A prediction model of pathological complete response in patients with locally advanced rectal cancer after PD-1 antibody combined with total neoadjuvant chemoradiotherapy based on MRI radiomics / 中华胃肠外科杂志

Objective: To construct a prediction model of pathologic complete response (pCR) in locally advanced rectal cancer patients who received programmed cell death protein-1 (PD-1) antibody and total neoadjuvant chemoradiotherapy by using radiomics based on MR imaging data and to investigate its predictive value. Methods: A clinical diagnostic test study was carried out. Clinicopathalogical and radiological data of 38 patients with middle-low rectal cancer who received PD-1 antibody combined with total neoadjuvant chemoradiotherapy and underwent TME surgery from January 2019 to September 2021 in our hospital were retrospectively collected. Among 38 patients, 23 were males and 15 were females with a median age of 68 (47-79) years and 13 (34.2%) a chieved pCR. These 38 patients were stratified and randomly divided into the training group (n=26) and test group (n=12) for modeling. All the patients underwent rectal MRI before treatment. The clinical, imaging and radiomics features of all the patients were collected, and the clinical feature model and radiomics model were constructed. The receiver operating characteristic (ROC) curves of each model were drawn, and the constructed model was evaluated through the area under the curve (AUC), accuracy, sensitivity, specificity, positive predictive value and negative predictive value. Results: There were no significant differences in age, gender, primary location of tumor and postoperative pathology between the two groups (all P>0.05). Forty-one features were extracted from region of interest in each modality, including 9 first-order features, 24 gray level co-occurrence matrix features and 8 shape features. From 38 patients, 41 features were extracted from each imaging modality of baseline and preoperative DWI and T2WI images, totally 164 features. Only 4 features were preserved after correlation analysis between each pair of features and t-test between pCR and non-pCR subjects. After LASSO cross validation, only the first-order skewness of the baseline DWI image before treatment and the volume in the baseline T2WI image before treatment were retained. The area under the curve, sensitivity, specificity, positive and negative predictive values of the prediction model established by applying these two features in the training group and the test group were 0.856 and 0.844, 77.8% and 100.0%, 88.2% and 75.0%, 77.8% and 66.7%, 88.2% and 100.0%, respectively. The decision curve analysis of the radiomics model showed that the strategy of this model in predicting pCR was better than that in treating all the patients as pCR and that in treating all the patients as non-pCR. Conclusion: The pCR prediction model for rectal cancer patients receiving PD-1 antibody combined with total neoadjuvant radiochemotherapy based on MRI radiomics has the potential to be used in clinical screening or rectal cancer patients who can be spared from radical surgery.

Short-term outcome of programmed cell death protein1 (PD-1) antibody combined with total neoadjuvant chemoradiotherapy in the treatment of locally advanced middle-low rectal cancer with high risk factors / 中华胃肠外科杂志

