Analysis of Spatial Dose-Volume Relationships and Decline in Sexual Function Following Permanent Brachytherapy for Prostate Cancer

OBJECTIVE

To explore relationships between dose to periprostatic anatomic structures and erectile dysfunction (ED) outcomes in an institutional cohort treated with prostate brachytherapy.

METHODS

The Sexual Health Inventory for Men (SHIM) instrument was administered for stage cT1-T2 prostate cancer patients treated with Pd-103 brachytherapy over a 10-year interval. Dose volume histograms for regional organs at risk and periprostatic regions were calculated with and without expansions to account for contouring uncertainty. Regression tree analysis clustered patients into ED risk groups.

RESULTS

We identified 115 men treated with definitive prostate brachytherapy who had 2 years of complete follow-up. On univariate analysis, the subapical region (SAR) caudal to prostate was the only defined region with dose volume histograms parameters significant for potency outcomes. Regression tree analysis separated patients into low ED risk (mean 2-year SHIM 20.03), medium ED risk (15.02), and high ED risk (5.54) groups. Among patients with good baseline function (SHIM ≥ 17), a dose ≥72.75 Gy to 20% of the SAR with 1 cm expansion was most predictive for 2-year potency outcome. On multivariate analysis, regression tree risk group remained significant for predicting potency outcomes even after adjustment for baseline SHIM and age.

CONCLUSION

Dose to the SAR immediately caudal to prostate was predictive for potency outcomes in patients with good baseline function. Minimization of dose to this region may improve potency outcomes following prostate brachytherapy.

Low-Intensity Shockwave Therapy Improves Hemodynamic Parameters in Patients With Vasculogenic Erectile Dysfunction: A Triplex Ultrasonography-Based Sham-Controlled Trial

BACKGROUND

Although several reports have documented the subjective improvement of erectile function after low-intensity extracorporeal shockwave therapy (LI-ESWT) in patients with vasculogenic erectile dysfunction (ED), objective assessment data of penile hemodynamics are lacking.

AIM

To assess penile hemodynamics before and 3 months after LI-ESWT in a group of patients with documented vasculogenic ED.

METHODS

This was a double-blinded, randomized, sham-controlled trial. Forty-six patients with ED were randomized; 30 underwent LI-ESWT and 16 had a sham procedure in double-blinded fashion. All patients underwent penile triplex ultrasonography by the same investigator immediately before and 3 months after treatment. Patient demographics, International Index of Erectile Function erectile function domain (IIEF-ED) score, and minimal clinically important difference were assessed at baseline and 1, 3, 6, 9, and 12 months after treatment.

OUTCOMES

Changes in peak systolic velocity and resistance index as measured by triplex ultrasonography at baseline and 3 months after treatment were the main outcomes of the study. Secondary outcomes were changes in the IIEF-EF score from baseline to 1, 3, 6, 9, and 12 months after treatment and the percentage of patients reaching a minimal clinically important difference during the same period for the two groups.

RESULTS

IIEF-EF minimal clinically important differences for the active vs sham group were observed for 56.7% vs 12.5% (P = .005) at 1 month, 56.7% vs 12.5% (P = .003) at 3 months, 63.3% vs 18.8% (P = .006) at 6 months, 66.7% vs 31.3% (P = .022) at 9 months, and 75% vs 25% (P = .008) at 12 months. Mean peak systolic velocity increased by 4.5 and 0.6 cm/s in the LI-ESWT and sham groups, respectively (P < .001).

CLINICAL IMPLICATIONS

Such results offer objective and subjective documentation of the value of this novel treatment modality for men with vasculogenic ED.

STRENGTHS AND LIMITATIONS

Strengths include the prospective, randomized, sham-controlled type of study and the assessment of penile hemodynamics. Limitations include the small sample and strict inclusion criteria that do not reflect everyday clinical practice.

CONCLUSION

The present study confirms the beneficial effect of LI-ESWT on penile hemodynamics and the beneficial effect of this treatment up to 12 months. Kalyvianakis D, Hatzichristou D. Low-Intensity Shockwave Therapy Improves Hemodynamic Parameters in Patients With Vasculogenic Erectile Dysfunction: A Triplex Ultrasonography-Based Sham-Controlled Trial. J Sex Med 2017;14:891-897.

Sexual function and the use of medical devices or drugs to optimize potency after prostate brachytherapy

PURPOSE

Prospective evaluation of sexual outcomes after prostate brachytherapy with iodine-125 seeds as monotherapy at a tertiary cancer care center.

METHODS AND MATERIALS

Subjects were 129 men with prostate cancer with I-125 seed implants (prescribed dose, 145 Gy) without supplemental hormonal or external beam radiation therapy. Sexual function, potency, and bother were prospectively assessed at baseline and at 1, 4, 8, and 12 months using validated quality-of-life self-assessment surveys. Postimplant dosimetry values, including dose to 10% of the penile bulb (D10), D20, D33, D50, D75, D90, and penile volume receiving 100% of the prescribed dose (V100) were calculated.

RESULTS

At baseline, 56% of patients recorded having optimal erections; at 1 year, 62% of patients with baseline erectile function maintained optimal potency, 58% of whom with medically prescribed sexual aids or drugs. Variables associated with pretreatment-to-posttreatment decline in potency were time after implant (p = 0.04) and age (p = 0.01). Decline in urinary function may have been related to decline in potency. At 1 year, 69% of potent patients younger than 70 years maintained optimal potency, whereas 31% of patients older than 70 maintained optimal potency (p = 0.02). Diabetes was related to a decline in potency (p = 0.05), but neither smoking nor hypertension were. For patients with optimal potency at baseline, mean sexual bother scores had declined significantly at 1 year (p < 0.01). Sexual potency, sexual function, and sexual bother scores failed to correlate with any dosimetric variable tested.

CONCLUSIONS

Erections firm enough for intercourse can be achieved at 1 year after treatment, but most men will require medical aids to optimize potency. Although younger men were better able to maintain erections firm enough for intercourse than older men, there was no correlation between potency, sexual function, or sexual bother and penile bulb dosimetry.

Prediction of erectile function following treatment for prostate cancer

CONTEXT

Sexual function is the health-related quality of life (HRQOL) domain most commonly impaired after prostate cancer treatment; however, validated tools to enable personalized prediction of erectile dysfunction after prostate cancer treatment are lacking.

OBJECTIVE

To predict long-term erectile function following prostate cancer treatment based on individual patient and treatment characteristics.

DESIGN

Pretreatment patient characteristics, sexual HRQOL, and treatment details measured in a longitudinal academic multicenter cohort (Prostate Cancer Outcomes and Satisfaction With Treatment Quality Assessment; enrolled from 2003 through 2006), were used to develop models predicting erectile function 2 years after treatment. A community-based cohort (community-based Cancer of the Prostate Strategic Urologic Research Endeavor [CaPSURE]; enrolled 1995 through 2007) externally validated model performance. Patients in US academic and community-based practices whose HRQOL was measured pretreatment (N = 1201) underwent follow-up after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer. Sexual outcomes among men completing 2 years' follow-up (n = 1027) were used to develop models predicting erectile function that were externally validated among 1913 patients in a community-based cohort.

MAIN OUTCOME MEASURES

Patient-reported functional erections suitable for intercourse 2 years following prostate cancer treatment.

RESULTS

Two years after prostate cancer treatment, 368 (37% [95% CI, 34%-40%]) of all patients and 335 (48% [95% CI, 45%-52%]) of those with functional erections prior to treatment reported functional erections; 531 (53% [95% CI, 50%-56%]) of patients without penile prostheses reported use of medications or other devices for erectile dysfunction. Pretreatment sexual HRQOL score, age, serum prostate-specific antigen level, race/ethnicity, body mass index, and intended treatment details were associated with functional erections 2 years after treatment. Multivariable logistic regression models predicting erectile function estimated 2-year function probabilities from as low as 10% or less to as high as 70% or greater depending on the individual's pretreatment patient characteristics and treatment details. The models performed well in predicting erections in external validation among CaPSURE cohort patients (areas under the receiver operating characteristic curve, 0.77 [95% CI, 0.74-0.80] for prostatectomy; 0.87 [95% CI, 0.80-0.94] for external radiotherapy; and 0.90 [95% CI, 0.85-0.95] for brachytherapy).

CONCLUSION

Stratification by pretreatment patient characteristics and treatment details enables prediction of erectile function 2 years after prostatectomy, external radiotherapy, or brachytherapy for prostate cancer.

Comparison of tumor control and toxicity outcomes of high-dose intensity-modulated radiotherapy and brachytherapy for patients with favorable risk prostate cancer

OBJECTIVES

To compare the long-term, prostate-specific antigen relapse-free survival outcome and incidence of toxicity for patients with low-risk prostate cancer who underwent brachytherapy or intensity-modulated radiotherapy (RT).

METHODS

A total of 729 consecutive patients underwent brachytherapy (n = 448; prescription dose 144 Gy) or intensity-modulated RT alone (n = 281; prescription dose 81 Gy). The prostate-specific antigen relapse-free survival using the nadir plus 2 ng/mL definition and late toxicity using the National Cancer Institute's Common Terminology Criteria for Adverse Events were determined.

RESULTS

The 7-year prostate-specific antigen relapse-free survival rate for the brachytherapy and intensity-modulated RT groups was 95% and 89% for low-risk patients, respectively (P = .004). Cox regression analysis demonstrated that brachytherapy was associated with improved prostate-specific antigen relapse-free survival, even after adjustment for other variables. The incidence of metastatic disease between treatment sessions was low for both treatment groups. Late grade 2 gastrointestinal toxicity was observed in 5.1% and 1.4% of the brachytherapy and intensity-modulated RT groups, respectively (P = .02). No significant differences were seen between treatment groups for late grade 3 or greater rectal complications (brachytherapy 1.1% and intensity-modulated RT 0%; P = .19). Late grade 2 urinary toxicity occurred more often in the brachytherapy group than in the intensity-modulated RT group (15.6% and 4.3%, respectively; P < .0001). No significant differences were seen between the 2 treatment groups for late grade 3 urinary toxicity (brachytherapy 2.2% and intensity-modulated RT 1.4%; P = .62).

