Hyper-fractionated Intensity Modulated Radiation Therapy (HF-IMRT) in Head and Neck Cancer: The Technical Feasibility and Results of a Short Clinical Series XR01-XR04
Dr. Sasidharan Balukrishna,
Assiociate Professor, Department of Radiation Oncology, Christian medical College, Vellore, Tamil Nadu-632004, India.
Among various altered fractionation schedules, only hyper-fractionation has proven increased local control in head and neck cancers. MARCH (Metanalyses of Hyperfractionated or Accelerated radiotherapy in Head and neck cancer) concluded that hyper-fractionated radiotherapy in head and cancers had a survival benefit. This study attempts to combine the benefits of hyper-fractionation with the tissue sparing qualities of intensity modulated radiotherapy. Three patients with advanced oro-pharyngeal cancers were treated with HF-IMRT (Hyperfractionated-IMRT) (2 oropharynx, 1 hypopharynx). Two phase treatment planning with phase I prescribed to high risk volume (HRV) and intermediate risk volume (IRV), 60Gy in 50 fractions at 1.2Gy per fraction, 2 fractions/day, 6â€“8 h apart. The low risk volume (LRV) received 55Gy to the 95% volume at 1.1Gy per fraction in the same 50 fractions. In phase II, HRV alone was prescribed 1960cGy in 20 fractions over two weeks. Total dose to HRV was 7960cGy in 7 wk. No concurrent chemotherapy was given. Treatment was completed as planned (<60 days; break of 11 days was due to radiation toxicity). Only one patient had grade III toxicity. All three required diet modifications, an average weight loss of 3 kg and no hospitalization required during treatment. This pilot study shows the feasibility of an effective hyper-fractionation with IMRT for head and neck cancers. A Phase II trial is required to prove its efficacy.