The Change of Tumor Interstitial Fluid Pressure Affected by Radiation Therapy in Patients with Uterine Cervix Cancer / 대한암학회지

No abstract available.

The Change of Tumor Interstitial Fluid Pressure by Radiation Therapy in Patients with Metastatic Lymph Node in Head and Neck Area / 대한방사선종양학회지

PURPOSE: To determine if the tumor intersitial fluid pressure (TIFP) and/or its change in patients with metastatic lymph node in head and neck area can predict radiotherapy outcome. MATERIALS AND METHODS: In 26 biopsy proven metastatic lymph node patients in head and neck area with accessible by direct inspection and palpation, and of sufficient thickness (>1 cm) to permit accurate needle placement, we measured TIFP at cervical lymph node before and during radiotherapy. Tumor size was measured clinically and radiologically. RESULTS: The mean preradiotherapy TIFP was 24.7 mmHg. Preradiotherapy TIFP had marginally significant relationship with tumor size ( p=0.06). Preradiotherapy TIFP significantly decreased when tumor size decreased ( p=0.009). Preradiotherapy TIFP was not different between complete response group and group with partial or less respone ( p=0.75). Radiotherapy outcome was not different between group with above and group with below than average TIFP ( p=0.229). TIFP decreased 36 mmHg in complete response group and 29.7 mmHg in group with partial or less respone. CONCLUSION: The mean TIFP was elevated with 24.7 mmHg. Preradiotherapy TIFP had marginally significant relationship with tumor size ( p=0.06). TIFP decreased 36 mmHg in complete response group and 29.7 mmHg in group with partial or less respone but there was no statistically significant relationship in two groups.

Role of Blood Flow vs. O2 Consumption in Nicotinamide-induced Increase pO2 in a Murine Tumor / 대한치료방사선과학회지

We evaluated the effect of nicotinamide on cellular O2 consumption and metabolic status i.e., adenylate phosphates and NAD+ in-vitro, and changes in blood flow in-vivo, to determine whether changes in cellular metabolism or increased oxygen availability, was responsible for increased tumor oxygenation. Thirty min. Pre-incubation of cells with~4mM (=500mg/kg) nicotinamide resulted in no change in cellular O2 consumption. Similarly, neither the adenylate phosphates nor the cellular NAD+ levels were altered in the presence of~4mM nicotinamide. In-vivo, nicotinamide (500mg/kg) increased O2availability as estimated by changes in relative tumor blood flow (RBC flux). The changes in RBC flux measured by the laser Doppler method, were tumor volume dependent and increased from~35% in~150mmdegree tumors to~75% in~500mmdegree tumors. In conclusion, these observations indicate a reduction in local tissue O2 consumption is not a mechanism of improved tumor oxygenation by nicotinamide in FsaII murine tumor model. The primary mechanism of increased pO2 appears to be an increased local tumor blood flow.

Enhancement of in vivo Radiosensitization by Combination with Pentoxifylline and Nicotinamide / 대한치료방사선과학회지

Pentoxifylline (PENTO) has been known to improve RBC fluidity, and thus improve the flux of RBC through narrow capillaries. Additionally, PENTO also decreases the O2 release from RBC. Nicotinamide (N4) has been reported to decrease the number of acutely hypoxic cells in tumors by temporarily increasing tumor blood flow. Therefore, the purpose of this study was to examine whether the combination of PENTO and NA (PENTO+NA) would reduce the radioresistance of the the FSaII murine fibrosarcoma by oxygenation the hypoxic cells. We observed a significantly enhanced radiation-induced growth delay of the FSaII tumors by PENTO-NA. Thus the enhancement ration was between 2.5 and 2.8 in growth delay assay. The TCD50 of control tumors was about 57 Gy, but that of PENTO-NA treated tumors was about 32 Gy. The TCD50 was modified by a factor of 1.8. We also observed that PENTO+NA, changes in tumor blood flow and intratumor pO2 were measured using laser Doppler flowmetry and O2 microelectrode methods. The tumor blood flow significantly increased at 10 min. after injection of PENTO+NA. Furthermore, we also found that PENTO+NA significantly increased intratumor pO2 from 8 to 19 mmHg. We concluded that PENTO+NA was far more effective than NA alone or PENTO alone. The increase in the response of tumor in vivo to X-irradiation appeared to be due mainly to an increase in the tumor oxygenation. Further studies using various concentrations of PENTO alone and in combination with NA to obtain better sequencing and maximal radiosensitization are warranted.

Improving Oxygenation in the Murine Tumors by a perfluorochemical Emulsion (Fluosl-DA 20%) / 대한치료방사선과학회지

In the present study, a perfluorochemical emulsion (Fluosol-DA 20%) did not alter Do and and Dq values on cell survival curve, indicating that the lack of a direct effect of Fluosol-DA 20% on cellular radiosensitivity in vitro. The effect of Fluosol-DA 20% injection in combination with carbogen breathing was determined on the hupoxic cell fraction in SCK tumors. The hypoxic cell fraction in control SCK tumors was 0.39. This value decreased to 0.05 when the mice were i.v. injected with 12 ml/kg of Fluosol-DA 20% in a carbogen atomosphere. The measured mean and median PO2 values with a microelectorde in the control tumors was 9 mmHg and 4 mmHg, respectively. The treatment of the SCK tumors in the host mice with injected Fluosol-DA 20% in combination with carbogen breathing increased the mean and median PO2 values to 67 mmHg and 62 mmHg, respectively. Using carbogen breathing alone caused a moderate increase of tumor PO2. But Fluosol-DA 20% injection alone caused little change PO2 in the tumor. It was concluded that the combination of Fluosol-DA injection and carbogen breathing is an effective means to improve oxygenation of tumors.