Neutron Beam Radiation: Indications, Complications and Prognosis
Neutron Beam Radiation: Indications, Complications and Prognosis
C. Davis1, G. Laramore2, P. Namiranian3, J. Sikes3, J. K. Dillon4, 1Dental Student, University of Washington, Seattle, WA, 2 Chairman, Dept. of Radiation Oncology, University of Washington, Seattle, WA 3 Resident, Dept. of Oral & Maxillofacial Surgery, University of Washington, Seattle, WA, 4 Assistant Clinical Professor & Program Director, Dept. of Oral & Maxillofacial Surgery, University of Washington, Seattle, WA
Neutron Beam Radiotherapy has been shown to be effective in treating Adenoid Cystic Carcinoma and has been used with other salivary gland neoplasms. Treatment guidelines have evolved since the launch of neutron beam therapy to eliminate the devastating side effects of the early days. Neutron beam radiation for head and neck tumors now accounts for 7% of all radiation oncology treatment volume at the University of Washington. Currently, the literature is inadequate to predictably address the advantages of neutron therapy over other forms of radiation therapy. Likewise, neutron beam therapy has been associated with complications that have led to non-specific conventional radiation guidelines for using this treatment option for head and neck cancers. The purpose of this study is to further investigate the efficacy and complications of neutron beam radiation for malignant salivary gland tumors.
The medical records of 141 patients treated with neutron beam therapy by the Radiation Oncology Department at the University of Washington for salivary gland malignancies were reviewed. Patients were contacted by telephone for follow-up data and quality of life information. Data collected included demographics, tumor type, location, size, staging, surgical treatment, final pathology, perineural invasion, lymph node involvement, skull base invasion, other adjunctive treatment, dosing, complications, local/regional control and survival rates. Statistical analysis was performed using JMP software.
Adenoid cystic carcinomas and tumors of the submandibular glands comprised the most common tumor type and location. 42% had gross residual disease before neutron treatment. After neutron therapy, trismus occurred in 75% (n=33), xerostomia and mucositis in approximately 90% of patients. 6 yr. local/regional disease control was 72.2% (n=54). 5 year overall survival was 84.7% (n=59). Incidence of Osteoradionecrosis was 18.4% (n=7). Quality of Life measures evaluated were: Increase in dental caries, 63.4% (n=12/19), Pain 42.1%, n=16/38 (n=12 mild to moderate pain and n=2 moderate to severe), Difficulty with mastication 60.0%, n=15/25 (n=15 reported only mild to moderate decrease in masticatory function), Odynophagia 43.2%,n=16/37 (n=16, mild to moderate odynophagia), Hypogeusia 38.9%, n=14/36 (n=14, mild to moderate hypogeusia), Dysphonia 27.8%, n=10/36 (n=10, mild to moderate dysphonia)
The local/regional control was noted to be 72.2% and overall survival 84.7%. Although neutron therapy is not without complications and decreased quality of life, this treatment has been effective in treating aggressive salivary gland tumors such as adenoid cystic carcinoma.
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