This study aimed to evaluate the learning curve of transperineal magnetic resonance imaging (MRI)/ultrasound (US) fusion biopsy in a team composed of a single surgeon, a single radiologist, and a single pathologist. We prospectively enrolled 206 patients undergoing MRI/US fusion prostate biopsy and divided them into four cohorts by the year of biopsy. We analyzed temporal changes in clinically significant prostate cancer (csPC) detection rate, percentage of positive cores on biopsy, and Gleason upgrading rate after radical prostatectomy. The csPC detection rate by MRI/US fusion targeted biopsy (TB) increased significantly (from 35.3% to 60.0%, p = 0.01). With increased experience, the csPC detection rates for small ($\le$1 cm) and anterior target lesions gradually increased (from 41.2% to 51.6%, p = 0.5; from 54.5% to 88.2%, p = 0.8, respectively). The percentage of positive cores on TB increased significantly (from 18.4% to 44.2%, p = 0.001). The Gleason upgrading rate gradually decreased (from 22.2% to 11.1%, p = 0.4). In conclusion, with accumulated experience and teamwork, the csPC detection rate by TB significantly increased. Multidisciplinary team meetings and a free-hand biopsy technique were the key factors for overcoming the learning curve.

Chondrosarcoma is a rare type of cancer that can affect the upper urinary tract. Because of its rarity, the clinical presentation of chondrosarcoma can be similar to other urinary tract conditions, such as renal colic, hematuria, and urothelial carcinoma. The primary treatment for chondrosarcoma is the surgical removal of the tumor, and radiation or chemotherapy may be used for advanced cases. However, because of the limited number of patients with this condition, there are no established guidelines for chemotherapy, and the outcomes are unclear. In this case, we present a 71-year-old female patient who was diagnosed with ureteral chondrosarcoma. She presented with abdominal pain and hydronephrosis, and a tumor was found beneath a small stone. The patient underwent nephroureterectomy and received oral fluorouracil chemotherapy due to the advanced stage of the disease. Fortunately, the patient survived, and at the 7 months post-operative follow-up there was no evidence of recurrence. In conclusion, the chondrosarcoma of the upper urinary tract is a rare condition that can be difficult to diagnose due to its similarity to other urinary tract conditions. Treatment typically involves the surgical removal of the tumor, with radiation or chemotherapy reserved for advanced cases. However, because of the limited number of patients, there are no established guidelines for chemotherapy, and the outcomes of treatment are unclear.