None of the consultants disagree with the initial plan to treat this T1N0 squamous cell carcinoma of the true vocal cord with radiotherapy. The consensus is that 10% to 20% of these lesions can fail conventional treatment. Dr. Rice cites incorrect radiotherapy ports, understaging, and extension into muscle or cartilage as the likely reasons for failure. He also believes that a patient who continues to smoke is at risk for persistent or recurrent disease. Drs. Wetmore and Singer add that some tumors are radioresistant for indefinable reasons. Although all the consultants agree that the differentiation between severe atypia and carcinoma in situ can be very difficult, Dr. Singer warns that the surgeon should not play a role in the histologic decision-making. He does not make a distinction between the two and suggests treating a lesion on the basis of its clinical behavior. Dr. Rice draws the line at treating T3 glottic carcinomas with radiotherapy. He states that the greater the tumor bulk the less well the lesion will do with radiotherapy. All the experts caution that involvement of cartilage at the anterior commissure and arytenoid is also a reason for failure. Dr. Wetmore adds that subglottic extension and verrucous carcinoma also contribute to radiotherapy failure. The real controversy lay with how to proceed in this case. Dr. Rice suggests excision of the lesion with the laser or microsurgical stripping. If the margins were positive he would proceed with a vertical hemilaryngectomy. Dr. Wetmore would excise the lesion with a CO2 laser and would follow the patient closely thereafter. He would only plan a hemilaryngectomy if the lesion recurred again.(ABSTRACT TRUNCATED AT 250 WORDS)