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Re: Endo-Rectal Coil Magnetic Resonance Imaging in Clinically Localized Prostate Cancer: Is it Accurate?
~22-5347/97/15741371$03.00/0
Vol. 167,1371-1374, April 1997 Printed in LISA
THE JOUIWAL OF UROLOGY
copyright 0 1997 by AMERICAN UROLOGICAL. ASS~CIATION, INC.
Letters to the Editor RE: EDITORZAL. CAN PROSTATE SPECIFIC ANTIGEN DERIVATIVES REDUCE "HE FREQUENCY OF UNNECESSARY PROSTATE BIOPSIES? E.A. Klein J. Urol., 1sB:443-444,1996
TOthe Editor. Prestigiacomo et al recommended a 15% cutoff for the percentage ratio of free-to-total prostate specific antigen (MA) for 2 free-to-total PSA assays to distinguish between prostate cancer and benign prostatic hyperplasia (BPH).I The editorialto this article includes a table with indications for prostate biopsy. In a recent comparison between the C a d @ and the IMMULITEt essays,we suggested cutoffs of 15 and 1646,re9pectively, on the basis d the higheat diagnastic efficiency.*We concluded that to apply better the parameter of percent free PSA (free-to-totalPSA ratio) as a measure to decreasa r n . biopsies, at a normal digital rectal examination it is po% sible to consider prostate volume and total PSA (see table). Based on receiver operating characteristic analysis of our prior data? we recommend a 9% free-to-total PSA ratio cutoff for total PSA values of less than 4 MA. A 95% specificityis apparent at this cutoff. For totalPSA of more than 10 MA. it is better to choose the cutoff at the point of 95% sensitivity corresponding to a 21% free-btotal PSA ratio. If free-to-total PSA ratio values are more than 21% we do not advocate repeat biopsy. Considering the prostate volume as an additional marker, the recommended 15% free-to-total PSA ratio cutoff is valid for all total PSA values if prostate volume is less than 40 ml. because sensitivity and specificity are approximately 95%.5 However, due to the significant positive correlation between prostate volume and free-btotal PSA ratio for patients with prostate cancer and the decreasing freeto-total PSA ratio in patients with BPH with increasing prostate volumes, separation is impossible between BPH and prostate cancer if prostate volume exceeds 40 ml." For the total PSA range of less than 4 pgA. and prostate volume of more than 40 ml., we advise, independently of free-to-total PSA ratio, annual digital rectal examinations and measurements of serum total and free PSA If total PSA is more than 10 MA. and free-to-total PSA ratio exceeds 15% for glands more than 40 ml., no repeat biopsy seems necessary.
2. Jung K Ste han, C.. b i n , M., Henke, W., Schnorr, D., Brux,
B.,'Sch',iireo%amper, P..apd hemup& A: Analytic+ perforproatate-8 mance and clinical vahd~tyof two gen assays corn Clin. Chem., 4!k 1 0 2 6 , l e an'3. stephan,c . , J m , C EM.,schnprr, D. s. &:The ratio offree to totalpm&ate-spdc anhgen rn serum is ome lated to the proetate wIume. Int. J. Cams, 67: 461,1996.
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R E ENDO-ReCTAL COIL MAGNETIC ReSONANCE IMAGING IN CLINlcAuY LOCALIZED PROSTATE CANCER IS IT ACCURATE?
M. P e d , R.P. gwfman, Jr.. T.A. Jennings, H. T. T U r , S. M. Solaway, M.D. Rifiin and H. A G. Fisher J. Urol., 156: 106-109,1996
To the Editor. I agree with Perrotti et al that e n d e d coil magnetic resonance imaging (MRI) should not be used routinely in the preoperative staging of clinically localized prostate cancer. However, from a recently reported large series (598cases)select patienta (that is preoperative prostate specific antigen TpsAl greater than 10 and 20 or less ngJml., biopsy Gleason swre 7 or less and at least 50% positive biopsies) have been shown to benefit from the use of preoperative endo-rectal coil MRI.' Of these 36 select patients only 20 (56%) had pathological organ confined dieease. All 8 patients with evidence of extracapsular extension and/or seminal vesicle invasion on a preoperative enderectal coil MRI had extraprostatic disease noted at pathological examination of the radical prostatdomy specimen. In contrast 28 of the 36 patients had a negative endo-rectal coil MRI and 20 of these 28 (71%) had pathological organ confined disease. The sensitivity, specificity and overall accuracy of the endorectal coil MRI for predicting pathological stage T3 disease in this subgroup of clinical stage Tlc.2 cases was 60% (8of 16 cases),10096 (20of 20)and 78% (28of 36),respectively. Therefore, the pathological organ confinement rate in this subgroup would have improved by 15% (range 66 to 71%) if only MRI negative cases were selected for radical proatahtomy. Moreover no patient with pathological organ confined disease would have been excluded from surgery based on a false-positive endo-rectal coil MRI. In the study by P e m t t i et al, of only 12 patients with a PSA of 10 to 20 ngJml. those who also had a biopsy Gleason score of 7 or less Free-to-totalPSA ratios as guidelines for prostate biopsy at normal and at least 60% positive biopsies may be too few for relevant comment. In b y j , there is a select subgroup (36of 598 or 6%) of digital rectal examination patients with c h c a l l y localized prostate cancer who may benefit Total FSA 9b Free-to-Total Action from preoperative endo-rectal coil MRI,including those who meet (MA.) PSA Ratio the clinical criteria of preoperative FSA greater than 10 and 20 or Less than 4 Less than 9 Biopsy less ngJml., biopsy Gleason score 7 or less and at least 50% positive Morethan9 A n r ~ u a l d i g i t a l m c t d l t i O n a n d ~biopsies. 