Objective: Total neoadjuvant chemoradiotherapy is one of the standard treatments for locally advanced rectal cancer. This study aims to investigate the safety and feasibility of programmed cell death protein 1 (PD-1) antibody combined with total neoadjuvant chemoradiotherapy in the treatment of locally advanced middle-low rectal cancer with high-risk factors. Methods: A descriptive cohort study was conducted. Clinicopathological data of 24 patients with locally advanced middle-low rectal cancer with high-risk factors receiving PD-1 antibody combined with neoadjuvant chemoradiotherapy in Gastrointestinal Cancer Center, Unit III, Peking University Cancer Hospital between January 2019 and April 2021 were retrospectively analyzed. Inclusion criteria: (1) rectal adenocarcinoma confirmed by pathology; patient age of ≥ 18 years and ≤ 80 years; (2) the distance from low margin of tumor to anal verge ≤ 10 cm under sigmoidoscopy; (3) ECOG performance status score 0-1; (4) clinical stage T3c, T3d, T4a or T4b, or extramural venous invasion (EMVI) (+) or mrN2 (+) or mesorectal fasciae (MRF) (+) based on MRI; (5) no evidence of distant metastases; (6) no prior pelvic radiation therapy, no prior chemotherapy or surgery for rectal cancer; (7) no systemic infection requiring antibiotic treatment and no immune system disease. Exclusion criteria: (1) anticipated unresectable tumor after neoadjuvant treatment; (2) patients with a history of a prior malignancy within the past 5 years, or with a history of any arterial thrombotic event within the past 6 months; (3) patients received other types of antitumor or experimental therapy; (4) women who were pregnant or breast-feeding; (5) patients with any other concurrent medical or psychiatric condition or disease; (6) patients received immunotherapy (PD-1 antibody). The neoadjuvant therapy consisted of three stages: PD-1 antibody (sintilimab 200 mg, IV, Q3W) combined with CapeOx regimen for three cycles; long-course intensity modulated radiation therapy (IMRT) with gross tumor volume (GTV) 50.6 Gy/CTV 41.8 Gy/22f; CapeOx regimen for two cycles after radiotherapy. After oncological evaluation following the end of the third stage of treatment, surgery or watch and wait would be carried out. Surgical safety, histopathological changes and short-term oncological outcome were analyzed. Results: There were 15 males and 9 females with a median age of 65 (47-78) years. Median distance from the lower margin of the tumor to the anal verge was 4 (3-7) cm. The median maximal diameter of the tumor was 5.1 (2.1-7.5) cm. Twenty patients were cT3, 4 were cT4, 8 were cN1, 5 were cN2a, 11 were cN2b. Ten cases were MRF (+) and 10 were EMVI (+). All the patients were mismatch repair proficient (pMMR). During the neoadjuvant treatment period, 6 patients (25.0%) developed grade 1-2 treatment-related adverse events, including 3 immune-related adverse events. As of April 30, 2021, 20 patients (83.3%, 20/24) had received surgical resection, including 19 R0 resections and 16 sphincter-preservation operations. Morbidity of postoperative complication was 25.0% (5/20), including 2 cases of Clavien-Dindo grade II (1 of anastomotic bleeding and 1 of pseudomembranous enteritis), 3 cases of grade I anastomotic stenosis. Pathological complete response (pCR) rate was 30.0% (6/20) and major pathological response rate was 20.0% (4/20). None of Ras/Raf mutants had pCR or cCR (0/5), while 6 of 17 Ras/Raf wild-type patients had pCR and 3 had cCR, which was significantly higher than that of Ras/Raf mutants (P<0.01). Nine of 16 patients with Ras/Raf wild-type and differentiated adenocarcinoma had pCR or cCR. Among other 4 patients without surgery, 3 patients preferred watch and wait strategy because their tumors were assessed as clinical complete response (cCR), while another one patient refused surgery as the tumor remained stable. After a median follow-up of 11 (6-24) months, only 1 patient with signet ring cell carcinoma had recurrence. Conclusions: PD-1 antibody combined with total neoadjuvant chemoradiotherapy in the treatment of locally advanced rectal cancer has quite good safety and histopathological regression results. Combination of histology and genetic testing is helpful to screen potential beneficiaries.

Computed Tomography Arteriography for Detecting the Origin of the Inferior Pyloric Artery in Patients with Gastric Cancer

OBJECTIVE: To analyze the detection rate of the inferior pyloric artery (IPA) in patients with gastric cancer by computed tomography arteriography (CTA). MATERIALS AND METHODS: Fifty-four patients (48 males and 6 females; mean age, 59.0 ± 1.5 years) who had undergone radical gastrectomy for gastric cancer from September 2016 to July 2017 at our institution were recruited prospectively. Patients underwent abdominal contrast-enhanced CT scans and CTA imaging reconstruction before the operation. The origin of the IPA in all cases was determined by a radiologist based on CTA images and verified by the surgeon. The accuracy of CTA in diagnosing the origin of the IPA was calculated. Dominant vessels of the origin were analyzed. RESULTS: IPAs were detected by CTA in 51 patients (94.4%). Among these, IPAs originated from the right gastroepiploic artery (RGEA) (24 cases), the gastroduodenal artery (GDA) (4 cases), and the anterior superior pancreaticoduodenal artery (ASPDA) (20 cases). In the remaining 3 cases, the IPAs contained two branches originating from the RGEA and ASPDA, respectively. During surgery, in 2 (3.7%) of the 54 cases of gastric cancer, IPAs could not be detected; the IPAs originated from the RGEA (22 cases), GDA (5 cases), and ASPDA (24 cases). One case had an IPA originating from both the RGEA and the GDA. Finally, the accuracy of CTA in diagnosing the origin artery of the IPA was 85.2% (46/54). CONCLUSION: CTA can detect the origin of the IPA accurately, which can aid surgeons while performing pylorus-preserving operations.

