Postoperative chemoradiotherapy with capecitabine and oxaliplatin vs.capecitabine for pathological stage N2 rectal cancer

Objective:Several studies have been conducted on the effects and toxicity of adding oxaliplatin to fluorouracilbased or capecitabine-based chemoradiotherapy(CRT)regimens as significantly increasing the toxic response without benefit to survival.In this study,we further explored the role of these two postoperative CRT regimens in patients with pathological stage N2 rectal cancer.Methods:This study was a subgroup analysis of a randomized clinical trial.A total of 180 patients with pathological stage N2 rectal cancer were eligible,85 received capecitabine with radiotherapy(RT),and 95 received capecitabine and oxaliplatin with RT.Patients in both groups received adjuvant chemotherapy[capecitabine and oxaliplatin(XELOX);or fluorouracil,leucovorin,and oxaliplatin(FOLFOX)]after CRT.Results:At a median follow-up of 59.2[interquartile range(IQR),34.0−96.8]months,the three-year diseasefree survival(DFS)was 53.3%and 64.9%in the control group and the experimental group,respectively[hazard ratio(HR),0.63;95%confidence interval(95%CI),0.41−0.98;P=0.04].There was no significant difference between the groups in overall survival(OS)(HR,0.62;95%CI,0.37−1.05;P=0.07),the incidence of locoregional recurrence(HR,0.62;95%CI,0.24−1.64;P=0.33),the incidence of distant metastasis(HR,0.67;95%CI,0.42−1.06;P=0.09)and grade 3−4 acute toxicities(P=0.78).For patients with survival longer than 3 years,the conditional overall survival(COS)was significantly better in the experimental group(HR,0.39;95%CI,0.16−0.96;P=0.03).Conclusions:Our results indicated that adding oxaliplatin to capecitabine-based postoperative CRT is safe and effective in patients with pathological stage N2 rectal cancer.

Dosimetric study of five-field intensity-modulated radiotherapy compared with conventional three-dimensional conformal radiotherapy for rectal cancer

Objective： The aim of the study was to compare the difference of dose distribution in clinical target volume and organ at risk （OAR） between five-field intensity-modulated radiotherapy （IMRT） and conventional three-dimensional conformal radiotherapy （3DCRT） in the radiotherapy of rectal cancer. Methods： Fifteen patients with rectal cancer treated with radio- therapy （RT） were retrospectively analyzed. Among the patients, seven received RT preoperatively and 8 postoperatively. The target volume and the OARs such as the small bowel, bladder and femoral heads were contoured for each patient. 3DCRT-plan and IMRT-plan were performed for each patient respectively, with the prescribed dose covering at least 95% of the planning target volume （PTV）. The conformity index （CI） and homogeneity index （HI） were used for evaluation of the dose distribution in the target volume, and the Dx% （the lowest dose to the x% volume of the OARs that received the highest dose of irradiation） and the mean dose were used for evaluation of the dose to OARs. Paired-T test was used for companson of the difference between the two plans. Results： In the IMRT-plan and 3DCRT-plan, the CI were 0.94 and 0.87 （P = 0.000） and the HI were 1.13 and 1.17, respectively （P = 0.001）. For small bowel, the D30%, D50% and the mean dose were 19.67 Gy, 15.13 Gy and 18.81 Gy in the IMRT-plan and 25.20 Gy, 22.20 Gy and 22.89 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For bladder, the D30%, D50%, and the mean dose were 24.80 Gy, 34.20 Gy and 28.70 Gy in the IMRT- plan, and 35.07 Gy, 44.67 Gy and 35.68 Gy in the 3DCRT-plan, respectively （P 〈 0.001 for all pairs of parameters）. For femoral heads, the D5% in the IMRT-plan and 3DCRT-plan were 40.6 Gy and 40.47 Gy, respectively （P = 0.936）, and the mean dose were 30.14 Gy and 25.57 Gy, respectively （P = 0.001）. Conclusion： Five-field IMRT-plan is better than 3DCRT-plan in the conformity and the dose homogeneity within target volume and also better in sparing the small bowel and bladder.

