A prospective, double-blind study of prophylaxis of radioxerostomia by coumarin/troxerutine in patients with head and neck cancer

Aim: Prospective, randomized placebo-controlled double-blind study to prove the efficacy of Coumarin/Troxerutine (Venalot(R) Depot) for protection of salivary glands during a head and neck irradiation. Patients and Method: Forty-eight radiotherapy patients (60 Gy) with head an d neck cancer were included in this trial. During radiotherapy the salivary glands were located in the core irradiation field. Primary efficacy parame ters were sialometry, quantitative salivary gland scintigraphy and clinical evaluation of early effects of radiotherapy (RTOG-score, Table 1), All dat a were collected at 6 assessments: 1 week pre-radiation (U1), at start (U2) , half time (U3) and end (U4) of irradiation, 8 days (U5) and 28 days (U6) after the end of irradiation (Figure 1). Results: Twenty-three patients (11 verum, 12 placebo) completed the study w ith all assessments. Sialometrically, all patients were severely (half of r adiotherapy) or completely (end of radiotherapy) xerostomatic (Figure 2). I n a global efficacy measure according to O'Brien combining scintigraphy and RTOG there was a tendency for a higher efficacy of verum compared to place bo (p = 0.068). After start of irradiation therapy, the RTOG-score showed c ontinuously and significantly lower early radiation effects under verum tha n under placebo (U3 vs U6: p < 0.05, area under curve: p = 0.032; Table 2, Figure 3). The scintigraphically determined excretion fraction was slightly less impaired in the verum group compared to the placebo treatment (p = 0. 12. Figure 4). There was no difference in drug safety between placebo and v erum for adverse events, changes in the activity of liver enzymes and for g lobal impression of tolerability. Conclusions: The results give support for an advantageous effect of Venalot (R) Depot in the treatment of radiogenic sialadenitis and mucositis. In eve n a small number of evaluable patients, early clinical effects of irradiati on (RTOG-score) were less pronounced in the active treatment group than in the placebo group, but the sample size was too low to prove statistically a lso the benefit of coumarin/troxerutine with the scintigraphic method. Sial ometry seems not suitable for the assessment of early radiation effects.