Fractionated stereotactic radiation therapy for extracranial head and neck tumors

Background: This study is to report the clinical experiences of fractionated stereotactic radiation therapy (FSRT) for extracranial head and neck tumors. Methods and Materials: Between the period of July 1995 and November 1998, 48 patients with extracranial head and neck tumors were given FSRT as a boost and sole modality. Individualized treatment planning was performed using XKnife-3 system with relocatable Gill-Thomas-Cosman frame. In 24 patients, FSRT was applied as a boost technique following the 2-dimensional conventional external radiation therapy (ERT); in 24 patients FSRT was the sole radiotherapy modality. The primary diseases in the boost group consisted of nasopharynx cancer (19), lacrimal gland adenoid cystic carcinoma (3), orbital lymphoma (1), and skull-base recurrence of maxillary sinus adenoid cystic carcinoma (1). The primary diseases in the sole modality group consisted of recurrent nasopharynx cancer (12), orbital pseudotumor (4), skull-base recurrence of maxillary sinus, submandibular gland, and hypopharynx cancers (3), orbital rhabdomyosarcoma (2), orbital lymphoma (1), orbital metastasis of neuroblastoma (1), and nasal cavity melanoma (1). The fractionation schedule was to give 5 treatments per one week and the fractional doses were 2.0-3 Gy depending on the treatment aim and the FSRT volume. The FSRT doses varied depending on the nature of the primary diseases. Results: The local tumor response in nasopharynx cancer patients was excellent compared to retrospective data without occurrence of unexpectedly severe complication. FSRT to other regions was well tolerated by the patients and resulted in good to excellent local tumor responses with no unacceptable side effects as expected by the authors. Conclusion: Based on the current observations, FSRT is a very effective and safe modality in the treatment of extracranial head and neck tumors.