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Parasagittal biopsies add minimal information in repeat saturation prostate biopsy
ADULT UROLOGY
PARASAGITTAL BIOPSIES ADD MINIMAL INFORMATION IN REPEAT SATURATION PROSTATE BIOPSY AMIT R. PATEL, J. STEPHEN JONES, JOHN RABETS, GERARD DEOREO,
AND
CRAIG D. ZIPPE
ABSTRACT Objectives. To compare the outcome and efficacy of lateral biopsies with parasagittal biopsies in detecting prostate cancer during repeated biopsies performed using the “saturation” technique, which includes 24 cores per biopsy. Prostate biopsy may miss cancer in up to 38% of men eventually found to harbor the disease. Lateral biopsies are more likely than parasagittal biopsies to detect adenocarcinoma according to the findings of several studies. Methods. A total of 100 patients, average age 62.1 ⫾ 7.9 years, underwent repeated transrectal ultrasound-guided saturation biopsy. The study group included 31 patients with previous biopsy results demonstrating high-grade prostatic intraepithelial neoplasia, 7 with atypia, and 62 with benign prostatic tissue but persistently elevated prostate-specific antigen levels. Patients had undergone an average of 1.65 previous biopsies. The average prostate-specific antigen level was 9.4 ⫾ 6.8 ng/mL. Biopsies were obtained from five sectors on each side and examined histologically. Results. Cancer was detected in 25 (25%) of the 100 patients. Malignancy was identified in the lateral cores of all patients with positive biopsies. Parasagittal biopsy cores were positive in association with a lateralbased biopsy in 9 (36%) of the 25 malignancies, for an overall parasagittal biopsy core rate of 9% (9 of 100 patients). No cancers were detected in the parasagittal biopsy cores alone. Conclusions. Inclusion of parasagittal zone biopsy cores proved to have a low yield in detecting cancer on repeated biopsy. As all patients found to have cancer in the parasagittal biopsy cores also had cancer on the lateral biopsy cores, most time and effort can be spent obtaining lateral biopsy cores to increase the sensitivity on repeated saturation biopsy. UROLOGY 63: 87–89, 2004. © 2004 Elsevier Inc.
R
epeat prostate biopsy is a common procedure in men with increasing prostate-specific antigen (PSA) levels, abnormal digital rectal examination findings, or previous abnormal nonmalignant prostate pathologic findings such as prostatic intraepithelial neoplasia or atypia. Up to one third of men refuse to undergo repeated biopsy, regardless of the prior number of biopsies.1 Fortunately, with the popularization of the periprostatic block to achieve local anesthesia, the pain and morbidity have reached acceptable levels.2,3 Although debate continues about how to conduct the repeat biopsy, it is clear that location is an important factor in the detection of prostate cancer on repeat biopsy. Stamey4 found that performing sextant From the Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio Reprint requests: J. Stephen Jones, M.D., Glickman Urological Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Desk A-100, Cleveland, OH 44195 Submitted: May 30, 2003, accepted (with revisions): August 28, 2003 © 2004 ELSEVIER INC. ALL RIGHTS RESERVED
biopsies laterally instead of in the traditional parasagittal location increased biopsy accuracy. Gore et al.5 recommended a biopsy strategy that included laterally directed cores to increase the cancer detection yield. In addition, three-dimensional computer-simulated biopsy studies have suggested that lateral prostate biopsies increase the cancer detection rate.6 These recommendations contrast with saturation protocols that emphasize other areas of the prostate, specifically the one suggested by Eskew et al.7 of an extended five-region biopsy protocol that emphasized the inclusion of midline biopsies. We have found that most positive biopsies are located in the lateral cores and prospectively evaluated the location of positive biopsies to determine the sectors that are important during repeated 24core saturation prostate biopsy. MATERIAL AND METHODS From February 2002 to July 2003, a total of 100 patients underwent repeated transrectal ultrasound-guided saturation 0090-4295/04/$30.00 doi:10.1016/j.urology.2003.08.040 87
found in the parasagittal regions of the prostate, with no cancer detected exclusively in the parasagittal region. The parasagittal biopsy cores detected cancer in 9 (9%) of the total 100 patients. For treatment, 12 patients underwent iodine-125 brachytherapy, 2 underwent hormonal therapy, 4 underwent radical prostatectomy, 1 underwent external beam radiotherapy, and the remainder chose watchful waiting or had not yet chosen to proceed with treatment. Complications during the study included 1 patient who developed prostatitis requiring intravenous antibiotics with full recovery. Two patients developed self-limited lightheadedness when we used 20 mL of 2% lidocaine. We subsequently changed to 10 mL of 1% lidocaine, with no further complications to date. FIGURE 1. Location of five sectors on each side. Number of biopsy cores from each sector is indicated in parentheses. Sectors shaded in gray represent lateral biopsies. Reprinted with the permission of the Cleveland Clinic Foundation.