CONCLUSIONS

Among low-risk prostate cancer patients, the 7-year biochemical tumor control was superior for intraoperatively planned brachytherapy compared with high-dose intensity-modulated RT. Although significant toxicities were minimal for both groups, modest, but significant, increases in grade 2 urinary and rectal symptoms were noted for brachytherapy compared with intensity-modulated RT.

Time of decline in sexual function after external beam radiotherapy for prostate cancer

PURPOSE

Erectile dysfunction is one of the most concerning toxicities for patients in the treatment of prostate cancer. The inconsistent evaluation of sexual function (SF) and limited follow-up data have necessitated additional study to clarify the rate and timing of erectile dysfunction after external beam radiotherapy (EBRT) for prostate cancer.

METHODS AND MATERIALS

A total of 143 men completed baseline data on SF before treatment and at the subsequent follow-up visits. A total of 1187 validated SF inventories were analyzed from the study participants. Multiple domains of SF (sex drive, erectile function, ejaculatory function, and overall satisfaction) were analyzed for < or =8 years of follow-up.

RESULTS

The median follow-up was 4.03 years. The strongest predictor of SF after EBRT was SF before treatment. For all domains of SF, the only statistically significant decrease in function occurred in the first 24 months after EBRT. SF stabilized 2 years after treatment completion, with no statistically significant change in any area of SF >2 years after the end of EBRT.

CONCLUSION

These data suggest that SF does not have a continuous decline after EBRT. Instead, SF decreases maximally within the first 24 months after EBRT, with no significant changes thereafter.

ERECTILE FUNCTION AFTER BRACHYTHERAPY WITH EXTERNAL BEAM RADIATION FOR PROSTATE CANCER

The effect of therapeutic modalities on sexual potency is an important consideration for patients choosing a treatment for prostate cancer. We assessed erectile function after iridium-192 (1r-192) high-dose rate (HDR) brachytherapy with external beam radiation therapy (EBRT), and examined the efficacy of sildenafil after this treatment. Forty-two prostate cancer patients (T1c to T3bN0M0) were treated with 22Gy HDR brachytherapy with 36.8Gy EBRT without neoadjuvant hormone therapy. Erectile function was assessed using a 5-item version of the International Index of Erectile Function questionnaire (IIEF-5), pre, 3 and 12 months after treatment, Potency was defined as an IIEF-5 score > or = 11. Ten patients with potency before HDR brachytherapy with EBRT with or without neoadjuvant hormone therapy requested Sildenafil 3 months after treatment. The mean IIEF-5 score of all patients was 10.5 +/- 8.5, 4.5 +/- 5.3 (p < 0.001), and 3.8 +/- 4.7 (p < 0.001), pre, 3 and 12 months after treatment, respectively. Seventeen (40.4%) patients were potent before treatment. The mean IIEF-5 score of those patients was 15.8 +/- 3.2, 9.6 +/- 5.1 (p = 0.04), and 11.3 +/- 6.1 (p = 0.06), pre, 3 and 12 months after treatment, respectively. Ten of 17 (58.8%) patients maintained their potency 12 months after treatment. In 10 patients with potency before treatment who were treated with sildenafil, the mean IIEF-5 score increased from 6.2 +/- 3.5 at 3 months to 13.6 +/- 5.1 (p < 0.001) at 12 months after treatment. Eight of 10 (80%) patients treated with sildenafil had recovered 12 months after treatment. HDR brachytherapy with EBRT can be performed with favorable results for maintaining potency.

TGFB1 Single Nucleotide Polymorphisms Are Associated With Adverse Quality of Life in Prostate Cancer Patients Treated With Radiotherapy

PURPOSE

To investigate whether the presence of single nucleotide polymorphisms (SNPs) located within TGFB1 might be predictive for the development of adverse quality-of-life outcomes in prostate cancer patients treated with radiotherapy.

METHODS AND MATERIALS

A total of 141 prostate cancer patients treated with radiotherapy were screened for SNPs in TGFB1 using DNA sequencing. Three quality-of-life outcomes were investigated: (1) prospective decline in erectile function, (2) urinary quality of life, and (3) rectal bleeding. Median follow-up was 51.3 months (range, 12-138 months; SD, 24.4 months).

RESULTS

Those patients who possessed either the T/T genotype at position -509, the C/C genotype at position 869 (pro/pro, codon 10) or the G/C genotype at position 915 (arg/pro, codon 25) were significantly associated with the development of a decline in erectile function compared with those who did not have these genotypes: 56% (9 of 16) vs. 24% (11 of 45) (p = 0.02). In addition, patients with the -509 T/T genotype had a significantly increased risk of developing late rectal bleeding compared with those who had either the C/T or C/C genotype at this position: 55% (6 of 11) vs. 26% (34 of 130) (p = 0.05).

CONCLUSIONS

Possession of certain TGFB1 genotypes is associated with the development of both erectile dysfunction and late rectal bleeding in patients treated with radiotherapy for prostate cancer. Therefore, identification of patients harboring these genotypes may represent a means to predict which men are most likely to suffer from poor quality-of-life outcomes after radiotherapy for prostate cancer.

The Impact of Shock Wave Therapy at Varied Energy and Dose Levels on Functional and Structural Changes in Erectile Tissue

OBJECTIVES

Only minimal literature exists on consequences of shock wave therapy (SWT) on erectile function in treatment of Peyronie's disease (PD). This study was undertaken to define SWT impact at varied energy/dose levels at different time points on functional and structural changes in erectile tissue.

METHODS

In 45 rats 2000 shock waves (sw) at 2 BAR were applied to the penis weekly sorted by one, two, and three sessions (high-dose/energy level, HD-1, HD-2, HD-3). Each group was followed for 1, 7, or 28 d before measuring intracavernosal pressure (ICP) and mean arterial pressure (MAP). Fifteen control animals (C1, C7, C28) underwent anesthesia alone. Another 15 animals were exposed to three SWT sessions applying 1000 sw at 1 BAR and analyzed identically (low-dose/energy level, LD-3-1, -7, -28). Terminal deoxynucleotidyl transferase biotin-dUTP nick-end labeling assay was used to define the apoptotic index (AI) and Masson's trichrome (MT) staining was prepared to evaluate smooth muscle-to-collagen ratios.

RESULTS

ICP/MAP ratios for all C groups displayed a mean of 64%. All SWT groups demonstrated significantly reduced ICP/MAP ratios compared to their corresponding C groups (p<0.05). The LD-3 groups showed a trend toward improved ICP/MAP ratios. LD-3-28 demonstrated significant recovery compared to HD-3-28 (55+/-8% vs. 41+/-10%, p=0.004), but remained reduced compared to C28 (63+/-5%, p=0.03). No statistical differences were seen for MT staining in SWT groups compared to C (p>0.05). AIs for the LD-3 groups were significantly lower compared to the HD-3 groups (p<0.001), but all AIs were significantly increased compared to C groups (p<0.01).

CONCLUSIONS

Overall, at both energy/dose levels, SWT resulted in a time- and treatment-dependent reduction of ICP/MAP ratios, which might be mediated partly through apoptosis and collagenization of corporal smooth muscle.

Percutaneous perineal electrostimulation induces erection: clinical significance in patients with spinal cord injury and erectile dysfunction

OBJECTIVES

Approximately one third to one half of the penis is embedded in the pelvis and can be felt through the scrotum and in the perineum. The main arteries and nerves enter the penis through this perineal part of the penis, which seems to represent a highly sensitive area. We investigated the hypothesis that percutaneous perineal stimulation evokes erection in patients with neurogenic erectile dysfunction.

METHODS

Percutaneous electrostimulation of the perineum (PESP) with synchronous intracorporeal pressure (ICP) recording was performed in 28 healthy volunteers (age 36.3 +/-7.4 y) and 18 patients (age 36.6 +/- 6.8 y) with complete neurogenic erectile dysfunction (NED). Current was delivered in a sine wave summation fashion. Average maximal voltages and number of stimulations delivered per session were 15 to 18 volts and 15 to 25 stimulations, respectively.

RESULTS

PESP of healthy volunteers effected an ICP increase (P < 0.0001), which returned to the basal value upon stimulation cessation. The latent period recorded was 2.5 +/- 0.2 seconds. Results were reproducible on repeated PESP in the same subject but with an increase of the latent period. Patients with NED recorded an ICP increase that was lower (P < 0.05) and a latent period that was longer (P < 0.0001) than those of healthy volunteers.

CONCLUSION

PESP effected ICP increase in the healthy volunteers and patients with NED. The ICP was significantly higher and latent period shorter in the healthy volunteers than in the NED patients. PESP may be of value in the treatment of patients with NED, provided that further studies are performed to reproduce these results.

Preliminary Report of the Effect of High-Dose Adjuvant Intensity Modulated Radiation Therapy on the Sural Nerve Graft for Cavernosal Nerve Sacrifice After Radical Prostatectomy

PURPOSE

A sural nerve graft may replace a killed cavernosal nerve. The effect of intensity-modulated radiation therapy (IMRT) on function of the graft has not been reported.

MATERIALS AND METHODS

Between 1998 and 2001, 8 patients (9 nerve grafts) were treated with postoperative IMRT (mean dose, 70 Gy). Two patients had neoadjuvant Lupron 30 mg 2 months prior to radiation. Potency was defined as ability to achieve spontaneous erection sufficient for vaginal penetration. Median follow-up was 31.6 months.

