proton therapy for breast cancer treatment

Proton Therapy for breast cancer treatment ‘safe and effective’ concludes new study

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Proton therapy for breast cancer treatment is “safe and effective.” That’s the conclusion of a new study released in the Journal of Clinical Oncology, which highlighted proton therapy’s ability to control cancer cells with much less toxicity in the heart and lungs as compared to conventional (x-ray) radiation therapy.

“In our prospective trial of women with locally advanced breast cancer who required treatment of the internal mammary nodes, proton beam radiation therapy was safe and effective,” says Shannon M. MacDonald, MD, of Massachusetts General Hospital in Boston, and colleagues.

Breast cancer tumors usually occur in the lobules and ducts of the breast, which are used in the production and delivery of breast milk. Breast cancer is the most common cancer among women aside from skin cancer. Men are also susceptible to breast cancer, although the disease is rare among males.

As with other cancers, the best possible outcomes for breast cancer treatment come through early breast cancer care. Proton therapy has unique attributes that reduce radiation exposure to normal, healthy organs3,4. This is especially important in left-sided, node positive breast cancer patients (those who need the internal mammary nodes irradiated), as the cancer is close to critical organs such as the heart and the lungs.

How Massachusetts General Hospital conducted the study

Researchers enrolled 70 prospective patients with nonmetastatic breast cancer who required radiation therapy to the chest wall and regional lymph nodes. The average age of enrollees was 45, with patients ranging from 24 to 70 years old. The vast majority (91%) of evaluable patients had left-side breast cancer, and all but four patients had stage II-III disease. Only one patient did not receive chemotherapy in conjunction with proton radiation therapy.

The study, which lasted from 2011 to 2016, specifically chose patients whose treatment would include irradiation of the internal mammary nodes (IMNs). This made them suboptimal candidates for conventional radiation therapy, since exposure to the IMNs would also increase radiation to the heart and lungs. According to the study’s authors, that has been associated with an increased risk of cardiac events.

The benefits of proton therapy, however, significantly reduce exposure to the heart and lungs. It’s an advanced form of radiation therapy that precisely targets a tumor using a single beam of high-energy protons to kill cancer cells. Unlike conventional photons, which have almost no mass and extend beyond a tumor through the body, protons are relatively heavy and will hit their target – then stop. This spares nearby healthy tissues and organs from receiving unnecessary radiation.

Summary of the study’s results

Proton therapy for breast cancer treatment received high marks from this study. Of the 69 evaluable patients, the 5-year cancer recurrence rate was just 1.5% and the 5-year overall survival rate was 91%. Those positive results go hand-in-hand with low rates of severe side effects. Study authors reported no patient developed grade 3 pneumonitis (inflammation of the lungs) or grade 4 or higher toxicity in the lungs. They also reported no significant changes in cardiac function or key cardiac biomarkers.

Dr. MacDonald and colleagues concluded that “Proton beam radiation therapy (RT) for breast cancer has low toxicity rates and similar rates of disease control compared with historical data of conventional RT.”

Dr. Ben Wilkinson, MD, FACRO, Radiation Oncologist and Medical Director at Provision CARES Proton Therapy Knoxville says the findings of this study support the success he’s seen at Provision.

“Among mostly young women with left-sided breast cancer receiving regional nodal irradiation, proton therapy produces excellent target coverage with miniscule cardiac doses and low rates of lung toxicity,” Dr. Wilkinson says about the study’s conclusion. “When we treat breast cancer, those lymph nodes run very close to the heart. Proton therapy allows us to deliver the dose to the tumor site and spare the surrounding area – the heart, lung, chest wall, and even the esophagus.”

What’s next for proton therapy research?

The authors of the study from Massachusetts General Hospital say their findings open the door for more extensive studies in the future. “No early cardiac changes were observed,” they note, “Which paves the way for randomized studies to compare proton beam radiation therapy with standard radiation therapy.”

In fact, the results of the study bode well for a more comprehensive trial already underway to compare proton therapy with conventional x-ray therapy. The Radiotherapy Comparative Effectiveness (RADCOMP) Consortium Trial, which began in 2016 and will continue until at least 2022, is being conducted by the University of Pennsylvania, in conjunction with the Patient-Centered Outcomes Research Institute.