Dosimetric analysis of tomotherapy-based intensity-modulated radiotherapy with and without bone marrow sparing for the treatment of cervical cancer

Objective The aim of the study was to compare tomotherapy-based bone marrow-sparing intensity-mod- ulated radiotherapy （BMS-IMRT） with intensity-modulated radiotherapy （IMRT） without entering the pelvic bone marrow as a planning constraint in the treatment of cervical cancer after hysterectomy. Methods BMS-IMRT and IMRT plans were designed for a cohort of nine patients. The prescribed dose was 45 Gy in 1.8 Gy daily fractions, and 95% of the planned target volume received this dose. The doses were computed using a commercially available treatment planning system with the convolution/superposition algorithm. Plans were compared according to dose-volume histogram analysis in terms of planning target volume homogeneity and conformity indices （HI and CI） as well as organ at risk dose and volume parameters. Results BMS-IMRT had advantages over IMRT in terms of CI, but was equivalent to the latter in H1. V5, V10, V20, V30, and V40 of pelvic bone marrow in BMS-IMRT decreased by 0.06%, 17.33%, 22.19%, 13.85%, and 16.46%, respectively, compared with IMRT. Except for V30 of the small bowel and V30 and V40 of the bladder, no statistically significant differences were found between BMS-IMRT and IMRT in the small bowel, bladder, and rectum. Conclusion For cervical cancer patients receiving tomotherapy-based radiotherapy after hysterectomy, BMS-IMRT reduced pelvic bone marrow volume receiving low-dose radiation, and it may be conducive to preventing acute hematologic toxicity.

Three-dimensional conformal radiotherapy combined with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer

AIM： To investigate the effect of three-dimensional conformal radiotherapy （3-DCRT） in combination with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer. METHODS： Forty-eight patients with unresectable recurrent rectal cancer were randomized and treated by 3-DCRT or 3-DCRT combined with FOLFOX4 chemotherapy between September 2001 and October 2003. For the patients without prior radiation history, the initial radiation was given to the whole pelvis by traditional methods with tumor dose of 40 Gy, followed by 3-DCRT for the recurrent lesions to the median total cumulative tumor dose of 60 Gy （range 56-66 Gy）; for the post-radiation recurrent patients, 3-DCRT was directly given for the recurrent lesions to the median tumor dose of 40 Gy （36-46 Gy）. For patients in the study group, two cycles chemotherapy with FOLFOX4 regimen were given concurrently with radiotherapy, with the first cycle given simultaneously with the initiation of radiation and the second cycle given in the fifth week for patients receiving conventional pelvis radiation or given in the last week of 3-DCRT for patients receiving 3-DCRT directly. Another 2-4 cycles （average 3.6 cycles） sequential FOLFOX4 regimen chemotherapy were given to the patients in the study group, beginning at 2-3 wk after chemoradiation. The outcomes of symptoms relieve, tumor response, survival and toxicity were recorded and compared between the study group and the control group. RESULTS： For the study group and the control group, the pain-alleviation rates were 95.2% and 91.3%（P〉 0.05）; the overall response rates were 56.5% and 40.0% （P〉0.05）; the 1-year and 2-year survival rates were 86.9%, 50.2% and 80.0%, 23.9%, with median survival time of 25 mo and 16 mo （P〈 0.05）; the 2-year distant metastasis rates were 39.1% and 56.0% （P= 0.054）, respectively. The side effects, except peripheral neuropathy which was relatively severer in the study group, were similar in the the two groups and well tolerated. CONCLUSION： Three-dimensional conformal radiotherapy combined with FOLFOX4 chemotherapy for unresectable recurrent rectal cancer is a feasible and effective therapeutic approach, and can reduce distant metastasis rate and improve the survival rate.

Advances in radiotherapy and targeted therapies for rectal cancer

The last decade witnessed a significant progress in understanding the biology and immunology of colorectal cancer alongside with the technical innovations in radiotherapy.The stepwise implementation of intensitymodulated and image-guided radiation therapy by means of megavolt computed tomography and helical tomotherapy enabled us to anatomically sculpt dose delivery,reducing treatment related toxicity.In addition,the administration of a simultaneous integrated boost offers excellent local control rates.The novel challenge is the development of treatment strategies for medically inoperable patient and organ preserving approaches.However,distant control remains unsatisfactory and indicates an urgent need for biomarkers that predict the risk of tumor spread.The expected benefit of target?ed therapies that exploit the tumor genome alone is so far hindered by high cost techniques and pharmaceuticals,hence hardly justifying rather modest improvements in patient outcomes.On the other hand,the immune landscape of colorectal cancer is now better clarified with regard to the immunosuppressive network that promotes immune escape.Both N2 neutrophils and myeloid-derived suppressor cells(MDSC)emerge as useful clinical biomarkers of poor prognosis,while the growing list of anti-MDSC agents shows promising ability to boost antitumor T-cell immunity in preclinical settings.Therefore,integration of genetic and immune biomarkers is the next logical step towards effective targeted therapies in the context of personalized cancer treatment.

