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Long-term urinary function after transperineal brachytherapy for patients with large prostate glands
Int. J. Radiation Oncology Biol. Phys., Vol. 51, No. 5, pp. 1241–1245, 2001 Copyright © 2001 Elsevier Science Inc. Printed in the USA. All rights reserved 0360-3016/01/$–see front matter
PII S0360-3016(01)01738-2
CLINICAL INVESTIGATION
Prostate
LONG-TERM URINARY FUNCTION AFTER TRANSPERINEAL BRACHYTHERAPY FOR PATIENTS WITH LARGE PROSTATE GLANDS TRACY SHERERTZ,* KENT WALLNER, M.D.,*† HERBERT WANG, M.D.,‡ STEVEN SUTLIEF, PH.D.,*† KENNETH RUSSELL, M.D.*
AND
*Department of Radiation Oncology, University of Washington School of Medicine; †Radiation Oncology, Puget Sound Health Care System, Department of Veterans Affairs, Seattle, WA; ‡Department of Radiation Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL Purpose: To summarize longer-term postbrachytherapy morbidity in patients with prostate glands >50 cm3. Methods and Materials: From 1997 to 1998, 33 patients with a transrectal ultrasound-based prostate volume >50 cm3 were treated at the University of Washington by 125I (144 Gy) or 103Pd (115 Gy) implantation for prostate carcinoma. These 33 patients comprised 7% of the total implant patient population. Twelve patients were treated with neoadjuvant androgen ablation before implantation. The 125I source strength ranged from 0.34 to 0.5 mCi and the 103Pd source strength ranged from 1.1 to 1.4 mCi (pre-NIST-99). The total number of sources implanted was 94 –223 (median 155). Despite the typical implant-related volume increase, the postimplant CT-defined prostate volumes were generally well-covered by the prescription isodose (median coverage 92%, range 80 – 100%). The preimplant urinary obstructive symptoms were quantified by the criteria of the American Urological Association. Results: Of the 33 patients, 12 developed acute postimplant urinary retention, all presenting within 24 h of implantation. Patients who developed postimplant retention lasting >1 week were generally treated with intermittent self-catheterization. By 1 month, 85% of patients were catheter free. By 1 year, only 1 patient (4%) remained in urinary retention; the remainder of cases had resolved spontaneously. With follow-up of 1.7–2.6 years, the last American Urological Association scores were higher than the pretreatment scores in 15 patients and lower in 7 patients. No patient developed permanent urinary incontinence. Long-term changes in the American Urological Association scores were unrelated to whether the patient had been in urinary retention after implantation. Two patients developed rectal fistulas; they had preimplant transrectal ultrasound prostate volumes of 53 and 59 cm3, in the low range for this group of patients. No other patient had persistent rectal bleeding suggestive of clinically significant proctitis. The pretreatment serum prostate-specific antigen level was 3.3–15 ng/mL (median 7.2) and the last serum prostate-specific antigen level 0.1–1.6 ng/mL (median 0.2). Conclusion: Patients with larger prostate volumes appear to have moderate morbidity and a satisfactory technical outcome with brachytherapy. We do not believe the occurrence of two severe rectal complications was related to the prostate volume per se. Our experience and that of others calls into question the validity of using prostate volume as a criterion for patient suitability for prostate brachytherapy. © 2001 Elsevier Science Inc. Prostate cancer, Brachytherapy, Large.
INTRODUCTION During the past few years, there has been a resurgence in the treatment of early-stage prostate cancer with permanent radioactive seed implantation. Because of the relative novelty of ultrasound-guided brachytherapy, published data to guide physicians in determining who is most suitable for the procedure are still limited. Prostate volume is one commonly used selection criterion. There is a perception among brachytherapists that a large prostate volume is a contraindication to brachytherapy, the primary reason being a higher likelihood of postimplant
urinary retention or technical difficulty in achieving adequate source placement (1–3). It is true that patients with large prostate glands have a higher rate of acute postimplant urinary retention. However, retention is typically a transient phenomenon that should not, in itself, be a reason to institute hormonal therapy or pursue a different treatment modality. In fact, two investigator teams have reported short-term brachytherapy outcomes for patients with large prostates similar to results for those with smaller glands (4, 5). In this report, we update our preliminary experience with large prostate patients to clarify their longer term clinical outcomes.
