Is radiation therapy a preferred alternative to surgery for squamous cell carcinoma of the base of tongue?

Mendenhall WM, Stringer SP, Amdur RJ, Hinerman RW, Moore-Higgs GJ, Cassisi NJ
Journal of Clinical Oncology, Vol 18, Issue 1 (January), 2000: 35

Department of Radiation, University of Florida College of Medicine, Gainesville, FL,

In conclusion, patients treated with surgery (alone or combined with adjuvant radiation therapy) showed no significant difference in the likelihood of local control, local-regional control, or survival when they were compared with those who underwent radiation therapy alone. The risk of major complications and long-term morbidity (eg, permanent gastrostomy and/or tracheostomy) is higher after surgery. The functional results after radiotherapy are better than those obtained with surgery. Therefore, the treatment of choice at our institution is primary radiation therapy.

External-beam radiation therapy may be given alone or combined with an interstitial boost. The likelihood of local-regional control, survival, and major complications is similar after either technique. If the patient is treated with external-beam irradiation alone, there is probably a higher likelihood of local-regional control after some altered fractionation schedules than is found with conventionally fractionated irradiation.Patients at the University of Florida are treated at 1.2 Gy per fraction to total doses ranging from 74.4 to 79.2 Gy in a continuous course. Radiation portals should be designed to minimize irradiation of uninvolved mucosa. Unnecessarily large fields are associated with a greater number of acute effects and late complications.Treatment splits should be avoided because of the increased risk of local-regional failure, particularly for advanced cancers. Induction chemotherapy is not associated with better local-regional control.We have observed improved survival rates in patients with T4 oropharyngeal cancers treated with induction chemotherapy. The reasons for this are unclear, and this effect has not been observed in randomized trials. In contrast, concomitant chemotherapy and radiation therapy (chemoradiation) may provide a higher cure rate than irradiation alone.At present, the optimal combination of radiation therapy (conventional or altered fractionation) and concomitant chemotherapy is unclear. Increased acute toxicity is the major disadvantage in chemoradiation, particularly if an aggressive regimen of altered radiotherapy fractionation is used.

Observation may be the chosen approach for patients with N1 and early N2 neck disease located within the high-dose volume whose disease has totally regressed at completion of treatment. Otherwise, a planned neck dissection is performed 4 to 6 weeks after radiotherapy.Observation may also be the chosen approach for patients with more advanced neck disease that has responded completely after aggressive altered fractionation schedules. However, the likelihood of salvage of an isolated failure in the neck is remote. Therefore, when in doubt, we prefer to add the neck dissection. Patients with positive neck nodes who are treated with a lower dose of external-beam irradiation followed by an interstitial boost should also undergo a planned neck dissection to optimize the likelihood of local-regional control.