Quality control in planning and technique of radiotherapy with cobalt-60 for T1 glottic cancer increase local control and organ preservation.

BACKGROUND

In order to evaluate whether individualized technique and dosimetry of radiotherapy increase local control, organ preservation, and survival of patients with T1 glottic cancer, we reviewed 76 cases treated from 1979 to 1993.

METHODS

Group A included 32 patients treated from 1979 to 1989 with different techniques, based on clinical aspects. Group B included 44 patients treated from 1990 to 1993 with individualized technique according to tumor extension and patient's anatomy.

RESULTS

Five-year local control with radiotherapy alone was achieved in 53% of group A versus 91% of group B (P > 0.005). Survival was similar in both groups with rescue surgery (90% versus 96%). Five-year survival with larynx preservation was 65% in group A versus 88% in group B (P = 0.02). Most recurrences (78%) appeared within 24 months of follow-up.

CONCLUSION

Adequate staging, individualized technique, computing planning using simulation and use of immobilization devices during cobalt-60 radiotherapy significantly increase local control and organ preservation in T1 glottic cancer.