Reprint requests to: Kent Wallner, M.D., Department of Radiation Oncology (No. 174), Department of Veterans Affairs, 1660 S. Columbian Way, Seattle, WA 98108-1597. Tel: 206-768-5356;
Fax: 206-768-5331; E-mail: [email protected] Received Jan 16, 2001, and in revised form Jun 15, 2001. Accepted for publication Jun 25, 2001. 1241
1242
I. J. Radiation Oncology
● Biology ● Physics
Volume 51, Number 5, 2001
METHODS AND MATERIALS From 1997 to 1998, 33 patients with a transrectal ultrasound (TRUS)-based prostate volume ⬎50 cm3 were treated at the University of Washington by 125I (144 Gy) or 103 Pd (115 Gy) implantation for prostate carcinoma. The details of their care have been previously reported (5). These 33 patients comprised 7% of the total implant patient population. During that time, no official selection policy was in place regarding prostate volume. Some physicians preferred to downsize larger prostates hormonally before implantation, and others were less inclined to use this treatment approach. A pubic arch study was performed in most patients, but no policy had been set regarding the degree of pubic arch interference used to preclude patients from brachytherapy (6). Each patient underwent a preimplant TRUS study in the lithotomy position, with serial axial images taken of the prostate at 0.5-cm intervals from the base of the gland to the apex using a Siemens SONOLINE Prima ultrasound machine (6.0 MHz; Siemens Medical Group, Inc., Issaquah, WA) and a Barzell-Whitmore stepper unit (Barzell-Whitmore Maroon Bells, Inc., Sarasota, FL). The prostate contour was outlined at each level by the TRUS technologist and verified by the attending radiation oncologist. Treatment margins were used as previously described (7). The implants were performed as previously described (8). Only 1 patient received supplemental external beam irradiation before implantation. Twelve patients were treated with neoadjuvant androgen ablation before implantation. The prostate volumes reported here are those measured after hormonal downsizing. The 125I source strength ranged from 0.34 to 0.5 mCi and the 103Pd source strength ranged from 1.1 to 1.4 mCi (pre-NIST-99). The total number of sources implanted ranged from 94 to 223 (median 155). The morning after implantation, postimplant axial CT images of the prostate were obtained at 0.5-cm intervals with patients in the supine position. The attending radiation oncologist outlined the prostate margins, and the contours were digitized to calculate the CT-based target coverage (9). As reported earlier, the postimplant/preimplant prostate volume ratio ranged from 0.8 to 1.7 (median 1.15) Despite the typical implant-related volume increase, the postimplant CT-defined prostate volumes were generally well-covered by the prescription isodose (median coverage 92%, range 80 –100%). In all cases, at least 80% of the postimplant volume was covered (5). Preimplant urinary obstructive symptoms were quantified by the criteria of the American Urological Association (AUA) (10). Patients were contacted at the time of this report to update the postimplant morbidity information. Three patients were lost to follow-up.
Fig. 1. Postimplant urinary retention over time. By 1 year, only 1 patient was still in urinary retention.
tation. Patients who developed postimplant retention lasting ⬎1 week were generally treated with intermittent selfcatheterization. By 1 month, 85% of patients were catheter free. By 1 year, only 1 patient (4%) remained in urinary retention, the remainder of cases had resolved spontaneously (Fig. 2). The single patient without spontaneous resolution of implant-related retention underwent a neodymium:yttrium-aluminum-garnet interstitial laser procedure at 26 months after implantation. He developed a prostaticrectal fistula 2 months later and required a colostomy. With follow-up of 1.7–2.6 years, the last AUA scores were higher than the pretreatment scores in 15 patients and lower in 7 patients (Fig. 3A). No patient developed permanent urinary incontinence. Long-term changes in AUA scores were unrelated to whether the patient had been in urinary retention after implantation (Fig. 3B). No relationship was found between the long-term changes in the AUA scores and the preimplant TRUS volume (Fig. 4).
