Comparison of Cabozantinib and Axitinib as Second-line Therapy After Nivolumab Plus Ipilimumab in Patients With Metastatic Clear Cell Renal Cell Carcinoma: A Comparative Analysis of Retrospective Real-world Data.

BACKGROUND: To date, no studies have compared the treatment outcomes of second-line therapies in patients with metastatic clear cell renal cell carcinoma (ccRCC). This study retrospectively evaluated the efficacy of cabozantinib and axitinib as second-line treatments in patients with metastatic ccRCC who previously received immune-oncology combination therapy. PATIENTS AND METHODS: Patients with metastatic ccRCC treated with cabozantinib and axitinib as second-line therapy after nivolumab-ipilimumab treatment were identified among 243 patients with RCC treated between August 1, 2018 and January 31, 2022 at 34 institutions belonging to the Japanese Urological Oncology Group. Patients were assessed for treatment outcomes, including progression-free survival (PFS), overall survival, objective response rate (ORR), and incidence rate of treatment-related adverse events (AEs). RESULTS: Forty-eight patients treated with cabozantinib and 60 treated with axitinib as second-line therapy after nivolumab-ipilimumab treatment for metastatic ccRCC were identified. The median PFS (95% confidence interval) was 11.0 months (9.0-16.0) with cabozantinib and 9.5 months (6.0-13.0) with axitinib. The ORRs were 37.5% (cabozantinib) and 38.3% (axitinib). The rates of any-grade AEs and grade ≥3 AEs were 79.2% (cabozantinib) versus 63.3% (axitinib; P = .091) and 35.4% (cabozantinib) versus 23.3% (axitinib; P = .202), respectively. In the poor-risk group, PFS was longer in the cabozantinib group than in the axitinib group (P = .033). CONCLUSION: The efficacy and safety of cabozantinib and axitinib were comparable. In the poor-risk group, cabozantinib was more effective than axitinib. These findings provide valuable insights into the selection of second-line treatment options after nivolumab-ipilimumab treatment in patients with metastatic ccRCC.

Vision-based estimation of manipulation forces by deep learning of laparoscopic surgical images obtained in a porcine excised kidney experiment.

In robot-assisted surgery, in which haptics should be absent, surgeons experience haptics-like sensations as "pseudo-haptic feedback". As surgeons who routinely perform robot-assisted laparoscopic surgery, we wondered if we could make these "pseudo-haptics" explicit to surgeons. Therefore, we created a simulation model that estimates manipulation forces using only visual images in surgery. This study aimed to achieve vision-based estimations of the magnitude of forces during forceps manipulation of organs. We also attempted to detect over-force, exceeding the threshold of safe manipulation. We created a sensor forceps that can detect precise pressure at the tips with three vectors. Using an endoscopic system that is used in actual surgery, images of the manipulation of excised pig kidneys were recorded with synchronized force data. A force estimation model was then created using deep learning. Effective detection of over-force was achieved if the region of the visual images was restricted by the region of interest around the tips of the forceps. In this paper, we emphasize the importance of limiting the region of interest in vision-based force estimation tasks.

Spatial Pattern of Intraprostatic Recurrence after Definitive External-Beam Radiation Therapy for Prostate Cancer: Implications for Focal Boost to Intraprostatic Dominant Lesion.

Purpose: We retrospectively investigated spatial pattern associations between primary and recurrent tumor sites after definitive external-beam radiation therapy (EBRT) for prostate cancer, using positron emission tomography/computed tomography (PET/CT) with a prostate-specific membrane antigen (PSMA)-targeted probe, 18F-FSU-880. Methods and Materials: We used data from our prior phase 2 trial involving patients who received PET/CT with 18F-FSU-880, which was designed to evaluate the tumor detection efficacy of PSMA-PET/CT for recurrent prostate cancer. Data from patients with local intraprostatic recurrence detected by PSMA-PET/CT after definitive EBRT were retrospectively analyzed. The prostate and seminal vesicles were divided into 14 sections. Two diagnostic radiologists separately re-evaluated the intraprostatic location of the primary tumor on magnetic-resonance imaging and that of the recurrent tumor on PSMA-PET/CT, respectively, and the rate of overlap between primary and recurrent tumors was calculated. The overlap rate was defined as "the number of sections that overlapped between the primary tumor and recurrent tumor" divided by "the total number of sections of recurrent tumor". A recurrent tumor was considered to be at the same location as the primary tumor when the overlap rate was equal to or greater than 75%, and a partial overlap was defined as an overlap rate between 25 and 74%. Results: Twelve patients had local recurrence detected by PSMA-PET/CT. The median time to diagnosis of local recurrence was 9.1 (range, 2.2-12.3) years after definitive EBRT. The recurrent tumor was detected at the same location in 25.0%, and a partial overlap was noted in 41.7%. Conclusions: Local intraprostatic recurrence after definitive EBRT often occurs at the same site or at a partially overlapping site adjacent to the primary intraprostatic dominant lesion. Our results support the merit of focal dose-escalation for intraprostatic dominant lesions in definitive EBRT.