RESULTS

Five patients (62.5%) who had erectile function after prostatectomy preserved spontaneous erectile function after radiation. Of these, 3 patients had both nerves resected (two receiving unilateral grafts and one receiving bilateral grafts) and 2 others had one graft and one nerve preserved. The impotent patients were impotent after surgery.

CONCLUSION

High-dose postprostatectomy IMRT does not place sural nerve grafts at greater risk for failure. Larger numbers of patients are needed to confirm these encouraging, preliminary findings.

Long-Term Urinary, Sexual, and Rectal Morbidity in Patients Treated with Iodine-125 Prostate Brachytherapy Followed Up for a Minimum of 5 Years

OBJECTIVES

To define the long-term morbidity in patients with prostate cancer who underwent iodine-125 brachytherapy.

METHODS

A total of 325 men with localized prostate cancer treated with iodine-125 brachytherapy had a median follow-up of 7 years (range 5 to 15). The American Urological Association symptom score, erectile function status, rectal bleeding incidence, and presence of urinary incontinence were collected prospectively before implantation and every 6 months thereafter. Comparisons were made between the pretreatment and treatment-related factors and their associations with quality-of-life changes. Associations were tested using the Student t, chi-square, and Wilcoxon signed rank tests.

RESULTS

The median prostate volume and maximal dose to 90% of the prostate was 36.6 cm3 and 167 Gy, respectively. Of the 325 men, 15.7% experienced prostate-specific antigen failure and 4% started androgen deprivation therapy. The mean total symptom and bother scores increased from baseline (P <0.001) to 6 months after implantation, steadily decreased, and were unchanged at the last follow-up visit (P = 0.6). There were no significant associations among patient age, race, hormonal therapy use, prostate size, radiation dose, and urinary morbidity. Incontinence occurred in 4 (1.2%) of the 325 patients at the last follow-up visit and was associated with transurethral resection of the prostate (odds ratio 8.8, 95% confidence interval 1.3 to 62, P = 0.008). Before implantation, 77.2% were able to have an erection adequate for intercourse and 50.6% were able to at the last follow-up visit. A significant correlation was found between potency preservation and age (P <0.001). Rectal bleeding occurred in 78 men (24%) 1 to 3 years after implantation. Nine patients (2.8%) complained of minor bleeding beyond 5 years, which was associated with greater radiation doses (P = 0.023).

CONCLUSIONS

The preservation of urinary, sexual, and rectal quality of life is excellent at long follow-up for patients implanted with iodine-125.

An analysis of erectile function after intensity modulated radiation therapy for localized prostate carcinoma

Radiation therapy for prostate cancer can cause erectile dysfunction (ED). Intensity Modulated Radiation Therapy (IMRT) can reduce the amount of radiation to surrounding tissues associated with ED. We characterize the incidence of and factors associated with ED in prostate cancer patients after IMRT at the National Naval Medical Center (NNMC). Patients potent by definition of the Sexual Health Inventory for Men (SHIM) before treatment completed the specific erectile questions of the SHIM after IMRT. Statistical analyses were performed to examine the relationships between several factors and ED. Thirty-two of 45 patients with mean age of 68.2 years (50-86 years) completed the SHIM. The median follow-up was 36.8 months (16-63.6 months) as defined by the time from completion of therapy to reassessment with the SHIM. Eight of 32 patients (25%) had no post-treatment ED (SHIM score 22-25), three of 32 (9%) had mild post-treatment ED (SHIM score 17-21), five of 32 (16%) had mild to moderate ED (SHIM score 12-16), five of 32 (16%) had moderate ED (SHIM score 8-11) and 11 of 32 (34%) had severe post-treatment ED (SHIM score<8). Post-treatment potency was significantly associated with the pre-treatment SHIM score (P=0.001) and history of hypertension (P=0.03). The mean radiation dose to the penile bulb and volume of penile bulb treated were not associated with post-treatment potency (P=0.38, 0.76, respectively). IMRT maintains potency in the majority of patients. This analysis compares favorably in preserving erectile function to previously reported series using conventional external beam radiation therapy techniques. The dose of radiation received by the penile bulb and volume of penile bulb were not associated with post-treatment ED in this analysis.

Patient and Treatment Factors Associated With Complications After Prostate Brachytherapy

Purpose

To assess the prevalence and predictors of complications after prostate brachytherapy in a population-based sample of older men.

Patients and Methods

We analyzed claims for Medicare-enrolled men older than age 65 years living in Surveillance, Epidemiology, and End Results (SEER) surveillance areas diagnosed with prostate cancer from 1991 to 1999 who underwent brachytherapy as initial treatment.

Results

There were 5,621 men who had brachytherapy with at least 2 years of follow-up. A complication diagnosis or invasive procedure occurred in 54.5% of men within 2 years, with 14.1% undergoing an invasive procedure. Urinary, bowel, and erectile morbidity rates were 33.8%, 21.0%, and 16.7%, respectively, and invasive procedure rates were 10.3%, 0.8%, and 4.0%, respectively. On multivariable analysis, combined urinary diagnoses and invasive procedures (obstruction, incontinence, bleeding, fistula) were associated with older age (P < .01), nonwhite race (odds ratio [OR], 1.30; P = .01), low income (OR, 1.74; P < .01), external-beam radiotherapy (EBRT; OR, 0.85; P = .01), androgen deprivation (OR, 1.31; P < .01), later year of brachytherapy (OR, 1.03/yr; P = .02), higher Charlson comorbidity score (P < .01), and prior transurethral resection of the prostate (OR, 1.65; P < .01). Bowel morbidity (bleeding/proctitis, injury) was associated with older age (P = .04), EBRT (OR, 1.46; P < .01), later year (OR, 1.04/yr; P < .01), higher Charlson score (P = .01), and inflammatory bowel disease (OR, 2.60; P < .01). Erectile morbidity was associated with younger age (P < .01), nonwhite race (OR, 1.37; P < .01), AD (OR, 1.18; P = .04), and later year (OR, 1.08/yr; P < .01). Invasive procedure rates declined with later year of brachytherapy (OR, 0.93/yr; P < .01).

Conclusion

Morbidity after prostate brachytherapy was common, though invasive procedures were required infrequently. Invasive procedures for complications declined during the 1990s, suggesting technical improvement with experience.

Evaluating the relationship between erectile dysfunction and dose received by the penile bulb: Using data from a randomised controlled trial of conformal radiotherapy in prostate cancer (MRC RT01, ISRCTN47772397)

AIM

To evaluate the relationship between erectile function and the radiation dose to the penile bulb and other proximal penile structures in men receiving conformal radiotherapy (CFRT) for prostate cancer (PCa).

METHODS

The Medical Research Council (MRC) RT01 trial randomised 843 men who had localised PCa to receive either 64 or 74 Gy after 3 - 6 months neoadjuvant hormonal treatment. Fifty-one men were selected who were potent prior to hormonal treatment, having completed both pre-hormone and 2-year post-CFRT Quality of Life assessments, and on whom dose volume data were available for analysis. The men were divided into three groups according to 2-year follow-up: potent, reduced potency, and impotent. The bulb of the penis together with the crura, were outlined on restored treatment plans. Dose - volume histograms were generated and compared between the three groups. An ordered logistic regression model was used to calculate the odds ratio of a range of dose - volume parameters to the penile bulb and effect on erectile dysfunction. The dose to the penile bulb was correlated to the dose received by the crura.

RESULTS

Of the 51 patients, 12 remained potent, 22 had reduced potency, and 17 were impotent at 2 years. No differences were seen in mean dose to the penile bulb by allocated treatment (t test = 1.61, p = 0.11). The mean doses to the penile bulb received by the potent, reduced potency, and impotent groups were 45.5 Gy (SD 17.1), 48 Gy (SD 16.1), and 59.2 Gy (SD 13.8), respectively. There was a strong correlation between the mean dose received by the penile bulb and dose to the crura (r = 0.82, p < 0.0001). 83.3% of impotent patients received a D90 > or = 50 Gy to the penile bulb compared with 29.4% of patients who maintained potency at 2 years (p = 0.006).

CONCLUSION

There is evidence from this study to suggest a dose volume effect on the penile bulb and erectile dysfunction. A D90 > or = 50 Gy is associated with a significant risk of erectile dysfunction and this should form a basis for selecting dose constraints in future dose escalation studies.

Testosterone and erectile function recovery after radiotherapy and long-term androgen deprivation with luteinizing hormone-releasing hormone agonists

OBJECTIVE

To study the recovery of testosterone levels and erectile function in men who received radiotherapy plus long-term adjuvant androgen deprivation (LTAD) with luteinizing hormone-releasing hormone (LHRH) agonists.

PATIENTS AND METHODS

From April 2000 to July 2001, men who had completed prostate radiotherapy with > or = 2 years of LTAD, and had their last LHRH agonist injection at least 6 months before, were invited to participate. At study entry, the men completed the International Index of Erectile Function (IIEF), and their serum total testosterone (TT), prostate-specific antigen, LH, follicle-stimulating hormone, haemoglobin, and body mass were measured. This assessment was repeated at 1 year.

RESULTS

In all, 20 men were recruited, with a mean (range) age of 70 (55-81) years. Defining a normal TT level as > or = 8.0 nmol/L, the median time to a normal level was 2.3 years (95% confidence interval (CI), 1.9-4.2). The median duration of castrate TT levels was 8 months (95% CI, 6.2-14.9). LH recovered before TT, suggesting that the rate-limiting step in the recovery of TT may be at the testicular level. The median time to recovery of normal LH levels was 3.8 months, compared to 8.0 months to reach supracastrate TT levels, and 2.3 years to reach normal TT levels. Age and the LH/TT ratio were associated with the time to recovery of both supracastrate and normal levels of TT. The IIEF was completed by 17 men; there were no significant changes in the scores in any domain of the IIEF during the study.

