ABSTRACT
Objective To investigate the change in body weight over time in rectal cancer patients receiving radiotherapy and the correlation between setup errors and weight loss,and to establish the image-guided radiotherapy regimens in different periods of treatment.Methods A total of 24 postoperative patients with rectal cancer admitted to our hospital in 2016 were selected.Before each fraction of radiotherapy,the body weight was recorded,and the patients underwent cone-beam computed tomography (CBCT) with different frequencies in every week.The planning CT was matched with CBCT to obtain setup errors.The paired t test was used for difference analysis;the Pearson method was used to analyze the correlation between setup errors and weight loss.Results Body weight was measured 456 times in the 24 patients,and these patients underwent CBCT scans and image registration 456 times.Two patients were excluded because of treatment discontinuance.In the first and second weeks,there was no significant change in body weight.In the third week,the mean weight loss was 1.53 kg.In the fourth week,the mean weight loss was 2.48 kg.In the fifth week,the mean weight loss was 3.24 kg.The setup errors obtained by CBCT image registration in the superior-inferior (SI),anterior-posterior (AP),and left-right (LR) directions were 0.19 cm,0.20 cm,and 0.18 cm,respectively,in the first week,0.18 cm,0.17 cm,and 0.15 cm,respectively,in the second week,0.20 cm,0.22 cm,and 0.21 cm,respectively,in the third week,0.19 cm,0.25 cm,0.24 cm,respectively,in the fourth week,and 0.34 cm,0.33 cm,and 0.31 cm,respectively,in the fifth week.The Pearson correlation analysis showed that weight loss increased the setup errors,with P values of 0.140,0.046,and 0.044 in the SI,AP,and LR directions,respectively.Conclusions For rectal cancer patients receiving radiotherapy,the body weight decreases significantly in the late period (especially in the fifth week),which influences the setup errors.Therefore,in the fourth and fifth weeks of radiotherapy for rectal cancer,the weight loss should be closely monitored,and the number of CBCT scans can be increased before the treatment fraction to ensure the accuracy and optimization of treatment.
ABSTRACT
Objective To evaluate the effect of tumor infiltrating lymphocyte(TIL) on prognosis of rectal cancer treated with preoperative radiotherapy. Methods From Jan. 1999 to Oct. 2007,107 patients with rectal cancer were treated with preoperative radiotherapy of 30 Gy/10f/12 days. The relationships a-mong TIL,pathologic regression and prognosis were analyzed. Results Before radiotherapy,TIL in rectal cancer was 75 patients (70.1%) in grade 1,16 (15.0%) in grade 2 and 16 (15.0%) in grade 3; While after radiotherapy,it changed to 19 (17.7 %) in grade 1,43 (40.2%) in grade 2,35 (32.7 %) in grade 3 and 10 (9.3%) in grade 4. After radiotherapy,pathologic regression was 36 (33.6%) in grade 1,57 (53.3%) in grade 2 and 14 (13.1%) in grade 3. Univariate analysis showed that TIL both before and after radiotherapy was the significant prognostic factor for local pathologic regression (X2= 36.80, P < 0.01; X<'2>= 14.00, P<0.01). Kaplan Meier survival analysis showed that TIL and pathologic regression after radiother-apy were significant associated with the survival(X2=24.00, P < 0.01; X2=12.17, P<0.01 ). Logistic re-gression showed that TIL after radiotherapy had a significant effect on local pathologic regression(X2=8.05, P<0.01). Conclusions For rectal cancer treated with preoperative radiotherapy,TIL before and after ra-diotherapy is significantly related with local pathologic regression, and TIL after radiotherapy is a prognostic factor.