biopsy. The institutional review board approved the study of the patient database. All patients included in the study provided informed consent. The average patient age was 62.1 ⫾ 7.9 years. All patients had undergone at least one previous negative prostate biopsy. The patient population had undergone an average of 1.65 previous biopsies (range 1 to 7). The indications for repeat biopsy included persistently elevated or increasing PSA level, prior biopsy showing high-grade prostatic intraepithelial neoplasia (n ⫽ 31) or atypia (n ⫽ 7), or abnormal digital rectal examination findings (n ⫽ 9). The average PSA level was 9.4 ⫾ 6.8 ng/mL. Patients underwent transrectal ultrasound-guided saturation biopsy with a periprostatic block in the office, as described previously.8 After successful placement of local anesthesia, the prostate volume was calculated. Using a spring-loaded biopsy gun, 24 biopsies were taken from five sectors in each side (Fig. 1). On each side, two biopsies were obtained from the lateral base, three from the lateral midsection, three from the apex, two from the parasagittal midsection, and two from the parasagittal base. The final 8 patients in the series underwent 20-core saturation biopsies; only one core was taken from the parasagittal mid-section and parasagittal base on each side. Visualizing the needle tract of the current biopsy cores and separating the cores as much as possible in each sector ensured even distribution of the biopsy sites. Biopsies obtained from the two parasagittal regions were considered parasagittal biopsies, and the three lateral sectors, including the apex, were considered lateral biopsies.
RESULTS Prostate adenocarcinoma was detected in 25 (25%) of the 100 patients. All patients had Stage T1c cancer. Of the cancers detected, 2 were Gleason score 5, 17 were Gleason score 6, 5 were Gleason score 7, and 1 was Gleason score 9. All cancers were detected in the lateral regions of the prostate (lateral base, lateral mid-section, or apex). Only 9 (36%) of the 25 cancers were also 88
COMMENT Repeat prostate biopsy may be indicated for patients with prior negative biopsies who have persistently elevated PSA levels, prostatic intraepithelial neoplasia, or atypia. Many studies have shown the efficacy of repeated biopsy within those patient populations.1,9 –13 The approach to biopsy has been a continuing debate. Stamey4 stated that laterally directing sextant biopsies increased the detection rate of prostate cancer. Since then, numerous studies have looked at cancer detection rates using different biopsy strategies. To our knowledge, no study has directly compared the yield of parasagittal biopsies versus lateral biopsies in patients undergoing repeat biopsy. Bauer et al.6 used a three-dimensional computersimulated prostate model based on 201 radical prostatectomy specimens to determine the detection rate of lateral prostate biopsies. The four-pattern lateral biopsies yielded a 93.5% detection rate versus a traditional sextant detection rate of 72.6%. Most tumors in their specimens were near the posterior and lateral capsule. The 10-pattern biopsy protocol was optimal, identifying 99.0% of the cancers. Gore et al.5 looked at optimal combinations of number and location of biopsies. Their results showed that a similar 10-core method with emphasis on lateral biopsies yielded the overall greatest detection rate. Of 111 patients undergoing repeat biopsy in their study, 24.3% were found to have cancer, but they did not differentiate where the cancers were located. Eskew et al.7 described a five-region technique that included midline biopsies to increase the detection rate by 35% compared with sextant biopsies. Our results showed that midline biopsies might not be needed on repeat biopsy. In addition, UROLOGY 63 (1), 2004