CONCLUSIONS

Most men recover supracastrate testosterone levels after LTAD and external beam radiotherapy, but recovery of 'normal' testosterone levels is slow. Few men recover potency and sexual desire. The patients age and LH/TT ratio may be predictive of the time to recovery of both supracastrate and normal testosterone levels.

Radiation therapy for prostate cancer and erectile (dys)function: the role of imaging

Incidence of erectile dysfunction (ED) after radiotherapy reported in the literature varies from 7 to 72% after external-beam radiotherapy to 5-51% after brachytherapy. Most of these studies are retrospective, the definition of ED is variable and sexual functioning is frequently assessed by asking only one question. Already in the 1980's it was suggested that post-radiation ED was attributable to vascular damage. The most reliable method to assess vasculogenic ED is the use of the Doppler ultrasound. More recently, many studies have assessed the relationship between radiation dose and volume of the penile bulb and post-radiation ED, though the outcome is controversial. The penile structures and the neurovascular bundles are best seen on magnetic resonance imaging (MRI). Therefore the use of a computer tomography scan/MRI image fusion can result in reducing the planning target volume and consequently the radiation dose to the penile bulb and bodies. If radiation induces vascular damage that causes ED, any means of reducing the dose to the pelvic vascular structures would likely decrease ED, therefore new radiation techniques such as the intensity modulated radiation therapy or the implant of fiducial markers can help decrease the margins and therefore ED.

Predictive factors for erectile dysfunction in men with prostate cancer after brachytherapy: is dose to the penile bulb important?

PURPOSE

To determine predictive factors for postimplant erectile dysfunction (ED) in a cohort of patients, according to prospectively collected data; specifically, to assess the impact of penile bulb volume and D50 and D95 (dose covering 50% and 95% of the penile bulb volume, respectively) on ED.

METHODS AND MATERIALS

Three hundred forty-two patients were identified who were potent before implant and who had at least 2 years' follow-up. Patient, tumor, treatment, and dosimetric data were collected on all patients. Postimplant ED was defined according to both physician-documented and patient-documented outcome data. Binary logistic regression analysis was used to create multivariable models of predictors for ED at 1, 2, and 3 years after implant.

RESULTS

Physician-documented rates of ED were 57%, 48%, and 38% at 1, 2, and 3 years after implant, respectively. Patient-documented rates of ED were 70% and 66% at 1 and 2 years, respectively. Multivariable analyses revealed age and degree of pre-implant erectile function to be consistently significant predictors of ED. Use of hormones was significant at the 1-year physician-documented ED endpoint but not thereafter, in keeping with the time course of testosterone recovery. Penile bulb volume, D50, and D95 were not found to be predictive for ED at any time point, in contrast to previous studies. In addition, planning ultrasound target volume, number of needles, and institutional case sequence number were significant predictors of ED at various time points, consistent with a traumatic etiology of ED.

CONCLUSIONS

We found no evidence to support penile bulb dosimetry as an independent predictive factor for ED after implant, using physician-documented or patient-documented outcomes.

[Late effects following curative radiotherapy for prostate cancer]

In this study we report late bladder, gastrointestinal and sexual dysfunctions in 23 patients following radical radiotherapy (66Gy-70Gy/33-35fx, 5 fx/week) for prostate cancer. We interviewed the subjects by telephone and compared the results with those of 45 healthy population controls. In general, the patients' bladder function was well preserved. However, compared with the population controls, significantly more patients reported dysuria and hematuria. Twenty-six percent of the patients reported moderate distress from the gastrointestinal tract. Fecal urgency, incontinence and the use of sanitary pads, as well as diarrhoea, and blood and mucous were significantly more common among the patients. Thirty-nine percent of the patients reported moderate or worse distress upon sexual activity, and significantly more patients suffered from erectile impotence.

Erectile function after prostate brachytherapy

PURPOSE

To evaluate erectile function after permanent prostate brachytherapy using a validated patient-administered questionnaire and to determine the effect of multiple clinical, treatment, and dosimetric parameters on penile erectile function.

METHODS AND MATERIALS

A total of 226 patients with preimplant erectile function determined by the International Index of Erectile Function (IIEF) questionnaire underwent permanent prostate brachytherapy in two prospective randomized trials between February 2001 and January 2003 for clinical Stage T1c-T2c (2002 American Joint Committee on Cancer) prostate cancer. Of the 226 patients, 132 were potent before treatment and, of those, 128 (97%) completed and returned the IIEF questionnaire after brachytherapy. The median follow-up was 29.1 months. Potency was defined as an IIEF score of > or =13. The clinical, treatment, and dosimetric parameters evaluated included patient age; preimplant IIEF score; clinical T stage; pretreatment prostate-specific antigen level; Gleason score; elapsed time after implantation; preimplant nocturnal erections; body mass index; presence of hypertension or diabetes mellitus; tobacco consumption; the volume of the prostate gland receiving 100%, 150%, and 200% of the prescribed dose (V(100/150/200)); the dose delivered to 90% of the prostate gland (D(90)); androgen deprivation therapy; supplemental external beam radiotherapy (EBRT); isotope; prostate volume; planning volume; and radiation dose to the proximal penis.

RESULTS

The 3-year actuarial rate of potency preservation was 50.5%. For patients who maintained adequate posttreatment erectile function, the preimplant IIEF score was 29, and in patients with brachytherapy-related ED, the preimplant IIEF score was 25. The median time to the onset of ED was 5.4 months. After brachytherapy, the median IIEF score was 20 in potent patients and 3 in impotent patients. On univariate analysis, the preimplant IIEF score, patient age, presence of nocturnal erections, and dose to the proximal penis predicted for postimplant erectile function. However, in multivariate analysis, only the preimplant IIEF score and the D(50) to the proximal crura were statistically significant predictors of brachytherapy-related erectile function.

CONCLUSIONS

Using a patient-administered validated quality-of-life instrument, brachytherapy-induced ED occurred in 50% of patients at 3 years. On multivariate analysis, preimplant erectile function and the D(50) to the proximal crura were the best predictors of brachytherapy-related erectile function. Because the proximal penis is the most significant treatment-related predictor of brachytherapy-related ED, techniques to minimize the radiation dose to the proximal penis may result in improved rates of potency preservation.

Radiation dose delivered to the proximal penis as a predictor of the risk of erectile dysfunction after three-dimensional conformal radiotherapy for localized prostate cancer

PURPOSE/OBJECTIVE

In this study, we evaluated in a serial manner whether radiation dose to the bulb of the penis is predictive of erectile dysfunction, ejaculatory difficulty (EJ), and overall satisfaction with sex life (quality of life) by using serial validated self-administered questionnaires.

METHODS AND MATERIALS

Twenty-nine potent men with AJCC Stage II prostate cancer treated with three-dimensional conformal radiation therapy alone to a median dose 72.0 Gy (range: 66.6-79.2 Gy) were evaluated by determining the doses received by the penile bulb. The penile bulb was delineated volumetrically, and the dose-volume histogram was obtained on each patient.

RESULTS

The median follow-up time was 35 months (range, 16-43 months). We found that for D(30), D(45), D(60), and D(75) (doses to a percent volume of PB: 30%, 45%, 60%, and 75%), higher than the corresponding median dose (defined as high-dose group) correlated with an increased risk of impotence (erectile dysfunction firmness score = 0) (odds ratio [OR] = 7.5, p = 0.02; OR = 7.5, p = 0.02; OR = 8.6, p = 0.008; and OR = 6.9, p = 0.015, respectively). Similarly, for EJD D(30), D(45), D(60), and D(75), doses higher than the corresponding median ones correlated with worsening ejaculatory function score (EJ = 0 or 1) (OR = 8, p = 0.013; OR = 8, p = 0.013; OR = 9.2, p = 0.015; and OR = 8, p = 0.026, respectively). For quality of life, low (< or =median dose) dose groups of patients improve over time, whereas high-dose groups of patients worsen.

CONCLUSIONS

This study supports the existence of a penile bulb dose-volume relationship underlying the development of radiation-induced erectile dysfunction. Our data may guide the use of inverse treatment planning to maximize the probability of maintaining sexual potency after radiation therapy.

Lesions of the periaqueductal gray block the medial preoptic area-induced activation of the urethrogenital reflex in male rats

The medial preoptic area (MPOA) is important for male sexual behavior, including erections and ejaculation. Stimulation of the MPOA evokes urethrogenital reflex-like responses. However, the descending pathways mediating this response are unknown. We examined the effect of bilateral lesions of the periaqueductal gray (PAG) on the MPOA-induced response. Electrical stimulation of the MPOA was used to induce rhythmic motor patterns of the bulbospongiosus muscle, discrete regions of the PAG were lesioned and the response to MPOA stimulation re-examined. These studies demonstrate that the descending pathway mediating the MPOA-induced activation of the urethrogenital reflex-like responses travel through and may relay in the PAG.

Erectile function following external beam radiotherapy for clinically organ-confined or locally advanced prostate cancer

BACKGROUND

External beam radiotherapy (XRT) has been a standard treatment for clinically localized prostate cancer. However, preservation of erectile function following XRT is controversial. In this study, the influence of XRT on erectile function of patients with clinically organ-confined or locally advanced prostate cancer was retrospectively evaluated.

METHODS

The study included 34 of 84 patients with organ-confined or locally advanced prostate cancer who underwent XRT between 1995 and 2002. Erectile function following radiotherapy was assessed by a simple mailed questionnaire that was constructed for the study. To determine the predictive factors for erectile dysfunction following radiotherapy, data were analyzed by multivariate analysis with the Cox proportional hazards model.

RESULTS

The modality of XRT was the only factor to independently predict erectile dysfunction following XRT. The maintenance rates of erectile function were 47.6% at 1 year and 19% at 3 years in patients who received the 3-dimensional conformal radiotherapy, which were significantly higher than in those who received conventional radiotherapy (P = 0.026).