Usefulness of two independent hist classifications of tumor regression iUsefulness of two independent histopathological classifications of tumor regression in patients with rectal cancer submitted to hyperfractionated pre-operative radiotherapy

AIM： To assess the usefulness of two independent histopathological classifications of rectal cancer regression following neo-adjuvant therapy. METHODS： Forty patients at the initial stage cT3NxM0 submitted to preoperative radiotherapy （42 Gy during 18 d） and then to radical surgical treatment. The relationship between ＂T-downstaging＂ versus regressive changes expressed by tumor regression grade （TRG 1-5） and Nasierowska-Guttmejer classification （NG 1-3） was studied as well as the relationship between TRG and NG versus local tumor stage ypT and lymph nodes status, ypN. RESULTS： Complete regression （ypT0, TRG 1） was found in one patient. ＂T-downstaging＂ was observed in 11 （27.5%） patients. There was a weak statistical significance of the relationship between ＂T-downstaging＂ and TRG staging and NG stage. Patients with ypT1 were diagnosed as TRG 2-3 while those with ypT3 as TRGS. No lymph node metastases were found in patients with TRG 1-2. None of the patients without lymph node metastases were diagnosed as TRG 5. Patients in the ypT1 stage were NG 1-2. No lymph node metastases were found in NG 1. There was a significant correlation between TRG and NG. CONCLUSION： Histopathological classifications may be useful in the monitoring of the effects of hyperfractionated preoperative radiotherapy in patients with rectal cancer at the stage of cT3NxM0. There is no unequivocal relationship between ＂Todownstaging＂ and TRG and NG. There is some concordance in the assessment of lymph node status with ypT, TRG and NG. TRG and NG are of limited value for the risk assessment of the lymph node involvement.

Neoadjuvant radiotherapy dose escalation for locally advanced rectal cancers in the new era of radiotherapy:A review of literature

BACKGROUND The standard treatment of locally advanced rectal cancers(LARC)consists on neoadjuvant chemoradiotherapy followed by total mesorectal excision.Different data in literature showed a benefit on tumor downstaging and pathological complete response(pCR)rate using radiotherapy dose escalation,however there is shortage of studies regarding dose escalation using the innovative techniques for LARC(T3-4 or N1-2).AIM To analyze the role of neoadjuvant radiotherapy dose escalation for LARC using innovative radiotherapy techniques.METHODS In December 2020,we conducted a comprehensive literature search of the following electronic databases:PubMed,Web of Science,Scopus and Cochrane library.The limit period of research included articles published from January 2009 to December 2020.Screening by title and abstract was carried out to identify only studies using radiation doses equivalent dose 2 Gy fraction(EQD2)≥54 Gy and Volumetric Modulated Arc Therapy(VMAT),intensity-modulated radiotherapy or image-guided radiotherapy(IGRT)techniques.The authors’searches generated a total of 2287 results and,according to PRISMA Group(2009)screening process,21 publications fulfil selection criteria and were included for the review.RESULTS The main radiotherapy technique used consisted in VMAT and IGRT modality.The mainly dose prescription was 55 Gy to high risk volume and 45 Gy as prophylactic volume in 25 fractions given with simultaneous integrated boosts technique(42.85%).The mean pCR was 28.2%with no correlation between dose prescribed and response rates(P value≥0.5).The R0 margins and sphincter preservation rates were 98.88%and 76.03%,respectively.After a mean follow-up of 35 months local control was 92.29%.G3 or higher toxicity was 11.06%with no correlation between dose prescription and toxicities.Patients receiving EQD2 dose>58.9 Gy and BED>70.7 Gy had higher surgical complications rates compared to other group(P value=0.047).CONCLUSION Dose escalation neoadjuvant radiotherapy using innovative techniques is safe for LARC achieving higher rates of pCR.EQD2 doses>58.9 Gy is associated with higher rate of surgical complications.

