Prostate biopsy protocols: 3D visualization-based evaluation and clinical correlation.

OBJECTIVES: Systematic needle core biopsy is commonly used for the diagnosis of prostate cancer by urologists worldwide. As accurate and early diagnosis will result in more and better options for treatment, it is critical that the best possible protocols for biopsy be used clinically. In this study, we develop three-dimensional (3D) modeling and simulation technologies to evaluate most of the biopsy protocols in current clinical use, and correlate the results with those from clinical cases. MATERIALS AND METHODS: Using deformable modeling techniques, 3D computerized prostate surface models were reconstructed from step-sectioned, whole-mounted radical prostatectomy specimens with localized prostate cancer. A 3D computer simulation system was developed to accurately depict the anatomy of the prostate and all individual tumor foci. A user-friendly interface was developed in the system so that a physician can easily and interactively use it for prostate needle core biopsy. A total of 281 prostate models were reconstructed, and 18 biopsies were performed by a urologist on each model to determine the detection rates of seven different biopsy protocols. Clinical biopsies from 35 patient cases were also reviewed and correlated with the simulation results. RESULTS: The most commonly used sextant biopsy had only a 71.5% detection rate, while rates for the 10-pattern and 12-pattern protocols were much higher (96.4% and 97.2%, respectively). Even the lateral 4-pattern protocol performed better than the sextant protocol, with a detection rate of 89.3%. The lateral sextant biopsy protocol (using sites similar to, but more lateral than, those in the sextant protocol) achieved a rate of 92.5%. Although the rate of the 14-pattern biopsy was a little higher (97.5%), it used four more biopsies to achieve this increase, which, according to McNemar's test, is not statistically significant when compared to results with the 10-pattern protocol. The 5-region protocol, which uses 12 biopsies, had a detection rate of 89.7%. Transition zone and seminal vesicle biopsies did not result in a significantly increased detection rate when added to the patterns above. The clinical correlation also confirmed that the 10-pattern protocol was significantly superior to the traditional sextant biopsy pattern. CONCLUSIONS: The 10-pattern biopsy protocol was the most optimized among all the protocols evaluated. This protocol supplemented the sextant biopsy protocol with four more lateral biopsies in the mid and apical sites on both sides.     

Lateral biopsies added to the traditional sextant prostate biopsy pattern increases the detection rate of prostate cancer

Urologists routinely use the systematic sextant needle biopsy technique to detect prostate cancer. However, recent evidence suggests that this technique has a significant sampling error and data based upon whole-mounted step-sectioned radical prostatectomy specimens using a three-dimensional computer-assisted prostate biopsy simulator suggests that an increased detection rate is possible using laterally placed biopsies. The simulated 10-core biopsy pattern (traditional sextant biopsy cores and four laterally placed biopsies in the right and left apex and mid portion of the prostate gland) was shown to be superior to the traditional sextant biopsy. The objective of this pilot study was to confirm the higher prostate cancer detection rate obtained using the 10-core biopsy pattern in patients. We reviewed data on 35 consecutive patients with a pathologic diagnosis of prostate cancer biopsied by a single urologist using the 10-core biopsy pattern. The frequency of positive biopsy was determined for each core. Additionally, the sextant and 10-core prostate biopsy patterns were compared with respect to prostate cancer detection rate. Of the 35 patients diagnosed with prostate cancer, 54.3%(19/35) were diagnosed by the sextant biopsy only. The 10-core pattern resulted in an additional 45.7%(16/35) of patients being diagnosed solely with the laterally placed biopsies. The laterally placed biopsies had the highest frequency of positive biopsies when compared to the sextant cores. In conclusion, biopsy protocols that use laterally placed biopsies based upon a five region anatomical model are superior to the routinely used sextant prostate biopsy pattern. Prostate Cancer and Prostatic Diseases (2000) 3, 43-46     

Individualization of the biopsy protocol according to the prostate gland volume for prostate cancer detection