CONCLUSIONS

XRT significantly reduced the maintenance rate of erectile function during the follow-up period, with the rate being 19% at 3 years in patients who received 3-dimensional conformal radiation. The XRT modality was involved in the reduction of erectile function. These results suggest that erectile dysfunction is a possible adverse event following XRT.

Longitudinal comparison of sexual function after 3-dimensional conformal radiation therapy or prostate brachytherapy

PURPOSE

The risk of erectile dysfunction can influence treatment decisions for localized prostate cancer. To estimate the risk from 2 popular radiotherapies we compared erectile function and overall satisfaction with sexual function after 3-dimensional (D) conformal radiation therapy and transperineal prostate brachytherapy.

MATERIALS AND METHODS

A total of 128 patients with prostate cancer underwent 3-D conformal radiation therapy (median dose 70.2 Gy. to the planning target volume) and 60 underwent palladium transperineal prostate brachytherapy (median dose 90 or 115 Gy. to 80% of the prostate with or without external nonconformal beam radiation therapy. Of the 128 patients 47 (37%) also received a luteinizing hormone releasing hormone (LH-RH) agonist (3 to 4 months), whereas 26 (43%) of the 60 patients received external beam radiation therapy and LH-RH (8 to 9 months). We evaluated erectile function and overall satisfaction with questions from validated, self-administered questionnaires. Patients responded to the questions serially before any prostate cancer therapy and at regular followup visits thereafter. We used the time until a patient returned to baseline erectile function and overall satisfaction to compare treatment modalities.

RESULTS

Median followup was 21 months. Of patients receiving 3-D conformal radiation therapy with or without LH-RH agonists 65% (95% CI 47% to 82%) and 67% (53% to 81%), respectively, returned to baseline overall satisfaction within 12 months after treatment versus 23% (9% to 50%) and 56% (38% to 75%) of the patients treated with transperineal prostate brachytherapy with or without external beam radiation therapy and LH-RH agonists, respectively. Reductions in overall satisfaction appeared to relate to changes in erectile function.

CONCLUSIONS

These data suggest that in the absence of LH-RH agonist use 3-D conformal radiation therapy and transperineal prostate brachytherapy have a similar impact on erectile function and overall satisfaction. Differences observed in erectile function and overall satisfaction in the 2 groups of patients who received adjuvant LH-RH may be due to the different duration of therapy (3 versus 8 months). Longer followup will be needed to evaluate this hypothesis.

Effects of extra-corporeal shock waves on penile hemodynamics and histopathology in rats

AIM

To study the effect of extra-corporeal shock wave (ESW) on the penile hemodynamics and histopathology in rats.

METHODS

Adult male Sprague-Dawley rats were divided at random into 3 groups. ESW application was performed with a Siemens Lithostar with the rats under anesthesia lying prone on the balloon probe. Rats in Group I received a total of 1000 shocks at 18 kV and immediately underwent hemodynamic evaluation performed by direct electrostimulation of the cavernous nerve and measurement of intracavernous pressure (ICP). Rats in Group II received 3 times 1000 shocks at 18 kV at weekly intervals and hemodynamic evaluation was performed 1 month after the last ESW application. Group III served as the control. Histopathological examinations of penile tissues were done on Masson's trichrome and hematoxylin and eosin stained sections.

RESULTS

Penile hemodynamic evaluation showed a trend toward a diminished mean maximal ICP, duration of erection, ICP during the plateau phase and maximal ICP/ blood pressure ratio in Group I, although there was no significant significance. The mean latency period in Groups I and II was prolonged. Petechial bleeding within tunical layers and small foci of hemorrhage within the corpora cavernosa were observed in Group I. However, histopathological examination failed to reveal any significant differences between the groups in terms of smooth muscle content, tunical thickness, organization of collagen bundles and elastic fiber-lattice framework.

CONCLUSION

ESW has certain damaging effects on the penis.

Meta-analysis of rates of erectile function after treatment of localized prostate carcinoma

PURPOSE

The results of a 1997 meta-analysis of the rates of erectile function after external beam radiotherapy (EBRT) and radical prostatectomy have been widely used in patient and professional education materials and as a reference against which new findings are compared. With a number of recent publications, it is now possible to update this analysis and compare brachytherapy with or without EBRT with EBRT alone, standard and nerve-sparing radical prostatectomy, and cryotherapy.

METHODS

A comprehensive literature review and subsequent meta-analysis of the rates of erectile dysfunction associated with the treatments of localized prostate carcinoma was conducted. A simple logistic regression analysis was used to combine the data from the 54 articles that met the selection criteria.

RESULTS

The predicted probability of maintaining erectile function after brachytherapy was 0.76, after brachytherapy plus EBRT 0.60, after EBRT 0.55, after nerve-sparing radical prostatectomy 0.34, after standard radical prostatectomy 0.25, and after cryotherapy 0.13. When only studies reporting > or = 2 years follow-up were considered, the only significant change was a decline in the probability for nerve-sparing radical prostatectomy. No brachytherapy studies had a follow-up of > or = 2 years. When the probabilities were adjusted for age, the spread between the RT methods and surgical approaches was greater.

CONCLUSION

The differences in the probability of maintaining erectile function after different treatments of localized prostate cancer are significant.

High-dose rate brachytherapy of prostatic adenocarcinoma in combination with external beam radiotherapy a long-term follow-up of the first 50 patients at one center

AIM

To report the long-term follow-up of 50 patients with prostatic adenocarcinoma (PAC) treated by high-dose rate brachytherapy in combination with external beam radiotherapy.

PATIENTS AND METHODS

Between 1988 and 1995, 50 patients were treated with external beam radiotherapy delivered in 2 Gy fractions to a total dose of 50 Gy. Brachytherapy was delivered in two 10 Gy fractions. The mean follow-up time was 7.2 years.

RESULTS

42 patients are alive and four patients have deceased of prostatic adenocarcinoma. Of the remaining patients, 40 have a PSA < 1 ng/l. 41 patients were interviewed during the year 2000 and 91% of these were satisfied with the treatment. Four (8%) patients reported grade III/IV side effects. Ten of the 41 patients reported that they still had an erection allowing intercourse. Half of those who developed an erectile dysfunction did so in direct connection with the treatment. In the others erectile dysfunction developed gradually during the first 48 months after the treatment.

CONCLUSION

The combined treatment gave an exceptionally good local control (86%). The method represents a promising curative treatment, but the effect can be double edged. The small number of patients in this study restricts a more conclusive statement concerning this treatment modality.

Post-nerve-sparing prostatectomy, dose-escalated intensity-modulated radiotherapy: effect on erectile function

PURPOSE

The advent of widespread prostate-specific antigen screening has resulted in more younger, potent men being diagnosed with early-stage, organ-confined prostate cancer amenable to definitive surgery. Nerve-sparing prostatectomy is a relatively new surgical advance in the treatment of prostate cancer. Very few data exist on the effect of postoperative radiotherapy (RT) on erectile function after nerve-sparing prostatectomy. They are based on conventional techniques using moderate doses of radiation, 45-54 Gy. Intensity-modulated RT (IMRT) is becoming more widespread because it allows dose escalation with increased sparing of the surrounding normal tissue. We investigated the effect of postprostatectomy, high-dose IMRT on patients' erectile function.

METHODS AND MATERIALS

A review of patient records found 51 patients treated between April 1998 and December 2000 with IMRT after unilateral or bilateral nerve-sparing prostatectomy. The pathologic disease stage in these patients was T2 in 47.4% and T3 in 52.6%. Postoperatively, 4 patients received hormonal ablation consisting of one injection of Lupron Depot (30 mg) 2 months before RT. The median age was 65 years (range 46-77) at the time of RT. The prescribed dose was 64 Gy (range 60-66). The mean dose was 69.6 Gy (range 64.0-72.3). Erectile function was assessed before and after RT by questionnaires. Sexual potency was defined as erectile rigidity adequate for vaginal penetration.

RESULTS

Of the 51 patients, 18 (35.3%) maintained their potency and 33 (64.7%) became impotent after nerve-sparing prostatectomy. Patients who underwent bilateral nerve-sparing prostatectomy had higher rates of postoperative potency than did those who underwent unilateral nerve-sparing surgery (72.2% vs. 27.8%; p = 0.025). The follow-up for the entire group was 19.5 months. All 18 patients (100%) who were potent postoperatively remained potent after RT. The median follow-up for the 18 potent patients was 27.2 months, significantly longer than that of the impotent group, 13.0 months (p <0.001).

CONCLUSION

This is the first report on the effects of dose-escalated IMRT on men who have undergone nerve-sparing prostatectomy. Despite the high dose (mean dose 69.6 Gy) to the prostate bed and nerves, postoperative IMRT had no negative effect on erectile function for the patients who remained potent after nerve-sparing prostatectomy. Longer term follow-up and a larger cohort of patients are warranted to confirm these findings.

Does hormonal therapy influence sexual function in men receiving 3D conformal radiation therapy for prostate cancer?

PURPOSE

We evaluated the effect of three-dimensional conformal radiation therapy (3D-CRT) with or without hormonal therapy (HT) on sexual function (SF) in prostate cancer patients whose SF was known before all treatment.

METHODS AND MATERIALS

Between March 1996 and March 1999, 144 patients received 3D-CRT (median dose = 70.2 Gy, range 66.6-79.2 Gy) for prostate cancer and had pre- and post-therapy SF data. All SF data were obtained with the O'Leary Brief SF Inventory, a self-administered, multidimensional, validated instrument. We defined total sexual potency as erections firm enough for penetration during intercourse. Mean follow-up time was 21 months (SD +/- 11 months). The Wilcoxon signed-rank test was used to test for significance of the change from baseline.

