Japanese Journal of Radiology最新文献

Background and purpose: Loss of skeletal muscle mass is increasingly recognized as a poor prognostic indicator in patients with cancer, including those with head and neck squamous cell carcinoma (HNSCC). Emerging evidence suggests that the muscle area measured at the third cervical vertebra (C3) on CT serves as a practical surrogate for whole-body muscle status. This study aimed to evaluate the prognostic significance of C3-level body composition parameters in patients with HNSCC undergoing definitive radiotherapy.

Materials and methods: A total of 283 consecutive patients with HNSCC treated with definitive radiotherapy between 2013 and 2023 were retrospectively analyzed. Pre-treatment CT scans were used to assess six body composition metrics at the C3 level: skeletal muscle area (SMA), mean skeletal muscle density, visceral adipose tissue area, subcutaneous adipose tissue area, visceral-to-subcutaneous fat ratio, and skeletal muscle fat infiltration index. Patients were stratified into high and low groups based on sex-specific median values. Associations between each body composition metric (high vs. low) and survival outcomes were assessed using univariate and multivariate analyses.

Results: The cohort included 238 males and 45 females, with a median age of 67 years. Survival analysis showed a median follow-up period of 39.3 months. The 3-year overall survival (OS) rate for the entire cohort was 81.6%, and the 3-year progression free survival rate was 60.8%. In univariate analysis, only low SMA was significantly associated with poorer OS (hazard ratio: 1.841, p = 0.027). The median SMA was 35.0 cm² for males and 23.5 cm² for females. In multivariate analysis, low SMA remained an independent predictor of reduced OS (hazard ratio: 1.851, p = 0.028), along with clinical stage and chemotherapy status.

Conclusion: Among the CT-derived body composition parameters assessed at the C3 level, low SMA was the only significant independent predictor of OS in patients with HNSCC receiving definitive radiotherapy. These findings support the clinical relevance of SMA assessment as a straightforward and robust prognostic biomarker and underscore the need for further investigation into the prognostic potential of other body composition metrics.

Purpose: In patients with reduced remote flow, dynamic stress CT perfusion imaging (CTP) has limited utility for detecting obstructive coronary artery disease (CAD). We compared fractal analysis, a descriptor of macro- and microvascular ischemia patterns, with relative myocardial blood flow (MBF) for detecting obstructive CAD stratified by remote flow.

Materials and methods: This secondary analysis of the prospective multi-center AMPLIFiED trial included patients who underwent invasive coronary angiography (ICA) with fractional flow reserve (FFR) and dynamic stress CTP. Obstructive CAD was defined invasively (stenosis ≥ 90% or FFR < 0.8). We assessed diagnostic accuracy of fractal analysis and relative MBF in patient groups subdivided into high, intermediate, and low remote flow.

Results: In 148 patients (30% female; 416 vessels), obstructive CAD was present in 71/148 patients (48%), while signs of microvascular ischemia were found in 26/148 patients (prevalence in high, intermediate, low remote flow: 9%, 37%, 70%). Fractal analysis outperformed relative MBF in detecting obstructive CAD (patient-based sensitivity and specificity: 94% and 92% versus 80% and 64%, p < 0.005). In vessel-based subgroup analysis, both methods performed comparably in high remote flow (area under the receiver-operating curve [AUC]: 0.94 versus 0.88, p = 0.45), while fractal analysis outperformed relative MBF in intermediate and low remote flow (AUC: 0.93 versus 0.77, p = 0.004; 0.92 versus 0.6, p < 0.001).

Conclusion: Fractal analysis eliminates reliance on remote flow for CTP imaging, which improves diagnostic accuracy for obstructive CAD particularly in patients with reduced remote flow or microvascular ischemia.

Trial registration: This study reports about data from the prospective, multi-center AMPLIFiED trial (UMIN000016353).

Purpose: NUT (nuclear protein in testis) carcinoma is a highly aggressive malignancy with poor prognosis, often leading to under-diagnosis due to limited recognition of its radiological features. This study aims to comprehensively analyze the radiological characteristics of sinonasal NUT carcinoma through a systematic review supplemented by institutional cases to facilitate early diagnosis and appropriate treatment planning.