RESULTS Of the 33 patients, 12 developed acute postimplant urinary retention (Fig. 1). All presented within 24 h of implan-
Fig. 2. Patients arranged by increasing preimplant TRUS volume, with those who developed postimplant retention represented by filled circles.
Large prostates
● T. SHERERTZ et al.
1243
Fig. 3. (A) Pre- and postimplant AUA scores and (B) change in AUA scores, grouped by whether the patients experienced postimplant urinary retention.
A second patient developed a prostatic rectal fistula 24 months after implantation. A detailed dosimetric analysis failed to show higher-than-normal rectal radiation doses. He was the subject of a detailed report regarding implantrelated rectal fistulas (11). The 2 patients who developed rectal fistulas had preimplant TRUS prostate volumes of 53 and 59 cm3, within the low range for this group of patients (Fig. 5). No other patient had persistent rectal bleeding suggestive of clinically significant proctitis. The pretreatment serum prostate-specific antigen level ranged from 3.3 to 15 ng/mL (median 7.2). The last serum prostate-specific antigen level ranged from 0.1 to 1.6 ng/mL (median 0.2) (Fig. 6).
Fig. 4. Change in pre- to postimplant AUA score vs. the preimplant prostate volume.
DISCUSSION Within the group of patients with large prostate volumes reported here, the likelihood of implant-related urinary retention was not consistently related to the prostate volume or preimplant AUA score. The retention rate, although higher than that reported from some other institutions, was similar to the rate we have noted overall in our brachytherapy patients, including those with smaller prostate volumes (manuscript in preparation). Only 1 patient remained catheter-dependent at 2 years. It has been our experience that nearly all such patients will eventually return to normal after prolonged intermittent self-catheterization, a management policy we advise to avoid transurethral resection of the obstructing tissue (12). That the average long-term AUA
Fig. 5. Patients arranged in order of increasing prostate volume. The 2 patients with implant-related fistulas are represented by filled circles.
1244
I. J. Radiation Oncology
● Biology ● Physics
Fig. 6. Pre- and postimplant prostate-specific antigen values.
scores and the changes in the AUA scores were unrelated to the occurrence of postimplant retention suggests that longterm sequelae from postimplant urinary retention are unlikely. It is worrisome that 2 of our patients developed prostaticrectal fistulas, but the development was probably unrelated to their prostate volume per se. Our overall incidence of serious rectal complications has been very low, with the 2 reported here the only 2 in nearly 700 patients who underwent implantation at the University of Washington or Puget Sound Veterans Affairs Hospital from 1997 through 2000. Dosimetric analysis of these 2 cases provided no evidence of excessive rectal radiation doses (11). We believe that 1 patient’s fistula may have been related to his postimplant interstitial laser procedure. The second patient’s fistula is more difficult to explain. However, because his prostate volume was only 53 cm3, it is unlikely that his prostate volume per se was related to his complication. One major concern regarding brachytherapy for patients with a large prostate gland is the possibility of pubic arch interference. Achieving adequate implantation of the ante-
Volume 51, Number 5, 2001
