Author Topic: Radiating the tumor and not the healthy tissue.  (Read 3234 times)

KeepSmiling

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Radiating the tumor and not the healthy tissue.
« on: March 13, 2018, 02:26:51 pm »
All  brain tumor patients would prefer a form of radiation that deposits most of the radiation at the brain tumor site, without affecting the tissue around it or behind it. Proton Beam or Proton Therapy is rarely mentioned by doctors as a treatment for the acoustic neuroma (vestibular schwannoma) but proton therapy researchers claim it does not intensely radiate the tissue along the path and it does not radiate the tissue behind the tumor at all.

Please take note of a recent article in The Washington Post called: "How proton therapy attacks cancer. These once-exotic weapons in the cancer-fighting arsenal are getting faster, cheaper and more common" By Bonnie Berkowitz and Aaron Steckelberg, Updated March 5, 2018. It provides a really good description of how Proton Beam works, including a great graphic image. You can read how with Proton Therapy, a  beam of PROTONS is aimed at the tumor and how the beam, controlled by magnets, deposits most of the radiation at the tumor site without affecting most of the tissue behind it.  This is different from photon radiation, where the beam of photons is aimed at the tumor and it irradiates all tissue along its path relatively equally, including healthy tissue behind the tumor. (Examples of Photon radiation include: Cyber knife, Gamma Knife and other traditional radiation).

Critics of Proton Beam radiation express concern that some of the healthy tissue  gets irradiated with Proton Therapy. To understand this issue, look online for  publications about  the topic called "Proton Beam Range Uncertainty." There is a 2012 presentation published  by Harald Paganetti, PhD, the Director of Physics Research, Massachusetts General Hospital, Department of Radiation Oncology. Upon inquiry, in an e-mail response, Dr. Paganetti stated that it is true that predicting the correct range of proton beams in patients is subject to uncertainties. He said that his group, amongst others, has been doing research on this subject for many years. Having said this, because there are uncertainties in predicting the range to within mm accuracy, he said that they do add additional margins to the tumor. He said, that with Proton therapy they do treat additional healthy tissue to make sure that the tumor is always covered. So, while range uncertainties are of concern for acoustic neuromas, and other tumors, he said that they do this to ensure that tumor coverage is not compromised. He said his research group tries to reduce range uncertainties so that they can reduce those margins and thus reduce the amount of normal tissue being irradiated and to reduce potential side effects. The last thing he stated really stood out: He said "Note that the dose outside of the target is typically much higher with conventional photon treatments as compared to proton treatments."

To gain more knowledge, research and read here: https://www.ncbi.nlm.nih.gov/pubmed/?term=proton+beam+radiation. The author contact information for each study is available. Acoustic Neuroma patients really should be asking questions and probing deeply into the subject of Proton Beam radiation, in order to achieve truly informed consent.

 It is possible to send your MRI of the brain to Proton Therapy Centers and to get a response from the staff about whether Proton Therapy would be helpful for you, while only incurring the cost of shipping the MRI.  Depending on your diagnosis, Proton Therapy treatments may be the optimum solution to arrest the growth and/or to reduce the size of the acoustic neuroma. Proton Therapy is a life-saving method used  to treat children with cancer and it may be challenging for adults with acoustic neuromas to gain access to proton beam treatment, because there is such high demand for it and because other solutions seem more readily available and perhaps provide quicker treatment.  The good news is that now there are many new Proton Centers being constructed. A list of the centers is usually updated by the National Association for Proton Therapy (NAPT). Until future developments unfold that perhaps offer nanotechnology and/or other treatments, it seems likely that  in the near future, more acoustic neuroma patients will routinely seek more information about getting Proton Beam radiation treatment by those who have clearly mastered the art of planning the Proton Therapy treatments.