Impact of prostate position-based image-guidance in intensity-modulated radiation therapy for localized prostate cancer.

BACKGROUND/PURPOSE: The long-term clinical impact of prostate position-based image-guided radiotherapy (IGRT) for localized prostate cancer remains unclear. MATERIALS AND METHODS: We retrospectively compared clinical outcomes following intensity-modulated radiation therapy (IMRT) with cone-beam computed tomography-based prostate position-based IGRT (P-IGRT) or without P-IGRT (non-P-IGRT). From June 2011, we applied P-IGRT in IMRT for intermediate-risk (IR) prostate cancer (PCa) (D'Amico risk classification) (76 Gy in 38 fractions, with smaller margins). Clinical outcomes of patients who received P-IGRT between June 2011 and June 2019 were retrospectively compared with those of patients with IR PCa who received IMRT without P-IGRT between October 2002 and May 2011 in our institution (74 Gy in 37 fractions). RESULTS: A total of 222 consecutive patients were analyzed: 114 in the P-IGRT cohort and 108 in the non-P-IGRT cohort. The median follow-up period after IMRT was 7.1 years for the P-IGRT cohort and 10.8 years for the non-P-IGRT cohort. The biochemical failure-free rate was significantly better in the P-IGRT cohort (94.9% for the P-IGRT cohort vs 82.7% for the non-P-IGRT cohort at 10 years, p = 0.041). The rate of rectal bleeding which needs intervention including the use of suppositories was significantly lower in the P-IGRT cohort (p < 0.001). CONCLUSIONS: The use of P-IGRT with higher doses and smaller margins was correlated with significantly better biochemical control, and a lower incidence of rectal bleeding in IMRT for intermediate-risk prostate cancer. The enhanced accuracy using P-IGRT has the potential to independently improve disease control and reduce late rectal bleeding.

Current trends in the promising immune checkpoint inhibition and radiotherapy combination for locally advanced and metastatic urothelial carcinoma.

Locally advanced and metastatic urothelial carcinoma (UC) remains a challenging malignancy, though several novel therapeutic drugs have been developed in recent years. Over the past decade, immune checkpoint inhibitors (ICI) have shifted the paradigm of therapeutic strategies for UC; however, only a limited number of patients respond to ICI. Since radiotherapy (RT) is widely known to induce systemic immune activation, it may boost the efficacy of ICI. Conversely, RT also causes exhaustion of cytotoxic T cells, and the activation and recruitment of immunosuppressive cells; ICI may help overcome these immunosuppressive effects. Therefore, the combination of ICI and RT has attracted attention in recent years. The therapeutic benefits of this combination therapy and its optimal regimen have not yet been determined through prospective studies. Therefore, this review article aimed to provide an overview of the current preclinical and clinical studies that illustrate the underlying mechanisms and explore the optimization of the RT regimen along with the ICI and RT combination sequence. We also analyzed ongoing prospective studies on ICI and RT combination therapies for metastatic UC. We noted that the tumor response to ICI and RT combination seemingly differs among cancer types. Thus, our findings highlight the need for well-designed prospective trials to determine the optimal combination of ICI and RT for locally advanced and metastatic UC.

Efficacy and Tolerability of Second-line Pembrolizumab With Radiation Therapy in Advanced Urothelial Carcinoma.

