High-dose-rate brachytherapy with local injection of
bleomycin for N0 oral tongue cancer--possibilities of the control of tumor
implant by inserting applicators and the decrease in tumor dose
Ohga S, Uehara S, Miyoshi M, Jingu K.
Department of Radiology, National Kyushu Medical Center Hospital.
Twenty-eight patients with N0 oral tongue cancer were treated with
high-dose-rate (HDR) interstitial brachytherapy combined with local injection of
bleomycin between December 1997 and June 2001 at the Department of Radiology,
National Kyushu Medical Center Hospital. A median dose of 5 mg of bleomycin was
injected locally, and 16-20 Gy was delivered to the area surrounding applicators
for control of the tumor implant during the initial two days. The two-year local
recurrence-free survival rate was 96% [T1, 2: 100% (8/8, 15/15), T3: 80% (4/5)].
The two-year secondary neck node metastasis rate was 7.1% [T1: 12.5% (1/8), T2:
6.7% (1/15), T3:0% (0/5)]. There were no tumor implants in any patients. We
tried to decrease the minimal tumor dose step by step. The groups with median
minimal tumor doses of 60 Gy, 50 Gy, and 40 Gy had local recurrence rates of
12.5% (1/8), 0% (0/14), and 0% (0/6), respectively. Local recurrence rates were
not increased by decreasing the minimal tumor dose. Two patients (7%) had
secondary neck node metastasis. Late adverse effects were tongue ulcer: 11%
(3/28), oral floor ulcer: 4% (1/28), and osteonecrosis: 4% (1/28). These results
suggest that control of the tumor implant and the decrease in minimal tumor dose
below 60 Gy may be possible with the local injection of bleomycin and delivery
of doses to the area surrounding the applicators when NO tongue cancer is
treated using 192Ir-HDR brachytherapy.