A diagnostically challenging case of inflammatory myofibroblastic tumor primary to the peritoneum.

Introduction: Inflammatory myofibroblastic tumors are difficult to diagnose because of the lack of specific indicators. We describe a diagnostically challenging case of an inflammatory myofibroblastic tumor primary to the peritoneum. Case presentation: The patient was a 25-year-old male who presented at our hospital with lower abdominal pain. Computed tomography revealed a mass lesion 80 mm in diameter just above the bladder. This was suspected to be a bleeding tumor of the urachus. Since malignancy could not be ruled out, surgery was planned. This revealed a fragile tumor arising from the peritoneum. Following its removal, the tumor was diagnosed by histopathological analysis as an inflammatory myofibroblastic tumor. Conclusion: We describe a case of inflammatory myofibroblastic tumor primary to the peritoneum diagnosed by histopathology. Inflammatory myofibroblastic tumor should be considered in the differential diagnosis of abdominal wall and anterior bladder tumors.

Comparison of Urinary Liver Fatty Acid Binding Protein Level and Pathologic Biopsy Findings 1 Year After Kidney Transplantation.

BACKGROUND: For the early detection of abnormal findings considering for therapeutic intervention, we regularly undertake protocol renal allograft biopsy at 1 year after kidney transplantation (KT). We examined whether urinary liver fatty acid binding protein (L-FABP) level predicts some pathologic findings of renal allograft. METHODS: We retrospectively enrolled recipients with stable graft function who routinely were biopsied renal allograft specimens 1 year after KT between January 2015 and May 2021 in our center. We assessed the association urinary L-FABP level with pathologic findings of renal allograft biopsies. RESULTS: We enrolled 56 recipients in this study. Their median age at KT was 49.5 and their median serum creatinine at 1 year after KT was 1.22 mg/dL. In 9 of 56 patients, abnormal high value of urinary L-FABP were observed. All of them had abnormal findings pathologically in the renal allografts (border line change 3, medullary ray injury [MRI] with calcineurin inhibitor toxicity [CNI-T] 1, MRI without CNI-T 1, CNI-T with IgA deposition 1, and BK virus nephropathy 3). On the other hand, 30 of 47 patients with normal value of urinary LFABP had no pathologically abnormal findings. Both specificity and positive predictive value of urinary L-FABP for pathologic findings were 100.0༅. CONCLUSIONS: Our results suggest that patients with renal transplant with elevated urinary L-FABP levels might benefit from renal allograft biopsy. Comparison of urinary liver fatty acid binding protein level and pathologic biopsy findings 1 year after KT.

Transurethral laser lithotripsy using the Mitrofanoff urethral conduit for bladder stones: a case report.

BACKGROUND: The Mitrofanoff (appendicovesicostomy) procedure is a contraindicated urinary modification that maintains urinary continence by forming a flap-valve mechanism at the site of anastomosis between the appendage and bladder wall, which is used as a guide for urinary drainage. This technique has been used by intermittent self-catheterization patients who have difficulty voiding from the native urethra or in cases where voiding from the abdominal wall would improve quality of life. However, the risk of stone formation is high due to intermittent urinary catheterization using the Mitrofanoff conduit urethrostomy as a conduit. CASE PRESENTATION: The patient was a 22-year-old Asian-Japanese woman. At 6 years of age, she underwent bilateral vesicoureteral reflux surgery, Mitrofanoff urethrostomy using the appendix, abdominal wall plication, and vaginoplasty using the ileum. During follow-up, ultrasound performed due to persistent pain during urinary drainage revealed a 26 mm bladder stone. We performed ureteroscopic lithotripsy 6Fr using ureteral access sheath and made lithotripsy using Ho: YAG laser, then successfully removed the target stone. CONCLUSIONS: We report a case of transurethral laser lithotripsy using the Mitrofanoff urethral conduit for bladder stones. Using with ureteral access sheath made lithotripsy and retrieved ureteral stone more effective.

Administration of Enfortumab Vedotin after Immune-Checkpoint Inhibitor and the Prognosis in Japanese Metastatic Urothelial Carcinoma: A Large Database Study on Enfortumab Vedotin in Metastatic Urothelial Carcinoma.

