Ere as follows: detector configuration, two.5 four; slice thickness, three.two mm; increment, two.5 mm; pitch, 0.875; rotation time, 0.75 sec; 120 kV; and 150 mAsslice. All CT datasets have been imported to the image analysis technique, Dr. ViewLINAX (AJS Inc., Tokyo, Japan), and analyzed with the window level setting proper for the lung (window width, 1,400 Hounsfield units, HU; window level, -400 HU). We meticulously measured the CT number (HU) of lung tumors and pulmonary parenchyma, and determined the level of -250 HU as the optimal threshold that distinguishes amongst them. The area above -250 HU was automatically extracted and we then manually excluded the structures outside the tumors such as vessels and chest walls (Figure 1). Thereafter, tumor volumes have been calculated using this method. Preliminarily, this procedure was repeated three instances for five tumors selected randomly, and we confirmed that the tumor volumes have been calculated within three variation. Tumor diameter was estimated assuming a spherical shape in the equation: volume = six (diameter)3.P 0.31 0.Enlargement (+) (n = 16) 142 76 (683)Enlargement (-) (n = 34) 259 77(297)6199 28 (147)0.87 0.27 (183)19110.AD = adenocarcinoma, SCC = squamous cell carcinoma, other individuals = non-small-cell carcinoma, not specified.Tatekawa et al. Radiation Oncology 2014, 9:eight http:www.ro-journal.comcontent91Page three ofA)B)C)Figure 1 Process to evaluate tumor volume using an image analyzing technique, Dr. ViewLINAX. (A) Initial, the CT pictures had been displayed at an optimal window level of -400 HU using a width of 1,400 HU. (B) The area above -250 HU was automatically extracted (gray locations). (C) The gray-painted structures outdoors the tumors which include vessels and chest walls (arrows) were manually excluded, and the tumor volume with the gray-painted regions was calculated.Statistical methodsDifferences between pairs of groups had been examined by t-test or Fisher’s precise test.Results The median tumor volume was 7.3 ml (range, 0.5-35.7) on day 1 and 7.5 ml (range, 0.5-35.7) on day eight. Figure 2 shows the tumor volumes on days 1 and eight in all 50 patients. Alterations in the tumor volume plus the tumor diameter estimated from the tumor volume are shown in Table two. The partnership between tumor volume on day 1 and volume alter is shown in Figure 3. A volume improve of more than ten was observed in 16 cases (32 ); increases by 10 to 20 , 20 to 30 , and 30 were observed in 9, five, and two situations, CP21R7 respectively. An increase in the estimated tumor diameter over 1 mm was observed in 9 patients (18 ), amongst whom three (six ) showed an PubMed ID:http://www.ncbi.nlm.nih.gov/pubmed/21257508 increase over 2 mm. A volume decrease of 10 or additional was observed in three patients (6 ); two had an adenocarcinoma and one particular had a squamous cell carcinoma. The tumor displaying the greatestdecrease of 38 was a squamous cell carcinoma. Three patients (6 ) showed a lower of 1 mm or a lot more inside the estimated diameter. Traits of 16 individuals showing extra than 10 increase and 34 sufferers showing no boost are listed in Table 1. There were no differences in T-stage, tumor size, and distribution of histology involving the two groups. For 29 adenocarcinomas, the volume transform was 7.5 14 (imply SD), when it was 0.8 16 for 16 squamous cell carcinomas (P = 0.14).Tumor volume on day eight (ml)Discussion In this study, we evaluated alterations of tumor volume measured using an image-analyzing method, instead of the gross tumor volume (GTV) delineated manually in actual radiotherapy arranging. The tumor volume measured on the basis from the CT quantity is smaller.
