Editing Management of Localized Prostate Cancer (section)

=== <span style="color:#ff0000">Adverse events</span> ===
* '''<span style="color:#ff0000">Adverse effects are primarily related to injury to the microvasculature</span>''' of the bladder, rectum, striated sphincter muscle, cavernous nerves, corpora cavernosa, and urethra.
* '''≈1/3 of patients experience <span style="color:#ff0000">acute proctitis</span> or <span style="color:#ff0000">cystitis</span> during the course of radiotherapy.'''
** '''<span style="color:#ff0000">Symptoms usually subside after the completion of therapy, however, ≈5-10% have permanent symptoms, such as irritable bowel syndrome, intermittent rectal bleeding, bladder irritability and intermittent gross hematuria</span>[https://www.ncbi.nlm.nih.gov/pubmed/24440474]'''.
** '''In some patients, chronic symptoms develop years after treatment.'''
** '''Some patients require laser cauterization or argon plasma coagulation of radiation-induced telangiectasia for bleeding from the bladder or the rectum.'''
* '''<span style="color:#ff0000">GU toxicity</span>'''
** '''<span style="color:#ff0000">Less common with EBRT than brachytherapy,</span>''' especially in patients with prostatic hyperplasia.
** To avoid these problems, α-adrenergic blockers and ADT are usually administered before treatment and '''may decrease the severity and duration of urinary symptoms'''
** '''<span style="color:#ff0000">EBRT</span>'''
*** '''Acute urinary symptoms recover over time'''
*** '''Urinary incontinence is uncommon after RT'''
** '''<span style="color:#ff0000">Brachytherapy</span>'''
*** The IPSS tends to increase significantly immediately after implantation and then decrease, at a rate depending on the half-life of the isotope used
*** '''Significant post-brachytherapy voiding symptoms refractory to medical management occur in ≈2-3% of patients'''
*** '''Brachytherapy after TURP is associated with increased risk for urinary incontinence'''
*** '''Acute urinary retention'''
**** Occurs between 12-35% of patients undergoing brachytherapy
**** Risk factors[https://pubmed.ncbi.nlm.nih.gov/11849794/]
***** Prostate volume of > 35 grams
***** Post-treatment volume of > 55 grams
***** Number of needle punctures > 33
***** AUA Symptom Score of > 12.
**** '''Management'''
***** '''Usually initially treated with an indwelling urethral catheter and medical management with alpha-blocker and/or 5-alpha-reductase inhibitor.'''
***** '''After a 1-2 weeks with the catheter, a voiding trial is usually attempted, but patients often fail this and go on CIC'''
***** Patients with retention following seed implant may resolve retention following 6-12 months of CIC.
***** '''If patients remain in retention after an adequate trial of CIC, TURP may be required.'''
****** '''The timing of this second procedure should be delayed for as long as possible and should not be attempted until at least one year after seed implantation.'''
****** Iodine-125 (125I) has a half-life of 60 days and TURP has been suggested to be contraindicated in the first 9 months after treatment because of the risk of radioactive exposure to the surgeon, operating room personnel, and pathologists.
* '''<span style="color:#ff0000">GI toxicity</span>'''
** '''<span style="color:#ff0000">5-10% persistent irritable bowel symptoms and 10-15% intermittent rectal bleeding</span>'''
**Fecal leakage by 12 years: 12% radiotherapy vs. 6% active monitoring vs. 6% prostatectomy[https://evidence.nejm.org/doi/full/10.1056/EVIDoa2300018]
** '''<span style="color:#ff0000">More common with EBRT than brachytherapy</span>'''
** '''<span style="color:#ff0000">EBRT</span>'''
*** '''Acute bowel symptoms including urgency and frequency''', partially recover with time
*** '''Compared to 3DCRT, IMRT is associated with lower rates of acute and late GI toxicity, but not GU toxicity,''' despite being used to give higher doses to the prostate; advances in radiation technology have simultaneously allowed a higher radiation dose to be given while resulting in lower toxicity.
** '''<span style="color:#ff0000">Brachytherapy</span>'''
*** '''Acute minor rectal symptoms secondary to brachytherapy are usually self-limiting.'''
*** '''Late rectal toxicity—specifically, rectal bleeding secondary to radiation proctitis'''—can be a minor, self-limiting side effect of radiation or a major toxicity requiring surgical intervention such as argon plasma coagulation or, in the worst cases, diverting colostomy
*** Dose delivered to the rectum is directly related to the likelihood and degree of late morbidity from brachytherapy
* '''<span style="color:#ff0000">Erectile dysfunction</span>'''
** Studies suggest that erectile dysfunction after radiation is caused predominantly by vascular damage
** '''<span style="color:#ff00ff">Prostate Cancer Outcome Study</span>'''
*** Population: 1655 males who had undergone either surgery or radiotherapy for localized prostate cancer
*** Functional status was assessed at baseline and at 2, 5, and 15 years after diagnosis
*** Results
**** 78.8% of post-prostatectomy patients not having erections firm enough for intercourse two years after surgery compared to 60.8% of men having ED two years following prostate radiotherapy.
**** After 15 years from the time of treatment, the prevalence of ED increases further to 87% post-prostatectomy and 94% post-radiotherapy
*** [https://pubmed.ncbi.nlm.nih.gov/23363497/ Resnick, Matthew J., et al.] "Long-term functional outcomes after treatment for localized prostate cancer." ''N Engl J Med'' 368 (2013): 436-445.
** '''≈50% of patients develop erectile dysfunction after radiotherapy for prostate cancer'''
*** '''<span style="color:#ff0000">More common with EBRT than brachytherapy</span>'''
**** In a prospective QoL study, poor erections at 60 months increased by 44% after radical prostatectomy, 23% after EBRT, and 21% after brachytherapy from baseline
**** Another study found that 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.[https://www.ncbi.nlm.nih.gov/pubmed/12419432]
**** 2017 AUA Guidelines on Localized Prostate Cancer suggest similar ED rates
** '''<span style="color:#ff0000">Usually begins about 1 year after the completion of treatment</span>'''
*** '''Decline worse in patients receiving combination with ADT'''
** Younger patients with good baseline erectile function are more likely to retain adequate erections
* '''<span style="color:#ff0000">Secondary radiation-induced malignancies</span>'''
** '''Incidence of new primary prostate cancers and highly aggressive second malignancies ≈1/70 patients living > 10 years after treatment with radiotherapy for prostate cancer,''' especially radiation-induced cancers of the bladder and rectum; however, the true magnitude of risk is difficult to quantify
* '''<span style="color:#ff0000">Constitutional symptoms: fatigue</span>'''
*'''<span style="color:#ff0000">Other complications associated with brachytherapy include seed migration and rectourethral fistula</span>'''