Abstract
Abstract: Purpose: We analyzed treatment results of interstitial high dose rate (HDR) brachytherapy for cancer of the oral tongue.
Methods and Materials: Between October 1992 and March 1996, 34 patients with cancer of thetongue without nodal metastases underwent fractionated interstitial brachytherapy with a HDRiridium remote afterloader. There were 22 males and 12 females. Ages ranged from 23 to 84years; the median age was 59 years. The size of primary lesion was classfied as follows: T1: 3cases, T2: 27 cases, T3: 4 cases, thickness. 10mm: 27 cases, thickness>10mm: 7 cases. Thetypes of treatment consisted of (1) brachytherapy (BT) alone: 8 cases, (2) BT after surgery: 3cases, (3) BT after systemic chemotherapy: 3 cases, (4) BT after arterial infusion (AI): 14 cases, (5) BT after external beam radiotherapy (ERT): 5 cases, and (6) BT after AI+ERT: 1 case. Applicators were implanted under general anesthesia. Reference dose was estimated at point 5mm from source. Brachytherapy was carried out in 10 fractions twice a day for 5 days. Patientsreceived 60 Gy with BT alone, 45-55 Gy after ERT, and 50-55 Gy after chemotherapy.
Results: Local failure was found in 5 cases (14.7%) with T2 lesions. Recurrence occurred in 5 (18.5%) out of 27 cases with tumor thickness of 10mm or less. On the other hand, there were norecurrences in 7 cases with tumor thickness of more than 10mm. Among various types oftreatment, BT following systemic chemotherapy or AI exhibited better results (local failure: 1/17) than other modalities. Lymph node metastases appeared in 11 cases (32.4%). Causespecific survival was 91% at 2 years in all cases.
Ulcerations of the tongue were noted in 7 (26.9%) in 26 evaluable cases. Although ulcerationoccurred in 6/13 (46.1%) cases treated until March 1994, the incidence decreased to 1/13 (7.7%) afterwards. Careful implantation and dose prescription contributed to the decrease in ulceration.Ulcerative lesions healed with conservative care within 6 months in all cases. Bone exposureoccurred in 2 cases that received 60 Gy following AI for advanced diseases.
Conclusion: Our results suggests that HDR fractionated brachytherapy may be a workablealternative to LDR therapy for cancer of the tongue. Brachytherapy following chemotherapy canbe applied to more advanced cases of the disease.