RESULTS

Before 3D-CRT, 87 (60%) of 144 men were totally potent as compared to only 47 (47%) of 101 at 1-year follow-up. Of the 60 men totally potent at baseline and followed for at least 1 year, 35 (58%) remained totally potent. These changes corresponded to a significant reduction in SF (p < 0.05). Patients who had 3D-CRT alone were more likely to be totally potent at 1 year than those receiving 3D-CRT with HT (56% vs. 31%, p = 0.012); however, they were also more likely to be potent at baseline (71% vs. 44%, p = 0.001). Although these two groups had a significant reduction in SF from baseline, their change was not significantly different from each other.

CONCLUSION

These data indicate that 3D-CRT causes a significant reduction in total sexual potency as compared to pretreatment baseline. The addition of HT does not appear to increase the risk of sexual dysfunction.

Update on impact of moderate dose of adjuvant radiation on urinary continence and sexual potency in prostate cancer patients treated with nerve-sparing prostatectomy

OBJECTIVES

Adjuvant radiotherapy to the prostatic bed at moderate doses of 45 to 54 Gy achieves results comparable to higher doses. We studied the effect of moderate doses of postoperative radiation therapy on urinary continence and sexual potency in prostate cancer patients who had undergone nerve-sparing prostatectomy.

METHODS

Between November 1983 and December 1992, 255 prostate cancer patients were selected to undergo nerve-sparing prostatectomy. A total of 94 (37%) patients had received adjuvant postoperative radiotherapy, 45 to 54 Gy to the prostatic bed, based on microscopic positive margins, seminal vesicle involvement, and/or Gleason score. Subjective patient reports regarding the potency and urinary continence status were recorded during a semistructured telephone interview at 3 or more years after treatment. The findings in irradiated and nonirradiated patients were compared and correlated to those obtained from the same patients preoperatively and 1 year postoperatively.

RESULTS

At 3 or more years of follow-up no significant difference among irradiated and nonirradiated patients was detected. Most patients described optimal urinary continence and approximately one third had maintained potency after bilateral nerve-sparing prostatectomy. None of the patients who had undergone unilateral nerve-sparing surgery remained potent. Using a multivariable analysis, the significant predictors for maintaining potency were the status at 1 year postoperatively and bilateral versus unilateral nerve-sparing procedure.

CONCLUSIONS

Doses of adjuvant radiation therapy in the range used (45 to 54 Gy) did not affect the long-term pattern of maintenance of either function.

Erectile function and quality of life after interstitial radiation therapy for prostate cancer

Few studies have evaluated erectile function after interstitial radiation therapy for localized prostate cancer. Using a validated quality of life questionnaire, we assessed post-treatment erectile function and its relationship to treatment satisfaction and quality of life. We retrospectively reviewed the records of 171 consecutive patients who underwent Pd-103 or I-125 brachytherapy for prostate cancer between December 1992 and June 1998. Seventy percent of patients received neoadjuvant androgen deprivation therapy. All patients were mailed a validated questionnaire assessing sexual function and overall quality of life (UCLA Prostate Cancer Index and SF-36). Sixty-seven percent of all questionnaires were available for evaluation (114/171). The mean age was 69.1 y with a mean follow-up of 23 months (range 4-72, median 24). Seventy-one percent of patients (81/114) had pre-treatment erections sufficient for sustained vaginal penetration. Of these patients, potency was maintained in 49% of men (40/81). An additional 26% had erections firm enough for foreplay but not penetration (21/81). Erectile dysfunction rates were significantly lower in younger patients (48%) vs older patients (55%). There was no difference in post-treatment potency between men who received neoadjuvant hormonal therapy and those who did not (P>0.05). In addition, there were no differences in physical function (86, scale 0-100), general health perception (78), emotional well-being (83), energy/fatigue (74), and overall satisfaction (84) between men with erectile dysfunction and those without. In summary, two years following brachytherapy 25% of patients complained of complete (20/81) or partial (26%, 21/81) erectile dysfunction, for an overall rate of 51% (41/81). Short-term neoadjuvant hormonal therapy (<3-6 months) did not increase the likelihood of post-treatment erectile dysfunction. Interestingly, overall satisfaction rates among brachytherapy patients were high (84/100) and surprisingly did not correlate with post-treatment sexual function.

Potency preservation after three-dimensional conformal radiotherapy for prostate cancer: preliminary results

We sought to assess potency preservation after three-dimensional conformal radiotherapy (3D-CRT) in prostate cancer patients eligible for radical prostatectomy, conventional radiotherapy, 3D-CRT, or transperineal prostate implantation. Patients with more advanced disease are commonly treated with hormonal therapy, which can cause impotence, and were consequently excluded from the analysis. Between December 1991 and June 1998, 198 prostate cancer patients were treated with 3D-CRT at the University of California, Davis Medical Center. Fifty-two of these patients had a pretreatment prostate-specific antigen (PSA) level of 10.0 ng/ml or less, a Gleason score of 6 or less, and a 1997 AJCC clinical stage T1bN0M0 to T2bN0M0. One patient was not evaluable. None of the 51 evaluable patients had diabetes mellitus. In 40 patients, the prostate gland only was irradiated to a total dose of 66 to 79.2 Gy by using daily 1.8-Gy fractions. In 11 patients, the prostate and seminal vesicles were treated to 44 to 55.8 Gy. Lymph nodes were not included in the clinical target volume. The median age was 68 years, and the median length of follow-up was 15 months. Potency in this study is defined as an erection sufficient for vaginal penetration. Kaplan-Meier analysis was used to describe potency as a function of time after 3D-CRT. Of the 51 evaluable patients, 35 (69%) were potent, 15 were impotent, and 1 was sexually inactive before 3D-CRT. Kaplan-Meier estimates of the potency preservation rates 1, 2, and 3 years after 3D-CRT are 100%, 83%, and 63%, respectively. On multivariate analysis, age, total radiation dose, and a history of transurethral resection of the prostate did not significantly affect potency preservation rates. Three (43%) of 7 patients who became impotent after 3D-CRT and used sildenafil were subsequently able to achieve erections sufficient for vaginal penetration. The preliminary results reported herein suggest that approximately two thirds of prostate cancer patients will retain their potency 3 years after 3D-CRT. Further follow-up is necessary to assess long-term potency after 3D-CRT. Sildenafil should be considered in patients who develop radiation-induced impotence.

In the radiotherapy of prostate cancer, technique determines the doses to the penile structures

For 11 consecutive prostate cancer patients undergoing three-dimensional conformal radiotherapy (3DCRT) in our institution, penile structures (PNS) were outlined in CT images obtained for treatment planning purposes. Dose-volume histograms (DVHs) were compared in order to study dose-volume relations for three techniques: 4FLD, an axial coplanar, four-field box technique; 6FLD, a six-field coplanar technique; and 4NAX, a coplanar but non-axial, four-field technique. All three techniques delivered equal doses to the planning target volumes (PTV). Our statistical analyses strongly indicate that the three techniques can be ranked as 6FLD better than 4FLD (and 4FLD better than 4NAX) as far as irradiating PNS volume during treatment of prostate cancer (PC) is concerned. For each technique, there is a "spread" owing to differences in patient anatomy and/or target size, position, and extent, but each technique has a similar "profile" or "shape" distinct from other techniques. Whether irradiating smaller volumes of PNS will influence the sexual potency outcome remains to be demonstrated. However, PNS should be considered as another critical structure in addition to rectum, bladder and femoral heads in the radiotherapy (RT) of PC, especially in 3DCRT dose escalation studies. Sexual potency outcomes can be correlated to dose-volume relations in the future and this will help refine radiotherapy techniques further.

Sexual function following radical radiotherapy for bladder cancer

BACKGROUND AND PURPOSE

The effect of radical radiotherapy (RT) for bladder cancer on sexual function has not been previously investigated. The current study was designed as a pilot to assess sexual function in males pre- and post-radiotherapy.

MATERIALS AND METHODS

An anonymous questionnaire was devised to examine the following sexual domains: libido, frequency of sexual function, erectile capacity, orgasm and ejaculation in the 6 months prior to radiotherapy and following treatment. Serum testosterone, FSH and LH were measured in 10 patients.

RESULTS

Eighteen patients completed the questionnaire from 10 to 56 months following irradiation, 13 of whom were able to achieve an erection prior to RT. Over half of these patients noted a decline in the quality of erections after RT, with a similar proportion noting decreased libido and frequency of sexual activity. Three patients lost the ability to have any erections whatsoever. Of the 10 patients retaining erectile capacity, three noted reduced frequency of early morning erections suggesting a physical aetiology, five had decreased frequency of ejaculation and four had reduced intensity of orgasms. Seventy-one percent (12/17) felt their sex life was worse following RT but only 56% (9/16) were concerned about the deterioration. Testosterone levels were normal in all but one patient.

CONCLUSIONS

Radical RT to the bladder can cause a decrease in sexual function in males.

Elucidating the etiology of erectile dysfunction after definitive therapy for prostatic cancer

PURPOSE

To determine the etiology of treatment-induced erectile dysfunction among patients who underwent surgery or radiotherapy for prostatic cancer.

METHODS AND MATERIALS

Ninety-eight patients were evaluated for erectile dysfunction after definitive therapy for prostate cancer with Duplex ultrasonography before and after intracorporal prostaglandin injection. Patients were classified as having arteriogenic, cavernosal, mixed (arteriogenic/cavernosal), or neurogenic impotence based upon the results of the Duplex studies.

