ABSTRACT
Objective To compare the efficacy and toxicities between preoperative concomitant boost intensity-modulated radiotherapy (IMRT) and 3-dimensional conformal RT (3-DCRT) for locally advanced rectal cancer.Methods A prospective study from May 2010 to May 2015.A total of 130 patients with histologically confirmed,newly diagnosed,locally advanced rectal adenocarcinoma (cT3-T4 and/or cN +) located within 10 cm from the anal verge were included in this study.The patients were divided into IMRT and 3D-CRT groups by random number table method.Sixty-six patients were treated with IMRT,and the other sixty-four patients were treated with 3-DCRT.In the IMRT group,the prescription dose was 1.8 Gy/fraction to 45 Gy to the pelvis and 2.2 Gy/fraction to 55 Gy to the gross tumor volume simultaneously.The 3D-CRT prescription was 45 Gy in 25 fractions to the pelvis.Capecitabine (1 650 mg· m 2 · d-1) was given twice daily from days 1 to 14 and days 22 to 35 during RT in both arms.Total mesorectal excision (TME) was scheduled 6-8 weeks after the completion of chemoradiation.Results There were no significant differences in age,gender,tumor location,pathological differentiation degree and clinical stage between the two groups.Two patients withdrew from the study:one for grade 3 radiation dermatitis in IMRT group and the other for grade 3 fatigue in 3D-CRT.There was no significant difference in hematologic or nonhematologic toxicities between the two groups.No grade 4 or 5 toxicity was observed in either group.Compared with conformal radiotherapy,IMRT did not increase the difficulty of surgery.No significant difference was found in type of surgery or postoperative complications between the two groups.The rate of tumor regression grade (TRG) 4 (pathologic complete response,pCR) was 22.7％ for IMRT and 15.6％ for 3D-CRT,respectively(P ＞ 0.05).The rate of both TRG4 and 3 was 42.4％ for IMRT and 25.0％ for 3D-CRT,respectively (x2 =4.406,P=0.036).Conclusions Neoadjuvant concomitant boost IMRT is feasible and has a higher histopathological regression for patients with locally advanced rectal cancer.Trial registration Chinese clinical trial registry,ChiCTR-IN R-16008004.
ABSTRACT
Objective To investigate the normal position and configuration of anterior mediastinum.Methods Chest CT scanning was performed in 100 healthy volunteers. Various parameters of the anterior mediastinum were measured, including position (shift distance from medial line of the body),frontal and retral width, and anterioposterior dimension.Results The normal range (with the limit of 95%) of the anterior mediastinum included: the position was shifted 5 mm to right and 15 mm to left, the frontal width was under 30 mm in both man and woman, the posterior width was under 40 mm in woman, and under 50 mm in man, the anterioposterior diameter was under 30 mm in woman and under 35 mm in man.Conclusion The normal region about position and configuration of the anterior mediastinum is established in this study. These data will helpful in detecting the subtle mediastinal shift or other abnormal situation affected the mediastinum.