Mixed neutron/photon irradiation of unresectable XXXX of the head and neck: the final report of a randomized cooperative trial.

@entity1 @entity957 @entity5
Three hundred and twenty-seven @entity1 with inoperable @entity957 of the head and neck were entered on a randomized study comparing a mixture of neutron and photon ("mixed beam") radiation therapy with photon/electron radiation therapy. Neutron treatment was delivered with fixed-beam, physics-laboratory-based equipment. @entity1 with histologically proven @entity5 of T-stage T2, T3, or T4 and any N-stage were eligible for randomization. Primary @entity5 sites were limited to @entity5 originating in the oral cavity, oropharynx, supraglottic larynx, or hypopharynx. @entity1 entered on this study now have a minimum at-risk follow-up period of 6 years. Study results reveal no significant differences in overall loco-regional @entity5 control rates or survival. Subgroup analysis reveals significant differences based on whether or not @entity1 presented with positive lymph nodes. Loco-regional @entity5 control rates for @entity1 presenting with positive lymph nodes were 30% for mixed-beam-treated @entity1 versus 18% for photon-treated @entity1 (p = 0.05). Loco-regional @entity5 control rates for @entity1 presenting without positive lymph nodes were 64% for photon-treated @entity1 and 33% for mixed-beam-treated @entity1 (p = 0.004). Control of @entity5 located in the nodal sites favored mixed beam over photons by a margin of 45% (49/109) to 26% (23/87) with a significance of p = 0.004. Possible explanations for these contradictory findings are discussed.
