In Dr. John P. Mulhall's less technical monograph (op. cit., Part 1), in Chapter Five: "Prostate Radiation and Sexual Function", a wide array of information is presented along with summaries of erectile dysfunction for different treatment modalities, and we also see or understand why a dearth of longitudinal (over decades) studies exist in respect of radiation treatments for prostate cancer. As an early stage survivor who has received this treatment I will also share my experience.
Here's the key for seeing why such studies are sparse: Most men don't want to provide feedback on their sexual activity or sex lives, after such treatments. They feel, for whatever reason, this is no one else's business - but fail to understand that without feedback and information which can be integrated into analyses to grasp effects, they are doing an injustice to other men - who may also have to face such treatments. (In this respect, let me add that I recently completed a UCSF patient form in the aftermath of treatment, and will also be filling Dr. Hsu in on the after effects in an email -or phone consult next week.)
When I first began my search for treatment options, after learning I had stage T1c prostate cancer, I was dismayed by the dearth of solid, consistent information on the after -effects, and especially as they might impact sexual function. What I eventually decided is that there's no central core of agreement on the effects because the data are too sparse. This was confirmed for me as I read Mulhall's Chapter Five.
Let's cut to the chase: Mulhall superbly describes first how radiation works to effect a cancer treatment (p. 78):
"Radiation therapy works by killing cells. It kills not just cancer cells but normal cells. However, those cells that are the most rapidly dividing are the most sensitive to radiation (as is true for chemotherapy). Fortunately, most cancers have cells that are dividing more rapidly than normal cells.
Radiation attacks the DNA in our cells. It causes breakages in the DNA, and when this occurs, the cells commit suicide, a process known as apoptosis. Normal cells have better repair machinery to fix some radiation damage while cancer cells do not. As well as killing off the actual prostate cancer cells, radiation causes injury to the blood vessels that supply the cancer."
Alas, as Mulhall notes later, these blood vessels- many of them - also supply blood to the erectile tissues. Most shocking to me was to read that erectile success rates are the same for surgery and radiation after 24 months, and while radiation oncologists tend to look at sexual function after 12 months or so, Mulhall indicates it needs to be 3-5 YEARS after (p. 83) . He refers to this as a "glaring deficiency" (ibid.) and adds:
"Any study looking at erectile function outcomes should really assess these outcomes at no sooner than 24 months, if not 36 months, after the completion of radiation."
On reading this my own erectile success in the wake of my treatment (on Sept. 25th) was put into harsh perspective and my hubris vastly tempered. Indeed, within 3 days of the treatment I'd been able to get and hold an 8-9 pt. erection, and in doing so believed I'd "conquered the world". How foolish! On reading Mulhall's chapter, I am now left to wait and see what progressive deterioration awaits, and in fact, what assorted methods of "penile rehabilitation" I will be left to take, unless I want to just let everything atrophy.
But I get ahead of myself a bit. Another aspect is "loss of ejaculatory volume". Mulhall on p. 80:
"Radiation therapy results in reduced ejaculate volume as the function of the prostate and the seminal vesicles is to produce ejaculatory fluid, and in most men, will result in loss of ejaculation completely".
In my case, this has not yet transpired . I was first able to attempt an ejaculation two weeks and two days after my treatment, and following two successive massages from a trained massage therapist, who I will call 'Mrs. D'. This was mainly to try to eliminate a persistent painful kink-knot under the back left shoulder blade - caused by being in an uncomfortable position in the Treatment Room for nearly 4 hrs. She worked intensely on that area - and associated neck 'scalenes'- and also gave a whole body massage. Within a day of this the burning urination I'd been experiencing ceased. Causal connection? Maybe, maybe not. In any case, I felt confident enough to attempt an ejaculation but hadn't yet read Mulhall's warning about another unwelcome side effect, dysorgasmia (orgasmic pain, p. 113). As Mulhall observes:
"This is a peculiar problem which is seen more frequently after surgery than radiation, but is seen in both cases, and believed to be related to spasms of the muscles of the pelvic floor at the time of orgasm. The bladder neck is supposed to close at the time of orgasm, and the belief is that the bladder neck muscle and the muscle surrounding this in the pelvic floor may in some men go into spasm at the time of orgasm with pain referred to the penis, testicles, lower abdomen or rectal area."
Mulhall goes on to state the pain "typically lasts from seconds to a minute" but in some men can last for hours after orgasm. In my case, the pain was much like that experienced as the first needle entered for my prostate biopsy back in July, with an incinerating pain referred to the whole urethra. That lasted maybe a minute, but this first orgasm after radiation treatment saw the pain lasting up to five minutes afterward. It was so bad I almost felt I'd pass out, maybe 9.5 on a ten scale. Meanwhile, only bloody fluid was produced as ejaculate.
The negative indicator here, with which I certainly concur, is that such orgasmic pain can impede a man from any sex activity altogether. This is quite understandable! Why would you want to repeat a pain that is so horrendous via a sex outcome (orgasm) presumed to be pleasurable? The form of rehab or prescription for avoidance of the pain is Flomax (ibid.) So I will have to monitor and see if the pain subsides - if I ever attempt another orgasm! - or if not, obtain some Flomax!
Why such harsh results? Never mind the inflammation aspect, i.e. "radiation causes inflammation in the prostate, urethra and bladder" (p. 79), Mulhall also notes (ibid.):
"The amount of radiation needed to cause endothelial damage is tiny, ranging from 0.1 to 1 Gy. It is estimated that between 15 to 20 Gy is required to injure large blood vessels (when given in a single dose). This damage to blood vessels is known as endartertitis obliterans and may take up to a decade to manifest itself maximally."
Great! Recall my single dose for the whole prostate volume was 1930 cGy or 19.3 Gy, or near the top of the dose threshold to injure large blood vessels. In addition, I received 18.5 Gy for the urethra, rectum --- which means blood vessels in those areas will also likely be affected in ten years at the "maximal level" - whatever that means. (Mulhall suggests loss of any erectile capacity unless his "penile rehabilitation" methods are employed.)
But, suffice it to say, by age 76 I do not believe I will be getting any full surgery done for getting an implant in place, or injecting myself with a 29-gauge needle. Hopefully, as in all cases of aging, I learn to let go gracefully and just be thankful for the splendor of nature and being able to partake of it.