Stepwise algorithm using computed tomography and magnetic resonance imaging for differential diagnosis of fat-poor angiomyolipoma in small renal masses: A prospective validation study.

OBJECTIVES: To validate the diagnostic accuracy of a stepwise algorithm to differentiate fat-poor angiomyolipoma (fp-AML) from renal cancer in small renal masses (SRMs). METHODS: We prospectively enrolled 223 patients with solid renal masses <4 cm and no visible fat on unenhanced computed tomography (CT). Patients were assessed using an algorithm that utilized the dynamic CT and MRI findings in a stepwise manner. The diagnostic accuracy of the algorithm was evaluated in patients whose histology was confirmed through surgery or biopsy. The clinical course of the patients was further analyzed. RESULTS: The algorithm classified 151 (68%)/42 (19%)/30 (13%) patients into low/intermediate/high AML probability groups, respectively. Pathological diagnosis was made for 183 patients, including 10 (5.5%) with fp-AML. Of these, 135 (74%)/36 (20%)/12 (6.6%) were classified into the low/intermediate/high AML probability groups, and each group included 1 (0.7%)/3 (8.3%)/6 (50%) fp-AMLs, respectively, leading to the area under the curve for predicting AML of 0.889. Surgery was commonly opted in the low and intermediate AML probability groups (84% and 64%, respectively) for initial management, while surveillance was selected in the high AML probability group (63%). During the 56-month follow-up, 36 (82%) of 44 patients initially surveyed, including 13 of 18 (72%), 6 of 7 (86%), and 17 of 19 (89%) in the low/intermediate/high AML probability groups, respectively, continued surveillance without any progression. CONCLUSIONS: This study confirmed the high diagnostic accuracy for differentiating fp-AMLs. These findings may help in the management of patients with SRMs.

Detection support of lesions in patients with prostate cancer using 18 F -PSMA 1007 PET/CT.

PURPOSE: This study proposes a detection support system for primary and metastatic lesions of prostate cancer using 18 F -PSMA 1007 positron emission tomography/computed tomography (PET/CT) images with non-image information, including patient metadata and location information of an input slice image. METHODS: A convolutional neural network with condition generators and feature-wise linear modulation (FiLM) layers was employed to allow input of not only PET/CT images but also non-image information, namely, Gleason score, flag of pre- or post-prostatectomy, and normalized z-coordinate of an input slice. We explored the insertion position of the FiLM layers to optimize the conditioning of the network using non-image information. RESULTS: 18 F -PSMA 1007 PET/CT images were collected from 163 patients with prostate cancer and applied to the proposed system in a threefold cross-validation manner to evaluate the performance. The proposed system achieved a Dice score of 0.5732 (per case) and sensitivity of 0.8200 (per lesion), which are 3.87 and 4.16 points higher than the network without non-image information. CONCLUSION: This study demonstrated the effectiveness of the use of non-image information, including metadata of the patient and location information of the input slice image, in the detection of prostate cancer from 18 F -PSMA 1007 PET/CT images. Improvement in the sensitivity of inactive and small lesions remains a future challenge.

Kidney R2* Mapping for Noninvasive Evaluation of Iron Overload in Paroxysmal Nocturnal Hemoglobinuria.

PURPOSE: The kidney iron deposition can cause kidney damage and renal insufficiency in paroxysmal nocturnal hemoglobinuria (PNH) patients. Assessment of iron deposition in the kidney is essential for the early diagnosis of renal damage in PNH patients. The purpose of this study was to evaluate kidney R2* (T2* reciprocals) values in PNH patients using the iterative decomposition of water and fat with echo asymmetry and least-squares estimation (IDEAL-IQ). METHODS: Two radiologists measured the R2* values of the renal cortex in 14 PNH patients and 13 healthy volunteers using IDEAL-IQ. Lactate dehydrogenase (LDH), a reliable marker of intravascular hemolysis, was also measured in all participants. RESULTS: The kidney R2* values were significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). High inter-operator reproducibility of the measurements was also acquired using IDEAL-IQ. LDH levels were also significantly higher in PNH patients compared with those in healthy volunteers (P < 0.001). Kidney R2* values strongly correlated with LDH levels in PNH patients. CONCLUSION: IDEAL-IQ has a possibility of becoming a useful method for the noninvasive evaluation of renal iron overload in PNH patients.

