Die Abschrift als Schreibszene. Der ›Nuwe Parzifal‹ in der Handschrift Rom, Biblioteca Casanatense, Mss. 1409

The Codex Biblioteca Casanatense 1409 which has for a long time been neg- lected in Parzival scholarship, transmits German translations of three continuations of Chre ́tien de Troyes‘ Roman de Perceval ou Le Conte du Graal together with the last two books (XV/XVI) of Wolfram von Eschenbach’s Parzival. This article supports the for- merly casually made assumption that the Casanatense manuscript is in fact a direct copy of Codex Donaueschingen 97, the so called Rappoltsteiner Parzifal. As is to be shown, marks in the Donaueschingen codex, as well as significant copying errors in the Casanatense text and its treatment of initials suggest a direct relationship of the two witnesses. The notion of ,writing scene‘ (Schreibszene) with its implications of linguistic semantics, instrumentality, gesture and self reflection, proposed in modern literary scholarship, can help to understand peculiarities of the copying process in the Casanatensis, such as the numerous conceptual abbreviations and the adaptations in the handling of headings. In the final part of the article, the hypothesis is corroborated, that the copy of the Casa- natensis might have been produced in the surroundings of Lamprecht von Brunn (ca. 1320–1399), bishop of Strasburg and Bamberg, and counsellor of the emperor Charles IV.

Assessment of patient setup errors in IGRT in combination with a six degrees of freedom couch

PURPOSE The range of patient setup errors in six dimensions detected in clinical routine for cranial as well as for extracranial treatments, were analyzed while performing linear accelerator based stereotactic treatments with frameless patient setup systems. Additionally, the need for re-verification of the patient setup for situations where couch rotations are involved was analyzed for patients treated in the cranial region. METHODS AND MATERIALS A total of 2185 initial (i.e. after pre-positioning the patient with the infrared system but before image guidance) patient setup errors (1705 in the cranial and 480 in the extracranial region) obtained by using ExacTrac (BrainLAB AG, Feldkirchen, Germany) were analyzed. Additionally, the patient setup errors as a function of the couch rotation angle were obtained by analyzing 242 setup errors in the cranial region. Before the couch was rotated, the patient setup error was corrected at couch rotation angle 0° with the aid of image guidance and the six degrees of freedom (6DoF) couch. For both situations attainment rates for two different tolerances (tolerance A: ± 0.5mm, ± 0.5°; tolerance B: ± 1.0 mm, ± 1.0°) were calculated. RESULTS The mean (± one standard deviation) initial patient setup errors for the cranial cases were -0.24 ± 1.21°, -0.23 ± 0.91° and -0.03 ± 1.07° for the pitch, roll and couch rotation axes and 0.10 ± 1.17 mm, 0.10 ± 1.62 mm and 0.11 ± 1.29 mm for the lateral, longitudinal and vertical axes, respectively. Attainment rate (all six axes simultaneously) for tolerance A was 0.6% and 13.1% for tolerance B, respectively. For the extracranial cases the corresponding values were -0.21 ± 0.95°, -0.05 ± 1.08° and -0.14 ± 1.02° for the pitch, roll and couch rotation axes and 0.15 ± 1.77 mm, 0.62 ± 1.94 mm and -0.40 ± 2.15 mm for the lateral, longitudinal and vertical axes. Attainment rate (all six axes simultaneously) for tolerance A was 0.0% and 3.1% for tolerance B, respectively. After initial setup correction and rotation of the couch to treatment position a re-correction has to be performed in 77.4% of all cases to fulfill tolerance A and in 15.6% of all cases to fulfill tolerance B. CONCLUSION The analysis of the data shows that all six axes of a 6DoF couch are used extensively for patient setup in clinical routine. In order to fulfill high patient setup accuracies (e.g. for stereotactic treatments), a 6DoF couch is recommended. Moreover, re-verification of the patient setup after rotating the couch is required in clinical routine.