This study is a prospective, randomized, single-blinded, cross-over trial to investigate the efficacy of low-intensity extracorporeal shockwave therapy in the treatment of erectile dysfunction (ED). We will enroll 60 subjects (International Index of Erectile Function Questionnaires, 5 ≦ IIEF-5 ≦ 21). 30 subjects receive ESWT (LM-IASO, Litemed Co., Taiwan) for 6 courses in 3 weeks (0.05mJ/mm2, 3000 pulses) and 30 subjects receive Sham therapy for 3 weeks (the machine turning on but the energy is zero). After 3 weeks, the two groups are cross over. The primary outcome is the 4th week change from baseline for IIEF-5 score. Secondary outcomes are the 8th week change from baseline for IIEF-5 score, EHS, QoL; AEs. The between-group relationships of baseline and 4-week data were evaluated by using the Student's t-test or Mann-Whitney U-test where appropriate. Multiple linear regression was carried out to test the variables associated with treatment outcome. P-values < 0.05 were considered statistically significant.

Low-intensity extracorporeal shockwave therapy (LI-ESWT) was proved to be useful in various medical conditions; for example, neovascularization in myocardial ischemia, nonhealing wounds, ED and chronic pelvic pain syndrome.

The use of LI-ESWT has been increasingly proposed as a treatment for ED over the last decade. Overall, most of these studies reported encouraging results, regardless of variation in LI-ESWT set-up parameters or treatment protocols. As a whole these studies suggest that LI-ESWT could significantly improve the IIEF-5 and Erection Hardness Score of mild ED patients. However, no randomized control trial with cross-over designed studies so far.

This is a prospective, randomized, single-blind, cross-over clinical study. This study will be performed in outpatient setting of NTUH. Written informed consent will be given by all participants before entering the study. The subjects are treated at the therapy room of the department of urology, NTUH. All subjects would not pay any cost for this treatment/study. This study was approved by the institutional review board at National Taiwan University Hospital (NTUH, No. T-NTUH-57401).

Inclusion criteria: were patient age 20 ~ 70 year-old man, suffering from ED for over 6 months, and 5 ≦ IIEF-5 ≦ 21. The written informed consent forms from all subjects who met the inclusion criteria were obtained.

Exclusion criteria: Patients with penile implant, prior radical prostatectomy, rectal surgery, radiation therapy to the pelvic area, spinal cord injury, prostate cancer, bladder cancer, interstitial cystitis, or major depression were excluded. Patient ever received low intensity shockwave or who does not have sex intercourse in recent six months will be excluded.

Measurement of outcomes

Primary outcome: the 4th week and the 8th week change from baseline for IIEF-5 score change from baseline for IIEF-5 score.

Secondary outcomes: Penile Doppler Ultrasound (PDU) at 4th and 8th week , EHS, QoL; AEs

Methodology All patients diagnosed of erectile dysfunction will receive blood sampling of serum testosterone and lipid profile at the beginning of the study. All patients were treated at out-patient clinic. 30 subjects receive LI-ESWT (LM-IASO, Litemed Co., Taiwan) for 6 courses in 3 weeks (0.05mJ/mm2, 3000 pulses) and 30 subjects receive Sham therapy for 3 weeks (the machine turning on but the energy is zero). LI-ESWT is delivered by a probe that was attached to a electrohydraulic unit with a wide-focused shockwave source. The penis is manually stretched, and shockwaves are delivered to the whole penis shaft and penis base. The duration of each ESWT session is about 30 minutes, and comprised 3000 pulses (0.05mJ/mm2), and a frequency of 100/min.

Safety Considerations The peri- and post-treatment adverse events (AEs), including local pain, edema or hematoma were recorded and compared. With consideration of safety issue, any moderate/severe local pain or hematoma would be immediately reported and well inspected.

Follow-up The following parameters are assessed before treatment and weekly during the treatment: IIEF-5 score, EHS, QoL; AEs.

Inclusion Criteria:

1. Patients age 20 ~ 70 year-old man, suffering from ED for over 6 months.
2. 5 ≦ IIEF-5 ≦ 21.

Exclusion Criteria:

1. Patients with penile implant, prior radical prostatectomy, rectal surgery, radiation therapy to the pelvic area, spinal cord injury, prostate cancer, bladder cancer, interstitial cystitis, or major depression.
2. Patient ever received low intensity shockwave or who does not have sex intercourse in recent six months.

While subjects receive Sham therapy, the machine turning on but the energy is zero.