Application of CT subtraction technique in evaluating residual hepatocelluar carcinoma activity after transcatheter arterial chemoembolization / 介入放射学杂志

Objective To discuss the application of enhanced CT subtraction technique in evaluating residual hepatocelluar carcinoma activity after transcatheter arterial chemoembolization (TACE).Methods A total of consecutive 22 patients with clinically-confirmed hepatocellular carcinoma (HCC),who received TACE,were retrospectively collected.Multi-phase enhanced CT examination of liver was performed in all patients after the initial TACE,and the presence or absence of residual active tumor was determined at the second time of TACE.The enhanced arterial phase CT images were used to subtract the corresponding plain scan images,and the subtraction images were thus obtained.The post-subtraction CT values of the lesions that showed iodine oil deposit were measured,which were compared with angiography findings performed at the second time of TACE.The residual tumor activity indicated by post-subtraction images was statistically analyzed.Results In 22 HCC patients receiving TACE,a total of 37 lesions showed iodine oil deposit after the initial TACE.Assessment of tumor activity indicated that 34 lesions had tumor activity and 3 lesions had no tumor activity.The mean post-subtraction CT value of the lesions in the tumor activity group was (79±68) HU,while it was (1 ±1) HU in the tumor non-activity group;the difference between the two groups was statistically significant (P=0.007).Analysis with receiver operating characteristic (ROC) curve indicated that when the post-subtraction CT value of the lesion was greater than one HU,the sensitivity and specificity for diagnosing residual tumor were 97.06％ and 100％ respectively,and the area under the ROC curve was up to 0.975.Conclusion The subtraction images obtained by subtracting the enhanced arterial phase CT images from the plain scan images can accurately and intuitively determine the presence or absence of residual active HCC lesions after TACE.

Preoperative staging of rectal carcinoma with high-resolution MRI: correlation with histopathologic findings / 中华外科杂志

<p><b>OBJECTIVE</b>To assess the correlation of preoperative high-resolution-MRI with histopathologic findings in tumor staging of rectal carcinoma.</p><p><b>METHODS</b>From January 2005 to December 2008, 245 cases of pathologically confirmed rectal cancer, who received preoperative scan by a 1.5 T high-resolution-MRI were included in this retrospective study. To extract image signs from high-resolution MRI, and made a diagnosis for tumor staging classification. Assessment for diagnostic accuracy of high-resolution MRI was extract made with comparison of histopathological classification.</p><p><b>RESULTS</b>The overall diagnostic accuracy of T-stage was 83.7% (205/245). The consistency coefficient (κ) between the MRI and histopathologic T-stage was 0.693 (95%CI: 0.611 - 0.776), which was considered good. For the 97 cases with preoperative chemoradiotherapy, the agreement rate between the post-chemoradiotherapy MRI and histopathologic T-stage was 73.2% (71/97, κ = 0.563, 95%CI: 0.428 - 0.698). For the 148 cases without preoperative chemoradiotherapy, the agreement rate between the MRI and histopathologic T-stage was 90.5% (134/148, κ = 0.794, 95%CI: 0.692 - 0.896). The histopathologic T-stage and diameter infringement were in moderate related degree (ρ = 0.619, P < 0.01).</p><p><b>CONCLUSIONS</b>High-resolution MRI is proved to have a high degree of diagnostic accuracy for T-stage of rectal carcinoma. Preoperative MRI is helpful in treatment planning. Patients undergoing preoperative chemoradiotherapy should receive MRI scan again after neoadjuvant therapy for restaging. The assessment of circumference violation make sense for the accurate diagnosis for tumor staging.</p>

Imaging evaluation of response of rectal cancer to preoperative chemoradiotherapy / 中华胃肠外科杂志

In recent years, preoperative therapy has become the standard procedure to improve radical resection rate and local control for advanced rectal cancer. Tumor responses to chemoradiotherapy, however, vary considerably, thus increasing the demand for both functional and morphologic radiologic evaluation of response to chemoradiotherapy to distinguish responders from nonresponders. MR imaging is considered the most accurate tool for the primary staging of tumor extent, and can be used to evaluate the efficacy of chemoradiotherapy. Functional imaging modalities including DW-MRI and PET-CT have shown promising prospect in the early evaluation of the response of rectal cancer to preoperative chemoradiotherapy. However, wide clinical application will take some time.