BACKGROUND/AIM: Considering the limited data available on immune checkpoint inhibitors and radiation combination therapy in advanced urothelial carcinoma, this study evaluated the survival benefit and associated toxicity of adding radiation therapy to second-line pembrolizumab. PATIENTS AND METHODS: We retrospectively examined 24 consecutive patients with advanced bladder or upper urinary tract urothelial carcinoma and for whom second-line pembrolizumab was initiated between August 2018 and October 2021 in combination with radiation therapy (with curative intent in 12 patients, and palliative intent in 12 patients). Their survival outcomes and toxicities were compared with those of propensity-score-matched cohorts from a Japanese multicenter study with similar characteristics who received pembrolizumab monotherapy. RESULTS: The median follow-up periods after pembrolizumab initiation were 15 months for the curative cohort and 4 months for the palliative cohort. The median overall survival was 27.7 months for the curative cohort and 4.8 months for the palliative cohort. Compared with the matched pembrolizumab monotherapy cohort, overall survival was better among the curative cohort although not statistically significant (p=0.13), but similar between the palliative and matched pembrolizumab monotherapy cohorts (p=0.44). There was no difference in the incidence of grade ≥2 adverse events between the combination and monotherapy cohorts, irrespective of the intent of radiation therapy. CONCLUSION: The combination of radiation therapy and pembrolizumab can be performed with a clinically acceptable safety profile, and the addition of radiation therapy to immune checkpoint inhibitors may improve survival outcome after pembrolizumab treatment in cases where the intent of radiation therapy is curative.

Analysis of trifecta outcomes in a single center with robot-assisted partial nephrectomy for T1b renal tumors.

INTRODUCTION: This study was performed to investigate the preoperative factors associated with difficulty achieving trifecta in robot-assisted partial nephrectomy for clinical T1b renal cell carcinoma. METHODS: Among 187 patients who underwent robot-assisted partial nephrectomy at our hospital from March 2012 to February 2022, we retrospectively examined 30 patients with unilateral single clinical T1b renal cell carcinoma with at least 6 months of postoperative follow-up, excluding patients with hereditary disease. The following factors were examined in detail: patient-related factors, perioperative factors, surgical techniques, tumor factors, and R.E.N.A.L. nephrometry scores. We examined the preoperative factors associated with difficulty achieving trifecta. A positive surgical margin was pathologically defined as the presence of tumor cells at the margin of the resected specimen or visually defined as intraoperative tumor incision or pseudocapsular damage. RESULTS: Of the 30 patients in this study, 12 achieved trifecta and 18 did not. The reasons for not achieving trifecta were a warm ischemia time of >25 min (66.7%), positive surgical margin (23.3%), and Clavien-Dindo grade ≥3 complications (13.3%) (with overlapping factors). No patients had a pathologically positive surgical margin. Visually positive surgical margins were confirmed by the surgical records and surgical videos. Achieving trifecta was challenging in the multivariate analysis when the "L" component of the R.E.N.A.L. nephrometry score was ≥2 points. CONCLUSION: A preoperative "L" component of ≥2 points in the R.E.N.A.L. nephrometry score was associated with difficulty achieving trifecta.

Automatic segmentation of bladder cancer on MRI using a convolutional neural network and reproducibility of radiomics features: a two-center study.

This study aimed to develop a versatile automatic segmentation model of bladder cancer (BC) on MRI using a convolutional neural network and investigate the robustness of radiomics features automatically extracted from apparent diffusion coefficient (ADC) maps. This two-center retrospective study used multi-vendor MR units and included 170 patients with BC, of whom 140 were assigned to training datasets for the modified U-net model with five-fold cross-validation and 30 to test datasets for assessment of segmentation performance and reproducibility of automatically extracted radiomics features. For model input data, diffusion-weighted images with b = 0 and 1000 s/mm2, ADC maps, and multi-sequence images (b0-b1000-ADC maps) were used. Segmentation accuracy was compared between ours and existing models. The reproducibility of radiomics features on ADC maps was evaluated using intraclass correlation coefficient. The model with multi-sequence images achieved the highest Dice similarity coefficient (DSC) with five-fold cross-validation (mean DSC = 0.83 and 0.79 for the training and validation datasets, respectively). The median (interquartile range) DSC of the test dataset model was 0.81 (0.70-0.88). Radiomics features extracted from manually and automatically segmented BC exhibited good reproducibility. Thus, our U-net model performed highly accurate segmentation of BC, and radiomics features extracted from the automatic segmentation results exhibited high reproducibility.

Enzalutamide in patients with non-metastatic castration-resistant prostate cancer after combined androgen blockade for recurrence following radical treatment in Japan (Japanese research for patients with non-metastatic castration-resistant prostate cancer-enzalutamide: JCASTRE-zero)-a prospective single-arm interventional study.

