- Email: [email protected]
Reply of Dr. Nseyo
LETTERS
TO THE EDITOR
SIGNIFICANCE OF PAP LEVELS
OF TRANSIENT AFTER TUR
ELEVATION
To the Editor: In the article, “Serum Acid Phosphatase Elevation Associated with Transurethral Resection Syndromes,” published in the October issue (vol. 22, page 388) of UROLOC~ Dr. I? D. O’Donnell presents the intriguing hypothesis that transiently elevated prostatic acid phosphatase (PAP) levels after transurethral resection (TUR) of the prostate may indicate significant intraoperative absorption of prostatic tissue substances and provide an explanation for the “TUR syndrome.” One should keep in mind, however, that any situation that disrupts the integrity of the prostatic capsule is likelv to permit release of PAP from the prostate, resultmg in increased levels of this enzyme in the blood and bone marrow. We compared PAP levels preoperatively and immediately postoperatively in 48 men with benign prostatic hyperplasia and found an average five-fold increase, with 3 patients having more than a thirty-fold increase.* None had a clinical TUR syndrome. A similar comparison in 16 patients with carcinoma of the prostate also showed an increase in PAP immediately postoperatively, although not as great as in the patients with benign lesions. In all cases, PAP returned to preoperative levels within one to four days. The degree to which PAP is raised after prostatic manipulation seems to reflect its concentration in the underlying tissue: benign tissue is rich in PAP; carcinomatous tissue, with its impaired ability to synthesize the enzyme, contains much lesser amounts. It would be most interesting to compare the preand postoperative PAP levels in patients with and without a TUR syndrome (although the difficulty of collecting a series in sufficient numbers is great) to verify the hypothesis outlined by Dr. O’Donnell.
genie Impotence,” by Dr. U. 0. Nseyo et al. published in the January issue (vol. 23, page 31) of UHOI,OGYwas most interesting and stimulates several comments. Xenon washout studies are well known for sensitivity to temperatdre variation.* Does the ambient room temperature used represent adequate control of this factor? While there were apparent problems with prolonged Xenon-133 clearance with intracorporeal injections, one wonders whether subcutaneous injections accurately reflect flow in the cavernosal arteries of the penis. In regard to the formula on page 32, our understanding of the Kety-Schmidt equation is:
Q
=
P where X is blood-skin partition coefficient for Xenon 0.7 ml/Cm P = specific gravity of skin of 1.05 K = slow constant of disappearance of Xenon133 Q = perfusion in mllmin/lOO Gm K can also be expressed ln2/T% therefore
Q
=
435 (1974).
PENILE
XENON
To the Editor: Washout:
624
A Rapid
WASHOUT
STUDIES
The article, “Penile Xenon (133Xe) Method of Screening for Vasculo-
100 * X * ln2 T% *P
The article failed to address whether the washout curves for Xenon were monoexponential or multiexponential. Only monoexponential curves can be utilized for the determination of blood flow unless curve-stripping techniques are employed to look at the various components of flow expressed by multiexponential curves. John P Collins, Division
M.D. of Urology
Karen Y. Gulenchyn, M.D. Division of Nuclear Medicine
Sumner Marshall, M.D. Department of Urology University of California San Francisco, California 94143 *Marshall S, Lyon RP, and Scott MP Jr: Prostatic acid phosphatase levels, significance in serum and bone marroxv, Urology 4:
100 - X * K
’
Ottawa Civic Hospital University of Ottawa Ottawa, Ontario
*Daly MJ, and Henry RE: Quantitative measurement perfusion with Xenon-133, J Nucl Med 21: 156 (1980).
REPLY
of skin
OF DR. NSEYO
We wish to thank Dr. Collins for their comments and drawing
UROI.OGY
/ JUNE 1984
and Dr. Gulenchyn our attention to the
/ VOLUME
XXIII.
NUMBER
6
incorrect formula on page 32 of our article. rect formula should be:
Q=
X - ln2
* 100 ml/min/lOO
The cor-
Gm tissue
T ?4 In the study we assumed a steady state with a constant fraction of Xenon being removed per unit time. The elimination curve would be a monoexponential function which plots out as a straight line on a semilog scale. Sensitivity to temperature variation in Xenon washout studies is not disputed. We assumed minimal temperature effect on the saline-dissolved Xenon (133Xe), when we noted that a few trial runs in test subjects and normal volunteers yielded reproducible results. The choice of subcutaneous route of injection was empirical and supported by the reproducibility of
the results in both normal volunteers and in patients with history of erectile impotence. The observed disappearance curve for Xenon could not be explained entirely on local factors such as backflow or retrograde leak. There had to be an arterial inflow to produce the outflow/washout. The result of this screening would arouse the suspicion of a possible vasculogenic etiology and lead to a more invasive investigation to localize the lesion. Again we would like to reiterate the preliminary nature of our report which should stimulate further investigations.