Modified simultaneous integrated boost radiotherapy for an unresectable huge refractory pelvic tumor diagnosed as a rectal adenocarcinoma

A clinical trial of radiotherapy with modified simultaneous integrated boost(SIB)technique against huge tumors was conducted.A 58-year-old male patient who had a huge pelvic tumor diagnosed as a rectal adenocarcinoma due to familial adenomatous polyposis was enrolled in this trial.The total dose of 77 Gy(equivalent dose in 2Gy/fraction)and 64.5 Gy was delivered to the center of the tumor and the surrounding area respectively,andapproximately 20%dose escalation was achieved with the modified SIB technique.The tumor with an initial maximum size of 15 cm disappeared 120 d after the start of the radiotherapy.Performance status of the patient improved from 4 to 0.Radiotherapy with modified SIB may be effective for patients with a huge tumor in terms of tumor shrinkage/disappearance,improvement of QOL,and prolongation of survival.

The impact of artificial intelligence-assisted intensity-modulated radiotherapy plan optimization on the radiation doses received by the rectum and bladder as well as radiation-induced injuries in patients with locally advanced cervical cancer

This study aimed to investigate the impact of artificial intelligence-assisted intensity-modulated radiotherapy(IMRT)plan optimization on the radiation doses received by the rectum and bladder as well as radiation-induced injuries in patients with locally advanced cervical cancer.A total of 100 patients with locally advanced cervical cancer were enrolled and divided into a conventional IMRT group and an artificial intelligence-assisted IMRT group.The results showed that in terms of the radiation doses to the rectum and bladder,all dosimetric parameters(such as mean dose,maximum dose,and volume-dose parameters,etc.)in the artificial intelligence-assisted group were significantly lower than those in the conventional group(p<0.05).Regarding radiation-induced injuries,the incidences and severities of both acute and late radiation-induced proctitis and cystitis in the artificial intelligence-assisted group were lower than those in the conventional group(p<0.05).These findings suggest that artificial intelligence-assisted IMRT plan optimization can effectively reduce the radiation doses to the rectum and bladder and decrease radiation-induced injuries in patients with locally advanced cervical cancer,which is expected to provide a more precise and safer treatment strategy for radiotherapy of locally advanced cervical cancer.However,this study has limitations such as a limited sample size and being a single-center study.Future research with multi-center,large-sample,and more in-depth investigations is needed.

Down-staging depth score to predict outcomes in locally advanced rectal cancer achieving ypl stage after neoadjuvant chemo-radiotherapy versus de novo stage pl cohort:A propensity score-matched analysis

Objective：Prognosis of patients with locally advanced rectal cancer（LARC）but achieving yp T1–2N0 stage after neoadjuvant concurrent chemo-radiotherapy（CRT）has been shown to be favorable.This study aims to determine whether the long-term outcome of yp T1–2N0 cases can be comparable to that of p T1–2N0 cohort that received definitive surgery for early disease.Method：From January 2008 to December 2013,449 consecutive patients with rectal cancer were treated and their outcome maintained in a database.Patients with LARC underwent total mesorectal excision（TME）surgery at4–8 weeks after completion of CRT,and those achieving stage yp I were identified as a group.As a comparison,stage p I group pertains to patients whose initially limited disease was not upstaged after TME surgery alone.After propensity score matching（PSM）,comparisons of local regional control（LC）,distant metastasis-free survival（DMFS）,disease-free survival（DFS）and overall survival（OS）were performed using Kaplan-Meier analysis and log-rank test between yp I and p I groups.Down-staging depth score（DDS）,a novel method of evaluating CRT response,was used for subset analysis.Results：Of the 449 patients,168 matched cases were generated for analysis.Five-year LC,DMFS,DFS and OS for stage p I vs.yp I groups were 96.7%vs.96.4%（P=0.796）,92.7%vs.73.6%（P=0.025）,91.2%vs.73.6%（P=0.080）and 93.1%vs.72.3%（P=0.040）,respectively.In the DDS-favorable subset of the yp I group,LC,DMFS,DFS and OS resulted in no significant differences in comparison with the p I group（P=0.384,0.368,0.277 and0.458,respectively）.Conclusions：LC was comparable in both groups;however,distant metastasis developed more frequently in down-staged LARC than de novo early stage cases,reflecting the need to improve the efficacy of systemic treatment despite excellent pathologic response.DDS can be an indicator to identify a subset of the yp I group whose longterm oncologic outcomes are as good as those of stage p I cohort.

The clinical observation of three-dimensional conformal radiotherapy combined with FOLFOX chemotherapy for rectal cancer of postoperative local recurrence

Objective The aim of this study was to explore the three-dimensional conformal radiotherapy combined with FOLFOX scheme chemotherapy in the treatment of postoperative recurrence of rectal cancer.