BACKGROUND: The effect of enzalutamide in patients with non-metastatic castration-resistant prostate cancer after combined androgen blockade, which represents a patient profile similar to real-world clinical practice in Japan, remains unknown. Therefore, we investigate the efficacy and safety of enzalutamide after combined androgen blockade for recurrence following radical treatment in Japanese patients with non-metastatic castration-resistant prostate cancer. METHODS: We analyzed 66 patients with non-metastatic castration-resistant prostate cancer after combined androgen blockade for recurrence following radical prostatectomy or radiation therapy who were prospectively enrolled from October 2015 to March 2018. They received enzalutamide 160 mg orally once daily until the protocol treatment discontinuation criteria were met. The primary endpoint was prostate-specific antigen-progression-free survival, defined as the time from enrollment to prostate-specific antigen-based progression or death from any cause. The secondary endpoints included overall survival, progression-free survival, metastasis-free survival, time to prostate-specific antigen progression, prostate-specific antigen response rate, chemotherapy-free survival, and safety assessment. RESULTS: The median observation period was 27.3 months. The median prostate-specific antigen-progression-free survival was 35.0 months (95% confidence interval, 17.5 to not reached). The median overall survival, median progression-free survival, median metastasis-free survival, and chemotherapy-free survival were not reached, with the corresponding 2-year rates being 91.6%, 67.1%, 72.4%, and 85.8%, respectively. The 50% prostate-specific antigen response rate was 88.9%, with the median time being 2.8 months. In total, 42.2% of the patients experienced adverse events, with malaise being the most common. CONCLUSIONS: Enzalutamide effectively manages non-metastatic castration-resistant prostate cancer after combined androgen blockade for recurrence following radical treatment. TRIAL REGISTRATION:  UMIN000018964, CRB6180007.

Paraurachal paraganglioma.

Introduction: Paragangliomas (PGLs) are frequently reported around the abdominal aorta; however, are extremely rare near the urachus. Case presentation: A 78-year-old woman was referred to the urology department of our hospital for further examination and treatment of a 1.2-cm tumor in the lower abdominal wall, a tumor excision was then performed. On immunohistochemical staining, the tumor and supporting cells were positive for chromogranin A and the S 100 protein, respectively, and were diagnosed as PGL. The PGL was thought to be derived from chromaffin cells that migrated to the wall of the urachus during embryonic life and remained even after the wall regressed. Conclusion: We report a case of PGL near the urachus that can be explained by the distribution of the sympathetic network around the midline of the lower abdominal wall during embryonic development. Therefore, PGL should be considered in the differential diagnosis of periurachal tumors.

Incomplete sagittal septum of the bladder with cystolithiasis.

Introduction: Incomplete sagittal septum of the urinary bladder is an extremely rare congenital anomaly and one of the variations in bladder duplication. Herein, we report a case of incomplete sagittal septum of the bladder with cystolithiasis. Case presentation: A 20-year-old man was referred to our department for examination and treatment of symptomatic cystolithiasis and a suspected giant ureterocele on the left side. Cystoscopy and urography performed under general anesthesia revealed anatomical structures suggestive of the sagittal septum of the bladder. Subsequently, transurethral septostomy and cystolithotripsy were performed. The detrusor muscle was microscopically identified, leading to the diagnosis of an incomplete sagittal septum of the bladder. Conclusion: Although extremely rare, an incomplete sagittal septum of the bladder may be difficult to differentiate from a ureterocele, and should be considered when a large cystic lesion is found in the bladder.

[Tumor Lysis Syndrome in a Patient with Germ Cell Tumor : A Case Report].

A 36-year-old man presented to our hospital with right scrotal swelling. A computed tomographic scan revealed a mass in the right scrotum, multiple masses in the lung and liver, and enlarged cervical, mediastinal, and retroperitoneal lymph nodes. After right high orchiectomy, he was diagnosed with nonseminomatous germ cell tumor (pT3N3M1b), with poor risk prediction according to the International Germ Cell Consensus classification. We started chemotherapy with bleomycin, etoposide, and cisplatin. Since serum alphafetoprotein (AFP) and human chorionic gonadotropin (HCG) levels did not decrease to normal levels, second-line chemotherapy with paclitaxel, ifosfamide, and cisplatin was administered. Six days after the start of treatment, the patient became unconscious, and his blood pressure decreased. Seven days later, blood tests revealed high uric acid levels, hyperphosphatemia, and increased creatinine. This was diagnosed as tumor lysis syndrome. Following diagnosis, continuous hemodiafiltration was started, and his condition gradually improved.

A novel missense mutation in the folliculin gene associated with the renal tumor-only phenotype of Birt-Hogg-Dubé syndrome.