RESULTS

Among patients who underwent radical prostatectomy (RP), 31 (52%) had cavernosal dysfunction, 19 (32%) had arteriogenic dysfunction, 3 (5%) were classified as mixed, and 7 (12%) as neurogenic dysfunction. Among patients treated with radiotherapy (RT), 24 (63%) had arteriogenic dysfunction, 12 (32%) had cavernosal dysfunction, 1 (2.5%) were classified as mixed, and 1 (2.5%) as neurogenic dysfunction. A multivariate analysis identified prior RT as the only predictor of an arteriogenic etiology (p < 0.001) and prior RP as the only predictor of a cavernosal etiology (p < 0.04) for erectile dysfunction among these patients. In the RP and RT groups, the median erectile responses were 70 and 65%, respectively. Arterial peak flows < 25 cc/min predicted for a suboptimal erectile response with intracavernosal prostaglandin injections. Among 47 patients with arterial peak flows < 25 cc/min, 21 (55%) had erectile responses of < 70%, while for 51 patients with arterial peak flows > or = 25 cc/min, 31 (39%) had erectile responses of < 70% (p < 0.039).

CONCLUSIONS

While the etiology of erectile dysfunction after definitive therapy for prostatic cancer is likely a multifactorial phenomenon, these data suggest that the predominant etiology among patients who undergo RT is arteriogenic and among patients who undergo RP is veno-occlussive/cavernosal pathology. This information may have implications for the design of more effective therapies to address erectile dysfunction in this patient population.

Combined treatment with temporary short-term high dose rate iridium-192 brachytherapy and external beam radiotherapy for irradiation of localized prostatic carcinoma

PURPOSE

To evaluate the treatment outcome after radical radiotherapy of localized prostate cancer in 50 patients (38 patients with stage T1-2 and 12 patients with stage T3) after a median follow-up time of 45 months (range 18-92 months).

METHODS

The treatment was given by combination of external beam radiotherapy (50 Gy) and brachytherapy (2 x 10 Gy). The brachytherapy was given using TRUS-guided percutaneously inserted temporary needles with a high dose rate remote afterloading technique with Ir-192 as the radionuclide source. Three target definitions and dose levels inside the prostate gland were used. Local control was evaluated by digital rectal examination, TRUS-guided biopsies and serum PSA evaluations.

RESULTS

Clinical and biopsy verified local control was achieved in 48 of the 50 (96%) patients; for stage T1-2 in 37 of 38 (97%) patients and for stage T3 in 11 of 12 (92%) patients. A posttreatment serum PSA level < or =1.0 ng/ml was seen in 42 (84%) patients, values from >1.0 to < or =2.0 ng/ml were seen in four (8%) patients and values exceeding 2.0 were seen in four (8%) patients. The late toxicity was minimal.

CONCLUSION

The local control results and the minimal toxicity after the combined radiotherapy treatment are promising. However, long term results are necessary before general use.

Potency probability following conformal megavoltage radiotherapy using conventional doses for localized prostate cancer

PURPOSE

Impotence is a familiar sequela of definitive external beam radiation therapy (EBRT) for localized prostate cancer; however, nerve-sparing radical prostatectomy (NSRP) has offered potency rates as high as 70% for selected for patients in several large series. To the authors' knowledge, age and stage-matched comparisons between the effects of EBRT and NSRP upon the normal age trend of impotence have not been performed. Herein, we report the change in potency over time in an EBRT-treated population, determine the significantly predisposing health factors affecting potency in this population, and compare age and stage-matched potency rates with those of normal males and prostatectomy patients.

METHODS AND MATERIALS

Our results are obtained from a retrospective study of 114 patients ranging in age from 52 to 85 (mean, 68) who were diagnosed with clinical stages A-C C (T1-T4N0M0) prostate cancer and then treated conformally with megavoltage x-rays to 6500-7000 cGy (180-200 cGy per fraction) using the four-field box technique. Information concerning pre-RT potency, medical and surgical history, and medications was documented for each patient as was time of post-RT change in potency during regular follow-up. The median follow-up time was 18.5 months.

RESULTS

The actuarial probability of potency for all patients gradually decreased throughout post-RT follow-up. At months 1, 12, 24, and 36, potency rates were 98, 92, 75, and 66%, respectively. For those patients who became impotent, the median time to impotence was 14 months. Factors identified from logistic regression analysis as significant predictors of post-EBRT impotence include pre-EBRT partial potency (p < 0.001), vascular disease (p < 0.001), and diabetes (p = 0.003). Next, an actuarial plot of potency probability to patient age for the EBRT-treated population was compared to that obtained from the Massachusetts Male Aging Study of normal males. The two curves were not significantly different (logrank test, p = 0.741) between ages 50 and 65. Finally, potency probability after follow-up of 1 year or more in EBRT-treated patients was stratified by age and substratified by clinical stage and then compared to similarly stratified potencies for patients treated with NSRP. The prostatectomy data were derived from the pooled data of six large (total n, 952), independent series conducted at academic centers. For patients older than 70 years, 79.1% of EBRT patients and 32.9% of NSRP patients remained potent after treatment. For patients with stage B2 disease, 75.0% of EBRT patients and 49.3% of NSRP patients remained potent after treatment. Overall EBRT patient potency was 76.1% vs. 66.2% for NSRP patients.

CONCLUSIONS

1) By 36 months after completion of EBRT for localized prostate cancer, fully one-third of all patients becomes impotent; however, for patients younger than 70 years, the probability of impotence does not depart significantly from that for normal males. 2) In the EBRT-treated population, pre-EBRT partial potency, vascular disease, and diabetes are the most significant predispositions to the development of impotence. Patients with these predispositions, though, do not become impotent significantly earlier than other patients. 3) When comparing age and stage-stratified potency rates for EBRT and NSRP patients, potency is roughly equal for both modalities for most age and stage groups; however, for patients older than 70 years or with stage B2 disease, EBRT offers notably higher posttreatment potency rates than NSRP. Thus, for the treatment of localized prostate cancer, EBRT may not affect the normal age trend of impotence in younger patients and may induce impotence less frequently than NSRP in older patients or in patients with later stage disease.

Erectile functioning of men treated for prostate carcinoma

BACKGROUND

Published reports of complication rates, such as erectile dysfunction, associated with treatments for prostate carcinoma are often used to guide patient decision-making and develop clinical guidelines. Unfortunately, the published data are largely comprised of case series from single institutions. Meta-analysis is a methodology for combining findings from several studies to produce a better result.

METHODS

A comprehensive literature review and subsequent meta-analysis of the rates of erectile dysfunction associated with external beam radiotherapy and radical prostatectomy was conducted. A simple logistic regression model was used to combine the data from 40 articles that met selection criteria.

RESULTS

The probability of maintaining erectile functioning after radiotherapy is 0.69. The probability after surgery is 0.42. This difference is significant. Analysis of the effects of variables such as patient age and stage of disease on erectile functioning could not be performed due to inconsistencies across studies and the limited number of studies reporting such variables.

CONCLUSIONS

The published data indicate that men with normal erectile functioning are more likely to retain this function after radiotherapy than after surgery. Attention is drawn to the weaknesses in the reviewed studies in the hope that the clinical trials of emerging treatments, such as cryotherapy, brachytherapy, three-dimensional conformal radiotherapy, and neoadjuvant hormones can be strengthened to reflect more accurately the rate of treatment-associated erectile dysfunction.

103Pd brachytherapy and external beam irradiation for clinically localized, high-risk prostatic carcinoma

PURPOSE

To summarize biochemical failure rates and morbidity of external beam irradiation (EBRT) combined with palladium (103Pd) boost for clinically localized high-risk prostate carcinoma.

METHODS AND MATERIALS

Seventy-three consecutive patients with stage T2a-T3 prostatic carcinoma were treated from 1991 through 1994. Each patient had at least one of the following risk factors for extracapsular disease extension: Stage T2b or greater (71 patients), Gleason score 7-10 (40 patients), prostate specific antigen (PSA) > 15 (32 patients), or elevated prostatic acid phosphatase (PAP) (17 patients). Patients received 41 Gy EBRT to a limited pelvic field, followed 4 weeks later by a 103Pd boost (prescription dose: 80 Gy). Biochemical failure was defined as a PSA greater than 1.0 ng/ml (normal < 4.0 ng/ml). Patients whose PSA was still decreasing at the last follow-up were censored at that time. Patients whose PSA plateaued at a value greater than 1.0 were scored as failures at the time the PSA first plateaued.

RESULTS

The overall, actuarial freedom from biochemical failure at 3 years after treatment was 79%. In Cox proportional hazard multivariate analysis, the strongest predictor of failure was elevated acid phosphatase (p = 0.04), followed by PSA (p = 0.17), Stage (p = 0.23), and Gleason score (p = 0.6). Treatment-related morbidity was usually limited to temporary, RTOG Grade 1-2 urinary symptoms. One patient, who had both a transurethral incision of the prostate (TUIP) and a transurethral resection of the prostate (TURP), developed low-volume urinary incontinence. The actuarial potency rate at 3 years after implantation was 77% for 46 patients who were sexually potent prior to implant.

CONCLUSION

Biochemical freedom from failure rates following combined EBRT and 103Pd brachytherapy for clinically localized, high-risk prostate cancer compare favorably with that reported after conventional dose EBRT alone. Morbidity has been acceptable.

Potency following conformal neutron/photon irradiation for localized prostate cancer

PURPOSE

To assess the effect of conformal neutron/photon irradiation with or without neoadjuvant hormonal therapy on posttreatment potency.

MATERIALS AND METHODS

Seventy-six patients with localized adenocarcinoma of the prostate, State T1 or T2 N0 M0, Gleason score < or = 7, were enrolled on a prospective Phase II study. Each patient received 9-10 Neutron + 38 Photon Gy. Twenty-eight patients received neoadjuvant hormonal therapy in conjunction with radiation therapy. Potency was assessed prior to starting treatment and was assessed at each subsequent follow-up visit.

RESULTS

Fifty-two of patients (70%) were potent at the start of therapy. Thirty-eight of 52 (73%) had functional erections and 14 of 52 (27%) had erections termed nonfunctional, which were of insufficient strength for intercourse. After treatment, 35 of 52 (67%) retained potency. Twenty-nine of 38 (76%) with functional erections pretreatment maintained this ability. Only 6 of 14 patients (43%) with nonfunctional erection pretreatment maintained their level of potency. Neoadjuvant hormonal therapy did not impact on the ability to maintain erections. Sixty-five percent of those patients receiving hormones retained erectile function, while 69% of those who did not receive hormones maintained erectile function. Age was not a significant factor in posttreatment potency, although a trend towards potency in younger patients was observed. (p = 0.74).