rior portion of the prostate may be difficult if substantial pubic arch interference exists, but a variety of methods to identify and circumvent pubic arch interference have been published (5, 6, 13, 14). Stone and Stock (4) recently published their own short-term results for patients with prostate volumes ⬎60 cm3. They reported adequate dosimetric coverage, but gave no clinical follow-up. Although we have shown that patients with larger prostate volumes appear to have moderate morbidity and satisfactory technical outcome with brachytherapy, the proper use of the prostate volume as a patient selection criterion remains to be fully elucidated. The present study has substantial implications regarding patient selection, because it challenges the widespread notion that a large prostate volume is a contraindication to brachytherapy. Nonetheless, the study has several substantial limitations. First, we did not make a controlled comparison of postimplant morbidity between patients with large vs. smaller prostates; instead, we merely demonstrated that, as a group, patients with larger glands appear to have acceptable levels of postimplant morbidity. Second, it should be noted that most patients reported here had prostate volumes between 50 and 70 cm3, and our conclusions become much more tenuous for those with extremely large glands (⬎70 cm3). Finally, we made no comparison between patients with large glands treated with brachytherapy and those treated with external beam radiation. Because of the nature of our practice, very few patients are treated definitively with external beam radiation, and we cannot make such a comparison. However, it is our clinical impression that most patients, regardless of prostate size, have milder short-term urinary morbidity if treated with external beam radiation. The potential for substantial selection bias makes our data merely an initial attempt to bring some logic to patient selection criteria, and not the final word on the controversial role of prostate volume in brachytherapy patient selection. Nonetheless, our experience and that of Stone and Stock calls into question the validity of using prostate volume as a criterion for patient suitability for prostate brachytherapy.
REFERENCES 1. Tincher SA, Kim RY, Ezekiel MP, et al. Effects of pelvic rotation and needle angle on pubic arch interference during transperineal prostate implants. Int J Radiat Oncol Biol Phys 2000;47:361–363. 2. Terk MD, Stock RG, Stone NN. Identification of patients at increased risk for prolonged urinary retention following radioactive seed implantation of the prostate. J Urol 1998;160: 1379 –1382. 3. Thomas MD, Cormack R, Tempany CM, et al. Identifying the predictors of acute urinary retention following magnetic-resonance-guided prostate brachytherapy. Int J Radiat Oncol Biol Phys 2000;47:905–908. 4. Stone NN, Stock RG. Prostate brachytherapy in patients with prostate volumes ⱖ 50 cm3: Dosimetric analysis of implant quality. Int J Radiat Oncol Biol Phys 2000;46:1199 –1204. 5. Wang H, Wallner K, Sutlief S, et al. Transperineal brachy-
6.
7. 8.
9.
10.
therapy in patients with large prostate glands. Int J Cancer 2000;90:199 –205. Bellon J, Wallner K, Ellis W, et al. Use of pelvic CT scanning to evaluate pubic arch interference of transperineal prostate brachytherapy. Int J Radiat Oncol Biol Phys 1999;43:579 – 581. Han B, Wallner K, Aggarwal S, et al. Treatment margins for prostate brachytherapy. Semin Urol Oncol 2000;18:137–141. Blasko JC, Ragde H, Schumacher D. Transperineal percutaneous iodine-125 implantation for prostatic carcinoma using transrectal ultrasound and template guidance. Endo/Hypertherm 1987;3:131–139. Willins J, Wallner K. CT-based dosimetry for transperineal I-125 prostate brachytherapy. Int J Radiat Oncol Biol Phys 1997;39:347–353. Barry MJ, Fowler FJ, O’Leary MP, et al. The American
Large prostates
Urological Association symptom index for benign prostatic hyperplasia. J Urol 1992;148:1549. 11. Howard A, Wallner K, Han B, et al. Rectal fistulas after prostate brachytherapy. J Brachyther Int 2001;17:37– 42. 12. Hu K, Wallner KE. Urinary incontinence in patients who have a TURP/TUIP following prostate brachytherapy. Int J Radiat Oncol Biol Phys 1998;40:783–786.
● T. SHERERTZ et al.
1245
13. Wallner K, Blasko J, Dattoli M. Technique. In: Wallner K, Blasko J, Dattoli M, editors. Prostate brachytherapy made complicated. 2nd ed. Seattle: SmartMedicine Press; 2001. p. 8.1– 8.32. 14. Wallner K, Ellis W, Russell K, et al. Use of TRUS to predict pubic arch interference of prostate brachytherapy. Int J Radiat Oncol Biol Phys 1999;43:583–585.