4- 10 Lessthan 15 Biopay More than 15 Annual digital mctd examination and PSA R-peetfully, More than 10 Less than 2 1 Biopsy Anthony V. D h i c o More than 21 Annual digital rectalexamination and Joint Center for Radiation Thempy Hanmnl Medicul School 330 Brookline Aw. 6fh froor Boston, Massachusetts 02215 Respectfully, 1. DAmiw, A V., Whittington, R., Malkowin, S. B., Schultz, C. Stephan, M . &in, K. Jung,D. Schnorr and S. A Loening !%hall, M. D., Tomaezewski, J. E. and Wein, A: A multivaDepartment of Urology evaluating the role of the percent positive biUniversity Hospital ChariU nable opsies, an endo-rectal coil MRI in predicting extraprostatic Humboldt University Berlin disease and postoperative PSA failure in intermediate risk Schumannstmae 20121 prostate cancer patients. €%weedmgs of the Annual Meeting of 0-10098 Berlin the Americau Radium Society, abstract 31, p. 26,1996. Germany To the Editor. Perrotti et al suggested that endo-rectal coil MRI 1. Prestigiacomo, A. F.,Lilja, H., P e t t e m n , &, Wolfed, R. L. and has little clinical use in staging prostate cancer. We believe these Stamey, T. A.: A comparison of the free .fraction Of serum conclusions are unfounded because the study used suboptimal imagprostate specific antigen in men with beand cancerous ing techniques that are no longer in routine use.The techniques wed prostates: the best ca8e scenario. J. Urol., 1BB: 350,1996. would not be considered state of the art if the images were acquired after 1993.Our concern relate to 2 specific areas: the MRI acquisi* CanAg F a wtics, Gothenburg, Sweden. tion techniqueu used by the authors and the image audysia methods f DiagnOStlC %u& Corp., Lo8 Angela. California 1371
"'d""
Vol. 167,1371-1374, April 1997 Printed in LISA
THE JOUIWAL OF UROLOGY
copyright 0 1997 by AMERICAN UROLOGICAL. ASS~CIATION, INC.
Letters to the Editor RE: EDITORZAL. CAN PROSTATE SPECIFIC ANTIGEN DERIVATIVES REDUCE "HE FREQUENCY OF UNNECESSARY PROSTATE BIOPSIES? E.A. Klein J. Urol., 1sB:443-444,1996
TOthe Editor. Prestigiacomo et al recommended a 15% cutoff for the percentage ratio of free-to-total prostate specific antigen (MA) for 2 free-to-total PSA assays to distinguish between prostate cancer and benign prostatic hyperplasia (BPH).I The editorialto this article includes a table with indications for prostate biopsy. In a recent comparison between the C a d @ and the IMMULITEt essays,we suggested cutoffs of 15 and 1646,re9pectively, on the basis d the higheat diagnastic efficiency.*We concluded that to apply better the parameter of percent free PSA (free-to-totalPSA ratio) as a measure to decreasa r n . biopsies, at a normal digital rectal examination it is po% sible to consider prostate volume and total PSA (see table). Based on receiver operating characteristic analysis of our prior data? we recommend a 9% free-to-total PSA ratio cutoff for total PSA values of less than 4 MA. A 95% specificityis apparent at this cutoff. For totalPSA of more than 10 MA. it is better to choose the cutoff at the point of 95% sensitivity corresponding to a 21% free-btotal PSA ratio. If free-to-total PSA ratio values are more than 21% we do not advocate repeat biopsy. Considering the prostate volume as an additional marker, the recommended 15% free-to-total PSA ratio cutoff is valid for all total PSA values if prostate volume is less than 40 ml. because sensitivity and specificity are approximately 95%.5 However, due to the significant positive correlation between prostate volume and free-btotal PSA ratio for patients with prostate cancer and the decreasing freeto-total PSA ratio in patients with BPH with increasing prostate volumes, separation is impossible between BPH and prostate cancer if prostate volume exceeds 40 ml." For the total PSA range of less than 4 pgA. and prostate volume of more than 40 ml., we advise, independently of free-to-total PSA ratio, annual digital rectal examinations and measurements of serum total and free PSA If total PSA is more than 10 MA. and free-to-total PSA ratio exceeds 15% for glands more than 40 ml., no repeat biopsy seems necessary.
