on the right side. The right kidney weighed 11 kg, the left 9 kg. There were no postoperative problems. The massive relief resulted in an impressive improvement of this risk-patient's fitness and quality of life. There is a clear indication of unilateral nephrectomy in case of a renal transplantation. The role and necessity of a bilateral nephrectomy in the event of polycystic kidneys is discussed based on the respective literature.

[Gastrointestinal extramucous running suture anastomosis]. / Die gastrointestinale extramuköse Fortlauf-Anastomose.

There is an ongoing discussion in surgery about what is the best or "correct" technique for gastrointestinal anastomosis. An ideal anastomosis should fulfill the following criteria: it must be well vascularised, safe ("waterproof"), easily feasible, tension-free, spillage should be avoided and it should be inexpensive. We give an illustrated report of the surgical technique of the continuous single-layer anastomosis in the gastrointestinal tract. On the basis of a pilot study, a randomised comparative study, a Swiss multicenter trial and, finally, a prospective 5-year-follow-up quality control study we demonstrate that this "Schweizer (Swiss)"-technique fulfills the criteria of an "ideal" anastomosis and can be used in almost all intestinal localisations.