Évolutions dans la prise en charge des métastases ganglionnaires cervicales sans cancer primitif retrouvé : doses et volumes cibles de la radiothérapie avec modulation d'intensité

The definition of nodal and/or mucosal target volumes for radiation therapy for lymphadenopathies of unknown primary is controversial. Target volumes may include all nodal areas bilaterraly and be pan-mucosal or unilateral, selective, including the sole oropharyngeal mucosa. This review presents current recommendations in light of changes in the TNM classification, Human papillomavirus status and therapeutic advances. We conducted a systematic review of the literature with the following keywords: lymphadenopathy; head and neck; unknown primary and radiation therapy. There are no direct comparative studies between unilateral or bilateral nodal irradiation or pan-mucosal and selective mucosal irradiation. Contralateral lymph node failure rates range from 0 to 6% after unilateral nodal irradiation and 0 and 31% after bilateral irradiation. Occurrence of a mucosal primary varies between 0 and 19.2%. Initial clinical presentation and Human papillomavirus status are critical to define mucosal target volumes. Intensity-modulated radiotherapy is recommended (rather than three-dimensional irradiation) to avoid toxicities. Systemic treatments have similar indications as for identified primary head and neck cancers. Failures do not appear superior in case of unilateral nodal irradiation but comparative studies are warranted due to major biases hampering direct comparisons. Human papillomavirus status should be incorporated into the therapeutic strategy and practice-changing TNM staging changes will need to be evaluated.