BACKGROUND: Enfortumab vedotin shows promise as a targeted therapy for advanced urothelial carcinoma, particularly in patients who have previously received platinum-based chemotherapy and an immune-checkpoint inhibitor. The EV-301 phase III trial demonstrated significantly improved overall survival and response rates compared to standard chemotherapy. However, more data, especially from larger real-world studies, are needed to further assess its effectiveness in Japanese patients. METHODS: A total of 6007 urothelial cancer patients inducted with pembrolizumab as a second-line treatment were analyzed. Among them, 563 patients received enfortumab vedotin after pembrolizumab, while 443 patients received docetaxel or paclitaxel after pembrolizumab, and all were included in the study for efficacy as a life prolonging agent. RESULTS: The enfortumab vedotin group showed a longer overall survival than the paclitaxel/docetaxel group (p = 0.013, HR: 0.71). In multivariate analysis, enfortumab vedotin induction was the independent risk factor for overall survival (p = 0.013, HR: 0.70). There were no significant differences in cancer-specific survival. CONCLUSIONS: Enfortumab vedotin prolonged the overall survival for Japanese advanced or metastatic urothelial carcinoma patients compared to paclitaxel or docetaxel after pembrolizumab treatment.

Microsurgical varicocelectomy for intratesticular varicocele with a history of orchiopexy for undescended testis.

Introduction: We report a case series of six patients with a chief complaint of infertility who underwent microsurgical varicocelectomy for intratesticular varicocele (ITV) after undergoing orchiopexy for undescended testis in their childhood. Case presentation: The patients' median age was 34 years. The median age at which orchiopexy was performed was 4.5 years. All the cases of ITV were accompanied by extratesticular varicocele (ETV). All the patients underwent a microsurgical subinguinal varicocelectomy. At 3 months after operation, the ITV and ETV had disappeared in all the cases. Sperm density and motility increased in five and four patients, respectively. Conclusion: ITV occurs at a relatively high frequency after orchiopexy for undescended testis. Disorder of the valvular function of the testicular vein in peeling the testicular vessels was thought to be a primary cause and is often found on the left side. Doppler ultrasonography of the testis is considered important for diagnosis.

Small intestinal thrombotic microangiopathy following kidney transplantation diagnosed by balloon-assisted enteroscopy.

Thrombotic microangiopathy (TMA) is a serious complication following kidney transplantation. Although intestinal TMA is a major organ injury and causes abdominal pain, diarrhea and bloody stools, the clinical and endoscopic characteristics of small intestinal TMA remain unclear. Here, we report a drug-induced small intestinal TMA, which did not meet the laboratory-defined TMA criteria but was diagnosed by balloon-assisted enteroscopy (BAE). A 32-year-old woman who underwent kidney transplantation at the age of 10 years complained of abdominal pain, diarrhea and bloody stools one month after starting everolimus (EVE) as an immunosuppressant. Although she did not meet the diagnostic criteria for TMA serologically, BAE revealed a circumferential ulcer in the jejunum, and the pathological findings of a biopsy specimen showed microvascular thrombi, compatible with intestinal TMA. Her symptoms improved upon the discontinuation of EVE, demonstrating that EVE can cause drug-induced intestinal TMA. The present case suggests that BAE should be performed when abdominal pain, diarrhea, and bloody stools occur in patients receiving immunosuppressive medication following kidney transplantation, even if there is no evidence of TMA according to the laboratory definition.

Pediatric bilateral ureteral stone successfully removed using single-use flexible ureteroscopy with a holmium: YAG laser.

A 12-year-old boy received steroid for his minimal change nephrotic syndrome for 10 years, and bilateral renal and ureteral stones and hydronephrosis were observed. Single-use flexible ureteroscopy is usable for pediatric lithotripsy with Ho: YAG laser.

A case of allograft ureteral stone successfully treated with antegrade ureteroscopic lithotripsy: use of a 3D-printed model to determine the ideal approach.

We present the case of a 46-year-old man who underwent successful antegrade ureteroscopy for lithiasis in his allograft ureter. At a scheduled follow-up 15 years after transplantation, computed tomography (CT) detected a 12-mm renal stone in the renal pelvis of the transplanted kidney. During his follow-up, gross hematuria was seen; the stone moved to the ureter, causing hydronephrosis. Ultrasound and non-contrast CT revealed hydronephrosis and a 15-mm stone in the transplanted ureter. Considering the stone size, location, and the difficulty of the access to the anastomosed ureteral orifice, percutaneous ureteroscopic approach was planned. Due to the anatomical difficulty regarding his allograft kidney, we planned to prepare a 3D image and model for selecting the best percutaneous approach. The procedure was performed and a stone-free status was acquired without complication. Under precise simulation, we performed successful antegrade ureteroscopy for lithiasis in the allograft ureter supported by 3D imaging. Use of a 3D printed model may aid in a safe and effective procedure for lithiasis in the allograft kidney and ureter.