多参数MRI纹理分析预测直肠癌患者放射治疗后早期股骨头坏死

目的 探讨多参数MRI(mpMRI)纹理分析预测直肠癌患者放射治疗(放疗)后早期股骨头坏死(FHN)的价值。方法 回顾性分析52例接受盆腔放疗直肠癌患者放疗前2周及放疗后3个月内的盆腔MRI,其中31例未见FHN,21例出现早期FHN(Ⅰ期16例,Ⅱ期5例)。采用3D-slicer软件基于T1WI、T2WI和弥散加权成像(DWI)分割右侧股骨头,并提取其纹理参数;对比放疗前后纹理参数,将差异有统计学意义的放疗前参数纳入多因素logistic回归分析,建立模型T1WI、模型T2WI、模型DWI及模型T1WI+T2WI+DWI。根据放疗后影像学所见行股骨头坏死骨循环研究协会(ARCO)分期,以受试者工作特征(ROC)曲线分析单一纹理参数及联合模型预测直肠癌患者放疗后早期FHN的效能。结果 T1WI及T2WI纹理参数中,放疗前股骨头能量及均匀性高于放疗后;DWI纹理参数中,放疗前股骨头能量高于、而长行程高灰度强调及短行程高灰度强调低于放疗后。上述放疗前纹理参数单一预测直肠癌患者放疗后早期FHN的曲线下面积(AUC)为0.581~0.712,模型T1WI、模型T2WI、模型DWI和模型T1WI+T2WI+DWI的AUC分别为0.660、0.713、0.770和0.853。结论 mpMRI纹理分析可有效预测直肠癌患者放疗后早期FHN。

真空垫联合CIVCO俯卧位托架在直肠癌放疗摆位中的应用

目的:改进CIVCO俯卧位托架在直肠癌中应用方法,探究真空垫与CIVCO俯卧位托架联合使用(改进型固定组A)与单独使用CIVCO俯卧位托架(一般型固定组B)摆位误差差异,制定真空垫固定下肢流程与要求。方法:基于CBCT(cone beam CT),采集摆位误差数据,回顾性选取2021年10月至2023年4月行俯卧位直肠癌放射治疗患者。改进型固定组32例,一般型固定组32例;两组中又以BMI(body mass index):24 kg/m^(2)为分界值进行亚组分类(肥胖体态A_(1)、B_(1),普通体态A_(2)、B_(2))。通过统计学方法两独立样本t检验,分别比较两组患者在X(lateral,LAT)、Y(length,LNG)、Z(vertal,VRT)三方向摆位误差均值差异;比较亚组间在X、Y、Z三方向摆位误差均值差异。采用秩和检验比较两组三维空间矢量误差差异;卡方检验展示三维空间矢量误差>0.52 cm占比。采用单因素方差分析探究改进型固定组与放疗摆位时间关系,经事后分析各方向误差均值变化趋势。根据PTV边界公式评估改进型固定在俯卧位直肠癌放射治疗临床应用价值。结果:两组摆位误差均值t检验结果:X(t=2.404,P=0.017),Y(t=4.864,P<0.05),Z(t=3.704,P<0.05),三方向误差均值差异有统计学意义。三维空间矢量误差分析结果:改进型固定组0.35(0.25~0.42)cm,一般型固定组0.42(0.29~0.61)cm(Z=-5.783,P<0.05);其中改进型固定组Δ>0.52 cm占比8.7%,一般型固定组Δ>0.52 cm占比28.2%(Z=-5.718,χ^(2)=32.757,P<0.05),差异具有统计学意义,改进型固定组患者其三位空间矢量误差漂移范围更小。两组在X、Y、Z三方向PTV外放值M PTV分别为A(0.51,0.49,0.58)cm,B(0.73,0.92,0.83)cm。基于BMI指数:在A组中误差均值差异X(t=-2.053,P=0.042),Y(t=-4.621,P<0.05),Z(t=-3.676,P<0.05)差异具有统计学意义;在A、B两组肥胖患者中误差均值差异仅发现在Z(t=3.431,P=0.002)差异具有统计学意义,X(t=1.170,P=0.244),Y(t=1.969,P=0.051)差异无统计学意义。在A、B两组普通BMI患者比较中X(t=-2.39,P=0.017),Y(t=-5.734,P<0.05)和Z(t=-2.722,P=0.007)差异有统计学意义。对改进型固定组单因素方差分析,各时段摆位误差均值组间两两比较仅在Y(F=5.951,P<0.05)、Z(F=3.155,P=0.015)方向上不同摆位时期误差均值差异有统计学意义,且第1周摆位误差均值差异大于其他几周(P<0.05)。X(F=0.625,P=0.645)方向上随摆位时间推移误差均值无显著差异。结论:经综合评估真空垫与CIVCO俯卧位托架联合使用对直肠癌俯卧位放疗摆位误差改善总体效果优于单纯使用俯卧位托架,但是改进型固定方式对肥胖患者摆位误差改善仍不甚满意。改进型固定组在全疗程放射治疗过程中,第1周在Y和Z方向上误差较大,相较于第一周治疗随着时间推移Y、Z方向误差整体变小,除第一周之外的其他治疗时段误差是无差异的。摆位可重复性稳定。

