[Treatment of head and neck cancer: radiation therapy].

Radiation therapy is an effective modality for curative treatment with organ preservation, palliative treatment for pain control and combined/prophylactic treatment for local-regional control after surgery in head and neck cancer. For early lesions, 70-90% of local control may be expected in radiation therapy. However, some hurdles must be cleared with regard to advanced lesions. We reviewed the prospective randomized controlled trials (phase III trial) concerning adjuvant chemotherapy and multiple fractions per day of radiotherapy for advanced head and neck cancer. Adjuvant chemotherapy may be used in three ways in the treatment, i.e., induction therapy, concomitantly with radiotherapy and maintenance therapy. We reviewed the former two treatments because no "pure" phase III trial could be found in maintenance therapy after radiotherapy. As for multiple fractions per day of radiation therapy, the following definition is used. Hyperfractionation: Total dose is increased; dose per fraction is reduced; fractian number is increased,; overall time is relatively unchanged. Accelerated fractionation: Overall time is reduced; number of fraction total dose, and dose per fraction are either unchanged or somewhat reduced, depending on the extent of overall time reduction. Adjuvant chemotherapy combined with radiotherapy and multiple fractions per day of radiotherapy have been attempted to increase local-regional control and survival in a few randomized studies. However, these survival results were disappointing despite good local control. We need a more effective chemotherapy regime, fractionation schedule and also to clarify the indications for these treatments by analyzing the prognostic factors.