PII S0360-3016(01)01738-2
CLINICAL INVESTIGATION
Prostate
LONG-TERM URINARY FUNCTION AFTER TRANSPERINEAL BRACHYTHERAPY FOR PATIENTS WITH LARGE PROSTATE GLANDS TRACY SHERERTZ,* KENT WALLNER, M.D.,*† HERBERT WANG, M.D.,‡ STEVEN SUTLIEF, PH.D.,*† KENNETH RUSSELL, M.D.*
AND
*Department of Radiation Oncology, University of Washington School of Medicine; †Radiation Oncology, Puget Sound Health Care System, Department of Veterans Affairs, Seattle, WA; ‡Department of Radiation Oncology, University of Chicago Pritzker School of Medicine, Chicago, IL Purpose: To summarize longer-term postbrachytherapy morbidity in patients with prostate glands >50 cm3. Methods and Materials: From 1997 to 1998, 33 patients with a transrectal ultrasound-based prostate volume >50 cm3 were treated at the University of Washington by 125I (144 Gy) or 103Pd (115 Gy) implantation for prostate carcinoma. These 33 patients comprised 7% of the total implant patient population. Twelve patients were treated with neoadjuvant androgen ablation before implantation. The 125I source strength ranged from 0.34 to 0.5 mCi and the 103Pd source strength ranged from 1.1 to 1.4 mCi (pre-NIST-99). The total number of sources implanted was 94 –223 (median 155). Despite the typical implant-related volume increase, the postimplant CT-defined prostate volumes were generally well-covered by the prescription isodose (median coverage 92%, range 80 – 100%). The preimplant urinary obstructive symptoms were quantified by the criteria of the American Urological Association. Results: Of the 33 patients, 12 developed acute postimplant urinary retention, all presenting within 24 h of implantation. Patients who developed postimplant retention lasting >1 week were generally treated with intermittent self-catheterization. By 1 month, 85% of patients were catheter free. By 1 year, only 1 patient (4%) remained in urinary retention; the remainder of cases had resolved spontaneously. With follow-up of 1.7–2.6 years, the last American Urological Association scores were higher than the pretreatment scores in 15 patients and lower in 7 patients. No patient developed permanent urinary incontinence. Long-term changes in the American Urological Association scores were unrelated to whether the patient had been in urinary retention after implantation. Two patients developed rectal fistulas; they had preimplant transrectal ultrasound prostate volumes of 53 and 59 cm3, in the low range for this group of patients. No other patient had persistent rectal bleeding suggestive of clinically significant proctitis. The pretreatment serum prostate-specific antigen level was 3.3–15 ng/mL (median 7.2) and the last serum prostate-specific antigen level 0.1–1.6 ng/mL (median 0.2). Conclusion: Patients with larger prostate volumes appear to have moderate morbidity and a satisfactory technical outcome with brachytherapy. We do not believe the occurrence of two severe rectal complications was related to the prostate volume per se. Our experience and that of others calls into question the validity of using prostate volume as a criterion for patient suitability for prostate brachytherapy. © 2001 Elsevier Science Inc. Prostate cancer, Brachytherapy, Large.
INTRODUCTION During the past few years, there has been a resurgence in the treatment of early-stage prostate cancer with permanent radioactive seed implantation. Because of the relative novelty of ultrasound-guided brachytherapy, published data to guide physicians in determining who is most suitable for the procedure are still limited. Prostate volume is one commonly used selection criterion. There is a perception among brachytherapists that a large prostate volume is a contraindication to brachytherapy, the primary reason being a higher likelihood of postimplant
urinary retention or technical difficulty in achieving adequate source placement (1–3). It is true that patients with large prostate glands have a higher rate of acute postimplant urinary retention. However, retention is typically a transient phenomenon that should not, in itself, be a reason to institute hormonal therapy or pursue a different treatment modality. In fact, two investigator teams have reported short-term brachytherapy outcomes for patients with large prostates similar to results for those with smaller glands (4, 5). In this report, we update our preliminary experience with large prostate patients to clarify their longer term clinical outcomes.
