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Radioisotope penogram in diagnosis of vasculogenic impotence
RADIOISOTOPE VASCULOGENIC HAFEZ
N. FANOUS,
MILORAD DAVID
J. JEVTICH,
C. P. CHEN,
MITCHELL
EDSON,
PENOGRAM
IN DIAGNOSIS
OF
IMPOTENCE M.D. M.D. M.D. M.D.
From the Departments of Urology and Nuclear Medicine, Washington Hospital Center, Washington, D.C.
ABSTRACT -A radioisotope technique to estimate penile blood flow is described. The radioisotope penogram is noninvasive and gives a dynamic evaluation of the arterial supply, venous drainage, and bloodfEow in the corporeal bodies. The penogram is a valuable adjunct in evaluation of patients with vasculogenic impotence.
We herein present a radioisotope study designed to estimate the penile blood flow and its response to a peripheral vasodilator. The penogram is noninvasive and exposes the patient to less radiation than an x-ray study of the chest. It is also a dynamic evaluation of the arterial supply, corporeal bodies, and venous drainage.
Vasculogenic impotence had been recognized even before Leriche published and popularized this classic syndrome. ’ An increasing awareness of vascular causation of impotence has resulted from the development of various diagnostic tests. Doppler ultrasound determination of penile arteries, penile systolic pressure, and penile brachial index (PBI) are well-established tests but are not foolproof studies of the arterial supply introduced to the penis. 2,3 Phalloarteriography by Michal, Pospichal, and Lachman4 and Ginestie and Ramieu5 is at best very difficult to interpret, especially in mapping the small terminal branches of pudendal arteries. It is also an invasive technique requiring special skills and equipment. In addition, the hemodynamics of erection depend not only on the integrity of arterial blood supply but also on the corporeal sinusoids and venous drainage. 6,7 The concept of radioisotope study of penile blood flow was introduced by Shirai in 19708 using iodine-131 human serum albumin. In 1975 Shirai and Nakamurag used technetium99m to evaluate the blood flow through the penis with observation of changes occurring during visual sexual stimulation. They were able to differentiate between organic and functional impotence.
UROLOGY
/ NOVEMBER
1982 / VOLUME
XX, NUMBER
Material
and Methods
Twenty-eight patients were studied. There were 19 impotent patients ranging from nineteen to seventy-six years of age and 9 control volunteers, eighteen to sixty-four years of age. A careful history and physical examination were obtained. All were subjected to nocturnal penile tumescence tests and penile blood pressure studies with estimation of penile brachial index (PBI = Penile systolic blood pressure/Brachial systolic blood pressure). Two patients underwent penile arteriography for contemplated revascularization. The radioisotope penogram was performed by giving the patient 0.4 Gm of potassium perchlorate prior to the intravenous injection of 20 mCi of ggmTC pertechnetate. The perchlorate blocks absorption of the isotope by the thyroid gland. A lead shield was placed under the penis
5
499
FIGURE 1. (A) Time activity curve of normal penogram (type A) - activity markedly increased after injection of isoxsuprine (arrow), and (B) rapid rise in initial activity with minimal increase after intravenous injection of isoxsuprine (arrow).
TABLE I. Penogram index and penile brachiul index in control subjects Case No.
Age
NPT
PBI
1 2 3 4 5 6 7 8 9
24 22 36 58 61 43 64 18 32
N”
1.0 1.2 0.7 1.1 1.2 0.91 0.9 1.2 1.0
N N N
N N
N N
N
Penogram Index 3.2 0.2t 2.0 1.42 3.2 3.0 2.36 3.5 2.7
*N = Normal. tThis patient represents type of normal penogram wherein initial penile blood flow is so good that vasodilator does not increase it further.
to block the radioactivity from the scrotum and thighs. A gamma camera with parallel hole collimator was used to monitor the radioactivity. A digital computer also was interfaced with the camera to acquire the information for quantification. Twelve frames of three-seconds’ duration were obtained for measurement of the arterial flow, while a sixty-second frame was collected for sixty minutes for the dynamic study. A ZO-per cent window centered on 140 keV was used. At ten minutes postinjection of radioisotope, 10 mg of isoxsuprine HCl (Vasodilan) were demonstrated intravenously.
500
FIGURE 2. Penogram of impotent patient showing slow uptake of isotope and no response to isoxsuprine (arrow).