PURPOSE: In this study we assessed the relative yield of 10 core biopsy, and the whole range of alternative 8 and 6 core biopsy protocols over that of the classic sextant biopsy protocol. We determined the optimum number of cores per biopsy according to prostate volume in patients who experienced prostate biopsy for the first time. MATERIALS AND METHODS: A total of 503 men with the indications of abnormal digital rectal examination and/or serum prostate specific antigen greater than 2.5 ng/ml were included in the study. All patients underwent a 10 core biopsy protocol with an additional 1 core from each suspicious area detected by transrectal ultrasound. Prostate volume was divided into quartiles, namely 14.9 to 35, 35.1 to 50, 50.1 to 65 and 65.1 to 150 cc. The optimum number of biopsy cores was determined in patients with different prostate volumes. RESULTS: Median age was 63 years and prostate specific antigen was 7.4 ng/ml in the whole group. Of 503 patients 159 (31.6%) were positive for prostate cancer. Cancer detection rates decreased significantly from 49.6% to 20.8% as prostate volume increased in preset quartiles. Lesion biopsies revealed the lowest unique cancer detection rates for all prostate volume quartiles (0% to 3%). There was an obvious positive trend in cancer detection rates in favor of the 10 core biopsy protocol over sextant biopsies in all patient groups. Classic sextant biopsy protocol proved to be inadequate for all prostate volumes. Among sextant biopsy protocols laterally placed cores including the apex, lateral mid gland and lateral base had the best cancer detection rates (81% to 95%). The 8 core biopsy scheme consisting of the apex, mid gland, lateral mid gland and lateral base resulted in an only 1% lower detection rate (97%) than the 10 core biopsy protocol in the lowest quartile. The yield of the 10 core biopsy protocol in patients with a prostate volume of between 35.1 and 150 cc outscored that of the optimal 8 core biopsy scheme including the apex, base, lateral mid gland and lateral base with 3% to 8% differences in the cancer detection rate. CONCLUSIONS: The 10 core biopsy protocol must be used in all group of patients except patients with a prostate volume of 14.9 to 35 cc. In patients with a prostate volume of 14.9 to 35 cc the 8 core biopsy protocol consisting of the apex, mid gland, lateral mid gland and lateral base can be used since it revealed results similar to those of the 10 core biopsy protocol. The classic sextant biopsy protocol seemed inadequate for all prostate volumes. Patients with a larger prostate had lower cancer detection rates. Transrectal ultrasound directed lesion biopsies may be omitted when using 10 core biopsy protocols since the yield of these biopsies was less than 2%.     

Extended 21-sample needle biopsy protocol for diagnosis of prostate cancer in 1000 consecutive patients

OBJECTIVE: To prospectively evaluate the diagnostic yield of a 21-sample ultrasound-guided needle biopsy protocol as the initial diagnostic strategy for detection of prostate cancer. MATERIALS AND METHODS: Between December 2001 and October 2005, 1000 consecutive patients underwent 21-sample needle biopsies under local anesthesia, comprising sextant biopsies, 3 additional posterolateral biopsies in each peripheral zone, 3 biopsies in each transition zone (TZ), and 3 biopsies in the midline peripheral zone. Each prostate core was numbered and analyzed separately. The patients were divided into subgroups according to the result of digital rectal examination (DRE), serum prostate-specific antigen (PSA), and prostate volume. We evaluated the cancer detection rate overall and in each subgroup. We compared the results of our biopsy protocol to those from 6-, 12-, and 18-core biopsy protocols by analyzing only those cores from our protocol that would correspond to these biopsy schemes. RESULTS: Cancer detection rates using 6 biopsy samples (sextant biopsies only), 12 samples (sextant plus lateral biopsies), 18 samples (sextant, lateral, and TZ biopsies), and 21 samples (sextant, lateral, TZ, plus midline biopsies) were 31.7%, 38.7%, 41.5%, and 42.5%, respectively. The 12-sample procedure improved the cancer detection rate by 22% compared with the 6-sample procedure (p=0.0001). The improvement in the diagnostic yield was most marked in patients with a prostate volume > or =55 ml (36.9%), in patients with normal DRE (26.6%), and in patients with PSA<4 (37.5%). The addition of TZ biopsies to a 12-biopsy scheme increased the diagnostic yield by 7.2% overall (p=0.023). Only 10 of 425 (2.3%) patients were diagnosed on the sole basis of midline biopsies. CONCLUSIONS: Patients with suspected localized prostate cancer should be offered at least 12 biopsies in the peripheral zone and far lateral peripheral zone (statistically significant). TZ biopsies have to be considered, because these biopsies improve the diagnostic yield. For patients with abnormal DRE and/or PSA> or =20 ng/ml, the 6-biopsy scheme seems sufficient (statistically), but 6 far lateral peripheral zone biopsies as well as the TZ biopsies add little incremental value (not significant). Evidence does not support the use of routine midline peripheral zone needle biopsies in the initial biopsy to enhance the detection of prostate cancer.     

