May 28, 2010 - 12:25 pm
At age 59 I was diagnosed with PCa in mid-March after my PSA had risen from 3.8 to 4.3 in 18 months. 1 of 12 biopsy cores showed adenocarcinoma with 15% involvement. Gleason rating was 3+3=6. DRE was normal. Staged at T1c. I had a prostate volulme of 47 ml, a PSA velocity of 0.23 ng/ml/yr and a PSA doubling time of 9.3 years. There was no evidence of perineural invasion. A second opinion on the pathology slides confirmed the original reading of 3+3=6 Gleason score. Interestingly, after eliminating dairy and red meat from my diet my PSA score in mid-May had dropped to 2.8 which my doctor characterized as "great, but you still have cancer."
After several consulatations, a lot of study, and a careful investigation of surgery, various forms of radiation (both photon and proton), and active surveillance, I have elected to pursue treatment with the Cyberknife procedure.
Cyberknife uses a robot to deliver a high dose of radiation with sub-millimeter accuracy to the prostate. Four gold markers (called fiducials) -- about the size of a grain of rice -- are inserted into the prostate and detailed MRI and CT scans are used to track the movement of the prostate in real time so that the dosage is accurately delivered without damaging surrounding organs and tissue.
I had the fiducials implanted yesterday. It was a pretty simple procedue that inserted the fiducials into the prostaste via the perineum using a live sonagram video taken with a rectal monitor. Unlike the biopsy procedure where the needles are inserted transrectally, this procedure did not require enemas or antibiotics and there was no resultant blood in the urine or stool. Best of all, there was essentially no pain. I was sedated during the procedure and it was conducted without incident or after effect. Afterwards, an x-ray of the prostate was taken to ensure the fiducials were properly placed. There is a very slight soreness in the area of my perineum today but not enough to warrant any pain killers.
The next step is to build a detailed 3-D picture of the prostate using a detailed MRI scan so that the dosage parameters can be calculated. This will take place in about a week as they have to wait to be sure that the fiducials are not moving. They will also build me a customized pod to lay in while undergoing radiation treatment to minimize body motion.
After the radiation plan is developed, the radiation is delivered in five sessions that each last about 45 minutes while the robot rotates about the body in six-degrees of axis while it adjusts itself to prostate movement. The prostate can move up to several millimeters in a short period of time through normal respiratory function, bladder filling, and gases in the colon so adjusting the robotic x-ray placement is critical in avoiding radiation to surrounding tissue.
In most cases, the radiation is delivered in five consecutive sessions. I had read a recent Stanford study that suggested a protocol that skipped a day between sessions to allow better recovery of tissue near the urethra and my physician team was ameniable to this delivery schedule.
I expect to start the radiation within a few weeks.
Cyberknife has a very low incidence of follow-on urinary difficulties which are mostly a sense of urgency and more frequent urination that resolves itself within a few days. Skipping days between radiation treatments is supposed to alleviate this potential side effect. Post treatment erectile function with Cyberknife indicates that men who have no ED before treatment are 85% potent following treatment. Men who experience a decrease in erectile function following treatment are treated successfully with Viagra-like drugs.
Success with Cyberknife, like all radiation treatments, is measured by reaching a stable PSA nadir at some point following treatment. Studies have shown that the higher dosages that can be delivered with Cyberknife are instrumental in a rapid PSA drop following treatment and a nadir that is typically below 1.0 ng/ml with a statistically insignificant percent of biological failures for men with early stage PCa (PSA <10, Gleason < 7, and Stage T1.)
My Tricare insurance covered Cyberknife without blinking. I understand Medicare also covers it. I've read that some insurance plans and HMOs may not cover Cyberknife although the procedure was approved for cancer treatment by the FDA in 2000.
Will keep you all posted as to the specifics of the treatment process and how it works for me.