Radiation oncology: cancer of the prostate

Sexual function after external-beam radiotherapy for prostate cancer: What do we know?

Quality of life in general and sexual functioning in particular have become very important in cancer patients. Due to modern surgical techniques, improved quality of drugs for chemotherapy and very modern radiation techniques, more patients can be successfully treated without largely compromising sexual functioning. One can assume that because of the life-threatening nature of cancer, sexual activity is not important to patients and their partners, but this is not true. Prostate cancer has become the most common non-skin malignant neoplasm in older men in Western countries. In this paper, we discuss the various methods used to evaluate erectile and sexual dysfunction and the definition of potency. Data on the etiology of erectile dysfunction after external-beam radiotherapy for prostate cancer is reviewed, and the literature is been summarized. Patients should be offered sexual counseling and informed about the availability of effective treatments for erectile dysfunction, such as sildenafil, intracavernosal injection, and vacuum devices. Cancer affects quality of life and sexual function. The challenge for oncologists is to address this with compassion.

Sexual (dys)function after radiotherapy for prostate cancer: a review

PURPOSE

Prostate cancer has become the most common nonskin malignant neoplasm in older men in Western countries. As treatment efficacy has improved, issues related to posttherapy quality of life and sexual functioning have become more important.

METHODS AND MATERIALS

We discuss the various methods used to evaluate erectile and sexual dysfunction and the definition of potency. The etiologies of erectile dysfunction after external beam radiotherapy and brachytherapy for prostate cancer are also reviewed. The literature is summarized, and comparative studies of radiation and surgery are surveyed briefly.

RESULTS

Rates of erectile dysfunction vary from 6 to 84% after external beam radiotherapy and from 0 to 51% after brachytherapy. In most of the studies, the analysis is retrospective, the definition of erectile dysfunction is not clear, only one question about sexual functioning is asked, and nonvalidated instruments are used. The etiology of erectile dysfunction after radiation for prostate cancer is not completely understood.

CONCLUSIONS

Because erectile function is only one component of sexual function, it is necessary to assess sexual desire, satisfaction, frequency of intercourse, and other such factors when evaluating the effects of therapy. Patients should be offered sexual counseling and informed about the availability of effective treatments for erectile dysfunction, such as sildenafil, intracavernosal injection, and vacuum devices.

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.

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.

Sexual function disorders after local radiotherapy for carcinoma of the prostate

In order to contribute some insight into the extent to which local radiotherapy for carcinoma of the prostate is followed by disorders in sexual functioning, 18 patients whose age ranged from 60 to 82, were interviewed 4 to 45 months after their Radiotherapy (RT). Our results confirmed the fact that RT was followed by impotence as such in only a minority of cases (3 out of 12 or 0.25). However, when other aspects of sexuality were taken into account, a higher proportion appeared to have problems. In a substantial number of patients, psychogenic factors seemed to be (at least partly) responsible. More attention to these facts and, when necessary, psychiatric assistance, may help reduce the incidence of sexual disorders following RT to the prostate.

Interstitial gold and external beam irradiation for prostate cancer

We treated 65 patients with prostatic cancer confined clinically to the prostate or periprostatic area during an 8-year period. Seven patients had stage A2, 38 stage B and 20 stage C disease. All 65 patients underwent staging pelvic lymphadenectomy and implantation of gold grains into the prostate (mean dose 3,167 rad). A total of 64 patients then completed a course of external beam irradiation to a mean total tumor dose of 6,965 rad. Complications of therapy were mild and limited (less than 3 months in duration) in most patients, and they included radiation cystitis (32 per cent), diarrhea (31 per cent), extremity lymphedema (7.7 per cent) and wound infection (3 per cent). Two patients suffered urinary incontinence after therapy and 2 (3 per cent) had diarrhea more than 3 months in duration. The actuarial 5-year survival rate for all patients was 87 per cent and the 5-year survival free of disease was 72 per cent.

Endocrine therapy for bladder outlet obstruction from carcinoma of the prostate

The optimum treatment of bladder outlet obstruction from prostatic cancer is controversial. Although transurethral resection of the prostate may provide immediate relief of the obstruction, there are attendant surgical and anesthetic risks, as well as accumulating clinical evidence to suggest that transurethral resection of the prostate may cause tumor dissemination and diminish patient survival. Orchiectomy, which can be performed safely with local anesthesia, provides definitive endocrine therapy and has been used at our institution in preference to transurethral resection to relieve bladder outlet obstruction from carcinoma of the prostate. There were 35 patients between 51 and 96 years old in urinary retention from carcinoma of the prostate. Patients were treated with orchiectomy and suprapubic or urethral catheter drainage, and subsequently were given voiding trials. If a patient failed to void satisfactorily within 60 days transurethral resection of the prostate was performed. Over-all, 24 of 35 patients (68.6 per cent) were relieved of bladder outlet obstruction by orchiectomy alone. Neither tumor stage nor grade correlated significantly with the response to orchiectomy. We conclude that transurethral resection of the prostate may be held in reserve for patients who do not respond to endocrine therapy or those who do not wish to risk sexual impotence.

