Long Term Follow-up After Charged Particle Therapy for Chordomas and Chondrosarcomas of the Head and Neck: the Lawrence Berkeley National Laboratory (LBNL) / University of California San Francisco (UCSF) Experience
Reviewer: Abigail Berman Milby, MD
The Abramson Cancer Center of the University of Pennsylvania
Last Modified: October 4, 2011
Presenting Author: K.K. Mishra Presenter's Affiliation:University of California San Francisco, San Francisco, CA
TheLawrence Berkeley National Laboratory (LBNL) performed helium and heavier charged particle radiotherapy jointly with MGH from 1975 to 1992. Unfortunately, follow-up ended in 1993 after the facility closed.
The first helium patient was treated in 1975, carbon and neon in 1977, argon in 1977, and silicon 1982.
This facility was the only facility in the United States and treated the most patients worldwide.
Heavy ion radiotherapy has a larger radiobiologic effect than photon radiation, and, combined with the possibility of a precise dose application, tumors can be irradiated with very high doses and minimal dose to organs-at-risk.
Chordomas and chondrosarcomas of the head and neck are usually located at the skull base and in close proximity to many radiosensitive organs-at-risk including the optic nerves and chiasm and brainstem.
Castro et. al (IJROBP, 1994)previously reported on the long-term follow up of 233 patients treated with charged particle radiotherapy to skull base tumors, showing excellent local control and survival outcomes.
This study reports the long-term clinical follow-up for LBNL-UCSF patients treated with charged particles for chordomas and chondrosarcomas of the head and neck.
From 1977 to 1992, 96 patients were irradiated with charged particles at the Lawrence Berkeley Laboratory for chordomas (64) and chondrosarcomas (32) of the head and neck.
There were 45 females and 51 males.
Median age at diagnosis was 40.5 years.
82 patients were treated for primary tumors and 14 were treated for recurrent lesions and had been treated previously with surgery or radiotherapy.
Patients were treated with neon and/or helium and in some cases also with photons for tumors with a total planned dose of 60-80 GyE.
RBE values used were 1.3 for helium and 2.5 for neon (except for CNS, in which RBE was 1.6 and 4.5 respectively).
Median follow-up was 7.4 years (8.8 years for chondrosarcomas and 7.2 years for chordomas).
14 patients had greater than 20 years of follow-up.
10 patients were alive and with no evidence of disease (range follow-up 20.7-31.7 years).
34 of 96 patients were alive at last follow-up. Median follow-up for surviving patients was 9.9 years.
Overall survival (OS) by Kaplan-Meier method was 66.6%, 54.8%, 34.6%%, and 28.2% at 5, 10, 15, and 20 years.
10-year OS for chondrosarcomas is 61.8% (13 of 32 surviving) and chordomas is 51.1% (21 of 64 surviving).
This data demonstrates long-term survival in chordomas and chondrosarcomas in the head and neck treated with charged particle therapy.
Twenty (20)-year OS was 28.2%, indicating a large percent of patients were most likely cured.
This is the longest follow-up data available on patients treated with charged particle therapy heavier than protons.
The investigators are exploring further long-term local control, disease specific survival, and late normal tissue effects to better understand charged particle radiotherapy.
The authors have impressively collected long-term follow up on patients treated up to 32 years ago with charged particle radiotherapy. The large 20-year overall survival indicates that a significant subset of patients with chordoma or chondrosarcoma of the head and neck are cured of disease.
The long-term toxicities from charged particle radiotherapy will be an excellent addition to this study reporting survival outcomes.
Proton therapy has also great potential for the treatment of skull base chordomas and chondrosarcomas (Munzenrider and Liebsch, Strahlenther Onkol 1999). A comparative study of the survival and toxicities following proton vs. heavy charged particle radiotherapy would be an interesting addition to the existing body of literature.
There are international phase III trials underway investigating charged particle therapy for chordomas and chondrosarcomas (Pommier et al. Radiotherapy and Oncology 2010).