there is concern of increased morbidity if the urethra is injured. Applewhite et al.14 followed with a study using the five-region technique on repeat biopsy at the same institution and demonstrated an increase in the cancer detection rates, but no comparison was done between the lateral and parasagittal cores according to detection rate. The cancer detection rate in our study was slightly less than that of Stewart et al.11 and Borboruglu et al.13 However, those studies were presumably performed on patients who had previously undergone multiple traditional sextant biopsies instead of laterally based biopsies. All but 11 of our patients had previously undergone biopsies using a minimum of 10 laterally based cores. Therefore, we believe that our false-negative rate on initial biopsy was less than it would have been if sextant biopsies had been performed initially. Therefore, the population in need of repeated biopsies according to the indications listed above has a theoretically lower rate of undiagnosed prostate cancer. Epstein et al.15 conducted posterolateral needle biopsies in addition to sextant biopsies on 150 radical prostatectomy specimens for T1c prostate cancer. Cancer was detected on repeat biopsy in 123 specimens. Their results supported the inclusion of additional posterolateral biopsies because of the amount of significant cancer cases that would have been missed with parasagittal biopsies. In addition, they detected 5 significant cancers (4.1%) solely in the parasagittal cores. Although our study revealed no cancers found solely in the parasagittal regions, we remain cognizant that a small percentage of cancers may be found solely in the parasagittal region. On the basis of these data, we have decreased the number of parasagittal cores on each side from four to two and now perform a 20-core repeat saturation biopsy. CONCLUSIONS The results of this study have shown that parasagittal biopsies provide a low yield on repeat prostate biopsy after an initial negative biopsy. Parasagittal biopsies may still be important for first-time prostate biopsies. The present study did not address the likelihood of detecting cancer in the para-
UROLOGY 63 (1), 2004
sagittal cores during a first-time biopsy. However, during repeated biopsy, more time and effort can be spent on lateral biopsies, which should increase the cancer detection rate. REFERENCES 1. Roehl KA, Antenor JAV, and Catalona WJ: Serial biopsy results in prostate cancer screening study. J Urol 167: 2435– 2439, 2002. 2. Soloway MS, and Obek C: Periprostatic local anesthesia before ultrasound guided prostate biopsy. J Urol 163: 172– 173, 2000. 3. Jones JS, Ulchaker JC, Nelson D, et al: Periprostatic local anesthesia eliminates pain of office-based transrectal prostate biopsy. Prostate Cancer Prostat Dis 6: 53–55, 2003. 4. Stamey TA: Making the most of six systemic sextant biopsies. Urology 45: 2–11, 1995. 5. Gore JL, Shariat SF, Miles BJ, et al: Optimal combinations of systematic sextant and laterally directed biopsies for the detection of prostate cancer. J Urol 165: 1554 –1559, 2001. 6. Bauer JJ, Zeng J, Weir J, et al: Three-dimensional computer-simulated prostate models: lateral prostate biopsies increase the detection rate of prostate cancer. Urology 53: 961– 967, 1999. 7. Eskew AL, Bare RL, and McCullough DL: Systematic 5 region prostate biopsy is superior to sextant method for diagnosing carcinoma of the prostate. J Urol 157: 199 –202, 1997. 8. Jones JS, Oder M, and Zippe CD: Saturation prostate biopsy with periprostatic block can be performed in the office. J Urol 168: 2108 –2110, 2002. 9. Keetch DW, and Catalona WJ: Prostatic transition zone biopsies in men with previous negative biopsies and persistently elevated serum prostate specific antigen values. J Urol 154: 1795–1797, 1995. 10. Keetch DW, Catalona WJ, and Smith DS: Serial prostatic biopsies in men with persistently elevated serum prostate specific antigen values. J Urol 151: 1571–1574, 1994. 11. Stewart CS, Leibovich BC, Weaver AL, et al: Prostate cancer diagnosis using a saturation needle biopsy technique after previous negative sextant biopsies. J Urol 168: 86 –92, 2001. 12. Fleshner NE, O’Sullivan M, and Fair WR: Prevalence and predictors of a positive repeat transrectal ultrasound guided needle biopsy of the prostate. J Urol 158: 505–508, 1997. 13. Borboruglu RG, Comer SW, Riffenburgh RH, et al: Extensive repeat transrectal ultrasound guided prostate biopsy in patients with previous benign sextant biopsies. J Urol 163: 158 –162, 2000. 14. Applewhite JC, Matagla BR, and McCullough DL: Results of the 5 region prostate biopsy method: the repeat biopsy population. J Urol 168: 500 –503, 2002. 15. Epstein JI, Walsh PC, and Carter HB: Importance of posterolateral needle biopsies in the detection of prostate cancer. Urology 57: 1112–1116, 2001.