An extended 10-core transrectal ultrasonography guided prostate biopsy protocol improves the detection of prostate cancer

OBJECTIVE: To evaluate the efficacy of TRUS guided 10-core biopsy strategy for Turkish patients who had biopsy of the prostate for the first time. METHODS: Between February 2001 and May 2003, 303 consecutive men with suspected prostate cancer were included in the study. Indications for TRUS guided prostate biopsy were: abnormal digital rectal examination and/or a serum PSA over 2.5 ng/ml. All of the patients underwent a 10-core biopsy protocol with additional core from the each suspicious area detected by TRUS. Besides the sextant technique, 4 more biopsies were obtained from the lateral peripheral zone. We aimed to analyze whether cancer detection improved with the extended versus the standard sextant biopsy in our series overall and in each subgroup. RESULTS: Of 303 patients 94 (31%) were positive for prostate cancer. Median age and PSA of prostate cancer patients were significantly higher than of the non-cancer patients. Besides prostate volumes of the cancer patients were significantly lower than of the non-cancer ones. The cancer detection rates were 31% (94/303) and 23.1% (70/303) for the 10-core biopsy strategy and sextant biopsy strategies, respectively. Thus the 10-core biopsy technique increased cancer detection rate by 25.5% (24/94) for the whole group of patients. A statistically significant number of additional cancers were detected with 10-core biopsy strategy for all the subgroups of the patients. Furthermore 10-core biopsy protocol detected more cancers (at least 6.4%) than all the probable different combinations of 8-core biopsy protocols. Among the 94 cancer patients, biopsy from a suspicious area revealed cancer in 31.9% of them; however, in all of these patients cancer was already present in the 10-core biopsy. On the other hand, lesion biopsies revealed 5.7% additional cancers if sextant technique was used. There were only 3 (0.9%) serious complications requiring hospitalization and all 3 were infections controlled by appropriate antibiotics. CONCLUSION: Adding 4 lateral peripheral biopsies to the conventional sextant biopsy (10-core biopsy strategy) technique has increased the cancer detection rate by 25.5% without significant morbidity and without increasing the number of insignificant cancers. 10-core biopsy protocol was superior to all probable 8-core biopsy protocols in our study group. Additional biopsies from suspicious areas detected by transrectal ultrasonography revealed no further benefit if 10-core technique was used. We therefore suggest that 10-core biopsy protocol should be the preferred strategy in early detection of prostate cancer.     

One 10-core prostate biopsy is superior to two sets of sextant prostate biopsies

OBJECTIVES: To compare the efficiency of different transrectal ultrasonography (TRUS)-guided prostate biopsy techniques for detecting prostate cancer. MATERIALS AND METHODS: In all, 81 prostates from radical prostatectomy were used and two consecutive sets of sextant biopsies and one 10-core biopsy taken in each specimen. The 10-core biopsy consisted of a sextant biopsy and four cores from the far lateral areas of the prostate. To simulate a transrectal biopsy procedure, all biopsies were taken under TRUS guidance. RESULTS: In the first set of sextant biopsies 44 prostate cancers (54%) were detected and in the second set 51 (63%). Combining both sets of sextant biopsies 57 (70%) of the carcinomas were detected. One set of 10-core biopsies detected 66 (82%) of all prostate cancers. Overall, with the 10-core biopsies 16% more prostate tumours were diagnosed than with two consecutive sets of sextant biopsies. To find the same number of prostate cancers as with the 10-core technique, 14% of patients undergoing sextant biopsy would require a second set and 11% at least a third set of biopsies. CONCLUSIONS: The 10-core prostate biopsy technique is superior to the commonly used sextant technique and could spare patients unnecessary repeated biopsy. Even after including a second set of sextant biopsies, the total detection rate with these 12 biopsies was inferior to the 10-core technique.     