Phase I/IIa trial of 18F-prostate specific membrane antigen (PSMA) 1007 PET/CT in healthy volunteers and prostate cancer patients.

OBJECTIVE: 18F-PSMA 1007 is a promising PET tracer for prostate cancer. We aimed to examine the safety, biodistribution, radiation dosimetry, and clinical effectiveness in Japanese healthy volunteers and patients with prostate cancer. METHODS: Part A evaluated the pharmacokinetics and exposure doses in three healthy volunteers. Part B evaluated the diagnostic accuracy in patients with untreated preoperative prostate cancer (Cohort 1, n = 7) and patients with biochemical recurrence (Cohort 2, n = 3). All subjects received a single dose of 3.7 MBq/kg 18F-PSMA 1007. Results: 18F-PSMA 1007 was found to be safe and well tolerated in all subjects. No serous AEs or drug-related AEs were identified during the present study. The average blood radioactivity concentration reached a maximum of 47.87 ± 1.05 (percentage of injected dose [%ID]/ml) at 5 min and then decreased to 1.60 ± 0.78 in 6 h. The systemic radioactivity reached a maximum of 211.05 ± 6.77 (%ID$\times$103) at 5 min and decreased to 7.18 ± 3.91 in 6 h. The sensitivity and positive predictive value were 100% and 100% based on both pathologic and imaging confirmation as gold standard. In Cohort 1, 15 primary foci (11.9%) were >5 mm in the largest diameter and identified in 39 of 126 segments (30.1%). The sensitivity, specificity, positive predictive value, negative predictive value, and accuracy for 60 min uptake time acquisition were 80.0, 96.5, 91.4, 91.2 and 91.3%, respectively. CONCLUSIONS: Our study revealed that 18F-PSMA 1007 was safe, well tolerated and showed high accuracy in the diagnosis of prostate cancer.

Prognostic impact of the radiological infiltrative feature of primary renal tumor in metastatic renal cell carcinoma.

OBJECTIVES: Recent studies suggest that the radiological infiltrative feature (r-IF) of renal tumors is strongly correlated with poor oncologic outcomes in locally advanced renal cell carcinoma (RCC). This study investigated the prognostic impact of r-IF of primary renal tumors in metastatic RCC (mRCC) in comparison with International Metastatic RCC Database Consortium (IMDC) risk model. METHODS: We retrospectively analyzed 91 patients with previously untreated mRCC. Dynamic computed tomography of the primary renal tumor was reviewed to assess r-IF, defined as a focally/extensively ill-defined tumor interface with normal renal parenchyma. RESULTS: The median age was 67 years, and 69 patients (76%) were men. Prior nephrectomy was performed in 47 patients (52%). The median size of the primary renal tumor was 6.7 cm, and 50 patients (55%) presented with cT3-4 stage. Overall, 25 (28%)/52 (57%)/14 (15%) patients were classified into IMDC favorable/intermediate/poor-risk groups, respectively. An image review identified r-IFs in the primary renal tumor in 40 patients (44%). The incidences of r-IFs were 28%/46%/64% in IMDC favorable/intermediate/poor-risk groups, respectively. During a median follow-up of 2.6 years, 31 patients (34%) died of RCC. On multivariable analysis, r-IF and IMDC intermediate-poor risks were independently associated with poor cancer-specific survival (CSS). Two-year CSS were 64%/87% in patients with/without r-IF, respectively. C-index was improved from 0.73 to 0.81 by adding r-IF to the IMDC risk factors. CONCLUSIONS: R-IF of the primary renal tumor was an independent risk factor for poor CSS in patients with mRCC, which may improve the prognostic accuracy when combined with the IMDC risk model.