Materials and methods: A systematic review of MEDLINE, Scopus, and Embase databases was conducted following PRISMA 2020 guidelines to identify studies reporting CT and/or MRI features of sinonasal NUT carcinoma published up to May 29, 2024. Additional cases from our institution were included. Two board-certified radiologists with 15 and 18 years of experience jointly evaluated all images by consensus.

Results: The study included 35 lesions from 35 patients (5 institutional, 30 from literature). Mean age was 37.3 years with equal sex distribution. The most commonly involved locations were ethmoid sinus (57.1%), nasal cavity (51.4%), and maxillary sinus (31.4%), with mean lesion diameter of 4.5 cm. On CT, all lesions demonstrated heterogeneous moderate enhancement, with calcification in 25.0% of cases. MRI revealed variable T2 signal intensities: mixed iso- and high signal (41.7%), high signal (33.3%), and mixed iso- and low signal (8.3%). Contrast-enhanced MRI showed heterogeneous moderate enhancement in 93.3% of cases. Necrotic areas were present in 48.1% of cases. Mean ADC value was 0.84 × 10⁻³ mm²/s. Invasive/destructive changes occurred in 91.4% of cases, with intraorbital extension in 52.9% and intracranial extension in 29.4%.

Conclusion: Sinonasal NUT carcinoma demonstrates characteristic imaging features including predilection for ethmoid sinus and nasal cavity, heterogeneous enhancement, and extensive invasive/destructive changes with frequent orbital and intracranial extension. While these features overlap with other sinonasal malignancies, recognition of these patterns may facilitate earlier diagnosis of this rare but highly aggressive tumor.

Purpose: Radioactive iodine therapy (RAIT) is used to treat patients with thyroid cancer at high risk of recurrence or those with distant metastases. Small amounts of iodine-131 (I-131) are excreted in the stool after RAIT. Thyroid hormone withdrawal (THW) before RAIT can cause constipation, increasing radiation exposure to the colon. Although measuring colonic radiation using I-131 dosimetry would be challenging, colonic radiation dose can be estimated using I-131 whole-body scintigraphy post-RAIT. Therefore, we aimed to determine the clinical risk factors, including THW, associated with colonic distribution on I-131 scintigraphy post-RAIT.

Materials and methods: We analyzed 251 patients who received 530 RAITs, categorized into two groups based on the preparation method. We compared the relationship between clinical risk factors (including preparation method) and colonic I-131 distribution 3 d post-RAIT. In addition, we compared the frequency and degree of colonic I-131 distribution between patients who received RAITs with stimulant laxatives and those who received RAITs with osmotic laxatives. Four subgroup analyses were conducted based on the preparation method and defecation frequency.

Results: We performed 253 RAITs (47.7%) using recombinant human thyrotropin, while the remaining 277 RAITs (52.3%) were performed using THW. In the multivariate analysis, THW, higher RAIT dose (≥ 3.7 GBq), and fewer defecation frequencies (≤ 2 times) were significantly associated with a higher frequency of colonic I-131 distribution (p = 0.0206, 0.0020, and 0.0006, respectively). Of the patients treated using THW RAITs, which relieved constipation, those treated with RAITs with stimulant laxatives had significantly lower colonic I-131 distribution than did those treated with RAITs with osmotic laxatives (p = 0.0378).

Conclusion: THW, high-dose RAIT, and defecation frequency were significantly associated with colonic I-131 distribution. Pre-treatment strategies, such as the use of stimulant laxatives should be considered to reduce colonic radiation exposure.