Significance of lateral biopsy specimens during transrectal ultrasound-guided prostate biopsies in Japanese men

OBJECTIVES: Lateral biopsies are thought to have a better cancer detection rate compared with standard sextant biopsies. This study aimed to determine whether lateral peripheral zone biopsies in Japanese men who underwent transrectal ultrasound-guided prostate biopsies provided a significantly higher cancer detection rate than sextant biopsies. METHODS: Between 1999 and 2004, data were collected from 461 men who underwent prostate biopsy and had enough data regarding the performance of lateral biopsies for statistical analysis. There were two categories in this study: (i) patients who underwent sextant prostate biopsies; and (ii) patients who underwent sextant biopsies plus lateral biopsies. RESULTS: Prostate cancer was detected in 141 (30.6%) of 461 patients. It was detected in 24 (22.2%) of 108 patients who underwent sextant biopsies and 117 (33.1%) of 353 patients who underwent sextant plus lateral biopsies. Lateral biopsies were not associated with a statistically higher rate of positive biopsy findings; however, we found a significantly higher ratio of patients with positive findings in those with prostate specific antigen (PSA) levels 10 ng/mL (one of 71, 1.4%) among those who had positive cores only in lateral biopsy samples (P < 0.0001). CONCLUSIONS: Lateral biopsies did not show a significantly higher detection ratio of prostate cancer compared to sextant biopsies. However, lateral biopsies were more effective than sextant biopsies in patients with lower PSA levels. Our findings might be useful for the establishment of biopsy strategies to detect prostate cancer, especially in patients with lower PSA levels.     

Effect of peripheral biopsies in maximising early prostate cancer detection in 8-, 10- or 12-core biopsy regimens

OBJECTIVE: To assess the cancer detection rate per individual core biopsy in a 12-core protocol and develop an optimal biopsy regimen for detecting early prostate cancer. PATIENTS AND METHODS: The study included 445 new patients who had a 12-core transrectal ultrasonography (TRUS)-guided prostatic biopsy over a 40-month period. The 12- core biopsy protocol included parasagittal sextant and six peripheral biopsies. The cancer detection rate per individual core was evaluated to give an optimal biopsy protocol. RESULTS: Prostate cancer was detected in 142 patients (31.9%). Parasagittal sextant biopsy would have failed to detect 40 (28.2%) of the cancers. Among the various possible biopsy protocols, the optimum 10-core biopsy strategy excluding the parasagittal mid-zone biopsies from the 12-core protocol achieved a cancer detection rate of 98.6%. CONCLUSION: The cancer detection rate increased from 71.8% for parasagittal sextant biopsies to 88.7% by adding peripheral basal biopsies (8-biopsy protocol); 98.6% of cancers in the series would have been detected with a 10-biopsy strategy omitting the parasagittal mid-zone biopsies. Thus we recommend a 10-core protocol incorporating six peripheral biopsies in patients with elevated age- specific prostate-specific antigen levels (2.6-10.0 ng/mL) for maximising cancer detection.     

Importance of posterolateral needle biopsies in the detection of prostate cancer

Objectives. To determine whether needle biopsy of the posterolateral aspects of the prostate aids in prostate cancer detection. In the routine sextant biopsy strategy, the posterolateral aspects of the prostate are not sampled.Methods. Using an 18-gauge biopsy gun, we performed sextant biopsies and an additional nine needle biopsies in the pathology laboratory on 150 radical prostatectomy specimens performed for Stage T1c prostate cancer. The additional nine biopsies consisted of three midline biopsies and six (three each from the left and right) posterolaterally aimed biopsies from the apex, mid, and base regions of the gland. Significant tumors were defined as those greater than 0.5 cm³, or with a Gleason score of 7 or greater, or non-organ confined.Results. Of the 123 cases with cancer on repeated biopsy, in only 3 (2.4%) was the only cancer found in the midline biopsies. For the following analysis, we analyzed the data as if we had not done the midline biopsies. If one had performed only the routine sextant needle biopsies, in 31 (25.2%) of the 123 cases, tumor would have been missed; 20 of these tumors were significant, including 5 with extraprostatic extension. If one had performed only the more posterolateral six biopsies, in 15 cases (12.2%), tumor would have been missed; 5 of these tumors were significant, all of which were organ confined.Conclusions. Adding routine midline biopsies does not appreciably increase the detection of cancer. If one were to only perform six needle biopsies of the prostate, these biopsies should be aimed more toward the posterolateral aspect of the gland. Maximum cancer detection results from combining both routine sextant and posterolateral needle biopsies.     