Novel utility of Vesical Imaging-Reporting and Data System in multimodal treatment for muscle-invasive bladder cancer.

OBJECTIVES: To examine the clinical significance of the Vesical Imaging-Reporting and Data System (VI-RADS) in predicting outcome of multimodal treatment (MMT) in muscle-invasive bladder cancer (MIBC) patients. METHODS: We reviewed 78 pathologically proven MIBC patients who underwent MMT including transurethral resection and chemoradiotherapy, followed by partial or radical cystectomy. Treatment response was assessed through histologic evaluation of cystectomy specimens. Two radiologists categorized the index lesions of pretherapeutic MRI according to the 5-point VI-RADS score. The associations of VI-RADS score with the therapeutic effect of MMT were analyzed. The diagnostic performance of VI-RADS scores with a cut-off VI-RADS scores ≤ 2 or ≤ 3 for predicting pathologic complete response to MMT (MMT-CR) was evaluated. RESULTS: MMT-CR was achieved in 2 (100%) of VI-RADS score 1 (n = 2), 16 (84%) of score 2 (n = 19), 12 (86%) of score 3 (n = 14), 7 (64%) of score 4 (n = 11), and 14 (44%) of score 5 (n = 32). VI-RADS score was inversely associated with the incidence of MMT-CR (p = 0.00049). The cut-off VI-RADS score ≤ 2 and ≤ 3 could predict the favorable therapeutic outcome of MMT with high specificity (0.89 with 95% confidence interval [CI]: 0.71-0.98 and 0.82 with 95% CI: 0.62-0.94, respectively) and high positive predictive value (0.86 with 95% CI: 0.64-0.97 and 0.86 with 95% CI: 0.70-0.95, respectively). CONCLUSION: VI-RADS score may serve as an imaging marker in MIBC patients for predicting the therapeutic outcome of MMT. CLINICAL RELEVANCE STATEMENT: Muscle-invasive bladder cancer patients with a lower Vesical Imaging-Reporting and Data System score can be a good candidate for bladder-sparing treatment incorporating multimodal treatment. KEY POINTS: • Vesical Imaging-Reporting and Data System (VI-RADS) score was potentially valuable for classifying pathologic tumor response in patients with muscle-invasive bladder cancer. • The likelihood of achieving complete response of multimodal treatment (MMT) decreased with increasing VI-RADS score. • VI-RADS score could serve as an imaging marker that optimizes patient selection for MMT.

Defining Tumour Shape Irregularity for Preoperative Risk Stratification of Clinically Localised Renal Cell Carcinoma.

