On hold pattern

[BB_1]

SpacerGel procedure was done on Oct. 3, 2022. Then schedule the 5 proton radiation treatments. Houston we have a problem. he subsequent MRI on Oct. 7 indicated that the spacer gel placement was not successful. I now have to wait 6 months until body absorbs all the gel and the anal wall heals. Test PSA again in December. Virtual visit with urologist Jan. 5, 2023. Then consider the options of redoing the spacer gel and do the 5 proton treatments or a longer course of a lower dose of proton radiation.

[michael1776]

Sorry to hear about this problem. My experience with spacer gel went well. I had fiducial markers installed at the same time through the perineum. I was apprehensive about the procedure, but all that went away when the anesthesia kicked in. Don't give up and keep fighting this thing. Keep us up to date and I hope the next plan you workout with the doctor is successful.

[BB_1 in reply to michael1776]

No worries. I also have the markers in. Did that at the same time with the gel in. Hmmm...will I need new markers 6- 7 months from now when they do the procedure again? What fun.

[michael1776 in reply to BB_1]

My understanding is the markers will be with you forever.

[BB_1 in reply to michael1776]

Guess we will collectors of markers...

[Tall_Allen]

I am not a fan of SpaceOAR. It does almost nothing.

prostatecancer.news/2017/01...

[Jancapper in reply to Tall_Allen]

Here is a larger review that concluded totally different results. One that stands out is the fact that the gel increases the distance between the prostate and the rectal wall from 7.7 mm to 16mm. Given that photons travel in an inverse square law fashion, meaning that doubling the distance (as with using Space Gel), the radiation dose to the rectal wall will be decreased by a factor of 4.

ncbi.nlm.nih.gov/pmc/articl...

[Tall_Allen in reply to Jancapper]

That link is with brachytherapy, not EBRT, and it doesn't address what is addressed in the article.

Providing extra space compresses the prostate and is an intrusive operation. Is the prostate radiation as effective on a compressed prostate, knowing that interstitial fluid and oxygen is necessary for radiation to work? With modern IGRT techniques the incidental rectal wall dose isn't enough to cause toxicity, which is very much the point. When the intra-operative risk (rectal ulcers, misplacements, protecting EPE) exceeds the potential benefit (late term rectal toxicity is negligible with modern IGRT), what is the point?

I call it a solution in search of a problem.

[Jancapper in reply to Tall_Allen]

I am scheduled to have the SpaceOAR Gel as well. As such, I have spent most of the day reading numerous articles involving this material. Not a single article that I read mentioned interstitial fluid or oxygen levels. There are numerous studies concluding that the use of SpaceOAR Gel is safe and effective. Here is one.

ncbi.nlm.nih.gov/pmc/articl...

[Tall_Allen in reply to Jancapper]

It's radiobiology: X-ray+H20+O2 -> OH• That is the ROS (reactive oxygen species) needed for DNA degradation by X-rays.

My RO refuses to use it because of unknown effect of prostate compression. None of the SpaceOAR trials have looked at how it might affect RT effectiveness.

That study you linked does not have a control group, so we have no idea if the results they quote are significantly better than without SpaceOAR. The big RCT that I reviewed only found a toxicity advantage only in late rectal toxicity, which affects almost no one.

Acute toxicity

The change at 3 months compared to baseline represents the acute effects of radiation. This is the period of maximal deleterious effect of radiation on rectal and urinary quality of life. After 3 months, quality of life typically improves. The exception to this rule is sexual quality of life, which may continue to deteriorate, largely due to age (see this link).

At 3 months, the percent of patients who were bothered by any bowel-related side effect (moderate or big bother) was 9.4% among the Spacer group, and 5.7% among the Control group. The difference was not statistically significant. The only component (components included such morbidities of diarrhea, blood in stools, urgency, frequency, etc.) of bowel bother that was statistically significant was bowel pain, which was reported as a moderate or big bother by 6.8% of the Spacer group and none of the control group. The spacer made bowel pain worse rather than better.

Physician-reported grade 2 acute toxicity at 3 months was exactly the same (4%) for both the Spacer and the Control group. The spacer had no effect on any but the mildest acute toxicity.

Urinary scores were not significantly affected by the spacer. Among the Spacer group, 22.8% evaluated their urinary-related side effects as a moderate or big bother. Among the Control group, 17.1% evaluated it as a moderate or big bother. The difference between the two groups was not statistically significant, nor were any of the components of urinary function (e.g., pain, urgency, waking up to urinate, weak stream, frequency, etc.).

