Proton radiation for treatment of cancer of the oropharynx: early experience at Loma Linda University Medical Center using a concomitant boost technique.
OBJECTIVE
To assess accelerated fractionation using photon and proton radiation to improve local control and reduce complications in treating locally advanced oropharyngeal cancer.


METHODS
Twenty-nine patients with localized Stage II-IV oropharyngeal cancer received accelerated photon and proton radiation, 75.9 GyE in 45 fractions/5.5 weeks, to the primary disease, involved lymph nodes, and potential areas of subclinical spread. Follow-up ranged from 2 to 96 months.


RESULTS
Five-year actuarial control for local disease was 88%, and for neck node disease, 96%; yielding a 84% locoregional control rate at 5 years. Four patients developed distant metastases. The 5-year actuarial locoregional control rate was 84%. The actuarial 2-year disease-free survival rate was 81%; at 5 years, it was 65%. All patients completed the prescribed treatment; though aggressive nutritional and anesthetic support was necessary. Late Grade 3 toxicity was seen in 3 patients.


CONCLUSIONS
Protons used as a concomitant boost with photons effectively delivered an accelerated time-dose schedule to the cancer with a more tolerable schedule to surrounding normal tissues. Preliminary results reveal increased locoregional control without increased toxicity. Future studies must evaluate the optimum time-dose schedule.
Slater
Jerry D
JD
Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, CA 92354, USA. jdslater@dominion.llumc.edu
Yonemoto
Les T
LT
Mantik
David W
DW
Bush
David A
DA
Preston
William
W
Grove
Roger I
RI
Miller
Daniel W
DW
Slater
James M
JM
D002294:Carcinoma, Squamous Cell / Q000473:pathology / Q000532:radiotherapy*; D018572:Disease-Free Survival; D019583:Dose Fractionation, Radiation; D006801:Humans; D009367:Neoplasm Staging; D009959:Oropharyngeal Neoplasms / Q000473:pathology / Q000532:radiotherapy*; D017785:Photons / Q000627:therapeutic use*; D061766:Proton Therapy; D011522:Protons
D011522:Protons