Enhanced skin toxicity with concomitant cetuximab and radiotherapy in patients with locally advanced head and neck squamous cell carcinoma

Purpose: When associated with radiotherapy the monoclonal antibodies such as cetuximab might be exacerbate skin toxicity. The aim of this study was to retrospectively analyze acute dermatological toxicity in ten consecutive patients with locally advanced head and neck squamous cell carcinoma treated from march 2008 to May 2009 according to Bonner protocol. Patients and methods: We have treated with radiotherapy and cetuximab ten patients with locally advanced head and neck squamous cell carcinoma of the oropharynx, hypopharynx, larynx or oral cavity, stage 3-4B and non metastatic. All our patients were 3D planned and scheduled for conventional fractionation 70 Gy/35 fractions over 47 days, five days weekly. Uninvolved neck received 50 Gy and gross nodal disease received 70 Gy as the primary tumor. Cetuximab was administered one week before radiotherapy at a loading dose of 400 mg per square meter of body surface area over 120 minutes, followed by weekly 60 minutes infusions at 250 mg per square meter for the duration of radiotherapy. Results: In eight patients (80%) grade 3 radiation dermatitis occurred as early as with 28 Gy at a median dose of 42 Gy (range 28-60 Gy). the median radiotherapy dose was 6 Gy with an overall treatment time of 57.7 days (range 41-70 days). were administered 78 cycles of cetuximab, one patient discontinued after five cycles due to infusion reactions. There was no correlation between toxicity and acne-like rash due to cetuximab. Conclusion: Our results albeit in disagreement with the original study are rather similar with the experience of other European centers that encounter grade 3-4 radiation dermatitis in 49% of their patients or Australian centers that reported 79% of same degree of toxicity. (authors)