Background: Unexpected adverse pathology is a major concern in surgical management of clinically localised renal cell carcinoma (RCC). Further studies are needed to improve preoperative risk stratification. Objective: To define and classify tumour shape irregularity (TSI) based on preoperative imaging, and to investigate its effect on pathological and oncological outcomes in clinically localised RCC. Design setting and participants: We retrospectively analysed 474 patients with cT1-2N0M0 RCC managed by partial or radical nephrectomy. Preoperative dynamic computed tomography was used to define and classify TSI, graded as 1 (completely elliptical shape), 2 (elliptical shape with minor and focal protrusions), or 3 (nonelliptical shape presenting with major and/or extensive protrusions). Intervention: Partial or radical nephrectomy. Outcome measurements and statistical analysis: A logistic regression analysis evaluated the risk factors for pT3a upstaging and Fuhrman grade 3-4. A Cox proportional hazard analysis assessed preoperative variables for recurrence-free survival (RFS). Results and limitations: The median tumour size was 3.5 cm, and 94 patients (20%) had (R)adius (tumour size as maximal diameter), (E)xophytic/endophytic properties of tumour, (N)earness of tumour deepest portion to collecting system or sinus, (A)nterior (a)/posterior (p) descriptor, and (L)ocation relative to polar lines (RENAL) score ≥10. TSI was graded as 1, 2, and 3 in 214 (45%), 151 (32%), and 109 (23%) patients, respectively. Higher TSI was significantly associated with a larger tumour size and a higher RENAL score. Overall, pT3a upstaging and Fuhrman grade 3-4 were observed in 45 (9.5%) and 116 patients (31% in 380 clear cell RCC cases), respectively. The incidence of pT3a upstaging and Fuhrman grade 3-4 was significantly higher in patients with higher TSI (0.5%, 8.6%, and 28% for pT3a upstaging and 12%, 33%, and 60% for Fuhrman grade 3-4 in TSI 1, 2, and 3 groups, respectively). In multivariable analyses, higher TSI was independently associated with adverse pathological outcomes. During the median follow-up of 6.0 yr, 49 patients (10%) developed recurrence. Multivariable analyses demonstrated that older age and higher TSI were independent risk factors for worse RFS. The limitations include the retrospective design. Conclusions: TSI may be a useful adjunct in preoperative risk stratification for adverse pathology and recurrence after surgery in clinically localised RCC. Patient summary: Tumour shape irregularity is significantly associated with unfavourable pathological outcomes, that is, locally advanced stage or high-grade cancer, and with a higher recurrence rate after surgery in patients with clinically localised renal cell carcinoma. Preoperative evaluation of the tumour shape may help in patient counselling and treatment decisions.

Patterns of recurrence in genuine and induced oligometastatic castration-resistant prostate cancer treated with progressive site-directed therapy.

OBJECTIVES: To describe oncological outcomes after progressive site-directed therapy (PSDT) in genuine and induced oligometasatic (OM)-castration-resistant prostate cancer (CRPC). METHODS: Thirty-seven patients with OM-CRPC treated with PSDT were retrospectively analyzed, and oncological outcomes and recurrence patterns on whole-body diffusion-weighted MRI (WB-DWI) were evaluated. RESULTS: Twenty-two (59%) were classified as genuine OM-CRPC and 15 (41%) as induced OM-CRPC. A 50% decline in PSA after PSDT was observed in 21 (95%) genuine OM-CRPCs and 7 (47%) induced OM-CRPCs (p = 0.0005). At a median observation period of 7.3 months, median PSA progression-free survival were 10.9 months in the genuine OM-CRPCs and 4.8 months in the induced OM-CRPCs (p = 0.015). Among the patients who developed PSA progression after PSDT, 11 of 15 in the genuine OM-CRPCs (73%) and 11 of 14 in the induced OM-CRPCs (79%) underwent WB-DWI at PSA progression. The median numbers of newly detected metastases were 2 (range: 1-5) in the genuine OM-CRPCs and 4 (range: 1-40) in the induced OM-CRPCs (p = 0.049). Only one new metastasis appeared in 5 patients from the genuine OM-CRPCs (46%) and 1 from the induced OM-CRPCs (9.1%, p = 0.048). In 7 of 9 patients from the genuine OM-CRPCs (78%) and 7 of 8 patients from the induced OM-CRPCs (88%) who had bone metastases alone, the newly detected metastasis limited to the bone. CONCLUSIONS: Genuine OM-CRPC had better oncological outcomes after PSDT than induced OM-CRPC, and the number of lesions detected at recurrence was limited. Induced OM-CRPC might be a disseminated condition with micrometastases at OM diagnosis.

Motility Mapping Quantification Using the Classical Optical Flow Algorithm for Small Bowel Crohn's Disease: Comparison with Balloon-assisted Enteroscopy Findings.

