Comparison between CT volume measurement and histopathological assessment of response to neoadjuvant therapy in rectal cancer. Eur J Radiol. 2012;81:3918-3924. [PMID: 22902408 DOI: 10.1016/j.ejrad.2012.04.038]

Assessment of immunotherapy response in intracranial malignancy using semi-automatic segmentation on magnetic resonance images

Objective

To explore multi-aspect radiologic assessment of immunotherapy response in intracranial malignancies based on a semi-automatic segmentation technique, and to explore volumetric thresholds with good performance according to RECIST 1.1 thresholds.

Methods

Patients diagnosed with intracranial malignancies and treated with immunotherapy were included retrospectively. In all MR images, target lesions were measured using a semi-automatic segmentation technique that could intelligently generate visual diagrams including RECIST 1.1, total volume, and max. 3D diameter. The changes in parameters were calculated for each patient after immunotherapy. The ROC curve was used to analyze the sensitivity and specificity of the size change of the legion. This was useful to find new volumetric thresholds with better efficiency in response assessment. The changes in total volume were assessed by conventional volumetric thresholds, while RECIST 1.1 thresholds were for the max. 3D diameter. A chi-square test was used to compare the concordance and diagnostic correlation between the response assessment results of the three criteria.

Results

A total of 20 cases (average age, 58 years; range, 23 to 84 years) and 58 follow-up MR examinations after immunotherapy were included in the analysis. The P-value of the chi-square test between RECIST 1.1 and total volume is 0 (P <0.05), same as that in RECIST 1.1 and max. 3D diameter. The kappa value of the former two was 0.775, and the kappa value for the latter two was 0.742. The above results indicate a significant correlation and good concordance for all three criteria. In addition, we also found that the volumetric assessment had the best sensitivity and specificity for the immunotherapy response in intracranial malignancies, with a PR threshold of -64.9% and a PD threshold of 21.4%.

Conclusions

Radiologic assessment of immunotherapy response in intracranial malignancy can be performed by multiple criteria based on semi-automatic segmentation technique on MR images, such as total volume, max. 3D diameter and RECIST 1.1. In addition, new volumetric thresholds with good sensitivity and specificity were found by volumetric assessment.

The predictive value of tumor volume reduction ratio on three-dimensional endorectal ultrasound for tumor response to chemoradiotherapy for locally advanced rectal cancer

Background

Preoperative chemoradiotherapy remains part of the standard treatment for patients with locally advanced rectal cancer. Subsequent treatment individualization requires accurate prediction of tumor response to chemoradiotherapy. Three-dimensional endorectal ultrasound (3D-ERUS) can automatically capture and store the images of the rectal wall and rectal cancer with high resolution. In this study, we aimed to assess the correlation and predictive value between tumor volume changes measured on 3D-ERUS and the histopathological tumor response after chemoradiotherapy for patients with locally advanced rectal cancer.

Methods

A total of 54 patients with locally advanced rectal cancer who underwent chemoradiotherapy and had complete 3D-ERUS data pre-and post-chemoradiotherapy were enrolled in the study. The tumor volume pre-and post-chemoradiotherapy was measured manually on 3D-ERUS, and the tumor volume reduction ratio was calculated. The histopathological tumor regression grade (TRG) was used to assess tumor response. The differences in volumetry parameters were compared between groups with varying tumor response. The diagnostic efficacy of the tumor volume reduction ratio was evaluated by the receiver operating characteristic (ROC) curve.

Results

The mean age of all patients was 55.19±12.46 years. The relative proportions of TRG 0–3 were 29.6% (16/54), 16.6% (9/54), 50% (27/54), and 3.8% (2/54), respectively. The median tumor volumes post-chemoradiotherapy in good responders (TRG 0–1, median tumor volume =3.26 cm³) and the complete response group (TRG 0, median tumor volume =2.61 cm³) were smaller than those in poor responders (TRG 2–3, median tumor volume =5.43 cm³) and the partial response group (TRG 1–3, median tumor volume =4.00 cm³), while tumor volume reduction ratios were higher than those of poor responders (79.32% vs. 59.67%) and the partial response group (82.22% vs. 61.64%), with significant differences (all P values <0.05). The ROC curves showed that the cut-off values of the tumor volume reduction ratio to predict good responders and complete response were 67.77% and 72.02%, respectively. The corresponding areas under the curve in the prediction of good responders and complete response were 0.830 and 0.829, respectively.