« Last Edit: March 16, 2018, 07:22:37 am by KeepSmiling »
12/O6/2O12: 1.5 cm lesion.Proton Therapy-July/Aug, 2013 Massachusetts General Hospital. 2/23/2018 MRI: 1. Small .5 cm x(AP) x .8 cm (TV) x .8 cm (CC )left intracanicular acoustic schwannoma) Completely deaf in one ear. Occasional tinnitus. Zero side effects.

notaclone13

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Re: Radiating the tumor and not the healthy tissue.
« Reply #1 on: March 13, 2018, 02:54:57 pm »
I just visited clinical trials.gov and found Dr. Shih at Mass General has an open clinical trial that administers proton therapy to patients with untreated ANs and follows up to analyze hearing retention. You must have hearing in your AN ear to qualify. The trial is still recruiting, but is scheduled to end in December 2018.  The treatment involves daily radiation for 5.5 weeks!! Sounds a little intense, but maybe this is the standard for proton therapy. I asked my neurosurgeon about proton therapy and he was not a fan of this approach. Maybe KeepSmiling could give some insight here.

Freelander

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Re: Radiating the tumor and not the healthy tissue.
« Reply #2 on: March 14, 2018, 08:56:54 am »
Notaclone, do you mind sharing why your doctor is not a fan of proton therapy for acoustic neuroma?   

notaclone13

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Re: Radiating the tumor and not the healthy tissue.
« Reply #3 on: March 14, 2018, 04:28:03 pm »
The neurosurgeon I met with is Head of Neurosurgery at a large academic medical center and is highly regarded in his field.  When I mentioned proton therapy he brushed it off and did not really give a reason. Perhaps it is because currently there is no proton radiation equipment at this medical center, although they have begun construction of a new facility for this type of therapy.  Even if construction runs on schedule (which seldom happens) the facility won't open until sometime in 2020, and I assume there will be an extensive training period.  Personally, I would not want to have treatment at a brand new facility lacking experience.

KeepSmiling

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Re: Radiating the tumor and not the healthy tissue.
« Reply #4 on: March 15, 2018, 08:29:22 am »
Multiple sessions of radiation are called fractionated radiation. Proton Therapy is available as a single dose or as a fractionated dose, spread over time, in our case, for 28 sessions.

 A study from 2002 , authored by doctors at Department of Radiation Medicine, Loma Linda University Medical Center, Loma Linda, California, concluded that fractionated proton beam therapy provided excellent local control of acoustic neuromas when treatment was administered in moderate doses. No injuries to the Vth or VIIth cranial nerves were observed. A reduction in the tumor dose is being evaluated to increase the hearing preservation rate. The study was small- only thirty patients. https://www.ncbi.nlm.nih.gov/pubmed/11844261

Depending on the location and size of the tumor and perhaps other variables, such as the age of the patient, brain tumor patients who consider radiation to treat their Vestibular Schwannomas (VS), which is also known as Acoustic Neuromas (AN), may be treated with a single dose (presumably at a high strength) or with multiple doses (presumably moderate dosages). The issue of whether the VS patient has become completely deaf in one ear may be important in deciding whether to proceed with Proton Beam radiation.

Proton Pencil Beam is a somewhat new offering and it is not the same as Proton Beam Radiation. It was just becoming available in 2013 and we asked our doctor, Jay Loeffler, MD, who is chief of the Department of Radiation Oncology at Massachusetts General Hospital and the Herman and Joan Suit Professor of Radiation Oncology at Harvard Medical School about it, but we were already scheduled for fractionated treatment at the time we asked about it. He commented that it was not advisable but provided no details.

We do not have medical backgrounds and we are simply recounting our positive experience after my husband had 28 sessions of Proton Therapy during July-Aug 2013. We are explaining what we believe to be a correct understanding of the issues at hand.   We lack medical credentials and the above is my attempt to answer your questions. Please independently confirm and verify  the information offered.  Perhaps Proton Therapy could be a good solution for your issues. Whatever you decide, we wish you well.