PURPOSE: To quantify bowel motility shown on cine MRI using the classical optical flow algorithm and compare it with balloon-assisted enteroscopy (BAE) findings in patients with Crohn's disease (CD). METHODS: This retrospective study included 29 consecutive patients with CD who had undergone MR enterocolonography (MREC) and BAE between March and May 2017. We developed computer software to present motion vector magnitudes between consecutive cine MR images as bowel motility maps via a classical optical flow algorithm using the Horn-Schunck method. Cine MR images were acquired with a balanced steady-state free precession sequence in the coronal direction to capture small bowel motility. The small bowels were divided into three segments. In total, 63 bowel segments were assessed via BAE and MREC. Motility scores on the maps, simplified MR index of activity (sMaRIA), and MREC score derived from a 5-point MR classification were assessed independently by two radiologists and compared with the CD endoscopic index of severity (CDEIS). Correlations were assessed using Spearman's rank coefficient. The areas under the receiver-operating characteristic curve (AUCs) of motility score for differentiating CDEIS was calculated; a P value < 0.05 was considered statistically significant. RESULTS: Motility score was negatively correlated with CDEIS (r = -0.59 [P < 0.001] and -0.54 [P < 0.001]), and the AUCs of motility scores for detecting CDEIS ≥ 3 were 88.2% and 78.6% for observers 1 and 2, respectively. There were no significant differences in the AUC for detecting CDEIS ≥ 3 and CDEIS ≥ 12 between motility and sMaRIA or MREC score. CONCLUSION: The motility map was feasible for locally quantifying the bowel motility. In addition, the motility score on the map reflected the endoscopic inflammatory activity of each small bowel segment in patients with CD; hence, it could be used as a tool in objectively interpreting cine MREC to predict inflammatory activity in CD.

Enhancement of 18F-Fluorodeoxyglucose PET Image Quality by Deep-Learning-Based Image Reconstruction Using Advanced Intelligent Clear-IQ Engine in Semiconductor-Based PET/CT Scanners.

Deep learning (DL) image quality improvement has been studied for application to 18F-fluorodeoxyglucose positron emission tomography/computed tomography (18F-FDG PET/CT). It is unclear, however, whether DL can increase the quality of images obtained with semiconductor-based PET/CT scanners. This study aimed to compare the quality of semiconductor-based PET/CT scanner images obtained by DL-based technology and conventional OSEM image with Gaussian postfilter. For DL-based data processing implementation, we used Advanced Intelligent Clear-IQ Engine (AiCE, Canon Medical Systems, Tochigi, Japan) and for OSEM images, Gaussian postfilter of 3 mm FWHM is used. Thirty patients who underwent semiconductor-based PET/CT scanner imaging between May 6, 2021, and May 19, 2021, were enrolled. We compared AiCE images and OSEM images and scored them for delineation, image noise, and overall image quality. We also measured standardized uptake values (SUVs) in tumors and healthy tissues and compared them between AiCE and OSEM. AiCE images scored significantly higher than OSEM images for delineation, image noise, and overall image quality. The Fleiss kappa value for the interobserver agreement was 0.57. Among the 21 SUV measurements in healthy organs, 11 (52.4%) measurements were significantly different between AiCE and OSEM images. More pathological lesions were detected in AiCE images as compared with OSEM images, with AiCE images showing higher SUVs for pathological lesions than OSEM images. AiCE can improve the quality of images acquired with semiconductor-based PET/CT scanners, including the noise level, contrast, and tumor detection capability.

Apparent Diffusion Coefficient Map-Based Texture Analysis for the Differentiation of Chromophobe Renal Cell Carcinoma from Renal Oncocytoma.

Preoperative imaging differentiation between ChRCC and RO is difficult with conventional subjective evaluation, and the development of quantitative analysis is a clinical challenge. Forty-nine patients underwent partial or radical nephrectomy preceded by MRI and followed by pathological diagnosis with ChRCC or RO (ChRCC: n = 41, RO: n = 8). The whole-lesion volume of interest was set on apparent diffusion coefficient (ADC) maps of 1.5T-MRI. The importance of selected texture features (TFs) was evaluated, and diagnostic models were created using random forest (RF) analysis. The Mean Decrease Gini as calculated through RF analysis was the highest for mean_ADC_value. ChRCC had a significantly lower mean_ADC_value than RO (1.26 vs. 1.79 × 10−3 mm2/s, p < 0.0001). Feature selection by the Boruta method identified the first-quartile ADC value and GLZLM_HGZE as important features. ROC curve analysis showed that there was no significant difference in the classification performances between the mean_ADC_value-only model and the Boruta model (AUC: 0.954 vs. 0.969, p = 0.236). The mean ADC value had good predictive ability for the distinction between ChRCC and RO, comparable to that of the combination of TFs optimized for the evaluated cohort. The mean ADC value may be useful in distinguishing between ChRCC and RO.

