Stamp Test Delivers Message on Erectile Dysfunction After High-dose Intensity-modulated Radiotherapy for Prostate Cancer

Abstract

Objectives To evaluate erectile function following high dose radiotherapy for prostate cancer using the international index of erectile function (IIEF), expanded prostate cancer index composite (EPIC), and stamp test. Methods Men with favorable and intermediate risk prostate cancer were assigned to receive prostate intensity modulated radiotherapy (IMRT) vs. an erectile tissue-sparing IMRT technique on a phase III randomized prospective study. The stamp test, IIEF, and EPIC questionnaires were completed at baseline, 6 months, one year, and two years after IMRT. Sexual Health Inventory for Men (SHIM) scores were abstracted from IIEF questionnaires. A partner questionnaire, designated IIEF-P, modeled after the IIEF but from the perspective of the partner, was collected. Results Ninety four men enrolled on the trial who completed at least one questionnaire or one stamp test were analyzed. The median age of the patient population was 62.5 years. The median RT dose was 76 Gy (range: 74–80 Gy). At 6-months and one year after high-dose IMRT, a positive stamp result significantly correlated with median EPIC sexual summary, sexual function (EF), and bother subscale scores. Additionally, 6-months after IMRT the stamp test correlated with median IIEF, IIEF EF domain, and SHIM scores. Robust concordance for the IIEF and SHIM results was appreciated between responding patients: partner pairs. Conclusions Nocturnal tumescence indicated by a positive stamp test correlates well with established quality of life questionnaires after IMRT. The stamp test should strongly be considered as an objective measure of erectile function in future studies of ED in prostate cancer patients.

Patient-reported sexual toxicity after radiation therapy in long-term prostate cancer survivors

“…The symptom profiles of the three investigated treatment groups were surprisingly similar but differed with respect to symptoms relating to erectile dysfunction. There is an up to 70% occurrence of erectile dysfunction in men treated with EBRT depending on the method of assessment (physician-reported leading to lower numbers than patient-reported) and time to follow-up ( Keller et al , 2012 ; Incrocci and Jensen, 2013 ). Vascular impairment and corporal fibrosis is associated with EBRT and is reported to result in lower symptom prevalence than the neurological damage that is associated with surgery ( Hoppe et al , 2012 ; Keller et al , 2012 ).…”

“…There is an up to 70% occurrence of erectile dysfunction in men treated with EBRT depending on the method of assessment (physician-reported leading to lower numbers than patient-reported) and time to follow-up ( Keller et al , 2012 ; Incrocci and Jensen, 2013 ). Vascular impairment and corporal fibrosis is associated with EBRT and is reported to result in lower symptom prevalence than the neurological damage that is associated with surgery ( Hoppe et al , 2012 ; Keller et al , 2012 ). The results of this work are in line with these previous publications with the symptom prevalence in both the primary EBRT group and the EBRT+BT group being lower than the symptom prevalence in the salvage EBRT group (25–65% vs 35–80%, respectively).…”

“…Patients may experience such symptoms for reasons other than those attributable to the treatment. Anxiety and depression ( De Sousa et al , 2012 ), diabetes mellitus ( Roach et al , 2010 ; Budaus et al , 2012 ; Hoppe et al , 2012 ; Magli et al , 2012 ; Kerns et al , 2013 ), hormonal treatments ( Roach et al , 2010 ; Budaus et al , 2012 ; Haugnes et al , 2012 ; Magli et al , 2012 ; Incrocci and Jensen, 2013 ; Kerns et al , 2013 ), and older age ( Mirza et al , 2011 ; Budaus et al , 2012 ; Keller et al , 2012 ; Incrocci and Jensen, 2013 ; Kerns et al , 2013 ) are all factors that have been reported to influence sexually related symptoms to various degrees. In addition, many prostate-cancer survivors use substances like sildenafil to compensate limitations in sexual performance, which also may cause confusion about the extent of an actual dysfunction ( Incrocci and Jensen, 2013 ).…”

“…Pre-treatment erectile function is one of the most important factors predicting post-treatment function ( Roach et al , 2010 ; Budaus et al , 2012 ; Hoppe et al , 2012 ; Keller et al , 2012 ; Incrocci and Jensen, 2013 ; Mirza et al , 2011 ). Although the structures most critical for sexual dysfunction after radiation therapy have not yet been conclusively determined, one recommendation is to keep the mean dose to 95% of the penile bulb volume to <50 Gy ( Roach et al , 2010 ).…”

“…Although the structures most critical for sexual dysfunction after radiation therapy have not yet been conclusively determined, one recommendation is to keep the mean dose to 95% of the penile bulb volume to <50 Gy ( Roach et al , 2010 ). There is also evidence that intensity-modulated radiation therapy result in less sexual toxicity than three-dimensional conformal radiation therapy ( Mirza et al , 2011 ; Keller et al , 2012 ).…”