Prostate biopsy - the "gold standard" for diagnosis of prostate cancer
With the advancement of medical technology in our country, tumor diagnosis technology is becoming more and more advanced, especially the application of imaging technology, but biopsy is still needed to diagnose tumor diseases. This article will guide you to learn more about prostate biopsy.
01
What is a prostate puncture
Prostate puncture is a minimally invasive surgical operation in which a fine needle is inserted into the prostate through the adjacent tissue or skin under the guidance of ultrasound, and thin strips of prostate tissue are cut and sent for pathological examination. It is the gold standard for the diagnosis of prostate cancer. There are two main methods, one is transrectal prostate biopsy, and the other is perineal prostate biopsy. Through pathological examination, the malignant degree of the tumor can be evaluated to choose the appropriate treatment plan for the patient and provide the pathological basis.
02
Prostatic puncture approach
Transrectal puncture
Transrectal prostate biopsy requires less anesthesia and surgical instruments, only ultrasound with rectal probe is required, and the procedure is simple and time-consuming. In addition, patients with transrectal prostate puncture have relatively little pain and are well tolerated by patients.
Figure 1 Prostate puncture approach (Source: Network)
Perineal puncture
There is no need for intestinal preparation before transperineal prostatic puncture, and the probability of urethral injury, postoperative infection and bleeding after puncture is lower than that of transrectal. Under the guidance of biplanar ultrasound, perineal prostate puncture can achieve accurate positioning, real-time grasp of needle depth and puncture site, and high satisfaction with tissue sampling. In addition, there is no "blind area" for transperineal prostate puncture, especially for the lesions located in the ventral and apex of the prostate, the positive rate of transperineal puncture is significantly higher than that of transrectal approach.
03
Indications and contraindications of prostate biopsy
Indication of primary biopsy
1. Suspected nodules of the prostate were found by digital rectal examination (DRE).
2. Transrectal ultrasound (TRUS) or prostate MRI, CT found suspicious lesions;
3. Serum total prostate-specific antigen (tPSA > 10 μg/L);
4. When blood tPSA was 4-10μg/L, the ratio of free to total prostate-specific antigen (f/t PSA) was < 0.16 and/or prostate-specific antigen density (PSAD) was > 0.15; And/or prostate-specific antigen rate (PSAV) > 0.75ng/(ml· year);
5. Abnormal results of other prostate tumor markers, such as positive urine prostate cancer antigen 3 (PCA3);
6. Diagnosis of prostate cancer with indications of metastatic disease.
Biopsy contraindications
1. Coagulation dysfunction, if recently taking anticoagulation, antiplatelet drugs, should inform the attending doctor, listen to professional advice, then perform puncture;
2. In the acute infection or fever period of the genitourinary system, there may be skin rupture at the puncture site, fungal dermatitis and other infection problems;
3. Patients with severe immunosuppression or poorly controlled or unstable complications such as hypertension and diabetes;
4. Patients with hypertensive crisis or in the compensatory stage of cardiac insufficiency;
6. Patients with severe internal and external hemorrhoids, perianal or rectal lesions, and anal stenosis should be contraindicated to perform transrectal puncture.
04
Prostatic needle biopsy quick question quick answer
q
What should I do to prepare for a prostate biopsy?
a
Routine examination before puncture to determine whether there are thrombocytopenia, bleeding tendency and other contraindicated signs of puncture; No intestinal preparation required; Stop anticoagulant drugs, general aspirin, clopidogrel need to stop for 7 days.
q
What are the complications after operation?
a
The complications of prostate puncture mainly include infection, hematuria, hematospermia, acute urinary retention, vagal reflex and so on.
q
What should be noted after prostate biopsy?
a
1. Try to get out of bed as little as possible on the day after the puncture. It is generally recommended to rest in bed for 24 hours, and strenuous waist activities are strictly prohibited within 3 weeks after the puncture.
2. Blood pressure, pulse, urine color, skin blood color, waist and abdominal symptoms and signs should be routinely monitored within 6 hours after puncture;
3. Bleeding is the most common complication after prostatocentesis, hemostatic drugs can be routinely administered, prophylactic antibiotics may reduce the occurrence of infection, and fever, chills and urinary tract infection can be symptomatic treatment in general;
4. If significant rectal bleeding is found after the puncture, a suitable size of vaginal sliver can be lubricated and inserted into the rectal indwelling for a few hours;
5. If blood clots occur after puncture, accompanied by dizziness, pale face, cold sweat, or persistent high fever, accompanied by perineal pain, it may be a serious urethral injury, and it is necessary to seek medical attention in time.
q
Can prostate puncture cause tumor metastasis?
a
In theory, any invasive operation on a tumor carries the risk of causing metastasis.
Puncture as a direct invasive examination, strictly speaking, may also promote tumor metastasis. On the one hand, puncture can destroy the tumor envelope or cause the loss of tissue debris, which may cause the tumor to implant metastasis. The tumor cells carried by the puncture needle may also adhere to the surrounding tissue when passing through the needle path, forming new lesions. Animal studies have shown that puncture may indeed cause implant metastasis of tumors, and this risk of metastasis is related to the thickness of the puncture needle, but it has not been confirmed by clinical data.
On the other hand, improper puncture operation may damage larger blood vessels, and blood metastasis may occur when tumor cells enter the blood vessels, resulting in involvement of distant organs. In fact, there are very few cases of transfer due to puncture in actual work. Studies have shown that the risk of puncture biopsy causing spread metastasis is less than 1 in 1,000, which is a rare event with a very low probability and almost negligible.
q
What are the indications for repeat puncture?
a
① Atypical hyperplasia or high-grade prostatic intraepithelial tumor (PIN) was found in the first biopsy.
② PSA>10μg/L;
③ Re-examination of PSA 4 ~ 10μg/L, free PSA ratio (% fPSA), PSA density (PSAD value), rectal digital examination or imaging abnormalities, such as transrectal prostate ultrasound or MRI examination indicating a suspected cancer focus, can be targeted puncture at the point of interest under image fusion technology;
④PSA 4 ~ 10μg/L, % fPSA, PSAD, digital rectal examination, imaging findings are normal, PSA review every 3 months. If PSA >10μg/L or PSAV>0.75ng/(ml· year) for two consecutive times, repeat puncture is required.
Prostate biopsy is the definitive means we use to rule out/confirm prostate cancer, and often only by biopsy can further treatment be given. Although it is an invasive pain diagnosis and treatment method, due to technical limitations, its status as the diagnostic "gold standard" is still unshaken, and we urgently need new technologies that can reduce pain and improve patient compliance.