Multiparametric magnetic resonance imaging of plasmacytoid urothelial carcinoma with histopathological correlation: A case report.

Plasmacytoid urothelial carcinomas of the bladder are rare, aggressive variants with a poor prognosis. Few reports have described the correlation of histopathological features with multiparametric magnetic resonance imaging findings in the local staging of plasmacytoid urothelial carcinoma. An 82-year-old woman with hematuria was referred to our hospital. Magnetic resonance imaging showed diffuse bladder wall thickening, with different signal intensities in the 2 layers-inner and outer. This case suggests that the presence of diffuse bladder wall thickening and varying signal intensities in the 2 layers could aid in the local staging of plasmacytoid urothelial carcinoma. A thickened bladder wall with restricted diffusion suggests tumor invasion, indicating that the tumor can invade the organ in contact with the thickened bladder wall.

Dose Reduction and Diagnostic Performance of Tin Filter-Based Spectral Shaping CT in Patients with Colorectal Cancer.

Routine CT examinations are crucial in colorectal cancer patients (CCPs); however, the high frequency of radiation exposure is a significant concern. This study investigated the radiation dose, image quality, and diagnostic performance of tin filter-based spectral shaping chest−abdominal−pelvic (CAP) CT for CCPs. We reviewed 44 CCPs who underwent single-phase enhanced tin-filtered 100 kV (TF100kV) and standard 120 kV (ST120kV) CAP CT on separate days. Radiation metrics including the volume CT dose index (CTDIvol), dose-length product (DLP), and effective dose (ED) were calculated for both protocols. Two radiologists assessed the presence of the following lesions: lung metastasis, liver metastasis, lymph node metastasis, peritoneal dissemination, and bone metastasis. The area under the receiver operating characteristic curve (AUC) was calculated for the diagnostic performance of each protocol. Radiation metrics of the TF100kV protocol were significantly lower than those of the ST120kV protocol (CDTIvol 1.60 ± 0.31 mGy vs. 14.4 ± 2.50, p < 0.0001; DLP 107.1 (95.9−125.5) mGy·cm vs. 996.7 (886.2−1144.3), p < 0.0001; ED 1.93 (1.73−2.26) mSv vs. 17.9 (16.0−20.6), p < 0.0001, respectively). TF100kV protocol achieved comparable diagnostic performance to that of the ST120kV protocol (AUC for lung metastasis: 1.00 vs. 0.94; liver metastasis: 0.88 vs. 0.83, respectively). TF100kV protocol could substantially reduce the radiation dose by 89% compared to that with the ST120kV protocol while maintaining good diagnostic performance in CCPs.

Utility of radiomics features of diffusion-weighted magnetic resonance imaging for differentiation of fat-poor angiomyolipoma from clear cell renal cell carcinoma: model development and external validation.

