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The latest linear accelerator equipped with a kilovoltage (kV) cone-beam CT (CBCT) unit is useful for registration at the time of treatment, and thus reduces the setup error [1 4]. But in the case of intracranial or abdominal tumors, the contours of the tumors are difficult to determine on the CT images without contrast media, since such tumors are located next to normal soft tissue whose Hounsfield unit is close to those of the tumors themselves. Image registration by CBCT is performed based on the bony structures or soft tissue around the tumor. But this process does not necessarily guarantee that the position of the isocenter at treatment is identical with that at the time of planning CT, since bone or soft-tissue registration is based on a volume-matching process. It is difficult to know the exact tumor location for a low-contrast tumor even if on-board registration of the tumor is intended, since the tumor contour is not well visualized even on planning CT images without contrast media. We attempted to visualize metastatic brain

X-ray-induced apoptosis/Edaravone/MOLT-4 cells/Radioprotective effect/Free radical scavenger. Edaravone, a clinical drug used widely for the treatm ent of acute cerebral infarction, is reported to scavenge free radicals. In the present study, we investigated the radioprotective effect of edaravone on Xray-induced apoptosis in MOLT-4 cells. Apoptosis was determined by the dye exclusion test, Annexin V binding assay, cleavage of caspase, and DNA fragmentation. We found that edaravone significantly suppressed the X-ray-induced apoptosis. The amount of in tracellular ROS production was determined by the chloromethyl-2’,7’-dichlorodihydro-fluorescein diacetate system. We found that the intracellular ROS production by X-irradiation was completely suppressed b y the addition of edaravone. The accumulation and phosphorylation of p53 and the expression of p21 WAF1 , a target protein of p53, which were induced by Xirradiation, were also suppressed by adding edaravone. We conclude that the free radical scavenger edaravone suppresses X-ray-induced apoptosis in MOLT-4 cells by inhibiting p53.

Background: Hepatocellular carcinoma with inferior vena cava invasion is a rare but fatal condition of disease progression. The aim of this study was to analyze the results of treatment for hepatocellular carcinoma with inferior vena cava invasion by three-dimensional conformal radiation therapy. Methods: From 1990 to 2006, 18 histopathologically confirmed hepatocellular carcinoma patients with inferior vena cava invasion who were unsuitable for surgery were treated by three-dimensional conformal radiation therapy at our hospital with two to four static or dynamic conformal arc fields. Results: A median total tumor dose of 50 Gy (range 30‐60 Gy) was delivered. The progression-free rate was 91.6% among the patients in whom follow-up computed tomography was obtained. Actuarial survival at 1 year was 33.3%, and the median survival period was 5.6 months. Conclusions: Three-dimensional conformal radiation therapy might offer a chance of long survival for a part of the hepatocellular carcinoma patients with inferior vena cava invasion, since a third of such patients survived more than a year. Additional treatments should be considered to prevent distant metastases and hepatic functional deterioration after threedimensional conformal radiation therapy.

Background To determine the usefulness of dose volume histogram (DVH) factors for predicting the occurrence of radiation pneumonitis (RP) after application of stereotactic radiation therapy (SRT) for lung tumors, DVH factors were measured before irradiation. Methods From May 2004 to April 2006, 25 patients were treated with SRT at the University of Tokyo Hospital. Eighteen patients had primary lung cancer and seven had metastatic lung cancer. SRT was given in 6–7 fields with an isocenter dose of 48 Gy in four fractions over 5–8 days by linear accelerator. Results Seven of the 25 patients suffered from RP of symptomatic grade 2–5 according to the NCI-CTC version 3.0. The overall incidence rate of RP grade2 or more was 29% at 18 months after completing SRT and three patients died from RP. RP occurred at significantly increased frequencies in patients with higher conformity index (CI) (p = 0.0394). Mean lung dose (MLD) showed a significant correlation with V5–V20 (irradiated lung volume) (p < 0.001) but showed no correlation with CI. RP did not statistically correlate with MLD. MLD had the strongest correlation with V5. Conclusion Even in SRT, when large volumes of lung parenchyma are irradiated to such high doses as the minimum dose within planning target volume, the incidence of lung toxicity can become high.

Objective To evaluate the therapeutic effects of radiotherapy on spinal bone metastases from hepatocellular carcinoma (HCC). Methods A retrospective review was conducted on 24 ambulatory patients with spinal bone metastases from HCC treated by radiotherapy from 1995 to 2004. Ambulatory rate and local progression-free rate after radiotherapy were analyzed. Eight (33%) of 24 patients had radiographic spinal cord compression from the spinal bone metastases before the treatment. Two (8.3%) of the 24 patients had some spinal deficits before the treatment. Biological equivalent dose (BED) with alpha/beta ratios of 10 ranged from 39 to 50.7 Gy (median 44.8 Gy). Results The median observation period was 5.1 months ranging from 0.9 to 36.0 months. Among the 24 patients, five (21%) underwent salvage therapies, while of the remaining 19 patients four (21%) became nonambulatory by the last follow-up. The ambulatory rates at 3 months and 6 months were 85 and 63%, respectively. The local progression-free rates at 3 months and 6 months were 53 and 47%, respectively. Conclusions Radiotherapy with a BED of 39-50.7 Gy (median 44.8 Gy) is not sufficiently effective for the patients with spinal bone metastases from HCC to prevent paralysis. Dose escalation with a highly precise radiation technique will need to be evaluated.