After collecting all of the information from the gamma camera, a time activity curve was plotted by choosing the region of interest over the penis, and a penogram index was calculated as Peak activity - Activity at 10 min/Activity at 10 min. Results The penogram curve of the 9 control patients acquired two forms: type A in 8 patients (Fig. lA), and type B in 1 patient (Fig. 1B). The penogram index in type A was 1.42-3.5 (Table I). In type B (Case 2) the initial activity rose
UROLOGY
/ NOVEMBER1982
/ VOLUMEXX,NUMBERS
FIGURE 3. Isotope penogram in potent subject in control group: (A) immediately postinjection - minimal activity; (B) 10 min. postinjection plus IV isorsuprine - slight increase in activity; (C) 60 min. postinjection signijcant increased radioactivity in penis.
rapidly, and no significant increase of flow was noted after injection of the vasodilator. This was considered a normal variant, and the penogram index would not apply in this situation. In the control group, the isotope was retained in the penis for at least sixty minutes. Nocturnal penile tumescence (NPT) studies of the control group revealed adequate erectionslO and the penile ranged from 0.7 to 1.2. brachial index (PBI) Nineteen patients had a history of erectile dysfunction ranging from partial to complete impotence. Their NPT ranged from weak erections to none; thus, all had organic failure. The penogram curve of an impotent patient showing no response to isoxsuprine is illustrated in Figure 2. Seven patients had diabetes, 4 had arteriosclerosis, 1 had end-stage renal disease, 1 leukemia, 1 carcinoma of the prostate, and 1 was an alcoholic. No causal factor was determined in 4 patients. Peripheral vascular disease was documented only in 3 of the aforementioned patients by vascular studies performed in the noninvasive vascular laboratory. In 13 patients the penogram index was 0.8 or less. The PBI was 0.76 or less in these patients with a correlation coefficient of 0.7 which is statistically significant (Table II). Hence, there is a significant correlation between the blood flow to the penis as determined by ultrasound and to that determined by isotope techniques. In 3 patients there was no correlation between the PBI and penogram index. This suggests arterial disease since there was poor flow demonstrated by decreased PBI but adequate trapping of blood in the corpora shown by penogram. This
UROLOGY
/ NOVEMBER1982
/ VOLUMEXX,NUMBERS
TABLE II. Penogram index and penile brachial index in impotent patients Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Age
NPT”
PBI
Penogram Index
54 76 66 32 60 70 51 66 35 70 36 72 19 58 32 45 70 66 67
None None scant None Poor Poor Scant Poor Poor Poor Scant None Poor Poor None Poor scant Scant Poor
0.5 0.6 0.84 0.8 0.75 0.45 0.4 0.62 1.0 0.63 0.87 0.6 0.76 0.75 0.5 0.65 0.75 0.58 0.75
0.8 0.45 1.44 0.96 0.79 0.62 1.37 0.66 1.3 0.7 2.33 Inflam. 0.3 0.64 0.4 0.72 0.79 0.8 0.48
*None = no erections; scant = 1 erection of testing; poor = occasional, weak erections.
or less on 2 nights
is the group that most likely would respond to vasodilators or revascularization. In 1 patient (Case 9) the PBI was normal (l.O), and the penogram index was only 1.3 (normal = 1.42-3.5). Th is suggests either a poor response to the vasodilator, pathologic disease of the corpora, or rapid venous drainage. Two patients underwent penile arteriography. Internal pudendal artery occlusion was documented in both. Their penogram indices were
501
Isotope penogram in impotent patient: (A) immediately postinjection - minimal activity; (B) 10 FIGURE 4. min. postinjection plus IV isoxsuprine - minimal activity; (C) 60 min. postinjection - no signajicant change. Y2.6375 R - 8.7257 5.1678 8.71
fX
4
-8.4929
4
26
/
Some patients have shown increased blood flow and improved erections when treated with vasodilators. The isotope penogram may be helpful in predicting which patients would respond best to therapy with vasodilators. The noninvasive penogram is a dynamic and functional study of penile blood flow. By demonstrating good vascular flow or poor trapping of blood in the corpora, this test will screen out patients who would not benefit from revascularization. Therefore, the invasive penile angiogram can be avoided in these patients. The radioisotope penogram is a valuable adjunct in the more effective selection of candidates for penile revascularization as well as for medical management. 110 Irving Street, N. W. Washington, D. C. 20010 (DR. EDSON)
FBI FIGURE
5.
