Induction of esophageal cancers by nitenpyram (NIT) in rats.

OBJECTIVE: This study was made to investigate and evaluate the safety and carcinogenicity of nitenpyram (NIT) in rats. MATERIALS AND METHODS: A totally 50 male and 50 female SD rats were treated with NIT at 0, 800, 2400, and 7200 ppm, respectively, for 104 w. The growth, clinical signs, and survival rates, as well as the body and organ weights of these animals, were analyzed. Histopathological examination was also performed. RESULTS: Compared with the control group, survival rates at 104 w were significantly decreased in the 7200 ppm dose group, for both the male and female animals. The occurrence of esophageal squamous papilloma (ESP) was significantly increased in the treated animals. The occurrences of ESP for the 0, 800, 2400, and 7200 ppm NIT treatment groups were 0/39, 0/39, 3/35, and 9/27 for the male animals, and 0/43, 0/43, 6/49, and 12/33 for the female animals, respectively. For pre-neoplastic lesion of ESP, the occurrences of esophageal squamous hyperplasia for the 0, 800, 2400 and 7200 ppm NIT treatment groups were 0/39, 1/39, 10/35, and 9/27 for the male animals, and 0/43, 2/43, 15/49, and 17/33 for the female animals, respectively. The basal cell hyperplasia from mild to severe degrees was observed in the treatment groups. CONCLUSIONS: NIT exhibits carcinogenicity of ESP in the male and female rats after the two-year treatment.

RapidArc combined with the active breathing coordinator provides an effective and accurate approach for the radiotherapy of hepatocellular carcinoma.

PURPOSE: The goal of this research was to investigate the feasibility of volumetric modulated arc therapy, RapidArc (RA), in association with the active breathing coordinator (ABC) for the treatment of hepatocellular carcinoma (HCC) with radiotherapy. PATIENTS AND MATERIALS: A total of 12 patients with HCC, after receiving transcatheter arterial chemoembolization (TACE) treatment, underwent three-dimensional computer tomography (3D-CT) scanning associated with ABC using end inspiration hold (EIH), end expiration hold (EEH), and free breathing (FB) techniques. The three-dimensional conformal radiotherapy (3D-CRT), intensity-modulated radiotherapy (IMRT), and RA plans (three 135° arcs) were designed on different CT images, respectively. The liver volume, gross tumor volume (GTV), and planning target volume (PTV) of the three breath status and the dosimetric differences of the different plans were compared. RESULTS: There were no significant differences in the volumes of live and GTV between the three breathing techniques (p > 0.05); the PTV in FB was greater than in the EEH and EIH (p < 0.05). The overall conformality index (CI) and homogeneity index (HI) for RA (CI 0.92, HI 0.90) were better than IMRT (CI 0.90, HI 0.89) and 3D-CRT (CI 0.70, HI 0.84) for the three breathing techniques (p< 0.05). The RA and IMRT significantly reduced the mean dose, V(20), V(30), and V(40) of normal liver compared to 3D-CRT, while the V(5) and V(10) in RA were higher than in IMRT. The mean values in mean dose, V(10), V(20), V(30), and V(40) of the normal liver were reduced from 13.12 Gy, 46%, 24%, 13%, and 8% in RA(FB) to 10.23 Gy, 35%, 16%, 8%, and 5% in RA(EEH) and 9.23 Gy, 32%, 16%, 8%, and 5% in RA(EIH ), respectively. In addition, the treatment time of RA was equal to 3D-CRT, which was significantly shorter than IMRT. CONCLUSION: RA in conjunction with ABC for the treatment of HCC with radiotherapy can achieve better dose delivery and ensure the accuracy of the target volume, which spares more organs at risk, uses fewer monitor units, and shortens treatment time.