A study of penile circulation before and after radiation in patients with prostate cancer and its effect on impotence

Decrease in penile blood flow has been implicated as the cause of erectile impotence in patients receiving pelvic irradiation. To determine any changes in the penile circulation secondary to pelvic irradiation, we measured the penile blood flow before and 6-9 months following completion of irradiation in six patients with prostate cancer. None of these patients had hormonal manipulation. The non-invasive techniques of Penile Brachial Index (PBI) and Penile Flow Index (PFI) were used to study penile circulation. Two patients developed impotence 2 to 4 1/2 months following completion of irradiation. There was no significant change in penile blood flow following irradiation in any of the six patients studied. The etiology of post-irradiation impotence is probably multifactorial and it may be an oversimplification to attribute it to a single organic cause.

Sexual function in prostatic cancer patients treated with radiotherapy, orchiectomy or oestrogens

Sexual function in prostatic carcinoma patients was studied in 12 patients from each of three treatment groups: radiotherapy, orchiectomy and oestrogen treatment. Significant deterioration occurred in all groups. Although erectile potency was preserved in 9 of 12 patients treated with radiotherapy, 7 of these had a marked reduction in the frequency of sexual activity. Men subjected to orchiectomy or oestrogen treatment were seldom capable of having intercourse or of experiencing orgasm. However, oestrogen-treated men continued sexual activity with their partner more often than orchiectomised subjects. Patients receiving oestrogen treatment scored significantly higher for mental depression than those in the other two treatment groups.

Pelvic complications after definitive treatment of prostate cancer by interstitial or external beam radiation

Radiation complications, after definitive treatment of localized prostatic carcinoma by either external beam or interstitial implantation with Iodine-125 seeds, are reviewed. Late serious complications to immediately adjacent structures of the anterior rectal wall, prostatic urethra, bladder neck, and external sphincter occurred with similar frequency in both treatment groups. However, late serious complications of the remotely adjacent structures of the bladder, urethra, distal ureters, and circumferential rectal wall occurred more frequently in the external beam treatment series, a reflection of the fact that larger tissue volumes were irradiated. Rectal ulceration, while occurring in both treatment groups, was amenable to surgical correction or underwent spontaneous healing only in the 125I group. At this point in our experience, morbidity from late radiation complications has been less among those patients having interstitial implantation for definitive treatment of localized prostatic carcinoma.

Pelvic lymphadenectomy in the management of carcinoma of the prostate

Between January 1, 1971 and December 30, 1977, 82 patients underwent bilateral pelvic lymph-adenectomy for carcinoma of the prostate, 65 with associated radical prostatectomy. Lymph node metastases were noted in 27 cases: 1 of 8 with A2, 3 of 16 with B1, 12 of 39 with B2 and 11 of 19 with C tumors. Of the 17 patients undergoing lymphadenectomy only as a staging procedure before definitive radiation therapy 12 had nodal involvement, while 15 of 64 patients with combined lymphadenectomy and prostatectomy had nodal disease. Early complications involved 6 patients with thromboembolic disease, including 1 death while the patient was hospitalized of pulmonary embolism. All 6 thromboembolic complications occurred among 52 patients who had not received anticoagulation, for an incidence of 11.5 per cent compared to no episode of thromboembolism among 30 patients prophylactically anticoagulated with warfarin sodium. Late complications of chronic lymphedema occurred in 15 patients, 10 of whom had postoperative radiation. We recommend lymphadenectomy as an adjunct to radical prostatectomy but its role as a staging procedure before definitive radiation therapy to the pelvis appears to yield increased morbidity in terms of incidence of chronic lymphedema, suggesting that its use be reserved for highly selected patients. We also recommend the prophylactic postoperative administration of anticoagulants and patients awareness of risk factors contributing to chronic lymphedema.

Radiation therapy as definitive treatment for localized carcinoma of prostate

A progress report on the treatment of 116 patients with adenocarcinoma of the prostate treated by external irradiation is presented. Fifteen, 60, and 41 patients presented initially with Stages A, B, and C, respectively. The majority of the patients received 7,000-7,500 rads during a period of seven to eight weeks, locally to the prostate gland. The five-year actuarial survival were 90, 70, and 40 per cent for Stages A, B, and C, respectively. The five-year survival rates for patients with well and moderately differentiated tumors were significantly better (45 per cent) than for those with poorly differentiated tumors (24 per cent). The five-year survival rate in the patients who received prior or concomitant hormone manipulation was lower (33 per cent) as compared with those receiving radiation therapy alone (43 per cent). All of the above differences were statistically significant (0.01 level). Of the patients failing, distant metastases have developed in 88 per cent suggesting that subclinical distant metastases might have been present prior to initiation of radiotherapy. The local control rate was 82 per cent. The morbidity of this mode of therapy was found to be acceptable. Radical radiation therapy is an effective method for control of carcinoma of the prostate and is potentially curative.

Radiation therapy for localized prostate cancer

Since 1965, 401 patients with prostate cancer have received intensive local pelvic radiation therapy at the Virginia Mason Medical Center. Two hundred seventy-seven of these patients were treated from 1965 through 1975, comprising the study group. Two hundred twenty-one of this series were in the Stage C category. The 36 Stage B cancers were either medically nonoperable, or advanced extent, or had high-grade histopathology. Ten patients each were in diffuse Stage A or Stage D groups, the latter receiving local palliative intensive treatment to the prostate area. The mean age of the patients was 67.6 years. The five year survival of the Stage C group was 57.7%. There was no apparent influence on the survival of irradiated Stage C patients who received estrogen therapy. Current treatment techniques employ 10 megavolt photon beam with whole pelvic nodal fields and bilateral arc rotational boost fields. The incidence of reactions and complications is presented.