Bothersome sexual effects were also not significantly different between the Spacer and Control group, and at 3 months, were similar to baseline.

Late-term toxicity

At 36 months after treatment, 2.2% of the men in the Spacer group evaluated their bowel function as a big or moderate bother. This compares to 4.4% in the Control group -- not a statistically significant difference. None of the components of rectal bother were significantly better in the men who received the Spacer, although the scores were directionally better in almost every component. Quality of life in the rectal domain for both the Spacer and Control groups were close to their baseline values.

This low rate of bothersome rectal toxicity was confirmed by physician reports of rectal toxicity. was confirmed by physician reports of rectal toxicity. Ignoring mild rectal side effects (i.e., grade 1, like blood spots on toilet paper or loose stool) that patients often do not bother to report to their doctors, we see that physician-reported grade 2 or higher rectal adverse events occurred in only 6% of patients, all in the Control group. Only one patient suffered a serious (grade 3) rectal injury in the Control group. It's worth noting that even this small number was an increase from the 15-month report. At 15 months, there was only one patient who had grade 2 or greater rectal toxicity. Late-term rectal toxicity is not a major issue with modern-day radiation.

Late-term urinary scores were not statistically significantly different for Spacer (4.4% big/moderate bother) and Control (8.9% big/moderate bother). Both were improved from baseline. The only component that was significantly worse was urinary frequency (18.2% vs 4.6%). It is unclear why any urinary side effects would be affected at all by a rectal spacer. It may be an artifact of the low sample size at 36 months - just 46 in the Control group, and 94 in the Spacer group.

There were no differences in overall sexual bother between Spacer and Control groups, or in any of its components. In the Control group, big/moderate sexual bother increased from 35.2% at baseline to 41.3% at 3 years. In the Spacer group, big/moderate sexual bother increased from 23.6% at baseline to 28.6% at 3 years. In both cases, sexual bother peaked at 1 year after treatment.

[Jancapper in reply to Tall_Allen]

I understand the radiobiology. However, researches just haven’t mentioned any decrease in the killing effect of the ionizing radiation used. Here is one additional review of spacers. It is very thorough and informative. Once again, the authors conclude “Spacer application reduces Normal Tissue Complication Probability and increases the probability of cure in cancer radiotherapy. 

ncbi.nlm.nih.gov/pmc/articl...

[Tall_Allen in reply to Jancapper]

That's because no research that I'm aware of has investigated effectiveness. Please cite any trial that shows it increases the probability of cure. NTCP is a mathematical concept, not a clinical effect. The only major RCT is the one I cited.

[Jancapper in reply to Tall_Allen]

Here you are.

pubmed.ncbi.nlm.nih.gov/282...

[Tall_Allen in reply to Jancapper]

That's just the clinical trial reviewed in my article. It makes no mention of effectiveness, only toxicity and patient reported outcomes.

[Jancapper in reply to Tall_Allen]

The FDA would not approve of “drug” unless it was proven both safe and effective. I have provided many studies demonstrating this. I have not provided any personal commentary, only conclusions reached by the study authors. Why would you demand to see RCT’s demonstrating increased cure rate, when in fact, the gel was not marked to do so? The gel is used to protect the rectal wall. And numerous studies have concluded that it does just that. If additional claims are made, I suggest you argue with the researchers. If a treating RO believes in and uses the gel, and has experienced good results with it, he/she can claim that it has helped cure his patients. If nasty grade 3&4 rectal side effects have been avoided or if the RO was confident in the product and hence used a higher Rx dose, and the patient was cured, I would consider the use of the gel part of that cure. I for one, will be using it.

[Tall_Allen in reply to Jancapper]

It only had to prove safety and that there was improvement in toxicity, however slight.. It never had to prove that it didn't impair the effectiveness of the radiation.

• My RO questions whether the compression of the prostate it causes diminishes the effectiveness of the radiation. There has never been a trial to test that - who would pay for the trial?

• It must never be used if there is any risk of EPE. That's what happened to a friend of mine. It protected the cancer and held it against the rectal wall. It grew there and was inoperable. Eventually it spread, caused a LOT of suffering and killed him.

• There are cases of rectal wall ulcers caused by it.

• It has minimal effect.

Urologists love it because they get paid a lot for the injection. I think the cost of the gel is $5000 on top of doctor and facility costs. All for a product that does little.

