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Objective To evaluate the efficacy and acute toxieities of postoperative intensity-modulated radiotherapy (IMRT) combined with concurrent (C-IMRCT) or sequential chemotherapy (S-IMRCT) in the treatment of high-risk early-stage cervical cancer.Methods A retrospective study was performed on the clinical data of 105 patients with high-risk early-stage (Ⅰ B1-Ⅱ A2) cervical cancer from 2009 to 2017.Those patients were divided into C-IMRCT group (n=73) and S-IMRCT group (n=32).The 5-year disease-free survival (DFS) and overall survival (OS) rates,recurrence rate,metastasis rate,and acute toxicities were compared between the two groups.The survival rates were calculated by the Kaplan-Meier method and analyzed by the log-rank test.Univariate prognostic analysis was performed by the log-rank test.Recurrence,metastasis,and adverse reactions were compared using continuous correction chi-square test.Results The median follow-up time was 20 and 23 months in the C-IMRCT group and the S-IMRCT group,respectively (P=0.813).There were no significant differences in the 5-year DFS and OS rates between the two groups (72.6％ vs.72.5％,P=0.918;82.8％ vs.78.5％,P=0.504).There were no significant differences in the recurrence and metastasis rates between the two groups (P=0.598;P=1.000).The univariate prognostic analysis showed that no pathological factor affected prognosis.There were no significant differences in the incidence rates of grade 1-2 hematological toxicity,diarrhea,and urinary tract infection between the two groups (46.6％ vs.41.9％,P=0.884;P=0.854;P=0.271).Conclusions Further clinical studies are needed in terms of the survival rate in patients with high-risk early-stage cervical cancer receiving C-IMRCT.
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Objective To investigate the effects of bone marrow(BM)-sparing pelvic intensity-modulated radiotherapy(IMRT)after surgery for cervical cancer on radiation dose to the target volume,organs at risk(OAR),and hematologic toxicity. Methods Ten patients with cervical cancer who would receive postoperative radiotherapy were selected.BM-sparing pelvic IMRT and conventional IMRT were performed for the same image by the Varian planning system. The radiation dose to the pelvis,the dose distribution of the target volume,and the radiation dose to OAR were compared between the two plans. A total of 30 patients with cervical cancer who had received postoperative radiotherapy were selected to investigate the relationships of the radiation dose to the pelvis with the lengths of the pelvis in coronal axis,sagittal axis,and vertical axis and the pelvic volume. A total of 41 patients with cervical cancer who would receive postoperative radiotherapy were randomly divided into observation group and control group. The observation group was given BM-sparing IMRT,while the control group was given conventional IMRT.The incidence of grade ≥2 hematologic toxicity was compared between the two groups and the relationship between the hematologic toxicity and the radiation dose to the pelvis was investigated. Results Both groups showed excellent dose coverage to the clinical target volume. There was no significant difference in radiation dose to the OAR between the two groups(all P>0.05).However,the observation group had significantly lower D mean,V 10,V 20,V 40,and V 50of the pelvis than the control group(P=0.003-0.045).The Pearson correlation analysis showed that D mean,V 20,V 30,V 40,and V 50of the pelvis were negatively correlated with the length of the pelvis in coronal axis(P=0.008-0.038).The observation group had a significantly lower incidence of hematologic toxicity than the control group(P=0.019).The logistic regression analysis showed that the development of hematologic toxicity was significantly associated with V 20of the pelvis (OR=1.191,P=0.042). Conclusions BM-sparing IMRT after surgery for cervical cancer can reduce the radiation dose to the pelvis and the incidence of blood toxicity. The radiation dose to the pelvis is negatively correlated with the length of the pelvis in coronal axis. The development of hematologic toxicity is associated with V 20of the pelvis.
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Objective To evaluate the dosimetric feasibility of three-dimensional(3D)intracavitary brachytherapy in combination with applicator-guided intensity-modulated radiation therapy(IMRT)boost for patients with locally advanced cervical cancer who have unfavorable topography following external beam irradiation. Methods A total of 7 patients with locally advanced cervical cancer who had unfavorable topography following external beam irradiation were included. Two plans were generated for brachytherapy using Oncentra 4.3 treatment planning system:3D intracavitary brachytherapy and 3D intracavitary brachytherapy in combination with applicator-guided IMRT boost.To further evaluate cumulative doses to organs at risk(OAR)in the four fractions of combined plans,two methods were used:simple dose-volume histograms(DVH)parameter addition and deformable image registration(DIR)-based DVH accumulation. The D90, V100, and conformity index(CI)were evaluated. The paired t-test or Wi1coxon signed rank test was used for statistical analysis. Results Compared with the 3D plan,the combined plan yielded higher D90, V100, and CI(P=0.000), but showed no significant difference in D2ccof the rectum,sigmoid colon,and bladder(P>0.05). There were also no significant differences in D2ccof the rectum, sigmoid colon, and bladder calculated by the two methods for calculating OAR cumulative doses, simple DVH parameter addition and DIR-based DVH accumulation(P>0.05). Conclusions For patients with cervical cancer who have unfavorable topography following external beam irradiation,3D intracavitary brachytherapy in combination with applicator-guided IMRT boost can improve target coverage and CI, without increasing OAR doses. DIR-based DVH accumulation and simple DVH parameter addition may be both acceptable for assessing OAR cumulative doses.
