64-row MDCT Perfusion Imaging In Patients With Peripheral Lung Carcinoma

Purpose The use of CT to provide both anatomic and physiological information would enable direct correlation between structure and functional abnormalities within tumors. With rapid scanning, high time-attenuation resolution, and simultaneous acquisition of multiple thin slices with high quality, 64-MDCT has sparked new interest in the noninvasive assessment of pulmonary neoplasm. To our best knowledge, there has been no reported series of 64-MDCT perfusion measurement in patients with peripheral lung carcinoma. The purpose of this study was to investigate the feasibility of 64-row MDCT perfusion in evaluating tumor microcirculation of peripheral lung carcinoma and perfusion parameters in different histological types, sizes, stages, metastasis and necrosis.The technique combines quantification and functional mapping of several perfusion parameters within one examination and has potential application in monitoring the response of lung carcinoma to therapy.Materials and Method Ninety-four patients, with histological proven peripheral lung cancer, underwent a series of 64-row MDCT scan (Philips Brilliance 64, Best Netherlands). Location, morphology, size, attenuation and metastasis of the mass were evaluated from the images of plane and enhanced CT scan. Time-attenuation curve (TAC) from the mass were generated from a dynamic sequence of images acquired over 55 to 60 sec following a 50 ml intravenous bolus of contrast medium (Ultravist 300, Shering, Berlin Germany) at 6.0-7.0 ml/sec. Data was analyzed using commercial software (Philips CT perfusion package) to generate perfusion, peak enhanced (PE), time to peak (TTP), and blood volume (BV). CT perfusion parameters were correlated with histological type, size, stages, metastasis and necrosis. A One-way ANOVA analysis of variance followed by LSD-t method of multiple comparisons was used to calculated variations in CT perfusion parameters among different categories.Results TACs of 94 lung carcinomas were classified into 6 types according to the slope of ascending and descending curve, which mainly manifested to the typeⅡc(47.9%). TypeⅡc was dominatly noted in adenocarcinoma (49.1%) and squamous cell carcinoma (51.9%), whereas small-cell carcinoma mainly manifested to typeⅠa (50.0%). Perfusion, PE, TTP and BV for all tumors were 58.9±45.8, range 5.9-243.0 (ml/min/ml), 55.2±41.7, range 10.4-231.6 (Hu), 35.1±10.7, range 12-60 (Sec) and 31.2±22.2, range 3.9-113.8 (ml/100ml), respectively. CT perfusion parameters of small-cell carcinoma and adenocarcinoma were higher than those of squamous cell carcinoma, but the differences were not statistically significant. Considerable differences with higher perfusion, PE and BV were noted in tumor (≤30mm) than in tumor (＞30mm)(p＜0.05). Perfusion in early stage tumors has higher than that of advanced tumors. Differences of perfusion, PE and BV between distant metastasis group and relapse-free group were statistically significant (p＜0.05). Tumor with necrosis showed lower perfusion, PE and BV as well as longer TTP compare to tumor without necrosis (p＜0.05). Furthermore, the perfusion within necrotic part of tumor manifest lower than that of solid part (p＜0.05).Conclusion The CT perfusion parameters were associated with tumor size, stage, metastasis, and necrosis, likely due to better depiction of heterogeneity for tumor microcirculation in peripheral lung carcinoma. 64-row MDCT opens a rapid, easy, invasive, and more effective road of investigating neovascularization of lung carcinoma and hopefully impacts on detection of lung cancer mortality rates when early diagnosis of bronchogenic carcinoma is achieved. Purpose The process of tumor neoangiogenesis and neovascularization appears to play a central role in the growth and spread tumors. Dynamic contrast-enhanced MDCT is a noninvessive and feasible modality of evaluating tumor angiogenesis superior to conventional immunohistochemistry technique for microvessel density (MVD), which is not capable of assessing tumor angiogenensis in vivo. To our best knowledge, there has been no reported correlative study of perfusion patterns and neoangiogenesis in patients with lung carcinoma using 64-row MDCT. The aim of this study was to evaluate the correlation between 64-row MDCT perfusion parameters and tumor microvessel density (MVD) in peripheral lung carcinoma.Materials and Method Forty-tow patients (32M:10F, mean age 59.5±9.2 years) with surgically peripheral lung carcinoma were examined with 64-row MDCT (Philips Brilliance 64, Best Netherlands) and microvessel density count by immunohistochemistry. The tumors (1.8-5.0cm) included 26 adenocarcinmas, 11 squamous cell carcinomas, 3 large cell carcinomas and 2 adenosquamous carcinomas. The difference in CT values (△CT) was recorded. Data was analyzed using commercial software (Philips CT perfusion package) to generate perfusion, peak enhanced (PE), time to peak (TTP), and blood volume (BV). Tumor specimens were immunostained by using the treptomycin advinbiotin complex technique with monoclonal antibodies against CD34 which mainly expressed on small-vessel endothelial cells. A One-way ANOVA analysis of variance followed by LSD-t method of multiple comparisons was used to calculated variations in MVDs among groups. A Pearson correlation coefficient test was conducted to compare MVD with CT perfusion parameters as well as△CT.Results MVD of the 42 peripheral lung carcinoma was 45.7±18.6, ranged from 18.8 to 86.3. The mirovessel in lung carcinoma labeled by anti-CD34 represented single and small clusters of endothelial cells and it's distribution was uneven and heterogeneous which was classified into 3 types. MVD of adenocarcinoma, adenosquamous carcinoma, squamous cell carcinoma, and large cell carcinoma was 53.5±18.6(range 27.8-86.3), 38.5±3.5(range 35.8-40.8), 33.2±9.4(range 23.3-46.2) and 19.5±2.2(range 18.8-21.2), respectively. Differences of MVD among tumor histological types were statistically significant (p＜0.05). No significant difference was found between tumor grade with pathologic confirmation (p＞0.05). Considerable difference with high MVD (54.1±18.2, range30.8-86.3) was noted in tumor with pathologic conformed lymph node involvemen than in tumor without lymph node involvement (42.5±17.7, range18.8-78.3) (p＜0.05). With regard to necrosis, the mirovessel in lung carcinoma with intratumor necrosis was heterogeneous, which MVD (28.6±8.1, rangel 8.8-36.3) was lower than that of tumor without necrosis (52.6±17.5, range21.8-86.3) (p＜0.05). Perfusion, PE and BV were correlated positively with extend of microvessel density (r=0.716, 0.670, 0.765, respectively, all p＜0.05). However, no significant correlation was found between TTP and MVD (r=-0.076, p＞0.05). Associations were also found between△CT and perfusion, PE and BV (r=0.0.586, 0. 670, 0. 614, respectively, all p＜0.05) and MVD of lung carcinoma (r=0. 639, p＜0.05).Conclusion MVD was associated with tumor histological type, metastasis and necrosis. 64-row MDCT perfusion could be a valuable technique for evaluating tumor angiogenesis and hopefully complement the efforts in anti-angiogenesis therapy.