| Abstrakt: |
Introduction: The results of radiosurgery depend largely on a proper and precise contouring of the target volume. The impact of protocol deviations in which the imprecision of tumor volumetric delimitation is one of the components has been associated with discouraging clinical outcomes. In this paper we present a crosssectional, analytical institutional study with the following objective: Quantify the degree of interobserver variability in the delimitation of target intracranial volumes, between a medical expert, doctors at the beginning and doctors at the end of one year of radiosurgery fellowship. Methods: 7 cases of pituitary adenomas, 25 of brain metastases, 9 of vestibular schwannomas, 13 of meningiomas and 17 of arteriovenous malformations were selected. 5 observers were included: 2 at the beginning of training, 2 at the end of training and one expert. To evaluate the degree of agreement between observers, the following metrics were used: DICE similarity coefficient, coefficient of variation and hausdorff distance. Results: The degree of agreement obtained in the delimitation of volumes, of most of the pathologies, was greater between observers at the end of training and the expert, compared to that obtained between observers without training and the expert (meningioma 86% vs 84%, pituitary adenoma 80% vs 79% and vestibular schwannoma 82% vs 76%), with a statistical significance in metastases (90% vs 83%, p= 0.05). In arteriovenous malformations, the degree of agreement of the observers without training with the expert was greater (61% vs 57%) without achieving a statistically significant difference (p = 0.21). Conclusions: The fellowship in radiosurgery improves the variability for delineation of volumes between observers. A dosimetric study is required to evaluate its impact on therapeutic index. [ABSTRACT FROM AUTHOR] |
