RESUMEN
OBJECTIVE: Contouring accuracy is critical in modern radiotherapy. Several tools are available to assist clinicians in this task. This study aims to evaluate the performance of the smoothing tool in the ARIA system to obtain more consistent volumes. METHODS: Eleven different geometric shapes were delineated in ARIA v15.6 (Sphere, Cube, Square Prism, Six-Pointed Star Prism, Arrow Prism, And Cylinder and the respective volumes at 45° of axis deviation (_45)) in 1, 3, 5, 7, and 10 cm side or diameter each. Post-processing drawing tools to smooth those first-generated volumes were applied in different options (2D-ALL vs 3D) and grades (1, 3, 5, 10, 15, and 20). These volumetric transformations were analyzed by comparing different parameters: volume changes, center of mass, and DICE similarity coefficient index. Then we studied how smoothing affected two different volumes in a head and neck cancer patient: a single rounded node and the volume delineating cervical nodal areas. RESULTS: No changes in data were found between 2D-ALL or 3D smoothing. Minimum deviations were found (range from 0 to 0.45 cm) in the center of mass. Volumes and the DICE index decreased as the degree of smoothing increased. Some discrepancies were found, especially in figures with cleft and spikes that behave differently. In the clinical case, smoothing should be applied only once throughout the target delineation process, preferably in the largest volume (PTV) to minimize errors. CONCLUSION: Smoothing is a good tool to reduce artifacts due to the manual delineation of radiotherapy volumes. The resulting volumes must be always carefully reviewed.
Asunto(s)
Neoplasias de Cabeza y Cuello , Planificación de la Radioterapia Asistida por Computador , Humanos , Planificación de la Radioterapia Asistida por Computador/métodos , Neoplasias de Cabeza y Cuello/radioterapia , Imagenología Tridimensional/métodos , Dosificación Radioterapéutica , Tomografía Computarizada por Rayos XRESUMEN
OBJECTIVE: Larynx preservation is the current standard for locally advanced (LA) laryngeal/hypopharyngeal tumors, but not all patients respond as expected. TALK score model measures four variables (T-staging, albumin levels, liquor consumption and Karnofsky score) to determine which cases are best suited to preservation treatment scheme. We aimed to validate this prognostic model in a Southern European population. METHODS: We retrospectively evaluated 175 patients diagnosed from July 2008 to December 2015 with LA laryngeal/hypopharyngeal carcinoma and treated with a laryngeal preservation scheme comprising induction chemotherapy followed by concomitant chemotherapy and radiotherapy. We applied the TALK score model to predict larynx preservation rate. RESULTS: Of the 175 patients evaluated, 96.6% were men, 98.3% were smokers and 77.1% misused alcohol. Tumors were laryngeal 66.3% vs 33.7% in hypopharynx, and all were either stage III (37.7%) or stage IV (62.3%). TALK prognostic subgroups were: good risk 40.0%; intermediate risk 52.5%; and poor risk 7.5%. With a median follow-up of 40.1 months, larynx preservation rate, laryngectomy-free survival and overall survival at 3 years was 84.5%, 63.7% and 68.2%, respectively. Although TALK score was not predictive of 3-year larynx preservation rate (good risk 85.5%; intermediate risk 83.1%; poor risk 91.6%), it was predictive of 3-year overall survival (good risk 81.9%; intermediate risk 62.9%; poor risk 33.5%) and 3-year laryngectomy-free survival (good risk 75.6%; intermediate risk 59.6%; poor risk 30.7%). CONCLUSION: TALK model could predict OS and laryngectomy-free survival, helping clinicians to decide which patients should avoid laryngeal preservation and undergo laryngectomy after diagnosis.