Reprint requests to: Kent Wallner, M.D., Department of Radiation Oncology (No. 174), Department of Veterans Affairs, 1660 S. Columbian Way, Seattle, WA 98108-1597. Tel: 206-768-5356;
Fax: 206-768-5331; E-mail: [email protected] Received Jan 16, 2001, and in revised form Jun 15, 2001. Accepted for publication Jun 25, 2001. 1241
1242
I. J. Radiation Oncology
● Biology ● Physics
Volume 51, Number 5, 2001
METHODS AND MATERIALS From 1997 to 1998, 33 patients with a transrectal ultrasound (TRUS)-based prostate volume ⬎50 cm3 were treated at the University of Washington by 125I (144 Gy) or 103 Pd (115 Gy) implantation for prostate carcinoma. The details of their care have been previously reported (5). These 33 patients comprised 7% of the total implant patient population. During that time, no official selection policy was in place regarding prostate volume. Some physicians preferred to downsize larger prostates hormonally before implantation, and others were less inclined to use this treatment approach. A pubic arch study was performed in most patients, but no policy had been set regarding the degree of pubic arch interference used to preclude patients from brachytherapy (6). Each patient underwent a preimplant TRUS study in the lithotomy position, with serial axial images taken of the prostate at 0.5-cm intervals from the base of the gland to the apex using a Siemens SONOLINE Prima ultrasound machine (6.0 MHz; Siemens Medical Group, Inc., Issaquah, WA) and a Barzell-Whitmore stepper unit (Barzell-Whitmore Maroon Bells, Inc., Sarasota, FL). The prostate contour was outlined at each level by the TRUS technologist and verified by the attending radiation oncologist. Treatment margins were used as previously described (7). The implants were performed as previously described (8). Only 1 patient received supplemental external beam irradiation before implantation. Twelve patients were treated with neoadjuvant androgen ablation before implantation. The prostate volumes reported here are those measured after hormonal downsizing. The 125I source strength ranged from 0.34 to 0.5 mCi and the 103Pd source strength ranged from 1.1 to 1.4 mCi (pre-NIST-99). The total number of sources implanted ranged from 94 to 223 (median 155). The morning after implantation, postimplant axial CT images of the prostate were obtained at 0.5-cm intervals with patients in the supine position. The attending radiation oncologist outlined the prostate margins, and the contours were digitized to calculate the CT-based target coverage (9). As reported earlier, the postimplant/preimplant prostate volume ratio ranged from 0.8 to 1.7 (median 1.15) Despite the typical implant-related volume increase, the postimplant CT-defined prostate volumes were generally well-covered by the prescription isodose (median coverage 92%, range 80 –100%). In all cases, at least 80% of the postimplant volume was covered (5). Preimplant urinary obstructive symptoms were quantified by the criteria of the American Urological Association (AUA) (10). Patients were contacted at the time of this report to update the postimplant morbidity information. Three patients were lost to follow-up.
Fig. 1. Postimplant urinary retention over time. By 1 year, only 1 patient was still in urinary retention.
tation. Patients who developed postimplant retention lasting ⬎1 week were generally treated with intermittent selfcatheterization. By 1 month, 85% of patients were catheter free. By 1 year, only 1 patient (4%) remained in urinary retention, the remainder of cases had resolved spontaneously (Fig. 2). The single patient without spontaneous resolution of implant-related retention underwent a neodymium:yttrium-aluminum-garnet interstitial laser procedure at 26 months after implantation. He developed a prostaticrectal fistula 2 months later and required a colostomy. With follow-up of 1.7–2.6 years, the last AUA scores were higher than the pretreatment scores in 15 patients and lower in 7 patients (Fig. 3A). No patient developed permanent urinary incontinence. Long-term changes in AUA scores were unrelated to whether the patient had been in urinary retention after implantation (Fig. 3B). No relationship was found between the long-term changes in the AUA scores and the preimplant TRUS volume (Fig. 4).
