Urology Glossary. Dr. Rastinehad

A

Ablation: Targeted destruction of tissue using heat, cold, or laser energy.; Ablation is the controlled killing of a specific volume of tissue, used in interventional urology to destroy a tumor while sparing surrounding structures. Cryoablation, HIFU, laser, and microwave ablation are the most common energy types.
Active surveillance: Structured monitoring of low-risk prostate cancer instead of immediate treatment.; A program of scheduled PSA tests, multiparametric MRI, and targeted re-biopsy used to safely defer treatment in men with low-volume, low-grade prostate cancer. Treatment is started only when biology shows the disease is progressing.
Adverse event: Any unwanted medical occurrence during a clinical trial or treatment.; In clinical trials, adverse events are tracked and reported regardless of whether they are believed to be caused by the study treatment. Serious adverse events trigger formal review and may pause the study.
Angiomyolipoma (AML): A benign kidney tumor made of blood vessels, smooth muscle, and fat.; Most AMLs are found incidentally on imaging. Tumors larger than 4 cm or those that bleed are candidates for selective renal artery embolization, which preserves kidney function and avoids surgery.

B

Benign prostatic hyperplasia (BPH): Non-cancerous enlargement of the prostate causing urinary symptoms.; BPH is the most common cause of urinary symptoms in men over 60: weak stream, urgency, frequency, and nocturia. Treatment ranges from medication to image-guided options like prostate artery embolization (PAE).
Biomarker: A measurable biological signal used to detect or stage disease.; PSA is the most familiar urology biomarker. Newer biomarkers, including blood, urine, and genomic tests on biopsy tissue, help refine who needs biopsy and how aggressively to treat.
Bladder outlet obstruction: Blockage of urine flow at the bladder neck, usually from BPH.; Bladder outlet obstruction causes weak stream, straining, and incomplete emptying. Long-standing obstruction can damage the bladder muscle and, eventually, the kidneys.

C

Catheter: A thin flexible tube used to drain urine or deliver treatment.; A Foley catheter drains the bladder after some procedures, typically for 1 to 3 days after focal therapy and rarely needed after PAE. A microcatheter is the pinhole tube used to deliver embolic particles in embolization procedures.
Clinical trial: A research study that tests a new treatment, device, or diagnostic in humans.; Trials are run in phases: Phase 1 (safety, small group), Phase 2 (efficacy signal), Phase 3 (large comparative), and Phase 4 (post-approval). Dr. Rastinehad has led first-in-human and pivotal focal therapy trials.
Clinically significant prostate cancer: Prostate cancer aggressive enough to need treatment, not just monitoring.; Generally defined as Gleason grade group 2 or higher, or grade group 1 with large volume. MRI-fusion biopsy was designed to find this disease and avoid overdiagnosing indolent cancers.
Cryotherapy: Image-guided freezing used to destroy targeted tissue.; Cryoprobes are placed under MRI or ultrasound guidance and cycled through freezing and thawing to ablate cancer cells. Used for select prostate and renal tumors as a focal therapy option.
Cystoscopy: A camera exam of the urethra and bladder.; A thin scope is passed through the urethra to inspect the bladder lining and prostatic urethra. Used in BPH workup, hematuria evaluation, and to assess stones or strictures.

D

Digital rectal exam (DRE): A clinical exam of the prostate through the rectum.; The DRE checks prostate size, contour, and any firm nodules. Paired with PSA and imaging it remains part of the standard prostate evaluation.
Dominant index lesion: The largest, most aggressive-appearing tumor focus in the prostate.; Prostate cancer is often multifocal, but the index lesion drives behavior. Focal therapy is designed to ablate the index lesion plus a safety margin while leaving the rest of the gland intact.

E

Embolization: Image-guided blocking of an artery using particles or coils.; A microcatheter is advanced from the wrist or groin into a target artery; embolic material then occludes blood flow to a specific organ or tumor. Used for BPH (PAE), varicocele, renal masses, and bleeding control.
Erectile dysfunction (ED): Difficulty achieving or maintaining an erection.; A common side effect of whole-gland prostate treatment. Focal therapy and PAE are designed to preserve the neurovascular bundles and dramatically reduce ED risk compared with surgery or radiation.

F

Focal therapy: Treating only the prostate tumor rather than the whole gland.; Focal therapy uses image-guided ablation — cryotherapy, HIFU, laser, or nanoparticle-directed methods — to destroy the cancer plus a safety margin, preserving urinary and sexual function for the majority of patients. Dr. Rastinehad helped pioneer MRI-guided focal laser ablation.