Correlation of PBI and penogram index.
and 0.96, respectively. Both underwent successful penile revascularization. Illustrative penograms of potent and impotent patients are shown in Figures 3 and 4. The significant correlation (p < 0.01) between the PBI and penogram index is shown in Figure 5. 0.3
Comment In evaluating the impotent male, an additional noninvasive study is needed to supplement the Doppler pulse and penile blood pressure studies. In the group of patients studied, a good correlation was found between the radioisotope penogram index and the penile brachial index in normal and impotent subjects. It is planned to evaluate a larger number of patients to establish more accurately normal and abnormal penogram indices.
502
References 1. Gee WF: A history of surgical treatment of impotence, Urology 5: 401 (1975). 2. Jevtich MJ: Importance of penile arterial pulse sound examination in impotance, J Urol 124: 821 (1980). 3. Blaivas JG, O’Donnell TF, Gottlieb P, and Labib KB: Comprehensive laboratory evaluation of impotent men, ibid. 124: 201 (1980). 4. Michal V, Pospichal J, and Lachman M: Penile artery occlusions in erection impotence, a new type of angiography phalloarteriography, Cas Lek Cesk 115: 1245 (1976). 5. Ginestie JF, and Ramieu A: Ftadiologic exploration of impotence, The Hague, Martinus NijhofT, 1978. 6. Cohen MS, Sharpe W, Warner RS, Zorgniotti A: Morphology of corporal cavernosa arterial bed in impotence, Urology 16: 382 (1980). 7. Zorgniotti AW, Rossi G, Padula G, and Makovsky RD: Diagnosis and therapy of vasculogenic impotence, J Urol 123: 674 (1980). 8. Shirai M: Differential diagnosis of organic and functional impotence by use of Y-human serum albumin, Tohoku J Exp Med 101: 317 (1970). 9. Shirai M, and Nakamura M: Diagnostic discrimination between organic and functional impotence by radioisotope penogram with -TcO.,, 116: 9 (1975). 10. Casey WC: Phallography: technique and results of nocturnal tumescence monitoring, J Urol 122: 752 (1979).
UROLOGY
/
NOVEMBER
1982
/
VOLUME
XX, NUMBER 5
N. FANOUS,
MILORAD DAVID
J. JEVTICH,
C. P. CHEN,
MITCHELL
EDSON,
PENOGRAM
IN DIAGNOSIS
OF
IMPOTENCE M.D. M.D. M.D. M.D.
From the Departments of Urology and Nuclear Medicine, Washington Hospital Center, Washington, D.C.
ABSTRACT -A radioisotope technique to estimate penile blood flow is described. The radioisotope penogram is noninvasive and gives a dynamic evaluation of the arterial supply, venous drainage, and bloodfEow in the corporeal bodies. The penogram is a valuable adjunct in evaluation of patients with vasculogenic impotence.
We herein present a radioisotope study designed to estimate the penile blood flow and its response to a peripheral vasodilator. The penogram is noninvasive and exposes the patient to less radiation than an x-ray study of the chest. It is also a dynamic evaluation of the arterial supply, corporeal bodies, and venous drainage.
Vasculogenic impotence had been recognized even before Leriche published and popularized this classic syndrome. ’ An increasing awareness of vascular causation of impotence has resulted from the development of various diagnostic tests. Doppler ultrasound determination of penile arteries, penile systolic pressure, and penile brachial index (PBI) are well-established tests but are not foolproof studies of the arterial supply introduced to the penis. 2,3 Phalloarteriography by Michal, Pospichal, and Lachman4 and Ginestie and Ramieu5 is at best very difficult to interpret, especially in mapping the small terminal branches of pudendal arteries. It is also an invasive technique requiring special skills and equipment. In addition, the hemodynamics of erection depend not only on the integrity of arterial blood supply but also on the corporeal sinusoids and venous drainage. 6,7 The concept of radioisotope study of penile blood flow was introduced by Shirai in 19708 using iodine-131 human serum albumin. In 1975 Shirai and Nakamurag used technetium99m to evaluate the blood flow through the penis with observation of changes occurring during visual sexual stimulation. They were able to differentiate between organic and functional impotence.