RESULTS Of the 33 patients, 12 developed acute postimplant urinary retention (Fig. 1). All presented within 24 h of implan-
Fig. 2. Patients arranged by increasing preimplant TRUS volume, with those who developed postimplant retention represented by filled circles.
Large prostates
● T. SHERERTZ et al.
1243
Fig. 3. (A) Pre- and postimplant AUA scores and (B) change in AUA scores, grouped by whether the patients experienced postimplant urinary retention.
A second patient developed a prostatic rectal fistula 24 months after implantation. A detailed dosimetric analysis failed to show higher-than-normal rectal radiation doses. He was the subject of a detailed report regarding implantrelated rectal fistulas (11). The 2 patients who developed rectal fistulas had preimplant TRUS prostate volumes of 53 and 59 cm3, within the low range for this group of patients (Fig. 5). No other patient had persistent rectal bleeding suggestive of clinically significant proctitis. The pretreatment serum prostate-specific antigen level ranged from 3.3 to 15 ng/mL (median 7.2). The last serum prostate-specific antigen level ranged from 0.1 to 1.6 ng/mL (median 0.2) (Fig. 6).
Fig. 4. Change in pre- to postimplant AUA score vs. the preimplant prostate volume.
DISCUSSION Within the group of patients with large prostate volumes reported here, the likelihood of implant-related urinary retention was not consistently related to the prostate volume or preimplant AUA score. The retention rate, although higher than that reported from some other institutions, was similar to the rate we have noted overall in our brachytherapy patients, including those with smaller prostate volumes (manuscript in preparation). Only 1 patient remained catheter-dependent at 2 years. It has been our experience that nearly all such patients will eventually return to normal after prolonged intermittent self-catheterization, a management policy we advise to avoid transurethral resection of the obstructing tissue (12). That the average long-term AUA
Fig. 5. Patients arranged in order of increasing prostate volume. The 2 patients with implant-related fistulas are represented by filled circles.
1244
I. J. Radiation Oncology
● Biology ● Physics
Fig. 6. Pre- and postimplant prostate-specific antigen values.
scores and the changes in the AUA scores were unrelated to the occurrence of postimplant retention suggests that longterm sequelae from postimplant urinary retention are unlikely. It is worrisome that 2 of our patients developed prostaticrectal fistulas, but the development was probably unrelated to their prostate volume per se. Our overall incidence of serious rectal complications has been very low, with the 2 reported here the only 2 in nearly 700 patients who underwent implantation at the University of Washington or Puget Sound Veterans Affairs Hospital from 1997 through 2000. Dosimetric analysis of these 2 cases provided no evidence of excessive rectal radiation doses (11). We believe that 1 patient’s fistula may have been related to his postimplant interstitial laser procedure. The second patient’s fistula is more difficult to explain. However, because his prostate volume was only 53 cm3, it is unlikely that his prostate volume per se was related to his complication. One major concern regarding brachytherapy for patients with a large prostate gland is the possibility of pubic arch interference. Achieving adequate implantation of the ante-
Volume 51, Number 5, 2001
rior portion of the prostate may be difficult if substantial pubic arch interference exists, but a variety of methods to identify and circumvent pubic arch interference have been published (5, 6, 13, 14). Stone and Stock (4) recently published their own short-term results for patients with prostate volumes ⬎60 cm3. They reported adequate dosimetric coverage, but gave no clinical follow-up. Although we have shown that patients with larger prostate volumes appear to have moderate morbidity and satisfactory technical outcome with brachytherapy, the proper use of the prostate volume as a patient selection criterion remains to be fully elucidated. The present study has substantial implications regarding patient selection, because it challenges the widespread notion that a large prostate volume is a contraindication to brachytherapy. Nonetheless, the study has several substantial limitations. First, we did not make a controlled comparison of postimplant morbidity between patients with large vs. smaller prostates; instead, we merely demonstrated that, as a group, patients with larger glands appear to have acceptable levels of postimplant morbidity. Second, it should be noted that most patients reported here had prostate volumes between 50 and 70 cm3, and our conclusions become much more tenuous for those with extremely large glands (⬎70 cm3). Finally, we made no comparison between patients with large glands treated with brachytherapy and those treated with external beam radiation. Because of the nature of our practice, very few patients are treated definitively with external beam radiation, and we cannot make such a comparison. However, it is our clinical impression that most patients, regardless of prostate size, have milder short-term urinary morbidity if treated with external beam radiation. The potential for substantial selection bias makes our data merely an initial attempt to bring some logic to patient selection criteria, and not the final word on the controversial role of prostate volume in brachytherapy patient selection. Nonetheless, our experience and that of Stone and Stock calls into question the validity of using prostate volume as a criterion for patient suitability for prostate brachytherapy.
