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Objective To analyze relevant clinical and dosimetric factors associated with radiation pneumonitis in patients with stage Ⅲ non-small cell lung cancer after they received radical radiotherapy.Methods A total of 126 patients with stage Ⅲ non-small cell lung cancer who received precision radiotherapy in Peking University Cancer Hospital were analyzed from January 2013 to December 2014.Data were collected including various clinical factors (including sex,age,histological type,tumor location,history of diabetes,history of hypertension,history of smoking,the season patients received treatment,ECOG performance status before treatment,chemotherapy before radiotherapy,concurrent chemotherapy and the classification of radiation pneumonitis),as well as related dosimetric parameters [including GTV,lung volume (LV),bilateral V5,V10,V20,V30 and MLD].SPSS 19.0 software was used to analyze the relation between correlation factors and radiation pneumonitis (RP≥2).Results Among the patients,31 cases (24.6％) had occurrance of radiation pneumonitis ≥ 2.Univariate analysis showed that age,ECOG performance status before treatment,concurrent chemotherapy and GTV/LV ratio were significantly correlated with RP ≥ 2 (R =0.157-0.222,P ＜ 0.05).Further multivariate Logistic regression showed that age,concurrent chemotherapy and GTV/LV ratio were significantly correlated (Wald =4.754,6.422,14.79,P ＜ 0.05).Conclusions In patients with stage Ⅲ non-small cell lung cancer after receiving thoracic radical radiotherapy,increasing age and GTV/LV ratio≥3.2％ are risk factors of RP≥2.The concurrent chemotherapy with low-dose paclitaxel might also increase the risk of RP≥2.
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Objective To investigate the correlations in target volumes based on positron emission tomography CT (PET/CT) and the end-expiration phase of four-dimensional CT (4D-CT) images for non-small cell lung cancer (NSCLC).Methods Seventeen patients with NSCLC sequentially underwent three-dimensional CT (3DCT),4D-CT and 18F-FDG PET/CT thoracic simulation scans.The gross target volume (GTV) was contoured on the end-expiration phase (50％) of 4D-CT and defined as GTV50％.The internal gross target volumes (IGTV) based on PET/CT images (IGTVPET) were determined by the standardized uptake value (SUV) 2.0 (IGTVPET2.0) and 20％ percentage of the maximal standardized uptake value (SUVmax) (IGTVPET20％).The following parameters were calculated to analyze the correlation between IGTVPET and GTV50％ in volume ratio (VR) and conformity index (CI):maximum transverse diameter of GTV50％,volume of GTV50％,the displacement of GTV in the cranial-caudal direction and 3D Vector calculated from 4D-CT dataset as well as the SUVmax.Results There was no significant correlation between the VR of IGTVPET2.0 to GTV50％ and the maximum transverse diameter of GTV50％,volume of GTV50％,the displacement of GTV in the cranial-caudal direction,3D Vector and the SUVmax (P ＞ 0.05).The VR between IGTVPET20％ and GTV50％ inversely related to maximum transverse diameter of GTV50％,volume of GTV50％ and SUVmax (r =-0.663,-0.669,-0.752,P ＜0.05).The CI between IGTVPET2.0 and GTV50％ positively related to volume of GTV50％ and maximum transverse diameter of GTV50％ (r =0.613,0.483,P ＜ 0.05).Conclusions 3D PET images provide a time-averaged image of the tumor during the numerous breathing cycle.They fail to include the full information of moving tumor.The target volumes based on 3D PET might not reflect the real IGTV of NSCLC.
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Objective To compare volumetric size, conformity index (CI), degree of inclusion (DI) of internal gross target volumes (IGTV) delineated on 4D-CT-MIP and PET-CT images for primary thoracic esophageal cancer. Methods Fifteen patients with thoracic esophageal cancer sequentially underwent enhanced 3D-CT, 4D-CT and PET-CT simulation scans. IGTVMIP was obtained by contouring on 4D-CT maximum intensity projection ( MIP). The PET contours were determined with nine different threshold methods (SUV≥2?0, 2?5, 3?0, 3?5), the percentages of the SUVmax(≥20%, 25%, 30%, 35%, 40%) and manual contours. The differences in size, conformity index (CI), degree of inclusion ( DI) of different volumes were compared. Results The volume ratios ( VRs) of IGTVPET2. 5 to IGTVMIP , IGTVPET20% to IGTVMIP, IGTVPETMAN to IGTVMIP were 0?86, 0?88, 1?06, respectively, which approached closest to 1. The CIs of IGTVPET2?0,IGTVPET2.5,IGTVPET20%,IGTVPETMAN and IGTVMIP which were 0?55, 0?56, 0?56, 0?54,0?55, respectively, were significantly larger than other CIs of IGTVPET and IGTVMIP (Z= -3?408-2?215,P 0?05). Conclusions The targets delineated based on SUV threshold setting of≥2?5, 20% of the SUVmax and manual contours on PET images correspond better with the target delineated on maximum intensity projection of 4D-CT images than other SUV thresholding methods.
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Objective To investigate the differences of measurement of gross target volume (GTV)between endoscopic ultrasonography ( EUS )-based ( GTVEUS ) and computed tomography ( CT ) -based (GTVCT) method for thoracic esophageal squamous cell carcinoma. Methods EUS was performed on 36consecutive patients with thoracic squamous cell carcinoma, and the superior and inferior boarders of the tumor defined by EUS were marked with hemoclips. The CT planning scan was then performed with the patient in supine position, and the GTVCT and GTVEUS were contoured respectively. The lengths ( LCT and LEUS) and spatial locations of longitudinal GTVCT and GTVEUS were compared. Results The mean LCT and LEUS were (7. 79 ± 3. 15 ) cm and (7. 42 ± 2. 72) cm, respectively ( t = 0. 82, P ＞ 0. 05 ), with a correlation coefficient of 0. 61 (P ＜0. 001 ). Locations of longitudinal GTVCT and GTVEUS were compared in 34cases, with 2 excluded for invisualization on CT. The mean conformal index (CI) was (0. 79 ± 0. 18 ), and spatial variations were found in 71% patients, with 8 patients at proximal end and 21 others at distal end.There was no clip placement associated complication. Conclusion Endoscopic hemoclips placement is safe and reliable. EUS can provide additional information to CT in defining longitudinal GTV in thoracic esophageal squamous cell carcinoma, especially in superficial and submucosal carcinomas.