Proton Beam vs Rapid Arc Image Guided... - Advanced Prostate...

Advanced Prostate Cancer
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Proton Beam vs Rapid Arc Image Guided Radiation Therapy

Tomorrow I will complete 39 radiation treatments for post prostatectomy salvage radiation therapy, which was delivered by a Rapid Arc machine. A friend of mine is now considering how his post prostatectomy salvage radiation therapy will be delivered. He knows about my Rapid Arc IGRT treatments. However, today he met with Dr Andrew Lee in the Dallas area. Dr Lee assured my friend that his proton beam machine would be just as good, if not better, than the latest IGRT machine. Any advice to help my friend make his radiation therapy decision? Thank you very much!

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Congratulations on completing your treatment therapy. Can you write a brief summary of what the 39 sessions were like for you, with helpful hints for those about to undergo similar radiation?

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Happy to. Treatments were every weekday for 8 weeks. First 24 treatments covered entire pelvic area. Last 15 narrowed treatment area to where the prostate used to be. Two/three weeks in, side effects of radiation were fatigue, increased frequency of urination and diarrhea. (Dr recommended Flomax and Imodium. I did neither because I have an aversion to taking drugs for “minor” symptoms.) All of these side effects diminished once the treatment area narrowed during the last 3 weeks. I also started hormone therapy (10 mg Bicalutamide) two months before start of radiation treatments. Will stay on hormone therapy for at least 2 months after last treatment...at time of first PSA. Hormone therapy also causes fatigue, as well as tender, enlarged breasts (despite chest radiation to prevent gynecomastia). 2 weeks ago I asked Dr for Tamoxifen, and it has seemed to help some. My best advice: get plenty of sleep and be consistent in light weight training.

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I completed my sessions in just over 7 weeks . I was fortunate enough to get the 1st session of the day (6:30) and the hospital was 4 miles from my home which helped tremendously . Although since I had to fill my bladder (drinking a large 20oz glass of water ) 1/2 hour before it made the 25 minute drive to work tough , and I often had to stop to pee at a convenience store .

The sessions were only 10 or 15 minutes on the table and the rad techs were all sooooo nice . I would even say it was easy . They were guided by prior scans and specifically an Axumin scan .

I would occasionally get tired in the afternoon but I can’t say that was a direct result of the rad . It could have been the lupron , or just the usual tiredness of a 53 year old who gets up at 530 am, works 50 hours a week , and doesn’t sleep enough .

I wish you and anyone else all the best with your radiation treatments ! Live long live strong my brothers !

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Thank you very much for your reply. Be well! God Bless You! Joe

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Glad to hear about the positive feedback. Will be starting the 1st of my 42 IGRT 4/2/18. Started taking casodex 3 wks ago after bilateral orcheotomy. Am wondering why my Urologist didnt give me the monthly injection like leupron.....is this required?

I have stage 4 prostate cancer with osteoblastic lesions in the pelvis, spine and femur.

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I think that most doctors go the Lupron route. I do not know why, in my case, my prostatectomy surgeon started me on Bicalutamide (casodex) in preparation for radiation therapy. I will ask him in June when I see him again. Of course, I did learn that Bicalutamide does not stop testosterone production, but rather blocks testosterone from getting to receptors. Lupron, on the other hand, stops testosterone production. Other members of this group know a lot more about hormone therapy than I do. But I get the impression that both drugs accomplish the same objective, although on different ways. How one tolerates each drug seems to be the key. Side effects may be different. As a matter of fact, when I complained to my radiation oncologist about experiencing the gynecomastia side effect from the Bicalutamide, he offered to switch me to Lupron. Rather than “switching horses midstream”, I stayed with Bicalutamide and requested tamoxifen in an attempt to counter the gynecomastia. (I discovered this option doing research...doctor would have not offered on his own.) The tamoxifen has made the gynecomastia a little less sensitive. Been on it about 3 weeks. Hope it works! Thank you very much for your response. Have a Blessed Easter! Joe

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I'm aware that there are a couple of clinical trials of salvage proton therapy. It is very experimental, and should not be done outside of a clinical trial. As primary therapy, protons have not lived up to their promise (Bragg effect). So far, the oncological and toxicity outcomes are indistinguishable from photon therapy. Your friend should make sure his insurance will cover it - many insurance companies won't, and it is very expensive.

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Thank you very much!

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

From the article's conclusion: "There is much discussion and disagreement concerning toxicities, cost–effectiveness, and the potential for better outcomes (2). However, PBT is certainly cost-intensive and yet has great potential with regard to basic physics and biological principles. Nevertheless, the advantages so far seem to remain theoretical and are brought about by a better dose distribution."

