Can whole-body MRI replace CT in management of metastatic testicular cancer? A prospective, non-inferiority study.

PURPOSE: Concerns of imaging-related radiation exposure in young patients with high survival rates have increased the use of magnetic resonance imaging (MRI) in testicular cancer (TC) stage I. However, computed tomography (CT) is still preferred for metastatic TC. The purpose of this study was to compare whole-body MRI incl. diffusion-weighted whole-body imaging with background body signal suppression (DWIBS) with contrast-enhanced, thoracoabdominal CT in metastatic TC. METHODS: A prospective, non-inferiority study of 84 consecutive patients (median age 33 years) with newly diagnosed metastatic TC (February 2018-January 2021). Patients had both MRI and CT before and after treatment. Anonymised images were reviewed by experienced radiologists. Lesion malignancy was evaluated on a Likert scale (1 benign-4 malignant). Sensitivity, specificity, positive predictive value, negative predictive value and accuracy were calculated on patient and lesion level. The primary outcome was demonstrating non-inferiority regarding sensitivity of MRI compared to CT. The non-inferiority margin was set at 5%. ROC curves and interobserver agreement were calculated. RESULTS: On patient level, MRI had 98% sensitivity and 75% specificity compared to CT. On lesion level within each modality, MRI had 99% sensitivity and 78% specificity, whereas CT had 98% sensitivity and 88% specificity. MRI sensitivity was non-inferior to CT (difference 0.57% (95% CI - 1.4-2.5%)). The interobserver agreement was substantial between CT and MRI. CONCLUSION: MRI with DWIBS was non-inferior to contrast-enhanced CT in detecting metastatic TC disease. TRIAL REGISTRATION: www. CLINICALTRIALS: gov NCT03436901, finished July 1st 2021.

Multi-band whole-body diffusion-weighted imaging with inversion recovery fat saturation: Effects of respiratory compensation.

PURPOSE: To prospectively compare artefacts and image quality in testicular stage I cancer patients using different combinations of breathing schemes and Multi-band (MB) in whole-body DWIBS at 1.5 T.Diffusion-Weighted whole-body Imaging with Background body signal Suppression (DWIBS) using inversion recovery (IR) fat saturation is a cornerstone in oncologic whole-body MRI, but implementation is restrained by long acquisition times. The new Multi-Band (MB) technique reduces scan time which can be reinvested in respiratory compensation. METHODS: Thirty testicular cancer stage I patients were included. Three variations of whole-body DWIBS were tested: Standard free Breathing (FB)-DWIBS, FB-MB-DWIBS and Respiratory triggered (RT)-MB-DWIBS. Artefacts and image quality of b = 800 s/mm2 images were evaluated using a Likert scale. No pathology was revealed. SNR was calculated in a healthy volunteer. RESULTS: RT-MB-DWIBS was rated significantly better than FB-DWIBS in the thorax (p < 0.001) and abdomen (p < 0.001), but not in the pelvis (p = 0.569). FB-MB-DWIBS was ranked significantly lower than both FB-DWIBS (p < 0.001) and RT-MB-DWIBS (p < 0.001) at all locations. However, FB-MB-DWIBS was scanned in half the time without being less than "satisfactory". Few artefacts were encountered. SNR was similar for low-intensity tissues, but the SNR in high-intensity and respiratory-prone tissue (spleen) was slightly lower for FB-DWIBS than the other sequences. CONCLUSION: Images produced by the sequences were similar. MB enables the use of respiratory trigger or can be used to produce very fast free-breathing DWI with acceptable image quality.

Ten years of experience with MRI follow-up of testicular cancer stage I: a retrospective study and an MRI protocol with DWI.

INTRODUCTION: Patients with testicular cancer (TC) are mainly young and survival rates are high. MRI has several times been proposed to replace CT in follow-up of this patient group to reduce image-related radiation exposure. However, current evidence is scarce for the use of MRI in this context. AIMS: First, to retrospectively evaluate the ability of MRI of the retroperitoneum and pelvis to detect relapse in patients with TC stage I. Second, to present a relevant MRI protocol of the retroperitoneum and pelvis with diffusion weighted imaging (DWI). MATERIAL AND METHODS: A retrospective analysis of written radiology reports compared to clinical data from clinical practice from 2010 to 2018. The cohort consists of 2487 MRIs of the retroperitoneum and pelvis in 759 patients with TC stage I (524 seminoma (69.0%), 235 non-seminoma (31.0%)), including 102 patients (13.4%) with confirmed relapse. Confirmed relapse was defined when treatment was initiated for metastatic TC. RESULTS: Ninety-five patients had a relapse in the MRI scan field during follow-up. MRI of the retroperitoneum and pelvis showed a high sensitivity of 93.8% and a high specificity of 97.4% for detecting TC relapse. The sensitivity for detecting relapse ≥10 mm in short axis lymph node diameter was 100%. The negative predictive value was 99.7%, the positive predictive value was 59.9% and the accuracy was 97.3%. CONCLUSIONS: MRI of the retroperitoneum and pelvis constitutes a safe alternative to CT in follow-up of patients with TC stage I with both a high sensitivity and a high specificity. We present a robust MRI protocol with DWI and estimate that MRI follow-up of TC stage I can be easily implemented in most modern radiology departments. Registration: Conducted with permission from the Danish Data Protection Agency (1-16-02-323-16) and the Danish Health Authority.

The lateral joint space width can be measured reliably with Telos valgus stress radiography in medial knee osteoarthritis.

OBJECTIVE: To examine the reproducibility of valgus stress radiographs with the Telos stress device for assessment of lateral compartment degenerative changes in patients with medial osteoarthritis of the knee. MATERIALS AND METHODS: A prospective reliability study was performed. Seventy-nine patients (80 knees) were included, and standardized valgus stress radiographs were obtained using the Telos stress device. Osteophytes and joint space narrowing (JSN) were graded using the OARSI (Osteoarthritis Research Society International) classification, and the joint space width (JSW) was measured in millimeters. Reproducibility was determined as intra-and inter-rater reliability and test-retest reliability. Weighted kappa was used to determine the reliability of osteophyte and JSN grading, and the intra-class correlation coefficient for JSW. RESULTS: Grading of osteophytes had an intra- and inter-rater reliability ranging from 0.40 to 0.83 on the medial side and ranging from 0.39 to 0.87 on the lateral side. Grading of medial JSN had an intra- and inter-rater reliability ranging from 0.62 to 0.84, and grading of lateral JSN had an intra- and inter-rater reliability ranging from 0.32 to 0.65. Intra- and inter-rater reliability of JSW ranged from 0.84 to 0.98 on the medial side, and from 0.59 to 0.89 on the lateral side. Test-retest reliability of JSW of the medial and lateral side ranged from 0.69 to 0.92. CONCLUSIONS: Standardized valgus stress radiographs taken with the Telos stress device are a reliable supplement in the assessment of medial OA of the knee. Evaluation of the lateral compartment on valgus stress radiographs is most reliable with measurement of the lateral JSW.