Birt-Hogg-Dubé syndrome is an autosomal dominant disease caused by germline mutations in the folliculin gene (FLCN), characterized by skin fibrofolliculomas, pulmonary cysts, and multiple renal tumors. We report the case of a 51-year-old woman with multiple bilateral renal tumors resected by bilateral open partial nephrectomy. Following pathological diagnosis of hybrid oncocytic/chromophobe tumors, targeted next-generation sequencing of FLCN of the patient's blood revealed a novel missense mutation (c.602A>C, p.Gln201Pro) in exon 6. Sanger sequencing revealed that this mutation was heterozygous. In silico prediction programs consistently indicated the mutation as pathogenic. Western blot analysis and immunohistochemistry revealed suppressed FLCN expression and the upregulation of glycoprotein nonmetastatic B, a downstream target negatively regulated by FLCN, in the tumor tissue, suggesting that the mutation resulted in reduction of functional FLCN expression. Whole-genome sequencing of one of the tumors identified another frameshift mutation in exon 4, suggesting a "second hit" leading to tumorigenesis. We recommend that gene sequencing should be considered in patients with multiple renal tumors to identify their genetic predisposition to renal tumors.

[Diagnostic Accuracy of Transperineal MRI-Ultrasound Fusion Biopsy at the Introduction Period].

Magnetic resonance imaging (MRI) ultrasound fusion biopsy is becoming popular owing to the better detection rate of clinically significant prostate cancer (csPCa). We retrospectively evaluated the accuracy of MRI-targeted biopsy during the period of introduction at a single academic center by comparing findings of its specimen and whole-mount histopathology. Between June 2018 and January 2021, 106 transperineal MRI-ultrasound fusion biopsies using BioJet software were performed. Among the cases, 15 subsequently underwent robotic-assisted laparoscopic radical prostatectomy and were eligible for analysis. This study included all regions of interest (ROIs) with a Prostate Imaging Reporting and Data System v2 category of 3 or greater on pre-biopsy MRI．For each lesion, grade group of MRI-targeted biopsy specimens and prostatectomy specimens were compared. From a total of 25 ROIs identified among 15 males, csPCa was found in 21 (84%) of the concordant locations of prostatectomy specimens. However, MRI-targeted biopsy could diagnose csPCa in only 12 (48%) of them. In the csPCa undetected group, the ROI volume was significantly smaller (median volume 0.23 ml vs 0.40 ml, p＝0.03). We also found that in cases where PCa was not detected through MRI-targeted biopsy, the biopsy sample length was significantly shorter (median length 9 mm vs 17 mm, p＝0.01). Our data suggest that failure of detecting PCa in MRI-targeted biopsy could be due to technical errors at the introduction period of the technique. A sufficient sampling length of 10 mm or more is desirable, especially for small lesions.

A rare case of intestinal lymphangiectasia induced by pazopanib.

A 62-year-old man underwent left radical nephrectomy for left renal cell carcinoma at our hospital in 1999. At the age of 79 years, he was diagnosed with intra-abdominal disseminations, lung metastases, pancreas metastases, and bilateral femoral muscle metastases during a routine follow-up computed tomography scan. The patient began treatment with pazopanib. Four years later, at the age of 83 years, he developed fever, abdominal pain, and general malaise. Blood samples showed liver dysfunction, hypoalbuminemia, and anemia. Contrast-enhanced computed tomography showed thickening of the small bowel wall with marked edema of the submucosa from the third part of the duodenum to the jejunum, suggesting intestinal lymphangiectasia. The diagnosis of intestinal lymphangiectasia was confirmed by small bowel endoscopy and histological examination. The patient's general condition improved after discontinuation of pazopanib without the need for any active therapeutic interventions. The possibility of intestinal lymphangiectasia should be considered in patients with hypoalbuminemia and general malaise during treatment with multikinase inhibitors.

Efficacy and safety of pembrolizumab for older patients with chemoresistant urothelial carcinoma assessed using propensity score matching.