Early assessment with 18F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography to predict short-term outcome in clear cell renal carcinoma treated with nivolumab.

BACKGROUND: We reported previously the usefulness of 18F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) to predict prognosis of renal cell carcinoma (RCC) treated with molecular targeted agents. Herein we describe a preliminary research of nine patients who underwent FDG-PET/CT before and after initiation of nivolumab. METHODS: Patients with metastatic RCC who were treated by nivolumab from October 2016 to March 2017 were enrolled in this study. All patients underwent FDG-PET/CT at baseline and 1 month as a first response assessment, and contrast-enhanced or non-contrast-enhanced CT scan at 4 month as a second response assessment. Logistic regression analysis was performed to assess the association of potential predictors, including age, gender, baseline diameter, baseline maximum standardized uptake value (SUVmax), lung or not lung metastasis, elevation of SUVmax at 1st assessment, and decrease in diameter at 1st assessment with the response at 2nd assessment (decrease in the diameter ≥ 30% or not). RESULTS: There were 9 patients and 30 lesions. Mean days of first assessment with FDG-PET/CT and second assessment by CT scan from initiation of treatment were 32.3 ± 6.4, 115.5 ± 14.9, respectively. Lesions whose diameter decreased ≥30% at second assessment were defined as responding, and lesions whose diameter did not decrease ≥30% were defined as non-responding. There were 18 responding lesions, and 12 non-responding lesions. We compared change in diameter and SUVmax at first assessment with FDG-PET/CT, respectively. All lesions with decreased diameter and elevated SUVmax at first assessment with FDG-PET/CT showed responding at second assessment by CT scan, while most lesions with increased diameter and declined SUVmax at first assessment showed non-responding at second assessment. The multivariate logistic regression analyses revealed that only the elevation of SUVmax at 1 month was an independent predictor (P = 0.025, OR: 13.087, 95%CI: 1.373-124.716). CONCLUSION: Our findings suggest that the early assessment using FDG-PET/CT can be effective to predict the response of RCC to nivolumab. However, larger prospective studies are needed to confirm these preliminary results. TRIAL REGISTRATION: Registered in University Hospital Medical Information Network in JAPAN [ UMIN0000008141 ], registration date: 11 Jun 2012.

Successful treatment with sorafenib for sunitinib-refractory metastatic papillary renal cell carcinoma: Potential impact of Raf overexpression on predicting the efficacy of sorafenib.

INTRODUCTION: The prognosis of type 2 papillary renal cell carcinoma is often poor. We herein report a case of papillary renal cell carcinoma with liver metastasis that was successfully treated with sorafenib as a second-line therapy. CASE PRESENTATION: An 82-year-old man who had undergone radical nephrectomy 5 years previously experienced biopsy-proven liver metastasis. He received sunitinib as a first-line treatment; the dose was initially 12.5 mg/day and was escalated to 25 mg/day, but it was discontinued due to several adverse events. We then switched to sorafenib as a second-line treatment, which resulted in a partial response (51% reduction in tumor size); the patient showed no recurrence 5 months after the initiation of sorafenib treatment. An immunohistochemical analysis revealed the overexpression of Raf in both the primary and metastatic tumors. CONCLUSION: As sorafenib blocks Raf signaling, the expression of Raf may serve as a useful predictor of the efficacy of sorafenib.

High orchiectomy and ipsilateral testicular sperm extraction in a man with a testicular tumor and Klinefelter syndrome: A case report.

INTRODUCTION: Testicular epidermal cysts in Klinefelter syndrome are very rare. We report a case of Klinefelter syndrome associated with a testicular epidermal cyst. To our knowledge, this is the first report showing successful spermatozoa retrieval from the affected testis. CASE PRESENTATION: A 25-year-old married man was referred to our hospital with right scrotal induration, which was in lower pole of the right testis. Testicular cancer tumor markers were normal; endocrinological findings indicated hypergonadotropic hypogonadism. Semen analyses revealed azoospermia. Preoperative chromosome test result: 47, XXY karyotype; ultrasonography report: 1.9-cm internal heterogeneous echoic mass in the right testis (malignancy not discarded). Because the patient hoped for children, he underwent high orchiectomy with ipsilateral testicular sperm extraction (200 spermatozoa from normal testicular tissue) for future fertilization procedures. Tumor pathology was an epidermal cyst. CONCLUSION: While performing orchiectomy for testicular tumors, sperm retrieval should be attempted from normal tissues in patients planning for children.

