Stereotactic Body Radiotherapy Plus Cetuximab Appears Safe, Effective in Previously Irradiated Recurrent Head and Neck Squamous Cell Carcinoma
In patients with previously irradiated recurrent squamous cell carcinoma of the head and neck, the combination of stereotactic body radiation therapy plus cetuximab (Erbitux) appears to be safe and effective, according to a study by Vargo et al in the International Journal of Radiation Oncology • Biology • Physics. Further evaluation of this combination treatment is warranted to establish the optimal dose and schedule.
Despite improvements in treatment approaches, head and neck squamous cell carcinoma remains associated with high locoregional recurrence rates. For patients with resectable recurrence, surgical salvage remains the accepted standard treatment. However, many patients with previously irradiated local head and neck squamous cell carcinoma are not suited for resection and have a poor prognosis. Reirradiation with or without chemotherapy provides the only potentially curative salvage option for unresectable recurrences, but this approach is associated with high rates of toxicities and low rates of overall survival.
In this phase II study, the investigators examined the efficacy and safety of reirradiation using stereotactic body radiation therapy in patients with inoperable, previously irradiated, recurrent squamous cell carcinoma of the head and neck. In addition, to address the issue of low survival rates, they included concomitant cetuximab therapy.
Study Details
Included in the study were 48 patients with recurrent squamous cell carcinoma of the head and neck. The median reirradiation interval was 18 months (range = 3–423 months), with a median gross recurrence tumor volume of 36.5 cm3 (range = 3.6–209.2 cm3). Response to treatment was assessed by subjective interpretation of the initial PET-CT scan.
Patients first received 400 mg/m2 of cetuximab, followed by stereotactic body radiation therapy plus 250 mg/m2 of cetuximab. Stereotactic body radiation therapy was delivered on alternating days on an outpatient basis over 1 to 2 weeks. Tumors < 25 cm3 received 8.0 Gy per fraction for five fractions to 40 Gy. Tumors > 25 cm3 received 8.8 Gy per fraction for five fractions to 44 Gy.
Overall Survival Rate of 40%
The median overall survival was 10 months (95% confidence interval [CI] = 7–16 months), with a 1-year overall survival rate of 40% (95% CI = 26%–54%). The 1-year local progression-free survival rate was 60% (95% CI = 44%–75%), and the locoregional progression-free survival rate was 37% (95% CI = 23%–53%). Fifteen patients (31%) had nodal recurrence in previously uninvolved neck lymph nodes, eight patients (17%) had isolated disease progression in the neck lymph nodes, and seven patients (15%) had simultaneous local disease progression plus regional disease progression in the neck.
Acute grade 3 toxicity and late grade 3 toxicity were observed in 6% of patients. They included dysphagia, mucositis, and aerodigestive fistula. In total, 62% of patients indicated improved or stable quality of life.
Closing Thoughts
The combination of stereotactic body radiation therapy plus three doses of concurrent cetuximab was shown to be a safe salvage treatment for recurrent squamous cell carcinoma of the head and neck.
The investigators concluded, “The 1-year progression-free survival in this cohort appears to be similar to that of standard of care retreatment regimens with improved patient compliance and fewer treatment-related toxicities.”
Dwight E. Heron, MD, FACR, FACRO, UPMC, of the Department of Radiation Oncology, University of Pittsburgh Cancer Institute, Pittsburgh, Pennsylvania,is the corresponding author of this article in the International Journal of Radiation Oncology • Biology • Physics.
The authors reported no potential conflicts of interest.
The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.
