2026-04-17T03:43:32Zhttps://recercat.cat/oai/request

oai:recercat.cat:11351/134052025-10-24T10:22:29Zcom_2072_378070com_2072_378040col_2072_378092

00925njm 22002777a 4500 dc Pérez Haas, Yoel Samuel author Benavente, Sergi author Ludwig, Roman author Balermpas, Panagiotis author Unkelbach, Jan author 2025-07-14T06:11:47Z 2025-07-14T06:11:47Z 2025-05-25 Probabilistic model; Bilateral lymphatic spread; Head and neck cancer Modelo probabilístico; Propagación linfática bilateral; Cáncer de cabeza y cuello Model probabilístic; Propagació limfàtica bilateral; Càncer de cap i coll Current guidelines for elective nodal irradiation in oropharyngeal squamous cell carcinoma (OPSCC) recommend including large portions of the contralateral lymphatic system in the clinical target volume (CTV-N), even for lateralized tumors with no clinical lymph node involvement in the contralateral neck. This study introduces a probabilistic model of bilateral lymphatic tumor progression in OPSCC to estimate personalized risks of occult disease in specific lymph node levels (LNLs) based on clinical lymph node involvement, T-stage, and tumor lateralization. Building on a previously developed hidden Markov model for ipsilateral lymphatic spread, we extend the approach to contralateral neck involvement. The model represents LNLs I, II, III, IV, V, and VII on both sides of the neck as binary hidden variables (healthy or involved), connected via arcs representing spread probabilities. These probabilities are learned using Markov chain Monte Carlo (MCMC) sampling from a dataset of 833 OPSCC patients, enabling the model to reflect the underlying lymphatic progression dynamics. The model accurately and precisely describes observed patterns of lymph node involvement with a compact set of interpretable parameters. Midline extension of the primary tumor is identified as the primary risk factor for contralateral involvement, with advanced T-stage and extensive ipsilateral involvement further increasing risk. Occult disease in contralateral LNL III is highly unlikely if upstream LNL II is clinically negative, and in contralateral LNL IV, occult disease is exceedingly rare without LNL III involvement. This model offers an interpretable, probabilistic framework to inform personalized elective CTV-N volume reduction. For lateralized tumors that do not cross the midline, it suggests the contralateral neck may safely be excluded from elective irradiation. For tumors extending across the midline but with a clinically negative contralateral neck, elective irradiation could be limited to LNL II, reducing unnecessary exposure of normal tissue while maintaining regional tumor control. http://hdl.handle.net/11351/13405 Cap - Càncer - Radioteràpia Coll - Càncer - Radioteràpia Metàstasi limfàtica Estadística DISEASES::Neoplasms::Neoplasms by Site::Head and Neck Neoplasms Other subheadings::Other subheadings::Other subheadings::/radiotherapy DISEASES::Neoplasms::Neoplastic Processes::Neoplasm Metastasis::Lymphatic Metastasis ANALYTICAL, DIAGNOSTIC AND THERAPEUTIC TECHNIQUES, AND EQUIPMENT::Investigative Techniques::Epidemiologic Methods::Statistics as Topic::Models, Statistical ENFERMEDADES::neoplasias::neoplasias por localización::neoplasias de cabeza y cuello Otros calificadores::Otros calificadores::Otros calificadores::/radioterapia ENFERMEDADES::neoplasias::procesos neoplásicos::metástasis neoplásica::metástasis linfática TÉCNICAS Y EQUIPOS ANALÍTICOS, DIAGNÓSTICOS Y TERAPÉUTICOS::técnicas de investigación::métodos epidemiológicos::estadística como asunto::modelos estadísticos A probabilistic model of bilateral lymphatic spread in head and neck cancer