G

Gleason score: A 6–10 score of prostate cancer aggressiveness on biopsy.; Pathologists grade the two most common cancer patterns from 3 to 5 and add them. Gleason 6 (3+3) is the least aggressive; Gleason 8–10 is high risk. Modern reporting also uses ISUP grade groups (1–5).
Gold-nanoshell ablation: Photothermal destruction of prostate tumors using laser-activated gold nanoparticles.; Engineered gold nanoshells accumulate in prostate tumors and convert near-infrared laser energy to heat, ablating the cancer with very high spatial precision. Dr. Rastinehad performed the first-in-human trial.

H

Hematuria: Blood in the urine.; Visible (gross) or microscopic hematuria warrants evaluation with imaging and cystoscopy to rule out stones, infection, BPH, and bladder or kidney cancer.
HIFU (high-intensity focused ultrasound): Focused sound waves used to thermally ablate prostate tumors.; HIFU delivers focused ultrasound energy through a transrectal probe to heat and destroy targeted prostate tissue without an incision. It is one of several focal therapy options.

I

Image-guided therapy: Treatment delivered using live imaging instead of open surgery.; MRI, ultrasound, CT, and fluoroscopy let interventional urologists place needles, probes, and catheters with millimeter precision through tiny access points, shortening recovery and preserving function.
Informed consent: A documented conversation explaining a procedure's risks, benefits, and alternatives.; Required for every procedure and clinical trial. The form is one piece — the conversation matters more. Patients can withdraw consent at any time, including in trials.
Interventional urology: Image-guided, minimally invasive treatment of urologic disease.; A subspecialty that combines urologic oncology with interventional radiology techniques to treat prostate, kidney, and male reproductive disease through tiny access points instead of incisions.
IPSS (International Prostate Symptom Score): A validated questionnaire that quantifies BPH urinary symptoms.; Seven questions score symptom severity from 0 to 35 and a quality-of-life item. The IPSS guides whether observation, medication, or a procedure is appropriate.
IRB (Institutional Review Board): A committee that reviews and oversees clinical research to protect participants.; Every clinical trial must be approved and continuously monitored by an IRB. The board reviews the protocol, consent forms, recruitment, and any adverse events.
ISUP grade group: A 1–5 simplification of the Gleason score.; Grade group 1 corresponds to Gleason 6; group 2 to 3+4; group 3 to 4+3; groups 4 and 5 to Gleason 8 and 9–10. Used to keep risk language clearer for patients.

K

Kidney stone: A hard mineral deposit that forms in the kidney and can block urine flow.; Stones cause sudden flank pain, hematuria, and nausea. Small stones often pass; larger stones are removed with ureteroscopy or percutaneous nephrolithotomy (PCNL). A 24-hour urine collection identifies the metabolic cause to prevent recurrence.

L

Laser ablation: Use of focused laser light to heat and destroy targeted tissue.; MRI-guided focal laser ablation delivers laser energy through a small fiber placed in the tumor, monitored in real time by MRI thermometry. Dr. Rastinehad was among the first to use this approach for prostate cancer.
Localized prostate cancer: Prostate cancer that has not spread outside the gland.; Localized disease is the target for active surveillance, focal therapy, surgery, and radiation. Modern imaging (mpMRI and PSMA PET) confirms localization before treatment selection.

M

MRI-fusion biopsy: A targeted prostate biopsy that fuses prior MRI with real-time ultrasound.; Suspicious zones identified on multiparametric MRI are co-registered with live ultrasound so the needle is placed directly into the lesion. MRI-fusion biopsy improves detection of clinically significant cancer and reduces detection of indolent disease.
Multiparametric MRI (mpMRI): A prostate MRI protocol that combines anatomical and functional sequences.; mpMRI combines T2-weighted imaging, diffusion-weighted imaging (DWI), and dynamic contrast-enhanced imaging (DCE) to identify and grade suspicious prostate lesions, scored using the PI-RADS system.

N

NCT number: A unique ID assigned to a registered clinical trial on ClinicalTrials.gov.; Every NCT number (e.g. NCT01792479) links to the trial's protocol summary, eligibility, locations, and status. Use it to verify a trial is real and currently enrolling.
Neurovascular bundles: Nerve and blood-vessel pairs running alongside the prostate that drive erectile function.; Preserving the neurovascular bundles is the single biggest determinant of post-treatment erectile function. Focal therapy and PAE are designed to leave these structures undisturbed.
Nocturia: Waking up at night to urinate.; A core BPH symptom captured in the IPSS. Two or more episodes per night meaningfully reduce sleep quality and quality of life.

