Scheduled for SRT - New Marker Option

New on this forum - have been watching and waiting after RRP in 9/06 with PSA every three months. Took a jump May 2010 to .20 and now is .28. I have been "comfortable" waiting and watching, but now I feel the time is right for Salvage RT. I have been waiting due to concerns for quality of life after SRT. The small positive margin is the driving force to SRT, along with the slowly rising PSA (current 6 yr prediction after SRT with my data is 82%).

My RT Dr. offered for me to be the first SRT to try gold markers in the prostate bed to better align the treatment. The marking technology has been practiced by my Dr. for initial RT for the in place prostate and has resulted in less treatment sessions and lower dose rates. The treatment software finds the markers and essentially reduces the treatment area. Normal treatment has to take into account slight movement of the prostate between RT sessions. The gold markers eliminate the need for extra dosage area. However, about 25% of the patients have some movement during the treatment session and in these cases the markers do not provide any advantage - the treatment area is widened out to compensate for the movement. The movement sometimes is internal or can be the patient can just not remain absolutely motionless during the treatment.

The think the marker technology is great for the initial treatment of the prostate, but have some reservations about it for SRT. It does take an extra step of inserting the markers under local anesthesia with of course the use of the ever popular ultrasound probe. I currently do not see enough advantage for the use of the marker technology for SRT - comments?

Right now set up to start SRT after the first of the year without the markers.

I would agree that the gold markers would provide a better alignment...but to align to what? There is no way to know where the cancer is actually located in the prostate bed to target any better than the already proven methods of traditional SRT.

I would like to read more information before jumping onto the gold marker stragedy for SRT.

not sure what they would be aligning too either, after the prostate is long gone. got any more info you can offer on how it would be done?

The markers for SRT are to avoid areas where you do not want to hit hard with treatment - bladder, rectum, etc. They do try to keep the highest quality of life after SRT and do not want shifting viscera to cause more than intended dose to the functional areas. Once they install markers it is a reference point so that some areas can be minimized or avoided. Since this is the start of this study the software will very slowly reduce treatment area - like 1mm at a time for a statistical number of SRT candidates in some of the key areas. Looks to me like a longer term study. If there were several years of study in the books with marked improvement without any statistical increase in cancer progression then I would be all over this procedure, but do not want to be the first one with an extra invasive procedure with no data at all for a better treatment.

But, as I stated earlier, about 25 % of the patients in treatment with markers with the prostate in place have shifting target areas during each treatment which makes the markers useless and the target areas have to be widened to compensate for the movement. But the 75% that have steady marker position do benefit from shorter treatment and overall lower doses of treatment. My Dr was trying to see if there was a use for this in SRT candidates.

I too, am quite perplexed with no "standard" guidelines for prostate cancer treatment - I have reviewed study after study - it is a statistical "mess"(IMO). I think there are enough cases that cover RRP where there is a psa failure after surgery with similar starting points to give us all some better guidance. I am part of a data base to do this in southeast Michigan, but need more data points in the study. I don't think this ever will be black and white, but it sure could use some improvement. I have read quite a few studies that show limited or no improvement with SRT for the lower Gleason scores, lower starting psa numbers with relative total containment of the cancer within the prostate - SRT does show marked improvement for the more aggressive prostate cancers after surgery. Then you have to select adjuvant (to be conservative) vs salvage upon psa failure test results.

Anyway, this is a great site, with great case histories and data to review. Great support network! Really appreciate everyone's story ............So, it's off to SRT (without markers) I go.

They seem to be making a big deal that the new Varian Trilogy Rapidarc adjusts for all this movement.

I hope so.

Mel

The Calypso markers seemed to work quite well for me. The only way I know that they really did something was in two sessions. One - I had some extreme back pain, and must have moved a tiny bit, at which point the calypso machine alarmed. In the other, it was gas, same thing but internal, the alarm hit, things stopped.

I do know that the surgeon put the markers in the prostate scar area, as it became more painful when he hit that mass. He did show me the overlay xrays of where the prostate was, and where the markers wound up. Also, they are not aiming directly at the markers. They are using them to create reference points for a 3-D map of the prostate bed area.

I had understood that the CT / Varian combo was to verify everything at startup of each session (the calypso monitors at the start, then all through the session - there is a panel placed over you that receives the gps-like signals, the CT may as well, but that was not described). This being from comments of one of the members who had that CT equipment 8 or 10 months ago - I had asked a radiologist friend (not one of my doctors) about that, and at the time, he said it was extreme cutting edge stuff, and there were just a couple of those systems in the field. He felt like the Calypso was a very valid choice as well.