[Jancapper in reply to Tall_Allen]

And there of plenty of instances of rectal wall burn absent the use of the gel. Even if the benefit is marginal, the stakes are high. I would like to receive the best treatment available, and any potential benefit, however small, should be considered. I too, would like to read studies demonstrating that the use of the gel does what you proclaim, lessons the killing effect of the directed ionizing radiation through the gel compressing the prostate to such a point that it directly caused hypoxia within the tumor. Frankly, I think this is absurd, but to each his own. The space created by the gel is 7-12 mm. I doubt this is sufficient to cause enough distortion and or pressure to cause hypoxia. Keep in mind, the gel creates the space by pushing the rectal wall inward. One one side you have a solid tissue organ, the prostate, and on the other a hollow lumen. Which side do you think is going to give to accommodate the added pressure of the expanded gel?

Yes, the use of the gel has some risks associated with it’s use. Read the articles above and you will find that they are minimal. SE are minimized by selection an experienced physician that has performed the procedure frequently. The SE argument is frivolous as all medical procedures have some risk.

Best regards. Mike

[Tall_Allen in reply to Jancapper]

My RO has seen prostate compression with it, in spite of what you imagine. We rely on empirical observation, not musings.

Rectal injury is rare, with or without the gel. 95% of patients receive no benefit from it. But it is not harmful in 95% of patients. Because there is an economic incentive for Uros to give it and because so many patients are taken in by the hype, we are starting to see reports such as these:

"there are a number of severe and debilitating complications recently reported in proximity to gel injection."

liebertpub.com/doi/10.1089/...

"postapproval surveillance of unexpected and potentially related injuries remains important to ensuring patient safety. To this end, we present a case of suspected contribution of significant hydrogel spacer gel rectal wall infiltration to a high-grade rectal injury and subsequent grade 3 to 4 urethral/infectious sequelae in a man undergoing high-dose RT for prostate cancer."

advancesradonc.org/article/...

"We present a case of rectal ulceration associated with SpaceOAR hydrogel insertion during low-dose-rate (LDR) brachytherapy in a patient with prostate cancer."

ncbi.nlm.nih.gov/pmc/articl...

Canada has rejected its use. You may be interested in why:

muhc.ca/sites/default/files...

[Jancapper in reply to Tall_Allen]

Thanks for the articles, particularly the last one. My situation is a bit different. I am on 3 months of ADT (Lupron/Casodex) followed by a single session of HDBT (15 Gy) followed again by 45 Gy of EBRT divided between 25 fractions. It was my understanding that the gel would be inserted first followed by the insertion of the Au fiducial markers. After these were complete, only then was the HDRT to begin. I am now not absolutely certain that my understanding of the sequence is correct. If it is, my thoughts were that the gel would be beneficial in some rectal wall burning prevention due to the HDBT. I have searched many hours but failed to find any publications studying this. If the gel is going to be inserted after the HDBT, I do agree with your assessment.

BTW, my RO is doing all the work himself, Dr. Logston is a HDBT specialist in the Sacramento area. My fist RO referred me to him after my first visit. During my first meeting with Dr. Logston, he assured me that his plan offered me the best chance of cure and survival. He gave me a web site that has all the different treatment plans available. I am new to this site, but so far, I haven’t seen anyone post it. I think I will share it later.

Thanks for the info.

Mike

[Tall_Allen in reply to Jancapper]

I think a better case can be made for its use with LDR-BT because of the long-time irritation of the rectal wall. HDR-BT can even do a zero margin on the rectal side. My friend who got the rectal tumor because of SpaceOAR had HDR-brachy boost therapy. The risk of an undiscovered EPE goes up with high-risk PCa. My friend only had an occult focal EPE which was not discovered until his RO reviewed his planning MRI after his rectal tumor became obvious.

You are right that the SpaceOAR has to be done first.

Brachy boost therapy has the best record of success with high risk PCa:

prostatecancer.news/2018/03...

It is certainly the tried-and-true therapy for high risk, with data going back to the mid 80s, I think. More recently, experimental protocols may give brachy boost some competition:

prostatecancer.news/2021/06...

[BB_1]

Thank you for the reference. They like almost nothing. Concept looks good on paper. Now I have to wait until the gel dissipates in me before I get any radiation treatment.

[timotur]

I had SpaceOar for HDR-Brachy with no issues, and may have prevented any radiation SE's. I recommend it based on my experience. There is some skill required to place it correctly, my RO had done several hundred, and an MRI showed it was placed perfectly (Dr Chang/UCLA).

[dadzone43]

sorry for this setback.

[NotDFL]

I have recommended the procedure on another prostate cancer website. But, based on Tall Allen's comments I will be more careful from now on. There's little doubt though that skill in placement is paramount. I wonder about the latter in this particular case. So sorry it happened!