PCLegacy said...
FLA will destroy your one lesion if the procedure is done by a skilled interventional radiologist. This will not however prevent additional lesions from potentially forming at a later date in the prostate. The "redo" rate mentioned by another poster would be more related to other lesions popping up at a later date, not so much that the original lesion is not fully cooked.

That is incorrect. With all forms of thermal ablation (like FLA, HIFU & cryo), ablation of the cancer has been found to be incomplete in the ablation zone. This has been found even when the f/u biopsy is done within 6 months. The reason is called the "heat sink effect." The prostate, which is mostly water, conducts the laser's heat away from the spot to which it's applied and carries it outward (where it may injure healthy tissue). This sub-lethal ablation is what causes the 20- 30% re-do rate. Interestingly, IRE, which is not thermal, and the hope was that it would ablate completely in the treatment zone, was recently found to be about 15% incomplete.

- Allen

I have read the studies published in peer-reviewed journals. One can argue over opinions, but not over facts. Here are a few:

"At [6-month] followup magnetic resonance-ultrasound fusion biopsy cancer was not detected in the ablation zone in 5 [out of 8] men but was present outside the treatment margin in 6 [out of 8] men." So, 3 of 8 men (38%) had residual cancer in the ablation zone.
/www.ncbi.nlm.nih.gov/pubmed/26748164

"Based on multicore total prostate biopsy at 6 months 67% of patients were free of tumor in the targeted area and 50% were free of disease." So 33% had residual cancer in the targeted area.
www.jurology.com/article/S0022-5347(09)01509-2/abstract

"MR imaging–guided biopsy [at 6 months] of the ablation zone showed no cancer in seven patients (78%) and Gleason grade 6 cancer in two (22%)."
pubs.rsna.org/doi/full/10.1148/radiol.13121652

So far, all studies have been very small like these. But as you see, ablation of the cancer has been incomplete in the ablation zone. The heat sink effect applies to all forms of thermal ablation - it's basic physics.

I don't think FLA is a bad therapy, I just think it's important to keep one's eyes open, especially when there is so little published data.

- Allen

Allen,
Everything that you have referenced is true, but these were the initial clinical trials. Hundreds of cases have been done since then very successfully.

The therapy has been refined and the experience in these cases has led to more accurate outcomes than the initial trials.

This therapy is game changer. That is why it is now being used in the brain. Much more efficient and controlled versus conventional methods.

Listen, Allen, it is obvious that you are passionate about all things PC related and you are a tremendous resource to many people on this forum, myself included. I have learned quite a bit reading many of the posts you have contributed on this forum.

You are accurate in that FLA cannot prevent additional tumors from occurring in the rest of the prostate, but reoccurrence and tissue damage are byproducts of user error and not limitations of Laser thermal ablation. What I stated before about Laser ablation being different is true. This "heat sink effect" only applies to other methods of ablation, in particular RF ablation.

It doesn't apply to FLA because of the more efficient laser heat source.

The reason why a few patients in the initial trials didn't get fully ablated was not heat sink. It was that the clinicians delivering the therapy were still trying to figure out how to maximize the effect of the therapy. These were literally the initial cases. Ablation times and temperature limits have been been refined since the initial trials. The entire therapy and delivery technique has since been refined.

I am sure you would agree that good advice when choosing a surgeon to do an RALP procedure, you would choose a surgeon with hundreds of cases under their belt. Surgeons clearly improve their technique the more procedures they do. Same with FLA. Outcomes by interventional radiologists with experience doing this procedure have improved since the initial trials.

I truly believe this is a therapy that can, in many cases delay or prevent someone from needing an RALP or radiation. Its not always a cure, but is definitely going to be a much larger part of the future treatment regimen for PC as we move forward.

just a fools thought here...I do not think any therapy that leaves healthy tissue aside and then cancer occur's in that tissue can be blamed on errors of anyone or faulty this or that. Its just healthy prostate tissue that turned cancerous....the possibility is there any time healthy prostate tissue exists, without regard to treatment or no treatment... the best way to avoid the problem is to remove the whole prostate and even that is not perfect as "benign" prostate " tissue left behind from spared nerve bundles could develop pca as well as other " benign " residual prostate tissue.. I say a fools thought because I merely perused the thread and may have foolishly gleaned something from the perusal that was totally irrevelent to the issue at hand.. if so...carry on ...if not... carry on.

ASAdvocate-

I'm glad you asked about the Index Lesion theory. For anyone who doesn't know, it is a theory that the spread of prostate cancer is from a primary, relatively large, and often higher-grade tumor called an index tumor. According to this theory, all metastases are clones from the original index tumor. If true, ablating the index tumor will stop the cancer. Prostate cancer is known to be multifocal (lots of little tumors) in 80 percent of men, but if the index tumor theory is correct, the multiple tumor foci will not seed any spread — only the index tumor can do that. In support of the theory, Liu et al. and Mao et al. showed that metastases arise as clones from a single parent cancer cell. However, they did not show that the parent cell was in an index tumor. Several studies provide evidence to the contrary:

• A case report by Haffner et al. (from Johns Hopkins) showed that metastases arose from a small, low grade tumor rather than an index tumor.

• Cheng et al. found that multiple tumors had independent origins. In 15/18 tumors, this research group found that they arose independently within a single gland, and in 3/18 tumors they arose through intraglandular dissemination from an index lesion.

• Ibeawuchi et al. showed that there was as much genetic diversity in a unifocal tumor as there were in multifocal tumors.

Clinical evidence for the index tumor theory is based on the fact that a single focal therapy treatment is effective much of the time, at least in the short term. Most likely, it is true in some men but not in others, and it may be true of some, but not all, of the cancers within a single man. Perhaps we will one day have a genetic test to screen for true index tumors. The other issue raised by the multifocal nature of prostate cancer is that the satellite tumors, whether they arise independently or are spawned from the index lesion, may be outside of the treatment range of the focal therapy. Hollmann et al. found that satellite tumors were a median of 1 cm, and up to 4.4 cm, away from the index lesion.

- Allen