Comparison of prostate biopsy schemes by computer simulation

OBJECTIVES: To compare the ability of different biopsy schemes to detect cancer and predict tumor volume using our previously described prostate biopsy simulation system. In addition, we used the simulation system to evaluate the optimal location of transition zone biopsies. METHODS: Digital reconstructions of 180 radical prostatectomy specimens were used. Forty simulations were performed on each prostate for 10 biopsy schemes, including a previously reported five-region peripheral zone biopsy pattern and a new 11-core multisite-directed scheme consisting of sextant, two transition zone, one midline, and two anterior horn biopsies. For simulation of the transition zone biopsies, paired near-midline biopsies were simulated, with needle insertion points from the apex to the base of the prostate and with needle advances of 1 to 4 cm before firing. A total of 1,180,800 individual biopsy tracks were simulated. RESULTS: The 11-core multisite-directed biopsy scheme had the highest detection rate for cancers greater than 0.5 cc. This scheme reliably detected cancer in 94% (138 of 147) of the cases. These results were significantly better than those of the sextant biopsy scheme (P <0.001) and the five-region 18-core peripheral zone scheme (P = 0.03). Compared with other schemes, there were increases in small-volume (0.5 cc or less) cancer detection by both the 11-core multisite-directed and five-region schemes, but they were not statistically significant. The multisite and the sextant plus four transition zone biopsy schemes had the best correlation of mean total core cancer length with total cancer volume. In the simulation of the transition zone biopsies, the highest detection rate was observed when the biopsies were initiated at the most apical section and inserted for a depth of 3 cm before firing. CONCLUSIONS: Our simulation results suggest that the detection rate of prostate biopsies is not related solely to the number of cores taken. Core placement (the regions of the prostate from which samples are taken) is also important. The 11-core multisite-directed biopsy scheme performed the best, with improved cancer detection rates and tumor volume correlation over other schemes. On the basis of our simulations, this scheme has been chosen for clinical evaluation.     

Ultrasound-guided transrectal extended prostate biopsy： a prospective study

AIM: To evaluate the diagnostic value of the 10 systematic transrectal ultrasound-guided (TRUS) prostate biopsy compared with the sextant biopsy technique for patients with suspected prostate cancer. Methods: One hundred and fifty-two patients with suspected prostate cancer were included in the study. Patients were entered in the study because they presented with high levels of prostate specific antigen (PSA) (over 4 ng/mL) and/or had undergone an abnormal digital rectal examination (DRE). In addition to sextant prostate biopsy cores, four more biopsies were obtained from the lateral peripheral zone with additional cores from each suspicious area revealed by transrectal ultrasound. Sextant, lateral peripheral zone and suspicious area biopsy cores were submitted separately to the pathological department. Results: Cancer detection rates were 27.6% (42/152) and 19.7% (30/152) for the 10-core and sextant core biopsy protocols, respectively. Adding the lateral peripheral zone (PZ) to the sextant prostate biopsy showed a 28.6% (12/42) increase in the cancer detection rate in patients with positive prostate cancer (P < 0.01). The cancer detection rate in patients who presented with elevated PSA was 29.3% (34/116). When serum PSA was 4-10 ng/mL TRUS-guided biopsy detected cancer in 20.6%, while the detection rate was 32.4% and 47.0% when serum PSA was 10-20 ng/mL and above 20 ng/mL, respectively. Conclusion: The 10 systematic TRUS-guided prostate biopsy improves the detection rate of prostate cancer by 28.6% when compared with the sextant biopsy technique alone, without increase in the morbidity. We therefore recommend the 10-core biopsy protocol to be the preferred method for early detection of prostate cancer.     

Improving prostate cancer detection with an extended-core transrectal ultrasonography-guided prostate biopsy protocol

OBJECTIVE: To investigate whether taking two transition zone (TZ) and four lateral peripheral zone (PZ) biopsies in addition to routine parasaggital sextant biopsies would improve detection rates in men with suspected prostate cancer. PATIENTS AND METHODS: The study included 493 consecutive men (mean age 68.7 years, sd 8.2) with elevated serum prostate-specific antigen (PSA) levels and/or abnormal findings on a digital rectal examination who underwent transrectal ultrasonography-guided prostate biopsy. In addition to sextant biopsies, six further biopsies were obtained, two from the TZ (mid-gland) and four from the lateral PZ (base and mid-gland). Pathological findings for the additional biopsies were compared with those of the sextant regions. RESULTS: Prostatic adenocarcinoma was diagnosed in 164 of the 493 (33%) men biopsied. Men with cancer were older, had smaller prostates and higher median PSA levels than men with negative biopsies. Sextant biopsies were positive for cancer in 133 of 164 (81%) men. All three sets of biopsies were positive in 53 (32%) cases. In 50 (30%) men both the sextant and lateral PZ biopsies were positive, while in six (4%) men, both sextant and TZ biopsies were positive. Thirty-one (19%) tumours were not detected by sextant biopsies, 10 (6%) where the lateral PZ biopsies alone were positive, 17 (10%) where the TZ biopsies alone were positive and four (3%) where both the TZ and lateral PZ together were positive. There were no differences in median PSA concentration, total prostate volume or TZ volume between men with an isolated TZ cancer and men with cancer elsewhere in the prostate. However, 77% of men with TZ cancer had a PSA of > 10 ng/mL, compared with 60% of men with cancer at other sites within the prostate (P = 0.015). CONCLUSION: An extended-core biopsy protocol significantly improves the detection rate for prostate cancer when compared with the standard sextant biopsy protocol alone. Routine TZ biopsies should be considered for men with serum PSA levels of >10 ng/mL.     