CONCLUSION

The majority (67%) of patients maintained their level of erectile function following conformal sequential neutron photon irradiation. This is comparable to that achieved with photon irradiation alone. No significant change in potency was seen with neoadjuvant hormonal therapy or with increasing patient age.

Sexual potency following interactive ultrasound-guided brachytherapy for prostate cancer

PURPOSE

The effect of a therapeutic modality on sexual potency is often an important consideration for patients choosing a treatment for prostate cancer. We prospectively assessed patients' penile erectile function before and following interactive ultrasound-guided transperineal permanent radioactive seed implantation to determine its effect on sexual function.

METHODS AND MATERIALS

Eighty-nine patients underwent permanent radioactive seed implantation from June 1990 to April 1994 for localized prostate cancer (T1-T2) and were followed for a median of 15 months (1.5-52 months). 125I seeds were implanted in 73 patients with a combined Gleason grade of 2-6, and 103Pd seeds were implanted in 16 patients with higher grade lesions. The sexual potency of these patients was assessed prior to, at 3 and 6 months, and every 6 months after implantation. Erectile function was graded using a numerical score of 0 to 3 (0 = impotent (no erections), 1 = ability to have erections but insufficient for vaginal penetration, 2 = erectile function sufficient for vaginal penetration but suboptimal, 3 = normal erectile function). The pretreatment potency scores were as follows: 0 in 24 patients, 1 in 6 patients, 2 in 22 patients, and 3 in 37 patients.

RESULTS

The actuarial impotency rates (score = 0) following implantation for those patients possessing some degree of erectile function prior to implantation (65 patients) were 2.5% at 1 year and 6% at 2 years. The actuarial decrease in sexual function rates (a drop in score of at least one point) were 29% at 1 year and 39% at 2 years. Only two patients became impotent following treatment and this occurred at 1 year and 16 months. The time period for a decrease in erectile function to occur ranged from 1.8 months to 32.7 months, with a median of 6.8 months. Patients with higher grade tumors showed a greater decrease in potency score compared to patients with lower grade tumors.

CONCLUSION

Interactive ultrasound-guided transperineal brachytherapy for the treatment of localized prostate cancer is associated with preservation of erectile function in the vast majority of patients, although a minor decrease in potency is not uncommon.

Effect of pelvic radiotherapy for prostate cancer on bowel, bladder, and sexual function: the patient's perspective

OBJECTIVES

To document the effects of pelvic radiotherapy on bowel, bladder, and sexual function, as reported by the patient.

METHODS

A confidential questionnaire was distributed to 202 prostate cancer patients. Mean age was 70 years (range, 49 to 87) and mean follow-up was 33 months (range, 12 to 72). Radiation was given by a standard four field box technique on a linear accelerator to 60 to 66 Gy over 6.5 weeks. Treatment was limited to the prostate and seminal vesicles for small well-differentiated tumors, but otherwise included internal and external iliac nodes.

RESULTS

Responses were obtained from 192 patients (95%). No or mild change in bowel function was reported by 64% of patients, 25% reported moderate change, and 11% reported severe change. Rectal urgency was a concern for 20%, and 5% reported fecal soiling in the preceding 6 months. Hematochezia at least once a week was reported by 9% and daily by 5%. Frequent hematochezia decreased from 17% in the second and third post-treatment years to 4% after 3 years (P = 0.02). Transfusions or laser surgery for proctitis was required by 4%. No patient required a colostomy for rectal complications. Urinary stream was unchanged or improved for 83%. Nocturia was unchanged or improved in 70%. Some form of protection for urinary incontinence was required by 2%, and 0.5% noted frequent hematuria and 2% moderate to severe dysuria. Potency prior to radiotherapy was reported by 82% and was lost following radiotherapy in 35%. Technical factors, including treatment volumes and total dose, did not correlate to the risk of moderate or severe complications.

CONCLUSIONS

The sequelae of pelvic radiotherapy as viewed from the patient's perspective reveal a major alteration in bowel function in 11%, significant bladder symptoms in 4%, and loss of potency in 35%.

Changes in sexual function after radiotherapy treatment of prostate cancer

OBJECTIVE

To assess sexual function before and after definitive irradiation for the treatment of cancer of the prostate.

PATIENTS AND METHODS

The study comprised 67 patients (mean age 68 years) treated in five radiotherapy departments and assessed with repeated questionnaires about their libido, arousal, frequency and quality of intercourse, and sexual satisfaction. Interviews were obtained before radiotherapy and at the end of the first year after treatment. Sixty-three patients were married and 50 had a sexually effective partner. Forty-six patients presented with another pathology or medical treatment capable of inducing sexual dysfunction. Before radiotherapy, 40 patients were sexually active, with good to acceptable intercourse.

RESULTS

Between 10 and 24 months after the end of radiotherapy, no disease progression was observed and prostate-specific antigen levels remained high in only two patients. Sexual function was preserved in 67% of patients but only 50% observed no change. The functional prognosis seemed to be related to the initial frequency and quality of intercourse; more than three times per month, the prognosis remained good, under three per month, it was poor. The patient's age was a predictive factor for the frequency of intercourse.

CONCLUSION

Several causes of impairment of sexual function may be associated and can change over a long time. A longer survey should be conducted to analyse the organic response to radiation.

Potency following high-dose three-dimensional conformal radiotherapy and the impact of prior major urologic surgical procedures in patients treated for prostate cancer

PURPOSE

To assess the impact of high-dose three-dimensional conformal radiotherapy (3DCRT) on potency in patients treated for clinically localized prostate cancer and to identify factors that might predict the outcome of sexual function following treatment.

METHODS AND MATERIALS

One hundred twenty-four consecutive patients treated with 3DCRT for localized prostate cancer at UCSF between 1991-1993 were included in this retrospective analysis. Patient responses were obtained from a mailed questionnaire, telephone interviews, or departmental records. Medial follow-up was 21 months.

RESULTS

Sixty patients reported having sexual function prior to 3DCRT, including 47 who were fully potent and 13 who were marginally potent. Of the remaining 64 patients, 45 were impotent, 7 were on hormones, 1 was status-postorchiectomy, and 11 were not evaluable. Following 3DCRT, 37 of 60 patients (62%) retained sexual function sufficient for intercourse. Of those with sexual function before irradiation, 33 of 47 (70%) of patients fully potent and 4 of 13 (31%) of patients marginally potent maintained function sufficient for intercourse (p < 0.01). Potency was retained in 6 of 15 (40%) patients with a history of a major urologic surgical procedure (MUSP) and in 31 of 45 (69%) with no history of a MUSP (p < 0.04). Transurethral resection of the prostate was the MUSP in eight of these patients, with four (50%) maintaining sexual function.

CONCLUSIONS

Patients who receive definitive 3DCRT for localized prostate cancer appear to maintain potency similar to patients treated with conventional radiotherapy. However, patients who are marginally potent at presentation or who have a history of a MUSP appear to be at increased risk of impotence following 3DCRT.

Decreased sexual capacity after external radiation therapy for prostate cancer impairs quality of life

PURPOSE

The aim of this study was to assess to what extent patients treated with radiation therapy for prostate cancer experience change in sexual functioning and to what extent this effects quality of life.

METHODS AND MATERIALS

Information was provided by 53 men treated with radiation therapy for localized prostate cancer. Assessment was made with the "Radiumhemmets Scale of Sexual Functioning," which measures sexual desire, erectile capacity, orgasm, and to what extent a decrease in any of these aspects of sexual functioning affects quality of life. Function before treatment was assessed retrospectively.

RESULTS

Sexual desire diminished among 77% after treatment. The erection stiffness decreased in 77%. Before external radiation therapy, 66% had an erection usually sufficient for intercourse. Half of the men lost this ability after treatment. Of those retaining orgasm after treatment, 47% reported a decreased orgasmic pleasure and 91% a reduced ejaculation volume. Of all men, 50% reported that quality of life had decreased much or very much due to a decline in the erectile capacity following external radiation therapy.

CONCLUSION

The results of the present study indicate that external radiation therapy for prostate cancer is associated with a reduction in sexual desire, erectile capacity, and organism functions. In a majority of patients this reduces quality of life. Previously, we may have underestimated the importance an intact sexual function has for the quality of life in this patient category of elderly men.

Radiation-induced decrease in nitric oxide synthase--containing nerves in the rat penis

PURPOSE

Evaluate effect of prostatic irradiation on erectile function.

MATERIALS AND METHODS

Forty-seven male adult rats were divided into three groups according to a single radiation dose to the prostate: control (no irradiation) (n = 15), 1,000 cGy (n = 15), and 2,000 cGy (n = 17). Five months after irradiation, rats underwent evaluation of penile vascularity and of erectile response to central and peripheral stimulation. After the study a proximal-shaft penile segment was obtained for staining.

RESULTS

Histologic evaluation demonstrated that, with increasing radiation, the number of nitric oxide synthase-containing nerve fibers per penile segment decreased significantly: control, 225.6 +/- 9.7; 1,000 cGy, 156.3 +/- 12.0; 2,000 cGy, 85.8 +/- 10.1 (standard error of the mean). Maximal intracavernous pressure induced with electrostimulation decreased significantly with increasing radiation dose. After injection of papaverine, maximal intracavernous pressure was significantly decreased in only the 2,000-cGy group.

CONCLUSION

A dose of 2,000 cGy over the prostatic bed induces erectile dysfunction by causing defects in the vascular supply of the erectile tissue and in the nerves and smooth muscle.