Functional paraganglioma of the bladder: Both radiographic-negative and laboratory-negative case.

INTRODUCTION: Paraganglioma has been determined to be an extra-adrenal pheochromocytoma. Paraganglioma of the bladder is a rare entity, accounting for 0.06% of all bladder tumors. CASE PRESENTATION: A 58-year-old woman had been annually followed up since being diagnosed with rectal cancer 5 years ago. In January 2018, follow-up computed tomography detected a bladder tumor, and she was referred to our department for a further examination. Cystoscopy revealed a submucosal tumor on her right bladder wall. We performed transurethral resection of the bladder tumor. When we first marked the tumor margin, the systolic blood pressure increased, so we abandoned resection. We performed meta-iodobenzylguanidine scintigraphy and acid urinary collection, neither of which revealed any abnormal findings. We therefore performed open partial cystectomy based on a clinical diagnosis of paraganglioma of the bladder. The pathological findings revealed paraganglioma of the bladder. CONCLUSION: We herein report a case of paraganglioma of the bladder.

Management of urethral stricture: High-pressure balloon dilation versus optical internal urethrotomy.

OBJECTIVE: Urethral stenosis is a disease in which the lumen of the urethra becomes constricted by fibrosis. Such stenoses have been treated by urethral dilation using a bougie and optical internal urethrotomy (OIU). Recently, high-pressure balloon dilation (BD) has been developed as a new treatment method for urethral stenosis. The present study compared the effectiveness of urethral dilation by BD and OIU. METHODS: Twenty-two patients of urethral stenosis were treated at Yokohama City University Medical Center between 2005 and 2015. Of these, 13 underwent BD, whereas OIU was performed in 9. BD was performed at 30 atm twice for 5 min each time. In OIU, an endoscopic knife was used to cut out the stenotic lesion in 3 directions. The endpoint was set as restenosis, which required additional surgical treatment, including BD, OIU, and the use of a urethral bougie. RESULTS: The causes of urethral stricture were endoscopic surgery (n = 7; 31.8%), development after total prostatectomy (n = 4; 18.2%), iatrogenic reasons associated with catheter insertion (n = 5; 22.7%), development after a prostate needle biopsy (n = 3; 13.6%), and unknown (n = 3; 13.6%). The site of the stenotic lesion site was the anastomosis (n = 3; 13.6%), bladder neck (n = 6; 27.3%), prostatic urethra (n = 4; 18.2%), anterior urethra (n = 7; 31.8%), and membranous urethra (n = 2; 9.1%). The stenosis-free rate was 84% for those undergoing BD and 22% for those receiving OIU. The median stenosis-free time was significantly longer after BD than OIU (1675 vs. 244 days, respectively; P < .01). CONCLUSION: The stenosis-free time was significantly longer after BD than OIU.

PD-1 and PD-L1 are more highly expressed in high-grade bladder cancer than in low-grade cases: PD-L1 might function as a mediator of stage progression in bladder cancer.

BACKGROUND: Bladder cancers have been characterized as a tumor group in which the immunological response is relatively well preserved. Programmed death ligand 1 (PD-L1, B7-H1, CD274) has been shown to be expressed in several malignancies, including bladder cancer. However, the clinicopathological impact of this biomarker has not yet been established. In the present study, a quantitative real-time polymerase chain reaction (qPCR) was performed using paired normal and cancerous bladder cancer tissue to investigate PD-1/PD-L1 gene expression. METHODS: We examined the mRNA expression of PD-1/PD-L1 by a qPCR using 58 pairs of normal and cancerous human bladder tissue specimens. We also examined the correlation with the expressions of the STAT1 and NFAT genes, which are thought to be upstream and downstream of the PD-L1 pathway, respectively. RESULTS: There were no significant differences between normal and cancerous tissue in the expression of the PD-1 and PD-L1 genes (p = 0.724 and p = 0.102, respectively). However, PD-1 and PD-L1 were both more highly expressed in high-grade bladder cancer than in low-grade bladder cancer (p < 0.050 and p < 0.010). PD-L1 was positively correlated with the expressions of both the STAT1 (r = 0.681, p < 0.001) and the NFATc1 genes (r = 0.444. p < 0.001). CONCLUSIONS: PD-1 and PD-L1 might be a new biomarker that correlates with the pathological grade of bladder cancer. PD-L1 might function as a mediator of stage progression in bladder cancer and STAT1-NFAT pathway might associate this function.