2. Jung K Ste han, C.. b i n , M., Henke, W., Schnorr, D., Brux,
B.,'Sch',iireo%amper, P..apd hemup& A: Analytic+ perforproatate-8 mance and clinical vahd~tyof two gen assays corn Clin. Chem., 4!k 1 0 2 6 , l e an'3. stephan,c . , J m , C EM.,schnprr, D. s. &:The ratio offree to totalpm&ate-spdc anhgen rn serum is ome lated to the proetate wIume. Int. J. Cams, 67: 461,1996.
.
++*,
R E ENDO-ReCTAL COIL MAGNETIC ReSONANCE IMAGING IN CLINlcAuY LOCALIZED PROSTATE CANCER IS IT ACCURATE?
M. P e d , R.P. gwfman, Jr.. T.A. Jennings, H. T. T U r , S. M. Solaway, M.D. Rifiin and H. A G. Fisher J. Urol., 156: 106-109,1996
To the Editor. I agree with Perrotti et al that e n d e d coil magnetic resonance imaging (MRI) should not be used routinely in the preoperative staging of clinically localized prostate cancer. However, from a recently reported large series (598cases)select patienta (that is preoperative prostate specific antigen TpsAl greater than 10 and 20 or less ngJml., biopsy Gleason swre 7 or less and at least 50% positive biopsies) have been shown to benefit from the use of preoperative endo-rectal coil MRI.' Of these 36 select patients only 20 (56%) had pathological organ confined dieease. All 8 patients with evidence of extracapsular extension and/or seminal vesicle invasion on a preoperative enderectal coil MRI had extraprostatic disease noted at pathological examination of the radical prostatdomy specimen. In contrast 28 of the 36 patients had a negative endo-rectal coil MRI and 20 of these 28 (71%) had pathological organ confined disease. The sensitivity, specificity and overall accuracy of the endorectal coil MRI for predicting pathological stage T3 disease in this subgroup of clinical stage Tlc.2 cases was 60% (8of 16 cases),10096 (20of 20)and 78% (28of 36),respectively. Therefore, the pathological organ confinement rate in this subgroup would have improved by 15% (range 66 to 71%) if only MRI negative cases were selected for radical proatahtomy. Moreover no patient with pathological organ confined disease would have been excluded from surgery based on a false-positive endo-rectal coil MRI. In the study by P e m t t i et al, of only 12 patients with a PSA of 10 to 20 ngJml. those who also had a biopsy Gleason score of 7 or less Free-to-totalPSA ratios as guidelines for prostate biopsy at normal and at least 60% positive biopsies may be too few for relevant comment. In b y j , there is a select subgroup (36of 598 or 6%) of digital rectal examination patients with c h c a l l y localized prostate cancer who may benefit Total FSA 9b Free-to-Total Action from preoperative endo-rectal coil MRI,including those who meet (MA.) PSA Ratio the clinical criteria of preoperative FSA greater than 10 and 20 or Less than 4 Less than 9 Biopsy less ngJml., biopsy Gleason score 7 or less and at least 50% positive Morethan9 A n r ~ u a l d i g i t a l m c t d l t i O n a n d ~biopsies. 4- 10 Lessthan 15 Biopay More than 15 Annual digital mctd examination and PSA R-peetfully, More than 10 Less than 2 1 Biopsy Anthony V. D h i c o More than 21 Annual digital rectalexamination and Joint Center for Radiation Thempy Hanmnl Medicul School 330 Brookline Aw. 6fh froor Boston, Massachusetts 02215 Respectfully, 1. DAmiw, A V., Whittington, R., Malkowin, S. B., Schultz, C. Stephan, M . &in, K. Jung,D. Schnorr and S. A Loening !%hall, M. D., Tomaezewski, J. E. and Wein, A: A multivaDepartment of Urology evaluating the role of the percent positive biUniversity Hospital ChariU nable opsies, an endo-rectal coil MRI in predicting extraprostatic Humboldt University Berlin disease and postoperative PSA failure in intermediate risk Schumannstmae 20121 prostate cancer patients. €%weedmgs of the Annual Meeting of 0-10098 Berlin the Americau Radium Society, abstract 31, p. 26,1996. Germany To the Editor. Perrotti et al suggested that endo-rectal coil MRI 1. Prestigiacomo, A. F.,Lilja, H., P e t t e m n , &, Wolfed, R. L. and has little clinical use in staging prostate cancer. We believe these Stamey, T. A.: A comparison of the free .fraction Of serum conclusions are unfounded because the study used suboptimal imagprostate specific antigen in men with beand cancerous ing techniques that are no longer in routine use.The techniques wed prostates: the best ca8e scenario. J. Urol., 1BB: 350,1996. would not be considered state of the art if the images were acquired after 1993.Our concern relate to 2 specific areas: the MRI acquisi* CanAg F a wtics, Gothenburg, Sweden. tion techniqueu used by the authors and the image audysia methods f DiagnOStlC %u& Corp., Lo8 Angela. California 1371
"'d""