Extended prostate needle biopsy improves concordance of Gleason grading between prostate needle biopsy and radical prostatectomy

PURPOSE: We examined the concordance of Gleason scores in prostate needle biopsy specimens and the corresponding radical retropubic prostatectomy specimens in a cohort of patients grouped according to the number of cores obtained during diagnostic needle biopsy. MATERIALS AND METHODS: We reviewed clinical and pathological data on a cohort of 466 men diagnosed with localized prostate cancer by needle biopsies who underwent radical retropubic prostatectomy between January 1, 1990 and July 31, 2001. Two study groups were identified, including 126 patients diagnosed with prostate cancer by extended needle biopsies (10 or more cores) and 340 diagnosed with cancer by nonextended needle biopsies (9 or fewer cores). Mean age was 60 years and median prostate specific antigen was 5.8 ng./ml. The median number of cores in the extended and nonextended biopsy groups was 12 and 6, respectively. The concordance of Gleason score in the needle biopsy and prostatectomy specimens was compared and correlated with the number of cores on needle biopsy. RESULTS: In the whole cohort 311 patients (67%) had identical Gleason scores on the needle biopsy and prostatectomy specimens, while 53 (11%) were over graded and 102 (22%) were under graded on needle biopsy. In patients who underwent extended needle biopsies the accuracy rate for Gleason scoring was 76% with 10% over and 14% under graded. The highest accuracy rates were in patients with 13, 14 and 16 cores (89%, 87% and 100%, respectively). No patients in the extended needle biopsy group had a discrepancy of more than 2 Gleason units in grade in the biopsy and surgical specimens. In those who underwent nonextended needle biopsies the accuracy rate for Gleason scoring was 63% with 12% over and 25% under graded. There were significantly different rates of accuracy (p = 0.008) and under grading (p = 0.01) in the 2 needle biopsy groups. Patients with a needle biopsy Gleason score of less than 7 had significantly higher concordance with the prostatectomy Gleason score when extended biopsies were done compared with nonextended biopsies (p = 0.001). CONCLUSIONS: Prostate cancer grading by extended needle biopsy is a better predictor of the final Gleason score than nonextended needle biopsy, as determined by radical prostatectomy histological evaluation. Therefore, extended prostate needle biopsy provides better guidance to determine the appropriate treatment in patients with prostate cancer.     

Differences in biopsy features between prostate cancers located in the transition and peripheral zone

OBJECTIVE: To identify the zonal location of prostate cancers before surgery, by analysing the mapping of ultrasonography-guided systematic sextant biopsies for differences between cancers located in the transition zone (TZ) and peripheral zone (PZ); and to compare the correlation between Gleason scores of needle biopsies and those of radical prostatectomy (RP) specimens. PATIENTS AND METHODS: In all, 186 patients with TZ (46) and PZ cancers (140) underwent ultrasonography-guided systematic sextant biopsy and RP at the same institution. The clinical and pathological characteristics, and the anatomical location of positive biopsies, were determined and compared using t-tests and chi-square tests. Differences between Gleason scores of needle biopsies and those of RP specimens were evaluated and compared by Cohen kappa testing. RESULTS: TZ cancers had a significantly lower rate of positive biopsies in the middle (63% vs 80%) and base (50% vs 80%) of the prostate than had PZ cancers. Positive biopsies were exclusively obtained from the apex in 19.6% of TZ and 5% of PZ cancers (P = 0.002). There was exact agreement between Gleason scores of needle biopsies and those of RP specimens in 15.2% of TZ (kappa = 0.02) and 55% of PZ cancers (kappa = 0.25), respectively. CONCLUSION: Compared with PZ cancers, TZ cancers had a different anatomical pattern of positive biopsies, with lower rates in the middle and base of the prostate. The finding of positive biopsies exclusively in the apex favoured prostate cancer located in the TZ. Furthermore, the correlation between needle biopsy Gleason scores and those of the RP specimens was clearly lower in TZ cancers.     