Conclusions

The tumor volume reduction ratio measured on 3D-ERUS might be a helpful indicator for tumor response in patients with locally advanced rectal cancer.

T2-weighted, apparent diffusion coefficient and 18F-FDG PET histogram analysis of rectal cancer after preoperative chemoradiotherapy

Background

The aim of our study was to investigate the correlation among T2-weighted (T2w) images, apparent diffusion coefficient (ADC) maps, ¹⁸F-fluorodeoxyglucose (¹⁸F-FDG) positron emission tomography (PET) images, histogram analysis and the pathological response in locally advanced rectal cancer (LARC) after preoperative chemoradiotherapy (pCRT).

Methods

Patients with LARC were prospectively enrolled between February 2015 and August 2018 and underwent PET/magnetic resonance imaging (MRI). MRI included T2w and diffusion-weighted imaging (DWI)-sequences. ADC maps and PET images were matched to the T2w images. Voxel-based standardized uptake values (SUVs,) ADC and T2w-signal-intensity values were collected from the volumes of interest (VOIs) and mean, skewness and kurtosis were calculated. Spearman’s correlation coefficient was applied to evaluate the correlation among the variables and tumor regression grade (TRG), T stage, N stage and fibrosis.

Results

Twenty-two patients with biopsy-proven LARC in the low or mid rectum were enrolled [17 males, mean age was 69 years (range 49–85 years)]. Seven patients experienced complete regression (TRG1). A significant positive correlation was found between SUV mean values (ρ = 0.480; p = 0.037) and TRG. No other significant correlations were found.

Conclusions

Histogram analysis of SUV values is a predictor of TRG in LARC.

Colorectal cancer: Parametric evaluation of morphological, functional and molecular tomographic imaging

Colorectal cancer (CRC) represents one of the leading causes of tumor-related deaths worldwide. Among the various tools at physicians' disposal for the diagnostic management of the disease, tomographic imaging (e.g., CT, MRI, and hybrid PET imaging) is considered essential. The qualitative and subjective evaluation of tomographic images is the main approach used to obtain valuable clinical information, although this strategy suffers from both intrinsic and operator-dependent limitations. More recently, advanced imaging techniques have been developed with the aim of overcoming these issues. Such techniques, such as diffusion-weighted MRI and perfusion imaging, were designed for the "in vivo" evaluation of specific biological tissue features in order to describe them in terms of quantitative parameters, which could answer questions difficult to address with conventional imaging alone (e.g., questions related to tissue characterization and prognosis). Furthermore, it has been observed that a large amount of numerical and statistical information is buried inside tomographic images, resulting in their invisibility during conventional assessment. This information can be extracted and represented in terms of quantitative parameters through different processes (e.g., texture analysis). Numerous researchers have focused their work on the significance of these quantitative imaging parameters for the management of CRC patients. In this review, we aimed to focus on evidence reported in the academic literature regarding the application of parametric imaging to the diagnosis, staging and prognosis of CRC while discussing future perspectives and present limitations. While the transition from purely anatomical to quantitative tomographic imaging appears achievable for CRC diagnostics, some essential milestones, such as scanning and analysis standardization and the definition of robust cut-off values, must be achieved before quantitative tomographic imaging can be incorporated into daily clinical practice.

Metabolic response evaluation for colorectal liver metastases and correlation to pathologic response and tumour markers

BACKGROUND

Tumour metabolic response to chemotherapy is increasingly recognized as a prognostic indicator for colorectal cancer liver metastases (CRCLM). However, its clinical role and the underlying biological mechanism of its prognostic ability are unclear. This study compares metabolic to pathologic response for CRCLM, and correlates metabolic response to tumour expression of six key biomarkers.

METHODS

Thirty-seven patients who had positron emission tomography imaging before and after pre-operative chemotherapy prior to liver resection for CRCLM were included. Metabolic response was assessed according to the positron emission tomography response criteria in solid tumours (PERCIST) and correlated to recurrence-free and overall survival. PERCIST was compared to tumour regression grading, computed tomography (CT) response, tumour necrosis and mucin and immunohistochemical expression of Ki-67, hypoxia inducible factor 1α, vascular endothelial growth factor, p53, p16 and vimentin. Area under the receiver operating characteristic curve (AUC), Kaplan-Meier survival, Spearman's correlation (r_s ) and multivariate Cox regression analyses were used.

