Definitive postoperative irradiation of bile duct carcinoma with charged particles and/or photons

To determine the rates of survival and local control in patients with bile duct adenocarcinomas treated with post-operative photons and/or charged particles.

A retrospective study was performed analyzing all patients with bile duct adenocarcinomas who received radiotherapy through the University of California San Francisco and at Lawrence Berkeley Laboratory between 1977 and 1987, a total of 62 patients. University of California San Francisco patients received photon therapy (median dose 5400 cGy), and Lawrence Berkeley Laboratory patients were treated with the charged particles helium and/or neon (median dose 6000 cGyE). Forty-eight patients were treated post-operatively with curative intent, 30 with photons and 18 with particles. Thirty-six patients in the study had gross residual disease; none had microscopically negative margins.

The overall two-year actuarial survival was 28%: 44% for particle-treated patients and 18% for patients treated with photons (p = .048). Median actuarial survival was 23 months in particle patients and 12 months in photon patients. Local control was also improved, though less significantly, in patients treated with particles (median disease-free survival 20 months vs. 4.5 months, p = .054). A univariate and multivariate analysis was performed and revealed that only extent of residual disease predicted local failure and overall survival; no other prognostic factors were identified.

Compared to conventional photon radiotherapy, treatment with post-operative charged particle irradiation at Lawrence Berkeley Laboratory appeared to offer a survival advantage in this non-randomized series. Additional investigation into protection of surrounding normal tissue with better dose localization through the use of charged particles is planned.