Imaging-detected extranodal extension (iENE) is increasingly recognized as an objective adverse prognostic factor in head and neck cancer. The newly published 9th edition of the UICC/AJCC TNM Classification now incorporates iENE into the nodal (N) categories for nasopharyngeal carcinoma, HPV-associated oropharyngeal carcinoma, and salivary gland carcinoma, typically upstaging patients to higher N categories, and designates imaging findings as an accepted standard for the clinical ENE (cENE) as the N3b category in all other head and neck subsites. To establish diagnostic criteria for iENE, the Head and Neck Cancer International Group (HNCIG) has proposed a four-tier grading system (2024): Grade 0 (iENE-negative), Grade 1 (perinodal fat extension), Grade 2 (coalescent lymph nodes), and Grade 3 (invasion of adjacent structures). Each grade carries distinct clinical implications, ranging from treatment de-escalation for Grade 0 to consideration of unresectable disease for Grade 3. Recent advances in ultra-high-resolution imaging, particularly photon-counting detector CT (PCD-CT) with 1024 × 1024 matrix in super-high-resolution (SHR) mode, may offer the spatial details necessary to more reliably detect these subtle findings compared with conventional imaging. Through direct comparisons with histopathological correlations, we demonstrate the potential of high-resolution imaging in detecting iENE. PCD-CT, with its simultaneous spectral imaging capabilities-including virtual monochromatic imaging-enhances soft tissue contrast for detecting subtle ENEs. In addition, material decomposition maps aid in the precise evaluation of tumor-tissue interfaces. This comprehensive review is an educational resource for radiologists applying the HNCIG consensus criteria including the newly adopted TNM staging requirements. While advanced imaging technologies such as PCD-CT show promising potential for enhanced tissue characterization, further validation studies are needed to establish their clinical utility in routine iENE assessment.

Purpose: External-beam radiation therapy is a treatment option for muscle-invasive bladder cancer (MIBC), which enables bladder preservation and is applicable to elderly or medically fragile patients. Since the accuracy of conventional intensity-modulated radiation therapy is vulnerable to even small daily changes, online adaptive radiation therapy (ART) may be a more appropriate option. This study aimed to evaluate the feasibility of cone-beam computed tomography (CBCT)-based online ART for MIBC in elderly or medically fragile patients.

Materials and methods: We applied CBCT-based online ART to treat two elderly patients with dementia and N0 M0 MIBC, who were deemed poor candidates for surgery or systemic therapies. A cumulative dose of 55 Gy in 20 fractions over 4 weeks was prescribed. Online ART was administered using Ethos™ Therapy.

Results: Both patients were able to follow the prescribed protocols with assistance (e.g., bladder voiding or filling and maintaining the treatment position), although full adherence was hindered by dementia. Nonetheless, they successfully completed the entire treatment regimen with manageable acute toxicities. The median treatment session duration was 23 (range 14-50, interquartile range 19-30) min. The median volume receiving at least 90% of the prescribed dose (V_90%) of the bowels was 1.25 (range 0.01-6.77) cm³ in the adapted plans and 24.78 (range 6.80-90.72) cm³ in the scheduled plan (P < 0.001) in the first patient, and 0.13 (range 0.00-2.96) cm³ in the adapted plans and 9.60 (range 4.65-18.62) cm³ in the scheduled plan (P < 0.001) in the second patient, respectively. A significant volume of the bowels was spared from receiving high doses in the adapted plans without compromising the target dose coverage.

Conclusions: CBCT-based online ART was considered a feasible therapeutic option for elderly or medically fragile patients with MIBC.

Objective: Chyloptysis indicates the presence of a lymphangio-bronchial fistula. This study compared the chest CT imaging features and clinical manifestations between CLA (complex lymphatic anomalies) patients with and without chyloptysis.

Materials and methods: A retrospective analysis was performed on 291 thoracic CLA patients (142 males, 149 females) admitted from December 2008 to February 2024. Divided into chyloptysis (152) and non-chyloptysis (139) groups, we compared their clinical data and chest CT features to find differences related to chyloptysis in CLA patients.

Results: The chyloptysis group had a significantly higher incidence of chyle pericardium, as well as more cystic lesions at the right lymphatic duct, and of the thoracic duct itself. In contrast, the non-chyloptysis group showed more cystic lesions of the liver, spleen, abdominal cavity, neck, and skeleton. All these differences were statistically significant (P < 0.05).The incidence of lymphedema in the non-chyloptysis group was higher than that in the chyloptysis group (P < 0.05), among which there was a significant statistical correlation between lymphedema of the lower limbs, lymphedema of the scrotum, lymphedema of the face and lymphedema of the upper limbs and chyloptysis (P < 0.05). The severity of chylopulmonary disease was closely related to the appearance of chyloptysis (P < 0.001). In terms of the characteristics of chest CT findings, the incidence of GGO, consolidation, grid shadow, vacuolar sign, nodular pleural thickening, solid nodules, perifascicular interstitial thickening, hilar opacity or swelling, and parapericardial effusion were higher in the chyloptysis group than in the non-chyloptysis group (P < 0.05).