RESULTS

PERCIST correlated significantly to 2-year mortality (AUC = 0.162, P < 0.01) and 2-year recurrence (AUC = 0.284, P = 0.03). Metabolically responsive tumours conferred a better overall survival (P = 0.01) and recurrence-free survival (P = 0.03). Tumour regression grading did not stratify for outcome. Metabolic response was significantly correlated to Ki-67 and p16 expression (r_s = 0.559 and r_s = -0.549, respectively). Multivariate analysis revealed only PERCIST to be correlated to death and recurrence.

CONCLUSION

Pre-operative PERCIST assessment of CRCLM was more prognostic than pathologic and CT response assessment. Metabolic non-response correlated with tumour proliferation and loss of tumour suppression.

The Prognostic Impact of Tumor Volume in Patients with Clinical Stage IA Non-Small Cell Lung Cancer

INTRODUCTION

Tumor volume promises to be an important factor for predicting the prognosis of patients with non-small cell lung cancer (NSCLC).

METHODS

A total of 255 patients who underwent curative surgical resection for clinical stage IA NSCLC were included. We performed semiautomated measurement of the whole tumor volume and the volume of the solid part (referred to as the solid part volume) from a volumetric analysis of chest three-dimensional computed tomography scans using the SYNAPSE VINCENT imaging software program (Fujifilm Medical, Tokyo, Japan). We evaluated the relationships among tumor size, tumor volume, and survival.

RESULTS

The mean whole tumor size, the ratio of the maximum diameter of consolidation to the maximum tumor diameter (CTR), the whole tumor volume, and the solid part volume were 20 mm (range 0-30 mm), 0.84 (range 0-1.0), 3080 mm(3) (range 123-17509 mm(3)), and 2032 mm(3) (0-12466 mm(3)), respectively. The receiver operating characteristic area under the curve for the whole tumor size, CTR, whole tumor volume, and solid part volume used to identify recurrence were 0.60, 0.68, 0.58, and 0.69, respectively. A univariate analysis revealed that the whole tumor size, CTR, whole tumor volume, and solid part volume were associated with disease-free survival (DFS). A multivariate analysis of these factors identified the solid part volume to be the only independent factor for the prediction of DFS.

CONCLUSIONS

The whole tumor volume and the solid part volume were associated with DFS. In particular, the solid part volume was a very useful factor for predicting prognosis in clinical stage IA NSCLC.

Decreased ERCC1 Expression After Platinum-Based Neoadjuvant Chemotherapy in non-Small Cell Lung Cancer

We have already demonstrated in a small cohort of 17 non-small cell lung cancer patients that ERCC1 (excision repair cross-complementation group 1) protein expression decreased after platinum-based treatment, however, certain clinicopathological parameters, such as histologic subtypes, ERCC1 expression scores, chemotherapeutic combinations, response rate, gender and smoking history were not analyzed. The aim of our present study was to extend the studied cohort and analyze those parameters. ERCC1 protein expression was examined in 46 patients treated with neoadjuvant chemotherapy. 46 bronchoscopic biopsy samples (27 squamous cell carcinomas /SCC/ and 19 adenocarcinomas /ADC/) together with their corresponding surgical biopsies were studied. ERCC1 immunohistochemistry was performed on formalin-fixed, paraffin-embedded tissues. Staining scores were calculated by multiplying the percentage of positive tumor cells (0-100) by the staining intensity (0-3). 24/27 bronchoscopic SCC tissues expressed ERCC1. Thirteen of these cases became negative after neoadjuvant therapy and the expression differences between pre- and postchemotherapy samples were highly significant (p < 0.001). 11/19 bronchoscopic ADC tissues expressed ERCC1. Six of these cases became negative after neoadjuvant therapy and the expression differences were significant (p < 0.010). There was no newly expressed ERCC1 postoperatively. Comparison of staining score changes revealed more pronounced decrease in SCC (p = 0.032). We observed no correlation between initial ERCC1 level or ERCC1 decrease and overall survival, but we demonstrated correlations between decrease in ERCC1 expression and histologic subtypes of tumors and gender. We could confirm our previous data in a larger cohort that platinum-based chemotherapy affects the ERCC1 expression probably referring to an induction of tumor cell selection.

