Unilateral radiotherapy was associated with effective regional control in patients with advanced tonsil cancer, according to study results presented at the 2014 Multidisciplinary Head and Neck Cancer Symposium. Additionally, the results supported previous findings that suggest the primary tumor location, not the extent of ipsilateral neck lymph node involvement on the tumor side of the neck, governs the disease risk in the contralateral side of the neck.
Researchers evaluated 153 consecutive patients diagnosed with squamous cell carcinoma of the tonsil who were treated with surgical removal and postoperative intensity-modulated radiation therapy.
Forty-six of the patients underwent unilateral radiotherapy. Of these patients, 72% were male. The average patient age was 59 years. Current or former smokers comprised 61% of the study population.
Lateralized primary tumors were confirmed in 40 (87%) of the patients. Two (4%) patients had non-lateralized tumors. Lateralization could not be retrospectively ascertained in four patients (9%).
The cancer stages for these patients were distributed as follows: TX, 2%; T1, 44%; T2, 41%; and T3, 13%. Lymph node involvement stages were as follows: N0, 11%; N1, 13%; and N2, 76%.
The patients underwent radiation doses of 60 Gy to 66 Gy to the postoperative bed and involved neck, and 52 Gy to 54 Gy to the elective region in 30 to 33 fractions using a simultaneous integrated boost technique. Concurrent chemotherapy was administered to 30 of the 46 patients. The median follow-up period was 2.8 years (range, 0.4-8.7 years).
Researchers reported no local or regional recurrences. Four patients (9%) developed distant metastasis, and two developed second primary cancers.
The findings suggest that, for suitable patients, radiation volume can be safely reduced, sparing these patients adverse effects and potential toxicity, according to study investigator Wade Thorstad, MD, chief of head and neck cancer services and associate professor of radiation oncology at Washington University School of Medicine.
“All treatments for cancer — surgery, radiation therapy, chemotherapy — although effective, can cause temporary and/or permanent toxicity that can affect long-term quality of life,” Thorstad said in a press release. “Our research indicates that for appropriately selected patients with tonsil cancer, the volume of radiation therapy necessary to control the cancer can be significantly reduced, therefore reducing the side effects and toxicity of radiation while maintaining a high rate of tumor control.”