PURPOSE: To investigate the utility of radiomics features of diffusion-weighted magnetic resonance imaging (DW-MRI) to differentiate fat-poor angiomyolipoma (fpAML) from clear cell renal cell carcinoma (ccRCC). MATERIALS AND METHODS: This multi-institutional study included two cohorts with pathologically confirmed renal tumors: 65 patients with ccRCC and 18 with fpAML in the model development cohort, and 17 with ccRCC and 13 with fpAML in the external validation cohort. All patients underwent magnetic resonance imaging (MRI) including DW-MRI. Radiomics analysis was used to extract 39 imaging features from the apparent diffusion coefficient (ADC) map. The radiomics features were analyzed with unsupervised hierarchical cluster analysis. A random forest (RF) model was used to identify radiomics features important for differentiating fpAML from ccRCC in the development cohort. The diagnostic performance of the RF model was evaluated in the development and validation cohorts. RESULTS: The cases in the developmental cohort were classified into three groups with different frequencies of fpAML by cluster analysis of radiomics features. RF analysis of the development cohort showed that the mean ADC value was important for differentiating fpAML from ccRCC, as well as higher-texture features including gray-level run length matrix (GLRLM)_long-run low gray-level enhancement (LRLGE), and GLRLM_low gray-level run emphasis (LGRE). The area under the curve values of the development [0.90, 95% confidence interval (CI) 0.80-1.00] and validation cohorts (0.87, 95% CI 0.74-1.00) were similar (P = 0.91). CONCLUSION: The radiomics features of ADC maps are useful for differentiating fpAML from ccRCC.

Clinical utility of comprehensive genomic profiling in Japan: Result of PROFILE-F study.

INTRODUCTION: Clinical sequencing has provided molecular and therapeutic insights into the field of clinical oncology. However, despite its significance, its clinical utility in Japanese patients remains unknown. Here, we examined the clinical utility of tissue-based clinical sequencing with FoundationOne® CDx and FoundationOne® Heme. Between August 2018 and August 2019, 130 Japanese pretreated patients with advanced solid tumors were tested with FoundationOne® CDx or FoundationOne® Heme. RESULTS: The median age of 130 patients was 60.5 years (range: 3 to 84 years), and among them, 64 were males and 66 were females. Major cancer types were gastrointestinal cancer (23 cases) and hepatic, biliary, and pancreatic cancer (21 cases). A molecular tumor board had been completed on all 130 cases by October 31, 2019. The median number of gene alterations detected by Foundation testing, excluding variants of unknown significance (VUS) was 4 (ranged 0 to 21) per case. Of the 130 cases, one or more alterations were found in 123 cases (94.6%), and in 114 cases (87.7%), actionable alterations with candidates for therapeutic agents were found. In 29 (22.3%) of them, treatment corresponding to the gene alteration was performed. Regarding secondary findings, 13 cases (10%) had an alteration suspected of a hereditary tumor. Of the 13 cases, only one case received a definite diagnosis of hereditary tumor. CONCLUSIONS: Our study showed that clinical sequencing might be useful for detecting gene alterations in various cancer types and exploring treatment options. However, many issues still need to be improved.

Impact of Progressive Site-Directed Therapy in Oligometastatic Castration-Resistant Prostate Cancer on Subsequent Treatment Response.

The purpose of this study was to evaluate the impact of progressive site-directed therapy (PSDT) for oligometastatic castration-resistant prostate cancer (OM-CRPC) on the efficacy of subsequent androgen receptor axis-targeted (ARAT) drugs, and to demonstrate the possibility of prolonging overall survival (OS). We performed a retrospective analysis of 15 OM-CRPC patients who underwent PSDT and subsequently received first-line ARAT drugs (PSDT group) and 13 OM-CRPC patients who were treated with first-line ARAT drugs without PSDT (non-PSDT group). PSDT was performed with the intention of treating all progressing sites detected by whole-body diffusion-weighted MRI with radiotherapy. Thirteen patients (86.7%) treated with PSDT had a decrease in PSA levels, which was at least 50% in 10 (66.7%) patients. The median PSA progression-free survival (PFS) for PSDT was 7.4 months. The median PSA-PFS for ARAT was 27.2 months in patients in the PSDT group and 11.7 months in the non-PSDT group, with a significant difference between the two groups (hazard ratio [HR], 0.28; p = 0.010). The median OS was not reached in the PSDT group and was significantly longer than 44.5 months in the non-PSDT group (HR, 0.11; p = 0.014). In OM-CRPC, PSDT may improve the efficacy of subsequent ARAT and OS.