Barium enema and CT volumetry for predicting pathologic response to preoperative chemoradiotherapy in rectal cancer patients

BACKGROUND

Preoperative chemoradiotherapy has been widely used for the prevention of local recurrence of locally advanced rectal cancer, and the effect of chemoradiotherapy is known to be associated with overall survival.

OBJECTIVE

We aimed to evaluate the association of the pathologic response grade with tumor recurrence rate after chemoradiotherapy, using radiographic analysis and the Response Evaluation Criteria in Solid Tumors as the parameters.

DESIGN

This study was conducted at a single tertiary care institution in Japan.

SETTING

This was a retrospective cohort study of patients undergoing preoperative chemoradiotherapy.

PATIENTS

A total of 101 low rectal cancer patients receiving preoperative chemoradiotherapy from July 2004 to August 2012 were enrolled.

MAIN OUTCOME MEASURES

The tumor reduction rate was measured with the use of traditional Response Evaluation Criteria in Solid Tumors, barium enema, and CT volumetry, and the correlation between the reduction rate and the pathologic response grade was examined.

RESULTS

The tumor reduction rate assessed according to Response Evaluation Criteria in Solid Tumors showed no association with the pathologic response grade (p =0.61). In contrast, the radiographic response rate by both barium enema and CT volumetry strongly correlated with the pathologic response grade (p < 0.0001 and p = 0.001).In terms of local tumor recurrence, those diagnosed as high responders by the pathologic response grade, Response Evaluation Criteria in Solid Tumors, barium enema, and CT volumetry had a lower recurrence rate (p =0.03, p =0.03, p =0.0002, and p =0.001). The difference between high responders and low responders was especially prominent by barium enema and CT volumetry.

LIMITATIONS

The study is limited by its retrospective nature.

CONCLUSIONS

Double-contrast barium enema and CT volumetry were superior to Response Evaluation Criteria in Solid Tumors in evaluating the effect of chemoradiotherapy and predicting the likelihood of tumor recurrence.

Relationship between histologic response and the degree of tumor shrinkage after chemoradiotherapy in patients with locally advanced rectal cancer

BACKGROUND

Preoperative chemoradiotherapy (CRT) significantly decreases local recurrence in advanced rectal cancer. We studied whether the degree of tumor shrinkage can be used as a predictor of histologic response.

METHODS

The subjects were 114 patients with locally advanced rectal cancer who underwent total mesorectal excision after receiving radiotherapy combined with uracil/tegafur (UFT) or S-1. The degree of tumor shrinkage based on barium enema examination and magnetic resonance imaging (MRI) were assessed before CRT and immediately before surgery.

RESULTS

A histologic complete response (ypCR), histologic marked regression, T and N downstaging were associated with significantly higher tumor-shrinkage rates on barium enema (P < 0.01, P < 0.01, P < 0.01, and P < 0.01, respectively) as well as on MRI (P < 0.01, P < 0.01, P < 0.01, and P = 0.01, respectively). On multivariate analysis, ypCR and histologic marked regression were significantly related only to tumor-shrinkage rates on barium enema (P < 0.01 and P < 0.01, respectively), and were not related to tumor-shrinkage rates on MRI.

CONCLUSIONS

The degree of tumor shrinkage is closely related to the final histologic response. Two-dimensionally evaluated tumor-shrinkage rates based on barium enema are adequate for the prediction of histologic response.

Future directions in combined modality therapy for rectal cancer: reevaluating the role of total mesorectal excision after chemoradiotherapy

Most patients who develop rectal cancer present with locoregionally advanced (T3 or node-positive) disease. The standard management of locoregionally advanced rectal cancer is neoadjuvant concurrent chemoradiotherapy (nCRT), followed by radical resection (low-anterior resection or abdominoperineal resection with total mesorectal excision). Approximately 15% of patients can have a pathologic complete response (pCR) at the time of surgery, indicating that some patients can have no detectable residual disease after nCRT. The actual benefit of surgery in this group of patients is unclear. It is possible that omission of surgery in these patients, termed selective nonoperative management, can limit the toxicities associated with standard, multimodal combined modality therapy without compromising disease control. In this review, we discuss the clinical experiences to date using selective nonoperative management and various attempts at escalation of nCRT to improve the number of patients who have a pCR. We also explore several clinical, laboratory, imaging, histopathologic, and genetic biomarkers that have been tested as tools to predict which patients are most likely to have a pCR after nCRT.