REFERENCES 1. Tincher SA, Kim RY, Ezekiel MP, et al. Effects of pelvic rotation and needle angle on pubic arch interference during transperineal prostate implants. Int J Radiat Oncol Biol Phys 2000;47:361–363. 2. Terk MD, Stock RG, Stone NN. Identification of patients at increased risk for prolonged urinary retention following radioactive seed implantation of the prostate. J Urol 1998;160: 1379 –1382. 3. Thomas MD, Cormack R, Tempany CM, et al. Identifying the predictors of acute urinary retention following magnetic-resonance-guided prostate brachytherapy. Int J Radiat Oncol Biol Phys 2000;47:905–908. 4. Stone NN, Stock RG. Prostate brachytherapy in patients with prostate volumes ⱖ 50 cm3: Dosimetric analysis of implant quality. Int J Radiat Oncol Biol Phys 2000;46:1199 –1204. 5. Wang H, Wallner K, Sutlief S, et al. Transperineal brachy-
6.
7. 8.
9.
10.
therapy in patients with large prostate glands. Int J Cancer 2000;90:199 –205. Bellon J, Wallner K, Ellis W, et al. Use of pelvic CT scanning to evaluate pubic arch interference of transperineal prostate brachytherapy. Int J Radiat Oncol Biol Phys 1999;43:579 – 581. Han B, Wallner K, Aggarwal S, et al. Treatment margins for prostate brachytherapy. Semin Urol Oncol 2000;18:137–141. Blasko JC, Ragde H, Schumacher D. Transperineal percutaneous iodine-125 implantation for prostatic carcinoma using transrectal ultrasound and template guidance. Endo/Hypertherm 1987;3:131–139. Willins J, Wallner K. CT-based dosimetry for transperineal I-125 prostate brachytherapy. Int J Radiat Oncol Biol Phys 1997;39:347–353. Barry MJ, Fowler FJ, O’Leary MP, et al. The American
Large prostates
Urological Association symptom index for benign prostatic hyperplasia. J Urol 1992;148:1549. 11. Howard A, Wallner K, Han B, et al. Rectal fistulas after prostate brachytherapy. J Brachyther Int 2001;17:37– 42. 12. Hu K, Wallner KE. Urinary incontinence in patients who have a TURP/TUIP following prostate brachytherapy. Int J Radiat Oncol Biol Phys 1998;40:783–786.
● T. SHERERTZ et al.
1245
13. Wallner K, Blasko J, Dattoli M. Technique. In: Wallner K, Blasko J, Dattoli M, editors. Prostate brachytherapy made complicated. 2nd ed. Seattle: SmartMedicine Press; 2001. p. 8.1– 8.32. 14. Wallner K, Ellis W, Russell K, et al. Use of TRUS to predict pubic arch interference of prostate brachytherapy. Int J Radiat Oncol Biol Phys 1999;43:583–585.