« Last Edit: March 16, 2018, 07:27:34 am by KeepSmiling »
12/O6/2O12: 1.5 cm lesion.Proton Therapy-July/Aug, 2013 Massachusetts General Hospital. 2/23/2018 MRI: 1. Small .5 cm x(AP) x .8 cm (TV) x .8 cm (CC )left intracanicular acoustic schwannoma) Completely deaf in one ear. Occasional tinnitus. Zero side effects.

Freelander

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Re: Radiating the tumor and not the healthy tissue.
« Reply #5 on: March 17, 2018, 12:06:51 pm »
This is one of the better presentations on the basics of proton therapy, prepared by a medical physicist.   In it, the presenter quotes three stages of truth: (a) First ridicule (b) then violent opposition (c) finally accepted as self evident.   His view is that proton therapy (especially pencil beam scanning proton therapy) is almost through the second stage.

https://www.youtube.com/watch?v=DFKAFXDguFo

KeepSmiling

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Re: Radiating the tumor and not the healthy tissue.
« Reply #6 on: March 26, 2018, 03:22:51 am »
Wow! Great video, Freelander! Thank you! In the video many details are explained, including the reason one might need multiple sessions - also known as Fractionated radiation treatments -and these details are offered by a credible authority.

Another great article, just published http://www.redjournal.org/article/S0360-3016(17)34284-0/pdf

"Survival After Proton and Photon Radiation Therapy in Patients With Head and Neck Cancers: A Study of the National Cancer Database"
M.R. Waddle, M. Heckman, N.N. Diehl, W. Stross, D. Miller, T. Kaleem, R.C. Miller, B.C. May Jr., and others
International Journal of Radiation Oncology • Biology • Physics, Vol. 100, Issue 5, p1330
Published in issue: April 01, 2018

"...This was the first study demonstrating increased survival of ProtonBeam radiation therapy PBRT  when compared with photon based radiation for all types of head and neck cancer. 
« Last Edit: March 26, 2018, 03:30:24 am by KeepSmiling »
12/O6/2O12: 1.5 cm lesion.Proton Therapy-July/Aug, 2013 Massachusetts General Hospital. 2/23/2018 MRI: 1. Small .5 cm x(AP) x .8 cm (TV) x .8 cm (CC )left intracanicular acoustic schwannoma) Completely deaf in one ear. Occasional tinnitus. Zero side effects.

KeepSmiling

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Re: Radiating the tumor and not the healthy tissue.
« Reply #7 on: March 26, 2018, 03:41:07 am »
Although Pencil Beam Scanning was not available to us at Mass General’s Francis H. Burr Proton Therapy Center in 2013, it appears that it apparently may now be available , per this web site: http://www.massgeneral.org/children/services/treatmentprograms.aspx?id=1624
…An integral part of one of the world’s most distinguished medical centers, Mass General’s Francis H. Burr Proton Therapy Center represents the forefront of technological advances in radiation therapy coupled with expert, comprehensive, and compassionate family-centered care. We employ image guidance with all of our proton treatments and use both passively scattered 3D conformal proton radiotherapy as well as pencil beam scanning. Proton radiosurgery is also readily available. Proton radiation therapy is unique, because more than any other type of radiation, protons allow radiation to be directed to a very limited area, which reduces potential damage to nearby healthy tissues. This is particularly useful for certain tumor types in children where long-term effects on growth and development are very important. Children’s bodies are more vulnerable to the effects of radiation, so any healthy tissue that can be spared becomes vital…
12/O6/2O12: 1.5 cm lesion.Proton Therapy-July/Aug, 2013 Massachusetts General Hospital. 2/23/2018 MRI: 1. Small .5 cm x(AP) x .8 cm (TV) x .8 cm (CC )left intracanicular acoustic schwannoma) Completely deaf in one ear. Occasional tinnitus. Zero side effects.

surfagain

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Re: Radiating the tumor and not the healthy tissue.
« Reply #8 on: March 29, 2018, 05:47:40 pm »
Does anyone have information about Proton Therapy's effectiveness on treating residual tumor left behind on the facial nerve during surgury?