Association of CT image changes and prognosis in gastrointestinal stromal tumor after targeted therapy / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To investigate the association between CT image changes and the prognosis in gastrointestinal stromal tumors (GIST) after targeted therapy.</p><p><b>METHODS</b>A total of 35 patients with GIST were treated by imatinib mesylate from April 2003 to June 2008. The longest diameter (LD) and mean enhanced CT values (HU) of tumors were measured on axial images. The CT classifying (number, location, liver metastasis, hemorrhage,cystic degeneration) and quantitative indices (pre- and 2-6 months post-treatment LD, HU, and their change rate) were compared between those with and without progress in two years.</p><p><b>RESULTS</b>During follow-up (median:285 months) 13 cases had tumor progress. The progress rate was higher in the group with extensive tumor involvement (> or = 5 lesions and > or = 2 parts), and that without hemorrhage demonstrated. The mean change rate was -14.29% (range, -67%, 11%) for LD and -12.25% (range, -55%, 39%) for HU in non-progressive group, while the mean change rate was 15.09%(range, -45%, 191%) for LD and 9.91% (-27%, 135%) for HU in progressive group. The differences were significantly different (P<0.01). The accuracies of predicting 2-year progress by LD and HU change rates were moderate, with area under ROC curve being 0.790 and 0.797, respectively.</p><p><b>CONCLUSIONS</b>The 2-year progress rate of GIST after targeted therapy is higher in extensively involved tumors. Higher decrease rates of LD and HU predict less 2-year progress, which possess moderate prediction accuracy and can be used as valuable indicators in the evaluation of targeted therapy for GIST.</p>

Comparison study of CT indicators and pathological N staging in lymph node metastasis of gastric cancer / 中华胃肠外科杂志

<p><b>OBJECTIVE</b>To explore the CT criteria for evaluating lymph node (LN) metastasis and preoperative N-staging of gastric cancer through the comparison of CT signs and surgical pathology.</p><p><b>METHODS</b>Eighty-nine patients with gastric cancer underwent CT examinations before radical resections. A soft-reading method on PACS workstation was employed to evaluate the detection of LNs. The size and number of LNs were registered, and the accumulated size of LNs was calculated in every case. The pathological N-staging (pN(0-3)) was considered on the basis of pathological examination of excised specimens according to UICC TNM-staging system (6th edition, 2002). The relationships between LN metastases and CT findings were analyzed by SPSS using t test and one-way ANOVA analysis.</p><p><b>RESULTS</b>The distribution of maximal size, CT detection number and accumulated size were significantly different among different pN stages (P<0.01). All these 3 indicators were significantly different between LN metastasis group and non-metastasis group (P<0.01). There was no significant difference of maximal size among different pN stages in positive metastasis LNs (P>0.05), while significant difference could be found in CT detection number between pN1 and pN3 (P<0.01), pN2 and pN3 (P<0.01), and in accumulated size between pN1 and pN3 (P<0.01), pN1 and pN2 (P<0.01).</p><p><b>CONCLUSIONS</b>The involvement of LNs in gastric cancer and pN staging are associated with size, number, and accumulated size of CT detection. CT detection number is more valuable in the evaluation of N staging than LNs size. CT detection number combined with accumulated size of LNs can provide meaningful information for preoperative N-staging.</p>

