Study on the clinical application of pulsed DC magnetic technology for tracking of intraoperative head motion during frameless stereotaxy

BACKGROUND: Tracking of post-registration head motion is one of the major problems in frameless stereotaxy. Various attempts in detecting and compensating for this phenomenon rely on a fixed reference device rigidly attached to the patient's head. However, most of such reference tools are either based on an invasive fixation technique or have physical limitations which allow mobility of the head only in a restricted range of motion after completion of the registration procedure. METHODS: A new sensor-based reference tool, the so-called Dynamic Reference Frame (DRF) which is designed to allow an unrestricted, 360° range of motion for the intraoperative use in pulsed DC magnetic navigation was tested in 40 patients. Different methods of non-invasive attachment dependent on the clinical need and type of procedure, as well as the resulting accuracies in the clinical application have been analyzed. RESULTS: Apart from conventional, completely rigid immobilization of the head (type A), four additional modes of head fixation and attachment of the DRF were distinguished on clinical grounds: type B1 = pin fixation plus oral DRF attachment; type B2 = pin fixation plus retroauricular DRF attachment; type C1 = free head positioning with oral DRF; and type C2 = free head positioning with retroauricular DRF. Mean fiducial registration errors (FRE) were as follows: type A interventions = 1.51 mm, B1 = 1.56 mm, B2 = 1.54 mm, C1 = 1.73 mm, and C2 = 1.75 mm. The mean position errors determined at the end of the intervention as a measure of application accuracy were: 1.45 mm in type A interventions, 1.26 mm in type B1, 1.44 mm in type B2, 1.86 mm in type C1, and 1.68 mm in type C2. CONCLUSION: Rigid head immobilization guarantees most reliable accuracy in various types of frameless stereotaxy. The use of an additional DRF, however, increases the application scope of frameless stereotaxy to include e.g. procedures in which rigid pin fixation of the cranium is not required or desired. Thus, continuous tracking of head motion allows highly flexible variation of the surgical strategy including intraoperative repositioning of the patient without impairment of navigational accuracy as it ensures automatic correction of spatial distortion. With a dental cast for oral attachment and the alternative option of non-invasive retroauricular attachment, flexibility in the clinical use of the DRF is ensured

Soziodemografische Aspekte und therapiebezogene Faktoren von Patienten mit Mundhöhlenkarzinomen bei der Teilnahme an einer Rehabilitation

Objectives: After resection of an oral carcinoma, patients are faced with physical, psychological, and socioeconomic challenges. Rehabilitation plays an essential role in patients' reintegration into their social and professional environment. This study evaluated whether socioeconomic aspects affect oral cancer patients' participation in rehabilitation treatment. Materials and methods: A retrospective analysis was conducted with 1,532 patients following surgical treatment of oral cancer during an international multicenter rehabilitation study of the German-Swiss-Austrian Cooperative Working Group on Maxillofacial Tumors using a questionnaire comprising disease-related and psychosocial items postoperatively and at least 6 months after surgery.Results: Only 35.4% of patients participated in rehabilitation. Age (p<0.001), sex (p<0.001), and marital status (p<0.05) significantly influenced participation in rehabilitation. Postoperative impairment (p<0.05) as well as quality of life (p<0.01) were significantly worse in patients who participated in rehabilitation. Nevertheless, this group of patients returned to work significantly more often, although later, than those who did not participate in rehabilitation (p<0.05). Conclusions: The findings show social inequalities and suggest a general undersupply of rehabilitative follow-up treatment in patients with oral cancer. More patients, especially older people and women should be referred to rehabilitation.Ziele: Nach Resektion eines Mundhöhlenkarzinoms stehen Patienten vor körperlichen, psychischen und sozioökonomischen Herausforderungen. Die Rehabilitation spielt eine wesentliche Rolle bei der Wiedereingliederung der Patienten in ihr soziales und berufliches Umfeld. In dieser Studie wurde untersucht, ob sozioökonomische Aspekte die Teilnahme von Mundkrebspatienten an einer Rehabilitationsbehandlung beeinflussen.Material und Methoden: Im Rahmen der internationalen multizentrischen Rehabilitationsstudie des Deutsch-Österreichisch-Schweizerischen Arbeitskreises für Tumoren des Kiefer-Gesichtsbereichs wurde mittels eines Fragebogens eine retrospektive Analyse von 1.532 Patienten mindestens 6 Monate nach operativer Behandlung eines Mundhöhlenkarzinoms durchgeführt.Ergebnisse: Nur 35,4% der Patienten nahmen an einer Rehabilitation teil. Alter (p<0,001), Geschlecht (p<0,001) und Familienstand (p<0,05) beeinflussten die Teilnahme an der Rehabilitation signifikant. Die postoperative Beeinträchtigung (p<0,05) sowie die Lebensqualität (p<0,01) waren bei Patienten, die an der Rehabilitation teilnahmen, signifikant schlechter. Dennoch kehrte diese Patientengruppe signifikant häufiger, wenn auch später, in den Beruf zurück als diejenigen, die nicht an der Rehabilitation teilnahmen (p<0,05).Schlussfolgerungen: Die Ergebnisse zeigen soziale Ungleichheiten und deuten auf eine generelle Unterversorgung bei der rehabilitativen Nachbehandlung von Patienten mit Mundhöhlenkarzinomen hin. Mehr Patienten, insbesondere ältere Menschen und Frauen, sollten zu Rehabilitationsmaßnahmen angeleitet werden