P

Percutaneous nephrolithotomy (PCNL): Image-guided removal of large kidney stones through a pinhole in the back.; A nephroscope is passed through a small flank tract directly into the kidney to fragment and remove stones too large for ureteroscopy. Dr. Rastinehad uses percutaneous renal access techniques refined during interventional radiology training.
PI-RADS: A standardized 1-to-5 scale for scoring suspicious prostate lesions on MRI.; Prostate Imaging Reporting and Data System (PI-RADS) grades lesions from 1 (very unlikely cancer) to 5 (very likely clinically significant cancer). PI-RADS ≥ 3 generally prompts targeted biopsy.
Prostate artery embolization (PAE): Minimally invasive embolization treatment for BPH.; A microcatheter is advanced from the wrist or groin into the prostatic arteries and embolic particles block blood flow, shrinking the prostate over 4–12 weeks. PAE relieves BPH without cutting prostate tissue and preserves ejaculation and erectile function.
PSA (prostate-specific antigen): A blood test used to screen for and monitor prostate disease.; PSA is a protein produced by prostate cells. Elevated or rising PSA can signal cancer but also BPH, prostatitis, or recent instrumentation, so it is interpreted in context with MRI and exam findings.
PSA density: PSA value divided by prostate volume on imaging.; PSA density helps distinguish PSA elevation from BPH alone versus clinically significant cancer. A density above ~0.15 ng/mL/cc raises suspicion and may push toward biopsy.
PSA velocity: How quickly PSA is rising over time.; Trended PSA values reveal kinetics that a single number cannot. A sharply rising PSA, even within the normal range, may warrant imaging.
PSMA PET: A nuclear scan that detects prostate cancer using a PSMA-targeted tracer.; PSMA PET/CT or PET/MRI binds to prostate-specific membrane antigen on prostate cancer cells and identifies disease outside the prostate at much lower volumes than conventional imaging.

R

Radical prostatectomy: Surgical removal of the entire prostate.; Often performed robotically. Highly effective for cancer control but carries meaningful rates of incontinence and erectile dysfunction, which is why focal therapy is preferred for appropriately selected disease.
Renal colic: Severe wave-like pain caused by a kidney stone blocking urine flow.; Classically sudden flank or groin pain, often with nausea. Fever with renal colic is a warning sign of infected obstruction and requires urgent drainage.
Renal embolization: Image-guided occlusion of arteries feeding a kidney tumor.; A microcatheter is advanced into the artery supplying a renal mass or angiomyolipoma; particles or coils shrink the tumor and reduce bleeding risk while preserving more kidney function than surgery.
Renal mass: Any solid or complex cystic lesion in the kidney.; Renal masses range from benign (AML, oncocytoma) to malignant (renal cell carcinoma). Modern management includes active surveillance for small masses, partial nephrectomy, ablation, and selective embolization.
Retrograde ejaculation: Semen entering the bladder instead of exiting during orgasm.; A common side effect of TURP and similar BPH surgeries. PAE preserves the bladder neck and ejaculatory function in the vast majority of patients.

S

Salvage focal therapy: Focal ablation used to treat prostate cancer that recurs after radiation.; After radiation failure, salvage focal therapy can ablate the recurrence with lower morbidity than salvage prostatectomy in carefully selected patients.
Sphincter (urinary): The muscle that holds urine in the bladder.; Preservation of the external urinary sphincter is essential for continence. Focal therapy and PAE are designed to leave it untouched.

T

Transperineal biopsy: A prostate biopsy approached through the perineum rather than the rectum.; Transperineal access reaches the entire prostate, including the anterior gland, and has a dramatically lower infection risk than the transrectal approach.
Transrectal ultrasound (TRUS): Ultrasound of the prostate performed via a rectal probe.; TRUS provides real-time prostate imaging used to guide biopsy and, when fused with prior MRI, enables MRI-fusion targeted biopsy.
TURP: Surgical removal of obstructing prostate tissue through the urethra.; Transurethral resection of the prostate has been the historical BPH benchmark. PAE matches symptom relief in many men with markedly fewer sexual side effects.

U

Ureteroscopy: Endoscopic stone removal through the urethra and ureter.; A thin scope is passed up to the stone; a laser fragments it and a basket removes the pieces. Used for most ureteral and many small-to-mid kidney stones.
Urinary retention: Inability to fully empty the bladder.; Acute retention is a urologic emergency, often from severe BPH. Chronic retention can damage the bladder and kidneys and is an indication to treat the underlying obstruction.
Uroflowmetry: A test that measures urine flow rate over time.; A low maximum flow (Qmax) with a flat curve suggests obstruction. Combined with post-void residual, uroflowmetry quantifies how much BPH is affecting bladder emptying.

V

Varicocele: Enlargement of the veins draining the testicle.; Varicoceles can cause scrotal pain, testicular atrophy, and male-factor infertility. Embolization through a single pinhole at the wrist or groin treats the problem without incisions or general anesthesia.
Varicocele embolization: No-incision treatment that closes the abnormal veins draining the testicle.; A microcatheter is advanced into the testicular vein and coils or sclerosant occlude the refluxing vessel. Outpatient, no general anesthesia, and same-day return to most activity.

A plain-language urology glossary.

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Personalized urologic care begins with a conversation.