Role of dynamic perfusion magnetic resonance imaging in patients with local advanced rectal cancer

BACKGROUND The management of rectal cancer patients is mainly based on the use of the magnetic resonance imaging(MRI)technique as a diagnostic tool for both staging and restaging.After treatment,to date,the evaluation of complete response is based on the histopathology assessment by using different tumor regression grade(TRG)features(e.g.,Dworak or Mandard classifications).While from the radiological point of view,the main attention for the prediction of a complete response after chemotherapy treatment focuses on MRI and the potential role of diffusion-weighted images and perfusion imaging represented by dynamiccontrast enhanced MRI.The main aim is to find a reliable tool to predict tumor response in comparison to histopathologic findings.AIM To investigate the value of dynamic contrast-enhanced perfusion-MRI parameters in the evaluation of the healthy rectal wall and tumor response to chemo-radiation therapy in patients with local advanced rectal cancer with histopathologic correlation.METHODS Twenty-eight patients with biopsy-proven rectal adenocarcinoma who underwent a dynamic contrast-enhanced MR study performed on a 1.5 T MRI system(Achieva,Philips),before(MR1)and after chemoradiation therapy(MR2),were enrolled in this study.The protocol included T1 gadolinium enhanced THRIVE sequences acquired on axial planes.A dedicated workstation was used to generate color permeability maps.Region of interest was manually drawn on tumor tissue and normal rectal wall,hence the following parameters were calculated and statistically analyzed:Relative arterial enhancement(RAE),relative venous enhancement(RVE),relative late enhancement(RLE),maximum enhancement(ME),time to peak and area under the curve(AUC).Perfusion parameters were related to pathologic TRG(Mandard’s criteria;TRG1=complete regression,TRG5=no regression).RESULTS Ten tumors(36%)showed complete or subtotal regression(TRG1-2)at histology and classified as responders;18 tumors(64%)were classified as non-responders(TRG3-5).Perfusion MRI parameters were significantly higher in the tumor tissue than in the healthy tissue in MR1(P<0.05).At baseline(MR1),no significant difference in perfusion parameters was found between responders and nonresponders.After chemo-radiation therapy,at MR2,responders showed significantly(P<0.05)lower perfusion values[RAE(%)54±20;RVE(%)73±24;RLE(%):82±29;ME(%):904±429]compared to non-responders[RAE(%):129±45;RVE(%):154±39;RLE(%):164±35;ME(%):1714±427].Moreover,in responders group perfusion values decreased significantly at MR2[RAE(%):54±20;RVE(%):73±24;RLE(%):82±29;ME(%):904±429]compared to the corresponding perfusion values at MR1[RAE(%):115±21;RVE(%):119±21;RLE(%):111±74;ME(%):1060±325];(P<0.05).Concerning the time-intensity curves,the AUC at MR2 showed significant difference(P=0.03)between responders and non-responders[AUC(mm2×10-3)121±50 vs 258±86],with lower AUC values of the tumor tissue in responders compared to nonresponders.In non-responders,there were no significant differences between perfusion values at MR1 and MR2.CONCLUSION Dynamic contrast perfusion-MRI analysis represents a complementary diagnostic tool for identifying vascularity characteristics of tumor tissue in local advanced rectal cancer,useful in the assessment of treatment response.