UROLOGY
/ NOVEMBER
1982 / VOLUME
XX, NUMBER
Material
and Methods
Twenty-eight patients were studied. There were 19 impotent patients ranging from nineteen to seventy-six years of age and 9 control volunteers, eighteen to sixty-four years of age. A careful history and physical examination were obtained. All were subjected to nocturnal penile tumescence tests and penile blood pressure studies with estimation of penile brachial index (PBI = Penile systolic blood pressure/Brachial systolic blood pressure). Two patients underwent penile arteriography for contemplated revascularization. The radioisotope penogram was performed by giving the patient 0.4 Gm of potassium perchlorate prior to the intravenous injection of 20 mCi of ggmTC pertechnetate. The perchlorate blocks absorption of the isotope by the thyroid gland. A lead shield was placed under the penis
5
499
FIGURE 1. (A) Time activity curve of normal penogram (type A) - activity markedly increased after injection of isoxsuprine (arrow), and (B) rapid rise in initial activity with minimal increase after intravenous injection of isoxsuprine (arrow).
TABLE I. Penogram index and penile brachiul index in control subjects Case No.
Age
NPT
PBI
1 2 3 4 5 6 7 8 9
24 22 36 58 61 43 64 18 32
N”
1.0 1.2 0.7 1.1 1.2 0.91 0.9 1.2 1.0
N N N
N N
N N
N
Penogram Index 3.2 0.2t 2.0 1.42 3.2 3.0 2.36 3.5 2.7
*N = Normal. tThis patient represents type of normal penogram wherein initial penile blood flow is so good that vasodilator does not increase it further.
to block the radioactivity from the scrotum and thighs. A gamma camera with parallel hole collimator was used to monitor the radioactivity. A digital computer also was interfaced with the camera to acquire the information for quantification. Twelve frames of three-seconds’ duration were obtained for measurement of the arterial flow, while a sixty-second frame was collected for sixty minutes for the dynamic study. A ZO-per cent window centered on 140 keV was used. At ten minutes postinjection of radioisotope, 10 mg of isoxsuprine HCl (Vasodilan) were demonstrated intravenously.
500
FIGURE 2. Penogram of impotent patient showing slow uptake of isotope and no response to isoxsuprine (arrow).
After collecting all of the information from the gamma camera, a time activity curve was plotted by choosing the region of interest over the penis, and a penogram index was calculated as Peak activity - Activity at 10 min/Activity at 10 min. Results The penogram curve of the 9 control patients acquired two forms: type A in 8 patients (Fig. lA), and type B in 1 patient (Fig. 1B). The penogram index in type A was 1.42-3.5 (Table I). In type B (Case 2) the initial activity rose
UROLOGY
/ NOVEMBER1982
/ VOLUMEXX,NUMBERS
FIGURE 3. Isotope penogram in potent subject in control group: (A) immediately postinjection - minimal activity; (B) 10 min. postinjection plus IV isorsuprine - slight increase in activity; (C) 60 min. postinjection signijcant increased radioactivity in penis.
rapidly, and no significant increase of flow was noted after injection of the vasodilator. This was considered a normal variant, and the penogram index would not apply in this situation. In the control group, the isotope was retained in the penis for at least sixty minutes. Nocturnal penile tumescence (NPT) studies of the control group revealed adequate erectionslO and the penile ranged from 0.7 to 1.2. brachial index (PBI) Nineteen patients had a history of erectile dysfunction ranging from partial to complete impotence. Their NPT ranged from weak erections to none; thus, all had organic failure. The penogram curve of an impotent patient showing no response to isoxsuprine is illustrated in Figure 2. Seven patients had diabetes, 4 had arteriosclerosis, 1 had end-stage renal disease, 1 leukemia, 1 carcinoma of the prostate, and 1 was an alcoholic. No causal factor was determined in 4 patients. Peripheral vascular disease was documented only in 3 of the aforementioned patients by vascular studies performed in the noninvasive vascular laboratory. In 13 patients the penogram index was 0.8 or less. The PBI was 0.76 or less in these patients with a correlation coefficient of 0.7 which is statistically significant (Table II). Hence, there is a significant correlation between the blood flow to the penis as determined by ultrasound and to that determined by isotope techniques. In 3 patients there was no correlation between the PBI and penogram index. This suggests arterial disease since there was poor flow demonstrated by decreased PBI but adequate trapping of blood in the corpora shown by penogram. This
UROLOGY
/ NOVEMBER1982
/ VOLUMEXX,NUMBERS
TABLE II. Penogram index and penile brachial index in impotent patients Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19
Age
NPT”
PBI
Penogram Index
54 76 66 32 60 70 51 66 35 70 36 72 19 58 32 45 70 66 67
None None scant None Poor Poor Scant Poor Poor Poor Scant None Poor Poor None Poor scant Scant Poor
0.5 0.6 0.84 0.8 0.75 0.45 0.4 0.62 1.0 0.63 0.87 0.6 0.76 0.75 0.5 0.65 0.75 0.58 0.75
0.8 0.45 1.44 0.96 0.79 0.62 1.37 0.66 1.3 0.7 2.33 Inflam. 0.3 0.64 0.4 0.72 0.79 0.8 0.48
*None = no erections; scant = 1 erection of testing; poor = occasional, weak erections.
