Patients were registered by contacting the University of Cincinnati Clinical Trials Office. Patients must be registered and consent obtained prior to initiation of any protocol therapy.
Treatment was administered on an outpatient basis. Adverse events and potential risks for metformin and cisplatin and radiation were reported.
Patients must have screening labs performed within 2 weeks of start of treatment including a complete blood count, liver function tests, metabolic renal panel including magnesium, vitamin B12 level, lactate, and C-peptide. Renal panel must be verified within 24 hours of cisplatin administration. They must fulfill inclusion criteria.
The recommended starting dose of metformin in diabetic patients is 500mg orally twice a day which can be escalated by 500mg increments weekly as tolerated with the maximum recommended daily dose of 2550mg.
Cisplatin was given either before or after the radiation therapy fraction that is given on the same day. If radiation is held for more than 2 days (for any reason), cisplatin may be held as well until radiation resumes.
The prescribed radiotherapy dose was be 70 Gy in 2 Gy once-daily fraction size (total of 35 fractions).