89
PARASAGITTAL BIOPSIES ADD MINIMAL INFORMATION IN REPEAT SATURATION PROSTATE BIOPSY AMIT R. PATEL, J. STEPHEN JONES, JOHN RABETS, GERARD DEOREO,
AND
CRAIG D. ZIPPE
ABSTRACT Objectives. To compare the outcome and efficacy of lateral biopsies with parasagittal biopsies in detecting prostate cancer during repeated biopsies performed using the “saturation” technique, which includes 24 cores per biopsy. Prostate biopsy may miss cancer in up to 38% of men eventually found to harbor the disease. Lateral biopsies are more likely than parasagittal biopsies to detect adenocarcinoma according to the findings of several studies. Methods. A total of 100 patients, average age 62.1 ⫾ 7.9 years, underwent repeated transrectal ultrasound-guided saturation biopsy. The study group included 31 patients with previous biopsy results demonstrating high-grade prostatic intraepithelial neoplasia, 7 with atypia, and 62 with benign prostatic tissue but persistently elevated prostate-specific antigen levels. Patients had undergone an average of 1.65 previous biopsies. The average prostate-specific antigen level was 9.4 ⫾ 6.8 ng/mL. Biopsies were obtained from five sectors on each side and examined histologically. Results. Cancer was detected in 25 (25%) of the 100 patients. Malignancy was identified in the lateral cores of all patients with positive biopsies. Parasagittal biopsy cores were positive in association with a lateralbased biopsy in 9 (36%) of the 25 malignancies, for an overall parasagittal biopsy core rate of 9% (9 of 100 patients). No cancers were detected in the parasagittal biopsy cores alone. Conclusions. Inclusion of parasagittal zone biopsy cores proved to have a low yield in detecting cancer on repeated biopsy. As all patients found to have cancer in the parasagittal biopsy cores also had cancer on the lateral biopsy cores, most time and effort can be spent obtaining lateral biopsy cores to increase the sensitivity on repeated saturation biopsy. UROLOGY 63: 87–89, 2004. © 2004 Elsevier Inc.
R
epeat prostate biopsy is a common procedure in men with increasing prostate-specific antigen (PSA) levels, abnormal digital rectal examination findings, or previous abnormal nonmalignant prostate pathologic findings such as prostatic intraepithelial neoplasia or atypia. Up to one third of men refuse to undergo repeated biopsy, regardless of the prior number of biopsies.1 Fortunately, with the popularization of the periprostatic block to achieve local anesthesia, the pain and morbidity have reached acceptable levels.2,3 Although debate continues about how to conduct the repeat biopsy, it is clear that location is an important factor in the detection of prostate cancer on repeat biopsy. Stamey4 found that performing sextant From the Glickman Urological Institute, Cleveland Clinic Foundation, Cleveland, Ohio Reprint requests: J. Stephen Jones, M.D., Glickman Urological Institute, Cleveland Clinic Foundation, 9500 Euclid Avenue, Desk A-100, Cleveland, OH 44195 Submitted: May 30, 2003, accepted (with revisions): August 28, 2003 © 2004 ELSEVIER INC. ALL RIGHTS RESERVED
biopsies laterally instead of in the traditional parasagittal location increased biopsy accuracy. Gore et al.5 recommended a biopsy strategy that included laterally directed cores to increase the cancer detection yield. In addition, three-dimensional computer-simulated biopsy studies have suggested that lateral prostate biopsies increase the cancer detection rate.6 These recommendations contrast with saturation protocols that emphasize other areas of the prostate, specifically the one suggested by Eskew et al.7 of an extended five-region biopsy protocol that emphasized the inclusion of midline biopsies. We have found that most positive biopsies are located in the lateral cores and prospectively evaluated the location of positive biopsies to determine the sectors that are important during repeated 24core saturation prostate biopsy. MATERIAL AND METHODS From February 2002 to July 2003, a total of 100 patients underwent repeated transrectal ultrasound-guided saturation 0090-4295/04/$30.00 doi:10.1016/j.urology.2003.08.040 87
found in the parasagittal regions of the prostate, with no cancer detected exclusively in the parasagittal region. The parasagittal biopsy cores detected cancer in 9 (9%) of the total 100 patients. For treatment, 12 patients underwent iodine-125 brachytherapy, 2 underwent hormonal therapy, 4 underwent radical prostatectomy, 1 underwent external beam radiotherapy, and the remainder chose watchful waiting or had not yet chosen to proceed with treatment. Complications during the study included 1 patient who developed prostatitis requiring intravenous antibiotics with full recovery. Two patients developed self-limited lightheadedness when we used 20 mL of 2% lidocaine. We subsequently changed to 10 mL of 1% lidocaine, with no further complications to date. FIGURE 1. Location of five sectors on each side. Number of biopsy cores from each sector is indicated in parentheses. Sectors shaded in gray represent lateral biopsies. Reprinted with the permission of the Cleveland Clinic Foundation.