Unyime 0. Nseyo. M.D. Department of Urologic Oncologic Hos\vell Park Memorial Institute 666 Elm Street Buffalo. KCW, X)rk 11263
TO THE EDITOR
SIGNIFICANCE OF PAP LEVELS
OF TRANSIENT AFTER TUR
ELEVATION
To the Editor: In the article, “Serum Acid Phosphatase Elevation Associated with Transurethral Resection Syndromes,” published in the October issue (vol. 22, page 388) of UROLOC~ Dr. I? D. O’Donnell presents the intriguing hypothesis that transiently elevated prostatic acid phosphatase (PAP) levels after transurethral resection (TUR) of the prostate may indicate significant intraoperative absorption of prostatic tissue substances and provide an explanation for the “TUR syndrome.” One should keep in mind, however, that any situation that disrupts the integrity of the prostatic capsule is likelv to permit release of PAP from the prostate, resultmg in increased levels of this enzyme in the blood and bone marrow. We compared PAP levels preoperatively and immediately postoperatively in 48 men with benign prostatic hyperplasia and found an average five-fold increase, with 3 patients having more than a thirty-fold increase.* None had a clinical TUR syndrome. A similar comparison in 16 patients with carcinoma of the prostate also showed an increase in PAP immediately postoperatively, although not as great as in the patients with benign lesions. In all cases, PAP returned to preoperative levels within one to four days. The degree to which PAP is raised after prostatic manipulation seems to reflect its concentration in the underlying tissue: benign tissue is rich in PAP; carcinomatous tissue, with its impaired ability to synthesize the enzyme, contains much lesser amounts. It would be most interesting to compare the preand postoperative PAP levels in patients with and without a TUR syndrome (although the difficulty of collecting a series in sufficient numbers is great) to verify the hypothesis outlined by Dr. O’Donnell.
genie Impotence,” by Dr. U. 0. Nseyo et al. published in the January issue (vol. 23, page 31) of UHOI,OGYwas most interesting and stimulates several comments. Xenon washout studies are well known for sensitivity to temperatdre variation.* Does the ambient room temperature used represent adequate control of this factor? While there were apparent problems with prolonged Xenon-133 clearance with intracorporeal injections, one wonders whether subcutaneous injections accurately reflect flow in the cavernosal arteries of the penis. In regard to the formula on page 32, our understanding of the Kety-Schmidt equation is:
Q
=
P where X is blood-skin partition coefficient for Xenon 0.7 ml/Cm P = specific gravity of skin of 1.05 K = slow constant of disappearance of Xenon133 Q = perfusion in mllmin/lOO Gm K can also be expressed ln2/T% therefore
Q
=
435 (1974).
PENILE
XENON
To the Editor: Washout:
624
A Rapid
WASHOUT
STUDIES
The article, “Penile Xenon (133Xe) Method of Screening for Vasculo-
100 * X * ln2 T% *P
The article failed to address whether the washout curves for Xenon were monoexponential or multiexponential. Only monoexponential curves can be utilized for the determination of blood flow unless curve-stripping techniques are employed to look at the various components of flow expressed by multiexponential curves. John P Collins, Division
M.D. of Urology
Karen Y. Gulenchyn, M.D. Division of Nuclear Medicine
Sumner Marshall, M.D. Department of Urology University of California San Francisco, California 94143 *Marshall S, Lyon RP, and Scott MP Jr: Prostatic acid phosphatase levels, significance in serum and bone marroxv, Urology 4:
100 - X * K
’
Ottawa Civic Hospital University of Ottawa Ottawa, Ontario
*Daly MJ, and Henry RE: Quantitative measurement perfusion with Xenon-133, J Nucl Med 21: 156 (1980).
REPLY
of skin
OF DR. NSEYO
We wish to thank Dr. Collins for their comments and drawing
UROI.OGY
/ JUNE 1984
and Dr. Gulenchyn our attention to the
/ VOLUME
XXIII.
NUMBER
6
incorrect formula on page 32 of our article. rect formula should be:
Q=
X - ln2
* 100 ml/min/lOO
The cor-
Gm tissue
T ?4 In the study we assumed a steady state with a constant fraction of Xenon being removed per unit time. The elimination curve would be a monoexponential function which plots out as a straight line on a semilog scale. Sensitivity to temperature variation in Xenon washout studies is not disputed. We assumed minimal temperature effect on the saline-dissolved Xenon (133Xe), when we noted that a few trial runs in test subjects and normal volunteers yielded reproducible results. The choice of subcutaneous route of injection was empirical and supported by the reproducibility of
the results in both normal volunteers and in patients with history of erectile impotence. The observed disappearance curve for Xenon could not be explained entirely on local factors such as backflow or retrograde leak. There had to be an arterial inflow to produce the outflow/washout. The result of this screening would arouse the suspicion of a possible vasculogenic etiology and lead to a more invasive investigation to localize the lesion. Again we would like to reiterate the preliminary nature of our report which should stimulate further investigations.
Unyime 0. Nseyo. M.D. Department of Urologic Oncologic Hos\vell Park Memorial Institute 666 Elm Street Buffalo. KCW, X)rk 11263