Neutrophil-to-Lymphocyte Ratio in Renal Transplant Patients.

OBJECTIVES: Because of recent developments in immunosuppressive therapy, renal transplant outcomes have improved. Although reports on the association between immunosuppressive therapy and malignant disease are available, the results are controversial. The neutrophil-to-lymphocyte ratio has been reported as an easy tumor marker for predicting the prognoses of some solid tumors. In the present study, we examined changes in neutrophil-to-lymphocyte ratio after renal transplant and discussed cases in which malignant disease developed after renal transplant. MATERIALS AND METHODS: Our study included 137 patients who underwent renal transplant between August 2001 and September 2015. Four of these patients (2.9%) developed malignant disease. The neutrophil-to-lymphocyte ratio was calculated based on the numbers of neutrophils and lymphocytes in the complete blood count and evaluated before and at 1, 3, 6, and 12 months and at 3 years after renal transplant. RESULTS: The neutrophil-to-lymphocyte ratio was markedly high at 1 week and 1 month after renal transplant and gradually decreased until it became stable at 3 months posttransplant. In patients with malignant disease, there was a gradual increase in the neutrophil-to-Iymphocyte ratio after renal transplant. CONCLUSIONS: We observed dramatic differences in the neutrophil-to-lymphocyte ratio at 1 and 3 months after renal transplant. The neutrophil-to-lymphocyte ratio of patients with malignant disease after renal transplant continued to increase.

Gastrointestinal cancer and bilateral hydronephrosis resulted in a high risk of ureteral stent failure.

BACKGROUND: Urologists frequently encounter malignant ureteral obstruction (MUO) caused by advanced urological or non-urological malignant disease, but the treatment policy is unclear. The present study examined the risk factors for predicting ureteral stent failure in patients with MUO after ureteral stent insertion and the change in the renal function after retrograde ureteral stent insertion in cases of bilateral hydronephrosis. METHODS: A total of 39 patients who required ureteral stent placement for MUO at Yokohama City University Medical Center (Yokohama, Japan) between February 2007 and May 2016 were included in this study. The age, gender, type of cancer, hydronephrosis side, pre-stenting estimated glomerular filtration rate (eGFR), and eGFR increase were assessed as predictive factors for stent failure. Among these 39 patients, 25 showed bilateral hydronephrosis. Thirteen of these patients had bilateral ureteral stents placed, and the remaining 12 had a unilateral ureteral stent placed. The renal function and overall survival (OS) were analyzed between these two groups. RESULTS: Among all 39 patients, 9 (23.1%) had stent failure. A univariate analysis revealed that causative disease (gastrointestinal cancer vs. others; p = 0.045) and laterality of hydronephrosis (bilateral vs. unilateral; p = 0.05) were associated with stent failure. A multivariate analysis revealed that only age (hazard ratio, 0.938; 95% confidence interval, 0.883-0.996; p = 0.038) was associated with stent failure. A Kaplan-Meier analysis and log-rank test indicated that having a unilateral ureteral stent placed was not correlated with a lower OS rate than having bilateral ureteral stents placed (p = 0.563). Among patients with bilateral hydronephrosis, the increase in the eGFR of those who had bilateral ureteral stents placed was not significantly different from that of those who had a unilateral ureteral stent placed (p = 0.152). CONCLUSIONS: We revealed that age > 60 years was helpful for predicting stent failure. MUO due to gastrointestinal cancer and bilateral hydronephrosis may be predictive of stent failure. These factors may help urologists decide the optimal time to perform early percutaneous nephrostomy. These findings suggest that patients with bilateral hydronephrosis do not necessarily need to have a ureteral stent placed into both sides of the hydronephrosis.

BHD-associated kidney cancer exhibits unique molecular characteristics and a wide variety of variants in chromatin remodeling genes.

