Radiation Oncology/Head & Neck/Neutrons

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Head & Neck Cancers: Neutron Therapy

  • Initial results from Hammersmith Hospital appeared promising
  • However, results from a randomized RTOG trial with mixed neutrons/photons did not show a benefit in local control or overall survival
  • A follow up randomized international study with pure neutrons compared with photons again did not show a benefit, with significantly worse long-term toxicity
  • Neutron trials in general head & neck cancers have for now been abandoned. There may be a role for neutrons in salivary gland therapy

  • NTCWG 85-22 (1986-1991) -- neutrons vs photons
    • Randomized. 5 institutions in US and UK. 169 patients, Stage III-IV (T1N3, T2N+, or T3-4) SCC of H&N. Arm 1) neutrons 20.4/12 over 4 weeks vs. Arm 2) photons 70/35
    • 3-years; 1995 PMID 7790244 -- "Fast-neutron therapy in advanced head and neck cancer: a collaborative international randomized trial." (Maor MH, Int J Radiat Oncol Biol Phys. 1995 Jun 15;32(3):599-604.)
      • 3-year outcome: CR neutrons 70% vs. photons 52% (SS); LRF 63% vs. 68% (NS); OS 27% both arms (NS)
      • Toxicity: acute comparable, late Grade 3-5 neutrons 40% vs. photons 18% (SS)
      • Conclusion: Long term outcomes comparable, but toxicity worse with neutrons
  • US Neutron Cooperative (1977-1982) -- neutron/photon vs electron/photon
    • Randomized. 327 patients, inoperable SCC of H&N (oral cavity, oropharynx, supraglottic larynx, hypopharynx), T2-4 any N. Arm 1) neutron/photon beams (photons 40-44 Gy + neutrons 7.5-10 Gy) vs. 2) photon/electron beams 66-74 Gy
    • 1989 PMID 2681103 -- "Mixed neutron/photon irradiation of unresectable squamous cell carcinomas of the head and neck: the final report of a randomized cooperative trial." (Griffin TW, Int J Radiat Oncol Biol Phys. 1989 Nov;17(5):959-65.). Minimum F/U 6 years
      • Outcome: no difference in LRC or OS; LRC subgroup N+ mixed 30% vs. photons 18% (p=0.05), N0 mixed 33% vs. photons 64% (SS); control of disease in LN 45% vs. 26% (SS)
      • Conclusion: No difference between neutron/photon vs. photon/electron beam