Treatment of locally advanced adenoid cystic carcinoma of the trachea with neutron radiotherapy.
OBJECTIVE
To examine the efficacy of fast neutron radiotherapy in the treatment of locally advanced adenoid cystic carcinoma (ACC) of the trachea and to compare outcomes with and without high-dose-rate (HDR) endobronchial brachytherapy boost.


METHODS
Between 1989 and 2005, a total of 20 patients with ACC of the trachea were treated with fast neutron radiotherapy at the University of Washington. Of these 20 patients, 19 were treated with curative intent. Neutron doses ranged from 10.7 to 19.95 Gy (median, 19.2 Gy). Six of these patients received an endobronchial brachytherapy boost using an HDR (192)Ir source (3.5 Gy x 2 fractions). Median duration of follow-up was 46 months (range, 10-121 months).


RESULTS
The 5-year actuarial overall survival rate and median overall survival for the entire cohort were 89.4%, and 97 months, respectively. Overall survival was not statistically different among those patients receiving an endobronchial boost compared with those receiving neutron radiotherapy alone (100% vs. 68%, p = 0.36). The 5-year actuarial locoregional control rate for the entire cohort was 54.1%. The locoregional control rate was not statistically different among patients who received an endobronchial boost compared with those who received neutron radiotherapy alone (40% vs. 58%, p = 0.94). There were no cases of Grade > or =3 acute toxicity. There were 2 cases of Grade 3/4 chronic toxicity.


CONCLUSIONS
Fast neutron radiotherapy is an effective treatment for locally advanced adenoid cystic carcinoma of the trachea, with acceptable treatment-related toxicity.
Bittner
Nathan
N
Department of Radiation Oncology, University of Washington Medical Center, Seattle, WA 98195, USA.
Koh
Wui-Jin
WJ
Laramore
George E
GE
Patel
Shilpen
S
Mulligan
Michael S
MS
Douglas
James G
JG
D000328:Adult; D000368:Aged; D001918:Brachytherapy / Q000379:methods; D003528:Carcinoma, Adenoid Cystic / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy* / Q000556:secondary; D005260:Female; D006801:Humans; D007496:Iridium Radioisotopes / Q000627:therapeutic use; D008297:Male; D008875:Middle Aged; D009502:Neutrons / Q000627:therapeutic use*; D011879:Radiotherapy Dosage; D016879:Salvage Therapy; D016019:Survival Analysis; D014134:Tracheal Neoplasms / Q000401:mortality / Q000473:pathology / Q000532:radiotherapy*; D017211:Treatment Failure
D007496:Iridium Radioisotopes