Preoperative evaluation of pathologic response in patients with breast cancer by dynamic contrast-enhanced magnetic resonance imaging / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the clinical value of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing pathologic responses in breast cancer treated with neoadjuvant chemotherapy.</p><p><b>METHODS</b>Forty-five patients with pathologically confirmed breast carcinoma who finished last course of neoadjuvant chemotherapy underwent preoperative breast MRI. All the specimen slices were blindly reviewed by one pathologist. Pathologic response was assessed according Miller & Payne five-point classification, of which grade 5 defined as pathological complete response (pCR) , and grade 5 or 4 defined as major histological response (MHR). DCE-MRI images were blindly reviewed by two radiologists retrospectively on workstation with Functool software. Any non-vessel enhancement in previous tumor bed in any phase of postcontrast acquisition was defined as residual disease. The diagnostic results of two radiologists were correlated to pathological gold standard. Inter-observer consistency was analyzed by Kappa statistics.</p><p><b>RESULTS</b>DCE-MRI for pathological invasive (pINV) residual disease detection in two radiologists had sensitivities of 94.7% and 97.4%, specificities of 42.8% and 57.1%, and accuracy of 86.6% and 91.1%, respectively, while MHR evaluation had sensitivities of 95.5% and 81.8%, specificities of 73.9% and 82.6%, and accuracies of 84.4% and 82.2%, respectively. K values in determine pINV and MHR were 0.728 and 0.778, respectively, showing good inter-observer consistency.</p><p><b>CONCLUSION</b>DCE-MRI is sensitive in detecting residual breast cancer after neoadjuvant chemotherapy, and can be used to predict the postoperative pathologic response.</p>

MR diffusion weighted imaging of gastric cancer:b-value determination and comparison with routine sequences / 中华放射学杂志

Objective To choose the optimal b-values for the DWI of gastric cancer(GC),and investigate the value of DWI in the diagnosis of GCs.Methods MRI examinations(T_1WI,T_2WI,and DWI)were performed on 31 patients with gastric cancer.Three diffusion-weighted sequences were designed with different b values,including 300 s/mm~2(low),600 s/mm~2(intermediate),and 1000 s/mm~2(high). Free water grade was used to evaluate the suppression of content in gastric lumen.Background contrast grade was used to evaluate the discriminating ability of different sequences between GC and nearby tissues.The ADCs of GCs,nearby gastric wall region,and free water in gastric lumen were measured.SNRc_(Ca),CNR_(Ca-Gw) and SIRc_(Ca-Gw)of high b-value DWI and routine MRI sequences were evaluated and compared.Results The signal intensity of free water in gastric lumen decreased as b-value increased,and the SIR were 8.11? 0.77(b=300 s/mm~2),2.70?0.35(b =600 s/mm~2),and 1.13?0.22(b=1000 s/mm~2)(F= 55.368,P

Dynamic contrast-enhanced MRI in breast cancer treated with neoadjuvant chemotherapy:correlation with pathological response / 中华放射学杂志

Objective To investigate the relationship of pathological response of breast cancer after neoadjuvant chemotherapy with the imaging findings in dynamic contrast-enhanced MRI.Methods Forty- five patients with pathologically confirmed breast carcinoma who finished courses of neoadjuvant chemotherapy had breast MRI prior to operation.Dynamic contrast-enhanced MRI scans were performed on a 1.5 T scanner using 3D SPGR sequence before and repeated 6 times after administration of Gd-DTPA. Pathological response was assessed by a pathologist according to Miller & Payne five points classification blinded to breast MRI results.Grade 5 was defined as pCR(pathological complete response).Grade 4 and 5 were defined as major histopathological response(MHR).The type of time signal intensity curve(TIC) (three types),pattern of residual enhancement of each breast cancer were recorded and correlated with pathological findings.Fisher exact test was used for statistical analysis.Results Grade 5 responses were achieved in seven patients;grade 4 in sixteen patients;grade 3 in sixteen patients and grade 1—2 in six patients.70.0%(14/20)of type Ⅰ time signal intensity curve correlated with MHR,while all 6 type Ⅲ curves showed non-MHR response.The type of time signal intensity curve and pathological response grades had statistically significant correlation(P=0.001).18 of the 23 cases with MHR exhibited residual enhancement,while the remaining 5 cases showed no enhancement.Of the 18 MHR cases with residual enhancement,11 showed non-mass-like enhancement and 7 showed mass-like enhancement.The mass(non- mass)morphological pattern in dynamic contrast enhanced-MRI had statistically significant differences in pathological response(P=0.012).Conclusions Pathological response of breast carcinoma after neoadjuvant chemotherapy could be characterized using dynamic contrast-enhanced MRI by identifying patterns of residual contrast enhancement and kinetic curve.Favorable pathological responses correlated with Type Ⅰ TIC,non-enhancement,and non-mass-like residual enhancement.