A prospective analysis of inter- and intrafractional errors to calculate CTV to PTV margins in head and neck patients

Purpose. To evaluate an institute-specific CTV–PTV margin for head and neck (HN) patients according to a 3-mm action level protocol. Methods/patients. Twenty-three HN patients were prospectively analysed. Patients were immobilized with a thermoplastic mask. Inter- and intrafractional set-up errors (in the three dimensions) were assessed from portal images (PI) registration. Digitally reconstructed radiographs (DRRs) were compared with two orthogonal PI by matching bone anatomy landmarks. The isocenter was verified during the first five consecutive days of treatment: if the mean error detected was greater than 2 mm the isocenter position was corrected for the rest of the treatment. Isocenter was checked weekly thereafter. Set-up images were obtained before and after treatment administration on 10, 20 and 30 fractions to quantify the intrafractional displacement. For the set-up errors, systematic (Σ), random (σ), overall standard deviations, and the overall mean displacement (M), were determined. CTV to PTV margin was calculated considering both inter- and intrafractional errors. Results. A total of 396 portal images was analysed in 23 patients. Systematic interfractional (Σinter) set-up errors ranged between 0.77 and 1.42 mm in the three directions, whereas the random (σ inter) errors were around 1–1.31 mm. Systematic intrafractional (Σintra) errors ranged between 0.65 and 1.11 mm, whereas the random (σ intra) errors were around 1.13–1.16 mm. Conclusions. A verification protocol (3-mm action level) provided by EPIDs improves the set-up accuracy. Intrafractional error is not negligible and contributes to create a larger CTV–PTV margin. The appropriate CTV–PTV margin for our institute is between 3 and 4.5 mm considering both inter- and intrafractional errors (AU)

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Manejo asistencial del paciente con hiperplasia benigna de próstata en España / Clinical Management of Patient With Benign Prostatic Hyperplasia in Spain

Objetivos: Conocer el manejo asistencial de la hiperplasia benigna de próstata (HBP) en España y el uso de recursos sanitarios asociado. Material y métodos: Estudio descriptivo transversal mediante entrevistas telefónicas a médicos de atención primaria (MAP) y urólogos. Se recogió información acerca del diagnóstico, tratamiento y seguimiento. Los resultados se agruparon por patrones asistenciales, definidos a partir de las variables: diagnóstico, clasificación según sintomatología, inicio de tratamiento farmacológico y seguimiento. Resultados: Participaron 153 MAP y 154 urólogos. Se identificaron 7 patrones asistenciales en atención primaria (AP). El uso de recursos sanitarios en el diagnóstico presenta cierta homogeneidad, empleando de 2,0 a 2,6 visitas, siendo las pruebas diagnósticas más habituales el análisis de PSA y de orina. En el seguimiento se observa heterogeneidad en el uso de recursos. Las visitas de seguimiento oscilan entre 3,2 y 7,0 visitas/ paciente/ año y el tipo de pruebas realizadas varía entre patrones y dentro del mismo patrón. En Urología se identificaron tres patrones asistenciales. Existe homogeneidad en el uso de recursos en el diagnóstico y en el seguimiento. La frecuencia de visitas es de 2 para el diagnóstico y entre 2,1 y 3,2 visitas/paciente/año en el seguimiento. Las pruebas más comúnmente realizadas en el diagnóstico y en el seguimiento son el análisis de PSA y el tacto rectal. Conclusiones: En AP la asistencia prestada al paciente con HBP está sujeta a variabilidad, encontrándose 7 patrones asistenciales diferentes con un seguimiento heterogéneo entre patrones y dentro del mismo patrón. Esta situación podría justificar la necesidad de difusión e implantación de protocolos asistenciales (AU)

Objectives: To identify clinical management of benign prostatic hyperplasia (BPH) in Spain and its associated health care resources. Material and methods: A qualitative cross-sectional study was conducted through telephone interviews to general practitioners (GP) and urologists. Information about diagnosis, pharmacologic treatment and follow-up was collected. Results were clustered according to the key variables considered as drivers of clinical practice patterns: BPH diagnosis, severity classification, treatment initiation and follow up of patients. Results: 153 GP and 154 urologists participated in the study. 7 different clinical patterns were identified in primary care (PC). Resource use during diagnosis is relatively homogeneous, reporting a range of 2.0 to 2.6 visits employed and being the most frequent test performed PSA and urine test. Follow-up is heterogeneous; frequency of follow-up visits oscillates from 3.2 to 7.0 visits/patient/year and type of tests performed is different among patterns and within the same pattern. In Urology, 3 clinical patterns were identified. Resource use is homogeneous in the diagnosis and in the follow-up; urologists employed 2 visits in diagnosis and a range of 2.1 to 3.2 visits/patient/year in the follow-up. The most frequent tests both in diagnosis and follow-up are PSA and digital test. Conclusions: BPH management shows variability in PC, identifying 7 different clinical practice patterns with different resource use during the follow-up among patterns and within the same pattern. The implementation of clinical guidelines could be justified to reduce heterogeneity (AU)