Local control rate by radical radiation therapy was analyzed in 33 pat
ients with a piriform sinus cancer. Twenty-five patients (76%) were in
stage T3 + T4. Local recurrence-free survival at 3 years was 49% in T
1 + T2 and 25% in T3 + T4 (p = 0.01). In TI + T2 lesions, a biological
ly effective dose for an acute reaction over 80 Gy and total treatment
time less than 70 days appeared to improve local control. In T3 + T4
lesions, good radiation response assessed by the regaining of laryngea
l mobility affected local control favorably. An esophageal involvement
and destruction of the laryngeal cartilage as well as soft tissue ext
ension precluded the possibility of local control by radiation therapy
alone. In addition to the T-stage, other tumor factors should also be
considered for predicting local control with radiation therapy.