Usefulness of texture features of apparent diffusion coefficient maps in predicting chemoradiotherapy response in muscle-invasive bladder cancer.

OBJECTIVES: To examine the usefulness of the texture analysis (TA) of apparent diffusion coefficient (ADC) maps in predicting the chemoradiotherapy (CRT) response of muscle-invasive bladder cancer (MIBC). METHODS: We reviewed 45 MIBC patients who underwent cystectomy after CRT. CRT response was assessed through histologic evaluation of cystectomy specimens. Two radiologists determined the volume of interest for the index lesions on ADC maps of pretherapeutic 1.5-T MRI and performed TA using the LIFEx software. Forty-six texture features (TFs) were selected based on their contribution to the prediction of CRT sensitivity. To evaluate diagnostic performance, diagnostic models from the selected TFs were created using random forest (RF) and support vector machine (SVM), respectively. RESULTS: Twenty-three patients achieved pathologic complete response (pCR) to CRT. The feature selection identified first quartile ADC (Q1 ADC), gray-level co-occurrence matrix (GLCM) correlation, and GLCM homogeneity as important in predicting CRT response. Patients who achieved pCR showed significantly lower Q1 ADC and GLCM correlation values (0.66 × 10-3 mm2/s and 0.53, respectively) than those who did not (0.81 × 10-3 mm2/s and 0.70, respectively; p < 0.05 for both). The AUCs of the RF and SVM models incorporating the selected TFs were 0.82 (95% confidence interval [CI]: 0.67-0.97) and 0.96 (95% CI: 0.91-1.00), respectively, and the AUC of the SVM model was better than that of the mean ADC value (0.76, 95% CI: 0.61-0.90; p = 0.0037). CONCLUSION: TFs can serve as imaging biomarkers in MIBC patients for predicting CRT sensitivity. TAs of ADC maps can potentially optimize patient selection for CRT. KEY POINTS: • Texture analysis of ADC maps and feature selection identified important texture features for classifying pathologic tumor response in patients with muscle-invasive bladder cancer. • The machine learning model incorporating the texture features set, which included first quartile ADC, GLCM correlation, and GLCM homogeneity, showed high performance in predicting chemoradiotherapy response. • Texture features could serve as imaging biomarkers that optimize eligible patient selection for chemoradiotherapy in muscle-invasive bladder cancer.

Can Deep Learning-Based Volumetric Analysis Predict Oxygen Demand Increase in Patients with COVID-19 Pneumonia?

Background and Objectives: This study aimed to investigate whether predictive indicators for the deterioration of respiratory status can be derived from the deep learning data analysis of initial chest computed tomography (CT) scans of patients with coronavirus disease 2019 (COVID-19). Materials and Methods: Out of 117 CT scans of 75 patients with COVID-19 admitted to our hospital between April and June 2020, we retrospectively analyzed 79 CT scans that had a definite time of onset and were performed prior to any medication intervention. Patients were grouped according to the presence or absence of increased oxygen demand after CT scan. Quantitative volume data of lung opacity were measured automatically using a deep learning-based image analysis system. The sensitivity, specificity, and area under the receiver operating characteristic curve (AUC) of the opacity volume data were calculated to evaluate the accuracy of the system in predicting the deterioration of respiratory status. Results: All 79 CT scans were included (median age, 62 years (interquartile range, 46-77 years); 56 (70.9%) were male. The volume of opacity was significantly higher for the increased oxygen demand group than for the nonincreased oxygen demand group (585.3 vs. 132.8 mL, p < 0.001). The sensitivity, specificity, and AUC were 76.5%, 68.2%, and 0.737, respectively, in the prediction of increased oxygen demand. Conclusion: Deep learning-based quantitative analysis of the affected lung volume in the initial CT scans of patients with COVID-19 can predict the deterioration of respiratory status to improve treatment and resource management.