A study evaluating the impact of nerve preserving surgery and adjuvant pelvic irradiation for rectal cancer on quality of life

Objective： Preservation of the pelvic autonomic nerves in order to lower bladder and sexual dysfunction after radical rectal cancer surgery ＆ to evaluate functional outcome, local recurrence. Methods： A prospective study was under- taken on Egyptian patients. Forty one patients participated in the study in the period from December 2002 till June 2004 where they underwent radical surgery but with preservation of the pelvic autonomic nerves this was followed by adjuvant pelvic radiotherapy. Results： Six months, 1-year and 2-year follow-up of urinary function was complete in 32 out of 41 （78%）, 30 out of 41 （73%） and 27 out of 41 patients （65%） respectively There was no statistically significant correlation between the extent of nerve preservation and the reported minor voiding dysfunction. None of the patients reported major incontinence. Six months, 1-year and 2-year follow-up of sexual function revealed that 22 out of 41 patients （53%） were sexually active. Three out of 41 patients （7.3%） developed local recurrence. 38 （92.7%） patients were free of local recurrence, regarding pa- tients who received adjuvant radiotherapy 3 out of the 34 （8.8%） patients developed local pelvic recurrence while 9 patients （26.5%） developed distant metastases （3 of them did not receive adjuvant chemotherapy）, while patients who received adju- vant chemotherapy, 2 out of 20 patients （10%） developed local recurrence while distant metastases developed in 6 patients （30%）. Conclusion： Preservation of the pelvic autonomic nerves minimizes bladder and sexual dysfunction especially in male patients after rectal cancer surgery.

引入靶区外扩预测放射治疗中危及器官自动分割的平均剂量偏差

目的观察引入靶区外扩预测放射治疗(放疗)中自动分割危及器官(OAR)的平均剂量偏差的价值。方法将100例接受放疗的直肠癌患者随机分为训练集(n=30)和测试集(n=70)。对训练集手动分割CT图中的靶区,之后分别对膀胱、小肠和双侧股骨头4个OAR进行手动和自动分割。根据自动分割的OAR设计放疗计划,得到对应的剂量分布;利用Python程序统计每个OAR与靶区外扩环重叠区域内的剂量平均值,以之作为代表剂量,用于预测测试集手动与自动分割平均剂量的差异,比较预测平均剂量与实际平均剂量的差异。再次随机将100例分为训练集、测试集各50例,重复上述过程。结果首次预测显示,测试集70例中,69例膀胱预测与实际剂量差异均<0.5 Gy,69例小肠预测与实际剂量差异均<3 Gy,全部70例双侧股骨头预测与实际剂量差异均<0.5 Gy;对于膀胱、小肠和左、右侧股骨头,预测与实际平均剂量差异的一致性相关系数(CCC)分别为0.96、0.86、0.81和0.69。第2次预测显示,测试集50例中,46例膀胱的预测与实际剂量差异均<0.5 Gy,49例小肠的预测和实际剂量差异均<3 Gy,所有病例双侧股骨头的预测和实际剂量差异均<0.5 Gy;对于膀胱、小肠和左、右侧股骨头,预测与实际平均剂量差异的CCC分别为0.97、0.90、0.82和0.78。结论引入靶区外扩可有效预测直肠癌放疗中自动分割OAR产生的剂量偏差。

放射治疗联合奥沙利铂与卡培他滨治疗局部晚期直肠癌的疗效观察

目的:评价术前放射治疗联合奥沙利铂与卡培他滨的方法治疗局部晚期(T3-4)直肠癌的临床疗效和安全性。方法:54例局部晚期直肠癌患者接受术前盆腔放射治疗(50Gy/25次),同步接受奥沙利铂联合卡培他滨的化疗方案(奥沙利铂100mg/m2,静脉滴注第1天和第22天;卡培他滨825mg/m2,口服2次/d,第1～14天以及第22～35天)。结果:54例患者中有51例接受了手术治疗,其中10例(19.7%)患者获得了病理完全缓解(pathologic complete response,pCR),R0切除率为100%,保肛率为51.0%。1年和2年生存率分别为91.0%和83.8%。最常见的不良反应是血液学不良反应,3度以上的不良反应主要是贫血(1.9%)、白细胞减少(11.2%)和血小板减少(1.9%);最常见的非血液学不良反应是腹泻。结论:术前放射治疗联合卡培他滨与奥沙利铂的治疗方案对局部晚期直肠癌有一定的疗效,且不良反应率较低,是一种有效及较为安全的综合治疗方法。