Optimal combinations of systematic sextant and laterally directed biopsies for the detection of prostate cancer

PURPOSE: The standard sextant protocol for obtaining transrectal ultrasound guided biopsy of the prostate has been shown to underestimate the presence of prostate cancer. Studies have demonstrated an increased cancer detection rate with additional laterally directed biopsies. We compared the sensitivity of individual biopsy cores and evaluated combinations of these cores to identify an optimal biopsy strategy. MATERIALS AND METHODS: A total of 396 consecutive patients underwent biopsy of the lateral peripheral zone in addition to standard sextant biopsy. The cancer detection rate for each biopsy core was calculated. The sensitivity of different combinations of biopsy cores was compared with those of standard sextant biopsies and with a 12 core biopsy protocol that combined the standard sextant biopsy with a complete set of laterally directed cores. RESULTS: Cancer was detected in 160 of 396 (40.3%) patients. Of the possible combinations of biopsy cores a strategy that included laterally directed cores at the base, mid gland and apex of the prostate with mid lobar base and apical cores detected 98.5% of cancers. The detection rate of this 10 core biopsy regimen was significantly better than that of the standard sextant protocol (p < or =0.001), and was equivalent to that of the 12 core regional biopsy (p > or =0.302). CONCLUSIONS: The standard sextant protocol failed to detect a large proportion of cancers located laterally in the peripheral zone. A 10 core biopsy regimen that combined laterally directed cores at the base, mid gland and apex of the prostate with mid lobar biopsy cores at the base and apex maximizes the sensitivity of transrectal ultrasound guided systematic biopsy.     

Biopsy standards for detection of prostate cancer

The widespread use of measurement of prostate-specific antigen for prostate cancer screening has led to a dramatic increase in the number of transrectal biopsies. Although transrectal ultrasound-guided prostate biopsy is the gold standard in the diagnosis of prostate cancer, the strategies for initial and repeat biopsies remain controversial. Over the past decade numerous biopsy protocols have been developed. Several protocols have been established that increase the number of cores by combining sextant and lateral biopsies to increase the cancer detection rate. We review the current methods of prostate biopsies, the indication to perform an initial and repeat biopsy, the impact of prostate volume on the number of cores taken, and the morbidity of the procedure.     

Transition zone biopsy in the detection of prostate cancer

OBJECTIVE: About 25% of all prostate cancers occur in the transition zone (TZ). We analyzed the impact of 4 systematic TZ and 2 systematic apex (AP) biopsies in addition to systematic sextant biopsies in an effort to establish the diagnostic importance of early prostate cancer. METHODS: One hundred and thirty patients underwent systematic transperineal multipoint prostate biopsy (biopsy of 12 sites, including 4 TZ and 2 AP biopsies). RESULTS: Forty-one of 130 men (31.5%) had biopsy specimens positive for cancer, and cancer originated in the TZ alone in 4 of these 41 patients (9.8%). Fourteen patients underwent radical retropubic prostatectomy. We compare the pathological findings of radical prostatectomy specimens and biopsy results. Prostate cancers predicted to be stage T(2c) by TZ biopsy were all classified as pT(2c) or greater. CONCLUSIONS: Routine TZ biopsy does not substantially increase the prostate cancer detection rate; however, it can be useful in patients who require repeat biopsy.     

The Effect of Prior Biopsy Scheme on Prostate Cancer Detection for Repeat Biopsy Population: Results of the 14-core Prostate Biopsy Technique