Conclusion: The analysis of these differences is of great clinical significance for understanding the distribution of chyloptysis in CLA patients with different CT signs, and it is convenient for clinicians to strengthen the risk prediction and management of chyloptysis in CLA patients.

Purpose: This study evaluates the prognostic value of baseline ¹⁸F-PSMA-1007 PET/CT-derived volumetric metabolic parameters in metastatic castration-resistant prostate cancer (mCRPC) patients initiating first-line androgen receptor pathway inhibitor (ARPI) therapy, while exploring their relationship with serum PSA and developing a risk stratification model.

Results: Both wbPSMA-TV (r = 0.70) and wbTL-PSMA (r = 0.67) correlated with baseline PSA. Multivariable analysis identified bone metastasis count (adjusted OR [aOR] 0.19, 95% CI 0.11-0.35; P < 0.001) and wbPSMA-TV (aOR = 0.77, 95% CI 0.65-0.91; P < 0.001) as independent predictors of early PSA response. Baseline wbTL-PSMA ≥ 231.4 SUV cm³ independently predicted shorter OS (10.3 vs. 22.2 months, P < 0.001). Multivariable Cox regression confirmed wbTL-PSMA (adjusted hazard ratio [aHR] 3.160, 95% CI 2.490-4.016; P < 0.001), wbPSMA-TV (aHR 3.010, 95% CI 2.467-3.683; P < 0.001), number of bone metastases (aHR 2.510, 95% CI 1.893-3.148; P < 0.001), and PSA level (aHR 2.995, 95% CI 2.810-3.190; P < 0.001) as OS determinants. The RF model stratified patients into low- (median OS not reached), intermediate-(11.8 months), and high-risk (9.55 months) groups (P < 0.001).

Conclusion: Baseline ¹⁸F-PSMA-1007 PET/CT-derived volumetric parameters (wbPSMA-TV and wbTL-PSMA) serve as independent prognostic biomarkers for survival in mCRPC patients receiving ARPI therapy. Integration of these metrics with clinical variables enhances risk stratification, potentially guiding personalized therapeutic strategies. Prospective validation is warranted to confirm clinical utility.

Purpose: Predicting treatment response in patients with colorectal cancer liver metastases (CRCLM) who have undergone transarterial radioembolization (TARE) based on pre-procedural fluorine-18-fluoro-deoxy glucose positron emission tomography (¹⁸F-FDG PET) radiomics and clinical information.

Materials and methods: Patients with CRCLM who underwent TARE, between March 2015 and May 2025, were consecutively included. Largest tumors were segmented semiautomatically using pre-procedural ¹⁸F-FDG PET images. Radiomics features were extracted, clinical information were collected. Two datasets were created comprising radiomics-only and clinico-radiomic features. Datasets were divided 60:40 for training and testing. Top 5 features were selected based on feature importances. Random Forest, Extreme Gradient Boosting, Logistic Regression models were trained. Test-set area under the curves (AUCs) for predicting post-treatment target lesion local progression were calculated and compared using DeLong's test. Sensitivity, specificity, accuracy and F1 scores were calculated at the optimal cut-offs.

Results: Seventy-four patients out of 96 patients were included. Top five selected features in the radiomics-only dataset were Coarseness, IMC1, Zone Entropy, Size-Zone Non-Uniformity, and Strength. In the clinico-radiomic dataset, AST and ALT levels were substituted among the top five features. Radiomics-only features demonstrated AUCs ranging from 0.90 (95% CI 0.71-1) to 0.81 (95% CI 0.51-1) in the test-set while clinico-radiomics dataset AUCs varied between 0.88 (95% CI 0.51-1) and 0.84 (0.62-1).

Conclusion: ¹⁸F-FDG PET radiomics based models can predict the local response to TARE in patients with CRCLM, in this series.