Birt-Hogg-Dubé (BHD) syndrome is a hereditary kidney cancer syndrome, which predisposes patients to develop kidney cancer, cutaneous fibrofolliculomas and pulmonary cysts. The responsible gene FLCN is a tumor suppressor for kidney cancer, which plays an important role in energy homeostasis through the regulation of mitochondrial oxidative metabolism. However, the process by which FLCN-deficiency leads to renal tumorigenesis is unclear. In order to clarify molecular pathogenesis of BHD-associated kidney cancer, we conducted whole-exome sequencing analysis using next-generation sequencing technology as well as metabolite analysis using liquid chromatography-mass spectrometry and gas chromatography-mass spectrometry. Whole-exome sequencing analysis of BHD-associated kidney cancer revealed that copy number variations of BHD-associated kidney cancer are considerably different from those already reported in sporadic cases. In somatic variant analysis, very few variants were commonly observed in BHD-associated kidney cancer; however, variants in chromatin remodeling genes were frequently observed in BHD-associated kidney cancer (17/29 tumors, 59%). Metabolite analysis of BHD-associated kidney cancer revealed metabolic reprogramming toward upregulated redox regulation which may neutralize reactive oxygen species potentially produced from mitochondria with increased respiratory capacity under FLCN-deficiency. BHD-associated kidney cancer displays unique molecular characteristics that are completely different from sporadic kidney cancer, providing mechanistic insight into tumorigenesis under FLCN-deficiency as well as a foundation for development of novel therapeutics for kidney cancer.

Adrenal Hemangioma: A Case of Retroperitoneal Tumor.

INTRODUCTION: Adrenal hemangioma is a rare disease, with only some 60 cases reported previously. Due to the difficulty of the preoperative diagnosis of adrenal hemangioma, almost all of the cases were diagnosed by a histopathological analysis of surgical specimens. CASE PRESENTATION: A 52-year-old man was referred to our department for further examination of his left retroperitoneal tumor. He had received hemodialysis due to chronic renal failure resulting from membranous nephropathy. Computed tomography revealed a mass around his left hilum. Magnetic resonance imaging (MRI) and positron-emission tomography (PET)-CT were unable to confirm or deny malignancy, and tumor markers, including CEA and CA19-9, showed slight elevation. His tumor grew from 38 mm to 54 mm in diameter in 7 months of follow-up. We therefore planned retroperitoneal tumor resection with left nephrectomy. Histopathologically, hyperplastic small vessels with hemorrhaging and denaturation were seen. The endothelial cells showed no variants or division of the nucleus. Based on this diagnosis, no further therapy was performed. He has had no recurrence in the eight months since the surgery. CONCLUSION: We herein report a rare case of adrenal hemangioma.

FDG PET/CT after first molecular targeted therapy predicts survival of patients with renal cell carcinoma.

PURPOSE: We investigated prospectively whether 18F-2-fluoro-2-deoxyglucose positron emission tomography/computed tomography (FDG PET/CT) can predict the overall survival (OS) of patients with advanced renal cell carcinoma (RCC) previously treated by molecular targeted therapies. METHODS: Between 2009 and 2016, 81 patients who had received single molecular targeted therapies (43 sorafenib, 27 sunitinib, 8 temsirolimus and others) and were scheduled for second line molecular targeted therapies for advanced RCC were enrolled in this prospective study. FDG PET/CT was performed after first line molecular targeted therapies, the max SUVmax (highest standardized uptake value for each patient) recorded, and its association with OS compared with those of known risk factors. The median follow-up was 15.4 months (range 0.9-97.4 months). RESULTS: The max SUVmax of the 81 subjects ranged from undetectable to 23.0 (median 7.1). Patients with high max SUVmax had a poor prognosis and multivariate analysis with established risk factors showed that it was an independent predictor of survival (p < 0.001; hazard ratio 1.156; 95% confidence interval 1.080-1.239). Subclassification of patients by max SUVmax showed that the median OS of patients with max SUVmax < 7.0 (39), 7.0-12.0 (30), and ≥ 12.0 (12) were 32.8, 15.2, and 6.0 months, respectively. These differences are statistically significant (< 7.0 versus 7.0-12.0: p = 0.0333, 7.0-12.0 versus ≥ 12.0: p = 0.0235). CONCLUSIONS: The max SUVmax by FDG PET/CT of patients with RCC evaluated after their first molecular targeted therapy predicts OS. FDG PET/CT is a useful "imaging biomarker" for patients with advanced RCC planning sequential molecular targeted therapies.