biopsy. The institutional review board approved the study of the patient database. All patients included in the study provided informed consent. The average patient age was 62.1 ⫾ 7.9 years. All patients had undergone at least one previous negative prostate biopsy. The patient population had undergone an average of 1.65 previous biopsies (range 1 to 7). The indications for repeat biopsy included persistently elevated or increasing PSA level, prior biopsy showing high-grade prostatic intraepithelial neoplasia (n ⫽ 31) or atypia (n ⫽ 7), or abnormal digital rectal examination findings (n ⫽ 9). The average PSA level was 9.4 ⫾ 6.8 ng/mL. Patients underwent transrectal ultrasound-guided saturation biopsy with a periprostatic block in the office, as described previously.8 After successful placement of local anesthesia, the prostate volume was calculated. Using a spring-loaded biopsy gun, 24 biopsies were taken from five sectors in each side (Fig. 1). On each side, two biopsies were obtained from the lateral base, three from the lateral midsection, three from the apex, two from the parasagittal midsection, and two from the parasagittal base. The final 8 patients in the series underwent 20-core saturation biopsies; only one core was taken from the parasagittal mid-section and parasagittal base on each side. Visualizing the needle tract of the current biopsy cores and separating the cores as much as possible in each sector ensured even distribution of the biopsy sites. Biopsies obtained from the two parasagittal regions were considered parasagittal biopsies, and the three lateral sectors, including the apex, were considered lateral biopsies.
RESULTS Prostate adenocarcinoma was detected in 25 (25%) of the 100 patients. All patients had Stage T1c cancer. Of the cancers detected, 2 were Gleason score 5, 17 were Gleason score 6, 5 were Gleason score 7, and 1 was Gleason score 9. All cancers were detected in the lateral regions of the prostate (lateral base, lateral mid-section, or apex). Only 9 (36%) of the 25 cancers were also 88
COMMENT Repeat prostate biopsy may be indicated for patients with prior negative biopsies who have persistently elevated PSA levels, prostatic intraepithelial neoplasia, or atypia. Many studies have shown the efficacy of repeated biopsy within those patient populations.1,9 –13 The approach to biopsy has been a continuing debate. Stamey4 stated that laterally directing sextant biopsies increased the detection rate of prostate cancer. Since then, numerous studies have looked at cancer detection rates using different biopsy strategies. To our knowledge, no study has directly compared the yield of parasagittal biopsies versus lateral biopsies in patients undergoing repeat biopsy. Bauer et al.6 used a three-dimensional computersimulated prostate model based on 201 radical prostatectomy specimens to determine the detection rate of lateral prostate biopsies. The four-pattern lateral biopsies yielded a 93.5% detection rate versus a traditional sextant detection rate of 72.6%. Most tumors in their specimens were near the posterior and lateral capsule. The 10-pattern biopsy protocol was optimal, identifying 99.0% of the cancers. Gore et al.5 looked at optimal combinations of number and location of biopsies. Their results showed that a similar 10-core method with emphasis on lateral biopsies yielded the overall greatest detection rate. Of 111 patients undergoing repeat biopsy in their study, 24.3% were found to have cancer, but they did not differentiate where the cancers were located. Eskew et al.7 described a five-region technique that included midline biopsies to increase the detection rate by 35% compared with sextant biopsies. Our results showed that midline biopsies might not be needed on repeat biopsy. In addition, UROLOGY 63 (1), 2004