三维适形放射治疗局部晚期和术后复发性直肠癌

目的:探讨局部晚期和术后复发性直肠癌三维适形放射治疗(three dimensional conformal radiation therapy,3D-CRT)的临床疗效。方法:60例局部晚期和术后复发性直肠癌均在外照射40Gy后随机分为后程适形放疗组(适形组)30例,常规放疗组(对照组)30例。结果:适形组及对照组有效率分别为86.7%和70.0%,2组差异无统计学意义(P>0.05);适形组及对照组1、2、3年生存率分别为80.0%、53.3%、36.7%和56.7%、40.0%、13.3%,P=0.02;1、2、3年局部控制率分别为86.7%、80.0%、50.0%和73.3%、53.3%、30.0%,2组差异均有统计学意义(P=0.0438);在副反应方面2组差异无统计学意义(P>0.05)。结论:局部晚期和术后复发性直肠癌常规外照射加三维适形放疗有较好疗效。

组织间植入放射碘-125粒子辅助治疗直肠癌的临床研究

目的 :探讨组织间植入放射碘 - 1 2 5 ( 12 5I)粒子近距离放疗辅助治疗直肠癌的疗效。方法 :对 1 997～ 1 998年间 1 1 2例施行前切除加全直肠系膜切除手术 ( TME)的直肠癌患者进行前瞻性对照性治疗研究。患者分 TME+静脉化疗 (四氢叶酸钙 + 5 Fu) +顺铂 ( DDP)腹腔灌注 +术中 12 5I植入组 (实验组 49例 )和 TME+静脉化疗 + DDP腹腔灌注 +术后放疗组 (对照组 63例 ) ,随访比较两组间控便功能、并发症、局部复发率、转移率和 5年生存率等。结果 :两组术后控便功能、吻合口瘘、吻合口狭窄发生率和远处转移率差异无统计学意义 ;实验组 Duke C、D期局部复发率低于对照组 ( P<0 .0 5 ) ,5年生存率高于对照组 ( P<0 .0 5 ) ,实验组放射反应少于对照组 ( P<0 .0 1 ) ;粒子植入数量超过 5 0枚时吻合口瘘的发生率增加( P<0 .0 5 ) ,并影响控便功能 ( P<0 .0 5 ) ,而 5年生存率并无增加。结论 :组织间植入 12 5I粒子近距离放疗辅助治疗直肠癌疗效优于外照射 ,能降低 Duke C、D期的局部复发率和提高 5年生存率 ,无严重放射反应。但可能会增加吻合口瘘的发生率 ,故应恰当使用放射剂量 。

接受术前新辅助放化疗及预防性造口术的中低位直肠癌患者肠道功能变化研究

目的探讨接受术前新辅助放化疗及预防性造口术的中低位直肠癌患者在不同时期肠道功能的变化特征,以期为制定改善中低位直肠癌患者肛门直肠功能的措施提供依据。方法本研究为前瞻性纵向研究,采用便利抽样法选取2015年10月—2016年10月就诊于中山大学肿瘤预防中心拟接受新辅助放化疗及预防性造口术的97例初次确诊的中低位直肠癌患者,运用一般资料调查表、中文版纪念斯隆-凯特林癌症中心(MSKCC)肠道功能问卷在不同时间点进行问卷调查,评估其肠道功能。结果患者入组(T1)、术前放化疗结束后1个月(T2)、造口回纳术后第4天(T3)、造口回纳术后3个月(T4)及造口回纳术后6个月(T5)时分别发放问卷97、92、84、84、82份,分别回收97、92、84、82、82份,其中文版MSKCC肠道功能问卷总得分分别为(69.5±8.9)、(63.9±9.0)、(59.9±7.2)、(63.3±9.3)、(66.3±7.5)分。其中,T1时中文版MSKCC肠道功能问卷总得分T1时高于T2、T3、T4、T5时,T2、T4、T5时高于T3时,T5时高于T4时(P<0.05)。T5时便频因子得分为(17.5±2.7)分,便急因子得分为(17.1±2.2)分,排便受饮食影响因子得分为(15.8±2.4)分,排便感觉异常因子得分为(11.7±3.1)分。结论中低位直肠癌患者在确诊时肠道功能较好,造口回纳术后6个月次之,造口回纳术后第4天肠道功能最差,因此,尤其应关注造口回纳术后早期患者的肠道症状,采取措施帮助其顺利渡过早期阶段,改善肠道功能,提高生活质量。