As Yogi Berra once said:

“In theory there is no difference between theory and practice – in practice there is”

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Awesome reply! I especially like your Yogi Berra quote! Be well! God Bless You! Joe

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It's interesting to read about. You can learn about cool things like Linear Energy Transfer, Bragg Peak, Depth of Ionization and other aspects of radiation physics.

Protons have a better theoretical dose distribution but the conventional linear accelerator delivering photons makes up for that with its ability to go at the tumor from every angle, modulating the dose delivered and shaping the beam accurately.

There are lots of interesting graphs, but at the end of the day the only graph that matters is patient outcomes. So far, the treatments are comparable in outcome. The price and availability of the two is where the big difference lies.

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Thank you again! Good stuff!

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"You better cut the pizza in four slices because I'm not hungry enough to eat six." ~ Yogi Berra at Yankees Stadium in 1959

Good Luck and Good Health.

j-o-h-n Saturday 03/31/2018 12:10 PM EDT

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One has to mention the following Facts that are not covered before:

1. In Proton Therapy the number of Radiation Sessions is lower than with Photon

Therapy, for the same Effect of Outcome for the Patient.

Compare : typically 36 Sessions with Photon Therapy to the typically 21 Sessions in Proton Therapy

for a typical Prostate-Cancer Treatment with Radiation Therapy.

2. The radiated total Body - Volume is ca. 30 Percent lower in Proton-Therapy than in

Phototon therapy with IGRT.

So the whole Radiation Dose to the whole Body is lower.

This will have an effect on the side effects of the Radiation therapy.

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Thank you very much for the info! Joe

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Initially, there is a difference in toxicity of the two treatments favoring PBT, but it disappears at 1 year.

"A retrospective analysis of the Medicare database compared early toxicity in 421 men using PBT with 842 matched controls treated with IMRT. A statistically significant decrease in GU toxicity at 6 months for PBT was seen, but this difference had disappeared at one year. There were no other significant differences in toxicity between the two techniques at either 6 or 12 months post-treatment. Yu et al. concluded that although PBT is substantially more cost-intensive than IMRT, no difference in toxicity in a comprehensive cohort of Medicare beneficiaries with PC at 12 months post-treatment was found "

"...Other studies have found IMRT to be favorable over PBT with regard to toxicity. An analysis from the Medicare Surveillance, Epidemiology, and End Results (SEER) database in the USA identified 684 men treated with PBT between 2002 and 2007 and compared these with a cohort treated with IMRT.

Intensity-modulated radiotherapy was associated with significantly less GI morbidity. However, there were no statistically significant differences in other toxicities, nor a significant difference in the frequency with which patients required additional cancer therapy."

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

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Thank you very much for the info! Have a Blessed Easter! Joe

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further Information :

Report at PTCOG : (from a Proton Beam MD)

ptcog.ch/archive/conference...

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Someone compared proton to a smart bomb and photon to carpet bombing. I went with the carpet bombing considering possible outliers.

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Thanks, Squiredog!

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As I understand it, in the past, proton therapy was never used for radiating the area around the prostate. If, for example, a radiation oncologist were planning to treat the prostate plus surrounding tissue for a high Gleason, high PSA, high risk cancer, he or she would treat the prostate with protons and use external beam radiation for the surrounding area.

<ignorant_speculation>

I don't know why they did it that way but I'd be happy to put on my ignorant speculation hat and speculate that the coverage of a large volume is more difficult to do with protons than with x-rays. Due to the Bragg Peak phenomenon (see Wikipedia entry for it), a proton beam deposits almost all its energy in a small target volume, with little treatment in front of or behind that target. That's a great thing for precision radiation, e.g., in eye or brain cancers. It's okay in prostate cancers (I'm not convinced it's better), but I speculate that its use gets harder the bigger the volume that is to be radiated. The risk of missing a spot or possibly even overradiating a spot, might increase. Also, the cost and time might increase.

</ignorant_speculation>

Having said all that, I'll add my opinion, which I hope is more than an ignorant speculation, that a key factor in success is not so much the radiation machine used as the human brains that guide it. Your friend should be as sure as he can be that he's found a radiation oncologist who is both highly competent and highly committed to curing his patients. A doctor with an attitude of "I'm hungry. This radiation plan is good enough. I'm going to lunch now." can screw up with any machine you put in his hands.

Alan

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Well said! Thank you! Joe

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Good Saturday Morning jdayoc,

I have been in this battle for almost six years (please see bio for complete treatment history).

In my experience, what matters is the competence of the facility. I had proton beam radiation and 1 year later have radiation proctitis in my rectum and avascular necrosis in left hip. Will never be able to prove the exact cause, but I have my suspicions.

Best wishes. Never Give In.

Mark, Atlanta

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Thank you, Mark! God Bless You!

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