Search

This study was conducted to evaluate the efficacy and feasibility of our accelerated hyperfractionation with concomitant boost for stage II laryngeal cancer and stages III-IVb locally advanced head and neck cancer.From January 2000 to October 2001, eight patients with AJCC 1998 stage II laryngeal cancer and 11 patients with AJCC 1998 stages III-IVb locally advanced head and neck cancer underwent accelerated hyperfractionated radiation therapy. For the stage II laryngeal cancer, radiation was delivered at a 2.0 Gy fraction a day, 5 fractions per week for the first 3 weeks, then 2 fractions (1.8 and 1.2 Gy) a day, 5 times a week for 2.5 weeks, with total dose of 69 Gy. For stages III-IVb head and neck cancer, radiation was given at a 1.8 Gy fraction a day, 5 fractions per week for 6 weeks and a boost was added up to 70.5 Gy with 1.5 Gy as a second daily fraction during the last 2.2 weeks. Among the patients, 16 (84%) received concomitant chemotherapy, mainly with low-dose carboplatin. Acute toxicity based on RTOG criteria and tumor response at 1 month post-treatment were estimated as initial effects.The overall response rate was 100% in patients with stage II laryngeal cancer and 91% in patients with stages III and IVb head and neck cancer. The incidence of grade 3 or worse acute effects was 47%. Eighteen patients (95%) completed radiation therapy without interruption related to acute side effects, while one had prolongation of the treatment for more than 1 week because of neutropenia.Our results demonstrated that accelerated hyperfractionation, mostly combined with concomitant chemotherapy, had a good overall response rate with acceptable toxicity in stage II laryngeal cancers and stages III-IVb head and neck tumors.

We examined linoleic acid hydroperoxide (hydroperoxyoctadecadienoic acid; HPOD) decomposition kinetically with or without various metal ions and at various pHs as effective factors on the stability of hydroperoxides. HPOD decomposition in the reaction system of this experiment was a first-order reaction. Manganese, copper, and especially iron accelerated the decomposition of HPOD, while lithium, sodium, potassium, magnesium, calcium, and aluminium stabilized HPOD. Besides, HPOD was comparatively stable at pH 3, 7, and 8, and unstable at pH 2, 4-6, and 9. According to activation energy, however, it was estimated that only in the reaction system with iron or at pH 2 and 9 the HPOD decomposition mechanism was different from that in water.