OBJECTIVES: To evaluate the diagnostic performance of 14-core repeat biopsy protocol and the impact of prior biopsy scheme on repeat prostate biopsy group. METHODS: 211 patients had repeat biopsy using 14-core protocol consisting of 10-core peripheral zone (classical sextant+4 lateral peripheral cores) and 4-core transitional zone (TZ) biopsies. The diagnostic yield was determined both in patients who had previously undergone sextant or 10-core biopsy protocol. RESULTS: Overall cancer detection rate was 25.6%. 14-core biopsy technique detected cancer in 36.1 and 18.7% of the patients who had a previous sextant biopsy and 10-core biopsy protocol, respectively (P = 0.005). Patients with and without high-grade prostatic intraepithelial neoplasia (HGPIN) in the previous sextant biopsy had 56.5 and 28.3% cancer detection rates on the subsequent extended biopsy, respectively (P = 0.017) Patients who had previous 10-core biopsy with and without HGPIN revealed 22.9 and 17.2% cancer detection rates, respectively (P = 0.465) Additional four lateral peripheral cores detected 33% (3/30) and 17% (4/24) of cancers in patients with previous sextant and 10-core biopsy, respectively. 3.7% of the patients had tumor only in the TZ and none of them had prior extended biopsy. CONCLUSIONS: The yield of extended 14-core repeat biopsy protocol was higher in patients with previous negative sextant biopsy compared to the patients with previous negative 10-core biopsy. HGPIN history found on previous sextant biopsy was a strong cancer predictor on repeat biopsy; same was not true for the patients with previous 10-core biopsy. The yield of lateral peripheral cores and TZ biopsies were lower in patients with prior negative extended biopsy.     

Impact of additional sampling in the TRUS-guided biopsy for the diagnosis of prostate cancer

AIM: To evaluate the diagnostic value of 10+ systematic sampling technique when performing transrectal ultrasound-guided (TRUS) prostate biopsy, compared with the sextant biopsy technique for patients with suspected prostate cancer. METHODS: 286 patients with suspected prostate cancer were included in the study. Patients were eligible for the study if they had serum levels of prostate-specific antigen (PSA) >4 ng/ml or ratio PSA <0.25 and/or an abnormal digital rectal examination (DRE). The population sample was divided in three groups: (1) those with positive PSA, PSA ratio and DRE (70 patients); (2) those with positive PSA and PSA ratio but normal DRE (178 patients), and (3) those with positive PSA and PSA ratio, positive PSA velocity and a negative biopsy in the previous 6-month period (38 patients). In addition to the conventional sextant prostate biopsy cores, four more biopsies were obtained from the lateral peripheral zone (10 core biopsy protocol). Additional cores (total of 12-14) were also randomly selected in case of larger prostates (>60 ml) or from suspicious foci revealed by transrectal ultrasound. All additional biopsy cores were submitted separately to the pathological department. RESULTS: Cancer was detected in 55.7% (39/70) and 69% (48/70) of the patients (for sextant core and for the extended biopsy protocols, respectively) in the first study group, 11% (20/178) and 23% (41/178) of the patients (for the sextant and the extended biopsy protocols, respectively) in the second study group, and 42% (16/38) and 63% (24/38) of the patients (for the sextant and the extended biopsy protocols, respectively) in the third study group. The addition of the lateral peripheral zone (PZ) of the prostate to the sextant biopsy showed a 23, 105 and 50% increase in the number of cancers diagnosed in the first, second and third study groups, respectively. The improvement of cancer detection rate (sensitivity) was statistically significant for all groups evaluated. CONCLUSION: The 10+ systematic TRUS-guided prostate biopsy improves the detection rate of prostate cancer compared to the sextant biopsy technique alone, especially when performed in men with positive PSA, PSA ratio, and negative DRE.     

Update on prostate biopsy technique

PURPOSE OF REVIEW: Over the past decade, a considerable number of modifications have been made to the techniques for prostate cancer biopsy. In this review, we discuss the developments reported in the literature since January 2003. RECENT FINDINGS: The addition of laterally directed biopsies has enhanced the diagnostic performance of the conventional sextant biopsy approach. Several models of the extended biopsy technique have been introduced that increase the number of cores by combining sextant and lateral biopsies to enhance the cancer detection rate. Several reports have shown that the cancer detection rate decreases as prostate volume increases, compared with an increasing cancer detection rate on repeat biopsy in men with large prostate gland volumes. Other studies have shown that the percentage of positive cores and the total percentage of tumor found at biopsy are significant independent predictors of pathological outcome on multivariate analysis. In randomized, double-blind studies, infiltration of the neurovascular bundles with lidocaine significantly reduces pain associated with extended biopsies. SUMMARY: Current reports have suggested that: (1) extended biopsy schemes decrease the false-negative rate compared with conventional sextant biopsy; (2) laterally directed biopsies from the anterior horn should be included in extended biopsy protocols; and (3) local anesthesia reduces pain associated with extended biopsy.