BACKGROUND: We used real-world and large-scale data to assess the clinical efficacy and safety of pembrolizumab in older patients with advanced urothelial carcinoma (UC). METHODS: A total of 608 patients who received pembrolizumab for the treatment of chemoresistant UC were retrospectively analyzed. All patients were histologically diagnosed with pure UC. Using propensity score matching (PSM) (ECOG performance status, site of metastasis, hemoglobin level and neutrophil-to-lymphocyte ratio, 1:1 matching), the overall survival (OS) and adverse events (AEs) of patients <75 and ≥75 years old were compared. RESULTS: The median follow-up (IQR) period was 16.1 (9.9-20.5) months. After PSM, there were 215 patients each in the aged <75 years and aged ≥75-year-old groups. The median OS of all patients was estimated to be 10.4 months (95% confidence interval [CI] = 8.8-12.1). After PSM, the median OS was 7.8 months (95% CI = 5.2-10.4) in the <75-year-old group and 10.4 months (95% CI = 7.3-13.5) in the ≥75-year-old group (P = 0.186). Any-grade AEs were more frequently reported in the ≥75-year-old group in comparison to the age <75-year-old group (55.3% vs. 41.9%, P = 0.007), whereas there was no significant difference between the two groups in the incidence of grade ≥3 AEs (10.2% vs. 12.6%, P = 0.544). The objective response rate, defined as complete remission or a partial response, was 22.8% in the <75-year-old group and 25.1% in the ≥75-year-old group (P = 0.651). CONCLUSIONS: The present study demonstrates that age does not affect the efficacy and safety of pembrolizumab treatment for advanced chemoresistant UC. Pembrolizumab treatment should not be avoided based on chronological age; however, close monitoring for the development of treatment-related AE should be considered for older patients.

Pre-pembrolizumab neutrophil-to-lymphocyte ratio (NLR) predicts the efficacy of second-line pembrolizumab treatment in urothelial cancer regardless of the pre-chemo NLR.

Neutrophil-to-lymphocyte ratio (NLR) was reported to be associated with prognosis of urothelial cancer (UC) patients receiving systemic chemotherapy or immunotherapy. However, it has not been elucidated how preceding first-line chemotherapy affects NLR and subsequent second-line pembrolizumab treatment. This multicenter study analyzed 458 patients with metastatic UC who received first-line chemotherapy and second-line pembrolizumab with regard to pre-chemotherapy and pre-pembrolizumab NLR in association with the efficacy of chemotherapy and pembrolizumab treatment. NLR was increased in 47% while decreased in 53% of patients before and after first-line chemotherapy. High pre-chemotherapy NLR (≥ 3) was significantly associated with unfavorable overall (OS, P = 0.0001) and progression-free (P < 0.0001) survivals after first-line chemotherapy. However, pre-chemotherapy NLR showed only modest influence on radiological response and survival after second-line pembrolizumab treatment, whereas pre-pembrolizumab NLR showed higher association. NLR decrease was associated with partial response or greater objective response by first-line chemotherapy, while NLR increase was associated with higher patient age. In conclusion, immediate pre-chemotherapy and pre-pembrolizumab NLR was significantly associated with efficacy of the following treatment, respectively. However, even patients with high pre-chemotherapy NLR achieved favorable OS if they had their NLR reduced by chemotherapy, whereas those with high pre-chemotherapy NLR yielded unfavorable OS if they had their NLR remained high after chemotherapy, suggesting that chemotherapy may have differential effect on the efficacy of subsequent pembrolizumab treatment in UC patients.

Preoperative ipilimumab/nivolumab combination therapy reduced operation risk by downstaging the inferior vena cava tumor thrombus extending to the right atrium in a metastatic renal cell carcinoma: A case report.

The success of immune checkpoint inhibitors in metastatic renal cell carcinoma (RCC) has renewed interest in studying these agents in preoperative settings. Here, we present a case of metastatic RCC with an inferior vena cava (IVC) tumor thrombus extending to the right atrium. Preoperative systemic therapy with ipilimumab/nivolumab was initiated for four cycles. The IVC tumor thrombus level was significantly downstaged from IV to I according to the Mayo classification, which enabled us to perform cytoreductive nephrectomy and IVC thrombectomy without extracorporeal circulation. Preoperative ipilimumab/nivolumab may lead to significant downstaging of caval tumor thrombus in metastatic RCC.

Computed tomography detected pyelovenous backflow associated with complete ureteral obstruction.

INTRODUCTION: Pyelovenous backflow is a rare condition resulting from an increase in pressure in the renal pelvis due to urinary obstruction. CASE PRESENTATION: A 49-year-old woman developed high-grade fever and right-sided hydronephrosis after undergoing hysterectomy. Although the hydronephrosis was mild, retrograde pyelography revealed complete obstruction of the right ureter. Excretory phase scans of contrast-enhanced computed tomography showed pyelovenous backflow, which presumably decompressed the hydronephrosis. The pyelovenous backflow immediately disappeared after ureteroneocystostomy. CONCLUSION: We were presented with a patient showing pyelovenous backflow detected by contrast-enhanced computed tomography, which completely disappeared after ureteral obstruction release.