there is concern of increased morbidity if the urethra is injured. Applewhite et al.14 followed with a study using the five-region technique on repeat biopsy at the same institution and demonstrated an increase in the cancer detection rates, but no comparison was done between the lateral and parasagittal cores according to detection rate. The cancer detection rate in our study was slightly less than that of Stewart et al.11 and Borboruglu et al.13 However, those studies were presumably performed on patients who had previously undergone multiple traditional sextant biopsies instead of laterally based biopsies. All but 11 of our patients had previously undergone biopsies using a minimum of 10 laterally based cores. Therefore, we believe that our false-negative rate on initial biopsy was less than it would have been if sextant biopsies had been performed initially. Therefore, the population in need of repeated biopsies according to the indications listed above has a theoretically lower rate of undiagnosed prostate cancer. Epstein et al.15 conducted posterolateral needle biopsies in addition to sextant biopsies on 150 radical prostatectomy specimens for T1c prostate cancer. Cancer was detected on repeat biopsy in 123 specimens. Their results supported the inclusion of additional posterolateral biopsies because of the amount of significant cancer cases that would have been missed with parasagittal biopsies. In addition, they detected 5 significant cancers (4.1%) solely in the parasagittal cores. Although our study revealed no cancers found solely in the parasagittal regions, we remain cognizant that a small percentage of cancers may be found solely in the parasagittal region. On the basis of these data, we have decreased the number of parasagittal cores on each side from four to two and now perform a 20-core repeat saturation biopsy. CONCLUSIONS The results of this study have shown that parasagittal biopsies provide a low yield on repeat prostate biopsy after an initial negative biopsy. Parasagittal biopsies may still be important for first-time prostate biopsies. The present study did not address the likelihood of detecting cancer in the para-
UROLOGY 63 (1), 2004
sagittal cores during a first-time biopsy. However, during repeated biopsy, more time and effort can be spent on lateral biopsies, which should increase the cancer detection rate. REFERENCES 1. Roehl KA, Antenor JAV, and Catalona WJ: Serial biopsy results in prostate cancer screening study. J Urol 167: 2435– 2439, 2002. 2. Soloway MS, and Obek C: Periprostatic local anesthesia before ultrasound guided prostate biopsy. J Urol 163: 172– 173, 2000. 3. Jones JS, Ulchaker JC, Nelson D, et al: Periprostatic local anesthesia eliminates pain of office-based transrectal prostate biopsy. Prostate Cancer Prostat Dis 6: 53–55, 2003. 4. Stamey TA: Making the most of six systemic sextant biopsies. Urology 45: 2–11, 1995. 5. Gore JL, Shariat SF, Miles BJ, et al: Optimal combinations of systematic sextant and laterally directed biopsies for the detection of prostate cancer. J Urol 165: 1554 –1559, 2001. 6. Bauer JJ, Zeng J, Weir J, et al: Three-dimensional computer-simulated prostate models: lateral prostate biopsies increase the detection rate of prostate cancer. Urology 53: 961– 967, 1999. 7. Eskew AL, Bare RL, and McCullough DL: Systematic 5 region prostate biopsy is superior to sextant method for diagnosing carcinoma of the prostate. J Urol 157: 199 –202, 1997. 8. Jones JS, Oder M, and Zippe CD: Saturation prostate biopsy with periprostatic block can be performed in the office. J Urol 168: 2108 –2110, 2002. 9. Keetch DW, and Catalona WJ: Prostatic transition zone biopsies in men with previous negative biopsies and persistently elevated serum prostate specific antigen values. J Urol 154: 1795–1797, 1995. 10. Keetch DW, Catalona WJ, and Smith DS: Serial prostatic biopsies in men with persistently elevated serum prostate specific antigen values. J Urol 151: 1571–1574, 1994. 11. Stewart CS, Leibovich BC, Weaver AL, et al: Prostate cancer diagnosis using a saturation needle biopsy technique after previous negative sextant biopsies. J Urol 168: 86 –92, 2001. 12. Fleshner NE, O’Sullivan M, and Fair WR: Prevalence and predictors of a positive repeat transrectal ultrasound guided needle biopsy of the prostate. J Urol 158: 505–508, 1997. 13. Borboruglu RG, Comer SW, Riffenburgh RH, et al: Extensive repeat transrectal ultrasound guided prostate biopsy in patients with previous benign sextant biopsies. J Urol 163: 158 –162, 2000. 14. Applewhite JC, Matagla BR, and McCullough DL: Results of the 5 region prostate biopsy method: the repeat biopsy population. J Urol 168: 500 –503, 2002. 15. Epstein JI, Walsh PC, and Carter HB: Importance of posterolateral needle biopsies in the detection of prostate cancer. Urology 57: 1112–1116, 2001.
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