Improving accuracy, reliability, and efficiency of the RENAL nephrometry score with 3D reconstructed virtual imaging

OBJECTIVE

To clarify the diagnostic performance of the three-dimensional reconstructed virtual image (3D-RVI) in evaluating RENAL nephrometry score (RENAL-NS).

METHODS

This study included 130 patients who underwent preoperative contrast-enhanced computed tomography (CECT) followed by partial nephrectomy for renal tumors suggestive of renal cell carcinoma. RENAL-NS was calculated prior to the surgery, and tumor resection was performed referring to the score. We retrospectively reviewed preoperative CECT images. We calculated the inter-observer variability of RENAL-NS using 3D-RVI versus two-dimensional (2D) imaging and compared the ability of RENAL-NS using 3D-RVI versus 2D imaging to predict the risk of opening of the urinary collecting system. We also compared the two modalities for the time required to evaluate RENAL-NS.

RESULTS

RENAL-NS evaluated using 3D-RVI showed a higher inter-observer agreement compared to 2D-imaging (r_s = 0.85 vs. r_s = 0.65). The "nearness to sinus" score was more strongly associated with the opening of the urinary collecting system when evaluated using 3D-RVI than 2D-imaging (AUC = 0.71 vs AUC = 0.57, p = 0.016). RENAL-NS using 2D-imaging required a significantly longer time compared to 3D-RVI (p = 0.036).

CONCLUSIONS

Using 3D-RVI improves the accuracy, reliability and efficiency of RENAL-NS evaluation in preoperative assessment and can play an important role in preoperative assessment and intraoperative navigation.

The utility of diffusion-weighted whole-body imaging with background body signal suppression in detecting metastatic lesion of germ cell carcinoma

INTRODUCTION

Although the utility of diffusion-weighted whole-body imaging with background body signal suppression for assessing lymph node involvement or distant metastasis is renowned in many cancers, only few studies have revealed its utility for germ cell carcinoma. Some metastatic lesions of germ cell carcinomas are difficult to detect by conventional imaging.

CASE PRESENTATION

We report a case of a 70-year-old man with relapsed retroperitoneal germ cell tumor. Although his human chorionic gonadotropin levels increased, conventional imaging analysis showed no evidence of recurrence. Diffusion-weighted whole-body imaging with background body signal suppression was performed to search the metastatic lesion and detected metastatic sacral lesions. The patient responded well to local radiotherapy added to the steroid pulse and salvage chemotherapy and achieved long-term recurrence-free survival.

CONCLUSION

Diffusion-weighted whole-body imaging with background body signal suppression has the potential to detect metastatic lesions not usually detected by conventional imaging methods.

External validation of the Briganti 2019 nomogram to identify candidates for extended pelvic lymph node dissection among patients with high-risk clinically localized prostate cancer

Background

We aimed to establish an external validation of the Briganti 2019 nomogram in a Japanese cohort to preoperatively evaluate the probability of lymph node invasion in patients with high-risk, clinically localized prostate cancer.

Methods

The cohort consisted of 278 patients with prostate cancer diagnosed using magnetic resonance imaging-targeted biopsy who underwent radical prostatectomy and extended pelvic lymph node dissection from 2012 to 2020. Patients were rated using the Briganti 2019 nomogram, which evaluates the probability of lymph node invasion. We used the area under curve of the receiver operating characteristic analysis to quantify the accuracy of the nomogram.

Results

Nineteen (6.8%) patients had lymph node invasion. The median number of lymph nodes removed was 18. The area under the curve for the Briganti 2019 was 0.71. When the cutoff was set at 7%, 84 (30.2%) patients with extended pelvic lymph node dissection could be omitted, and only 1 (1.2%) patient with lymph node invasion would be missed. Sensitivity, specificity, and negative predictive values at the 7% cutoff were 94.7, 32.0, and 98.8%, respectively.

Conclusion

This external validation showed that the Briganti 2019 nomogram was accurate, although there may still be scope for individual adjustments.