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Objective To investigate the changes in volume and spatial location of target areas and normal tissues before and during intensity?modulated radiotherapy (IMRT) for cervical cancer by quantitative means. Methods Forty patients with cervical cancer who were treated with IMRT were enrolled as subjects. Computed tomography ( CT) was performed before IMRT and during IMRT when a dose of 27 Gy ( 15 fractions) was reached. Clinicians delineated the target areas and organs at risk in the two groups of CT images. The target areas and organs at risk in one group of images were mapped to the other group of CT image by image registration using the Pinnacle treatment planning system. Volume changes in target areas and organs at risk were analyzed, and changes in the spatial location were evaluated by volume difference method and Dice similarity method. Comparison was made by paired t?test. Results There were significant differences in gross target volumes of primary tumor lesions ( GTV?T) and pelvic metastatic lymph nodes (GTV?N) before and during IMRT ( P= 0?? 000; P= 0?? 000). According to the evaluation by volume difference method, the average rate of change in GTV?T was (38.64±19?? 50)% with a range between 3?? 16%and 86?? 49%, while the average rate of change in GTV?N was (42.49± 25?? 68)% with a range between 2?? 79% and 87?? 42%. In the organs at risk, the bladder had the maximum rate of volume change, the average of which was (55.13±33?? 40)% with a range between 3?? 25% and 116?? 01%. According to the evaluation by Dice similarity method, the average Dice similarity coefficient for GTV?T was 0.50± 0?? 18 with a range between 0?? 10 and 0?? 85, while the average Dice similarity coefficient for GTV?N was 0.31±0?? 20 with a range between 0?? 00 and 0?? 71. The rectum had the minimum Dice coefficient in the organs at risk, the average of which was 0.57± 0?? 14 with a range between 0?? 18 and 0?? 76 . Conclusions For patients with cervical cancer to receive IMRT, since there are substantial changes in volume and spatial location of target areas and normal tissues before and during treatment, it is quite necessary to modify the treatment regimen in time in order to provide adequate doses for target areas and avoid overdose for organs at risk.
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ObjectiveTo investigate the anatomical changes and dose variation of rectum during radiotherapy in patients with cervical cancer.Methods Ten patients with cervical cancer underwent intensity-modulated radiotherapy using online cone beam computed tomography (CBCT) before each fraction.Rectum was contoured on each CBCT and projected onto the planning CT to analyze the changes of the rectal volume and position.The rectal volume receiving ≥ 45 Gy ( V45 ) was evaluated accordingly.Results227 CBCT images in 10 patients were collected.The rectal volume changed from ( 35.0 ± 7.3)cm3 to (97.7±14.7) cm3.The shift of rectal center was (0.14 ±0.06) cm in left and right direction,(0.24±0.10) cm in anterior and posterior direction,and (0.55±0.28) cm in superior and inferior direction.The V45 of rectum varied from (9.19±2.46)％ to (60.54 ±11.67)％.In7 of the 10 patients,rectal volume and V45 of the rectum had significant positive correlation (r =0.582 - 0.743,all P ＜ 0.01 ).Among the 227 images,the V45 of rectum was ≤50％ in 68 images (30.0％ ).ConclusionsSignificant changes in rectal volume and position occurred during fractionated radiotherapy in patients with cervical cancer,which resuhs in variations in the dose rectum received.For most patients,rectal volume and the V45of rectum had significant positive correlation.
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Objective To investigate bladder anatomical changes and dose variation in patients with cervical cancer.Methods We analyzed 20 patients,undergoing external beam radiotherapy scanning cone beam CT(CBCT)before each fraction.Bladder was contoured on each CBCT,was projected onto the planning CT and assesses anatomical changes and dose variation.Results A total 451 CBCT images,for 20 patients were collected for analysis,show more change in bladder volume and position.In 15 cases bladder volume and V45 had no significant correlation(r=0.225 -0.473,all P>0.05),4 cases shows negative correlation(r=-0.564,P<0.05;r=-0.597,P<0.01;r=-0.942,P<0.01;r=-0.816,P<0.01),1 case shows positive correlation(r=0.662,P<0.01).Have more than the criteria(V45≤50%)number is 64/451(14.2%)in whole treatment.Conclusions For most patients by filling adequacy bladder,bladder dose variation is acceptable:CTV lager for individual patients should be closely observed its regression,implementation of the offline or online calibration.