or less on 2 nights
is the group that most likely would respond to vasodilators or revascularization. In 1 patient (Case 9) the PBI was normal (l.O), and the penogram index was only 1.3 (normal = 1.42-3.5). Th is suggests either a poor response to the vasodilator, pathologic disease of the corpora, or rapid venous drainage. Two patients underwent penile arteriography. Internal pudendal artery occlusion was documented in both. Their penogram indices were
501
Isotope penogram in impotent patient: (A) immediately postinjection - minimal activity; (B) 10 FIGURE 4. min. postinjection plus IV isoxsuprine - minimal activity; (C) 60 min. postinjection - no signajicant change. Y2.6375 R - 8.7257 5.1678 8.71
fX
4
-8.4929
4
26
/
Some patients have shown increased blood flow and improved erections when treated with vasodilators. The isotope penogram may be helpful in predicting which patients would respond best to therapy with vasodilators. The noninvasive penogram is a dynamic and functional study of penile blood flow. By demonstrating good vascular flow or poor trapping of blood in the corpora, this test will screen out patients who would not benefit from revascularization. Therefore, the invasive penile angiogram can be avoided in these patients. The radioisotope penogram is a valuable adjunct in the more effective selection of candidates for penile revascularization as well as for medical management. 110 Irving Street, N. W. Washington, D. C. 20010 (DR. EDSON)
FBI FIGURE
5.
Correlation of PBI and penogram index.
and 0.96, respectively. Both underwent successful penile revascularization. Illustrative penograms of potent and impotent patients are shown in Figures 3 and 4. The significant correlation (p < 0.01) between the PBI and penogram index is shown in Figure 5. 0.3
Comment In evaluating the impotent male, an additional noninvasive study is needed to supplement the Doppler pulse and penile blood pressure studies. In the group of patients studied, a good correlation was found between the radioisotope penogram index and the penile brachial index in normal and impotent subjects. It is planned to evaluate a larger number of patients to establish more accurately normal and abnormal penogram indices.
502
References 1. Gee WF: A history of surgical treatment of impotence, Urology 5: 401 (1975). 2. Jevtich MJ: Importance of penile arterial pulse sound examination in impotance, J Urol 124: 821 (1980). 3. Blaivas JG, O’Donnell TF, Gottlieb P, and Labib KB: Comprehensive laboratory evaluation of impotent men, ibid. 124: 201 (1980). 4. Michal V, Pospichal J, and Lachman M: Penile artery occlusions in erection impotence, a new type of angiography phalloarteriography, Cas Lek Cesk 115: 1245 (1976). 5. Ginestie JF, and Ramieu A: Ftadiologic exploration of impotence, The Hague, Martinus NijhofT, 1978. 6. Cohen MS, Sharpe W, Warner RS, Zorgniotti A: Morphology of corporal cavernosa arterial bed in impotence, Urology 16: 382 (1980). 7. Zorgniotti AW, Rossi G, Padula G, and Makovsky RD: Diagnosis and therapy of vasculogenic impotence, J Urol 123: 674 (1980). 8. Shirai M: Differential diagnosis of organic and functional impotence by use of Y-human serum albumin, Tohoku J Exp Med 101: 317 (1970). 9. Shirai M, and Nakamura M: Diagnostic discrimination between organic and functional impotence by radioisotope penogram with -TcO.,, 116: 9 (1975). 10. Casey WC: Phallography: technique and results of nocturnal tumescence monitoring, J Urol 122: 752 (1979).
UROLOGY
/
NOVEMBER
1982
/
VOLUME
XX, NUMBER 5