Regional outcome in oropharyngeal and pharyngolaryngeal cancer treated with high dose per fraction radiotherapy. Analysis of neck disease response in 1646 cases.

Out of a series of 1666 consecutive patients with squamous cell carcinoma of oropharynx and pharyngolarynx, 1646 were evaluable at a 3-year interval following radical radiation therapy. The actuarial 3-year nodal control rate using the AJC classification was: N0 98%, N1 90%, N2 88%, N3 71% when the primary was controlled. The regional outcome is influenced by clinical features such as nodal size, multiplicity and fixity. Cervical recurrence frequency is higher for pharyngolaryngeal carcinoma than for oropharyngeal cancer. The impact of the treatment planning on regional control is discussed. Due to the of concomitant boosting of nodes, cervical metastases were treated according to a type of accelerated fractionation schedule with weekly doses of 12-15 Gy for a total of 70-85 Gy in 75% of the cases. Clear-cut dose control relationships are demonstrated for nodes larger than 3 cm in diameter. Overboosting residual cervical disease fails to yield a better nodal control. Comparative analysis is established between results obtained with this high dose per fraction radiotherapy schedule, conventional regimens of irradiation and other new approaches, combining chemical and physical agents. Therapeutic implications are also derived to define adequate field coverage.