Comparison of non-invasive measurements of penile curvature in Peyronie's Disease

Abstract

ABSTRACT Introduction Peyronie's disease (PD) is a fibrotic disorder of the tunica albuginea, leading to penile deformities. Non-invasive estimates of penile deformities are practical, but have low accuracy when compared to objective measurements with induced erection and a goniometer. Our aim was to evaluate the agreement between different non-invasive methods of measuring penile curvature and the objective measurement. Methods We retrospectively reviewed medical records of patients who underwent surgery in a sexual medicine tertiary center. During the clinical visit, pre-operatively, a set of different non-invasive estimates were performed including asking the patient to explain their primary curvature with a goniometer, a drawing of the penis and a malleable implant prosthesis to be molded. Also, at home photography were required with maximal erection. The agreement of those methods and intra-operative measurement using a goniometer after saline induced erection was analyzed. A tolerable error was considered if a difference smaller than 10o or 20% of the gold standard measurement was found. Results The sample consisted of 69 men with a mean age of 62 ± 6 y. The direction of the curvature was dorsal in 59%, left in 35%, right in 5% and ventral in 1%. Mean curvature with of estimates with the goniometer was 57o (±31), drawing 60 o (±28), Prosthesis 60o (±25), Photography 57 o (±27), and mean intra-operative measurement was 51 o (± 24). Overall precision considering the above mentioned tolerable error definition was 45%, and the single non-invasive method with better precision was Prosthesis with 46,5% fo concordance. There was no statistical difference between them (p=0.99) for concordance and disagreement by the Dunnett's multiple comparisons test. Conclusion In our comparison study of 4 non-invasive curvature assessment methods, we found a low precision (approximately 45%), regardless of the chosen method. Formal curvature assessment with induced erection and a goniometer appears to be imperative. Disclosure Work supported by industry: no.