According to the U.S. National Library of Medicine, it is a pragmatic randomized clinical trial of patients with locally advanced breast cancer. More than 1,000 patients will be randomly assigned to receive either proton therapy or x-ray therapy. Each patient will have a 50-50 chance of getting into either treatment group. Both groups will be followed for at least 10 years after completing radiation therapy. The trial’s ultimate goal to is to study the patients’ quality of life outcome to help decide which is the best treatment option for future patients with breast cancer – proton therapy or x-ray therapy.

The Benefits of Proton Therapy for Breast Cancer Treatment

Proton therapy shows remarkable promise and advantages over conventional therapy in the treatment of breast cancer. It is a type of radiation that stops at a very specific point in the targeted tissue; conventional radiation continues beyond the tumor. In breast cancer, this means on average no radiation to the heart and on average 50% less radiation to the lung5 as compared with conventional radiation.

Proton therapy is extremely precise and therefore more effective at targeting cancerous cells without causing damage to surrounding breast tissue. It is not a substitute for a lumpectomy. Rather, it is used as an alternative to conventional radiation therapy. After surgery a breast cancer patient may receive 2-6 weeks of proton therapy.

Sources:

  1. Phase II Study of Proton Beam Radiation Therapy for Patients with Breast Cancer Requiring Nodal Irradiation. Journal of Medical Oncology
  2. Pragmatic Randomized Trial of Proton vs. Photon Therapy for Patients with Non-Metastatic Breast Cancer: A Radiotherapy Comparative Effectiveness (RADCOMP) Consortium Trial. ClinicalTrials.gov
  3. MacDonald S, Specht M, Isakoff S, et al. Prospective pilot study of proton radiation therapy for invasive carcinoma of the breast following mastectomy in patients with unfavorable anatomy – first reported clinical experience. Int J Radiat Oncol. 2012;84(Suppl 3):S113-S114. Abstract 281
  4. Moon SH, Shin KH, Kim TH, et al. Dosimetric comparison of four different external beam partial breast irradiation techniques: three-dimensional conformal radiotherapy, intensity-modulated radiotherapy, helical tomotherapy, and proton beam therapy. Radiother Oncol. 2009;90:66-73.
  5. Early Toxicity in Patients Treated with Postoperative Proton Therapy for Locally Advanced Breast Cancer. U.S. National Library of Medicine, National Institutes of Health

 

East Tennessee plays role in atoms for war, for peace

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Back when the country’s great minds of science were cloistered in secret laboratories, manipulating the power of atoms into a weapon that would stop the world’s second great war, they were also dreaming of a time when such knowledge would be used for peace.

That work, carried on a few ridges and valleys away from Provision Center for Proton Therapy, now touches the lives of each patient who comes here for cancer treatment. (more…)

Provision looks back on 2016

Look back at 2016, ahead to the future

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The year 2016 has been a year of significant progress for Provision, and one that will enable us to aggressively pursue our “mission of developing innovative healthcare solutions focused on improving patient care and clinical outcomes and developing support for research, education and charitable causes.” This year has also been a year which tested our commitment, courage and resolve—and we passed the test.

Here is a summary of some of our key developments… (more…)

Provision reaches 1000-patient milestone!

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The gong—three clangs that echo through the lobby, treatment rooms, work station cubicles. It’s startling for first-time visitors and new employees.

It quickly becomes the joyous reminder of why we’re here.

Today, the 1000th patient rang the graduation bell to applause of patients, former graduates, employees and supporters of the Provision Center for Proton Therapy. (more…)

Provision Chairman & patient were college classmates

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As Paul Dyer scanned through a coffee table book about Knoxville while waiting in the lobby at Provision Center for Proton Therapy for his treatment, a name suddenly seized his attention: Terry Douglass.

The chapter was about Provision and outlined the role Douglass, chairman and founder, played in its start-up as well as the prior successful start-up and sale of CTI. That company, now owned by Siemens, developed and brought positron emission tomography, or PET scanning, to the healthcare market.

“I knew it had to be the same Terry Douglass,” Dyer says.

More than 50 years before, the two were classmates at the University of Tennessee’s School of Engineering—Douglass in electrical engineering, Dyer in the mechanical engineering program.

Dyer says he had no clue Douglass was the entrepreneur behind Provision before he traveled from Eagleville, a small town in middle Tennessee, for treatment. At a recent reunion with some fellow classmates, he says, he had learned about Douglass’s involvement with CTI.

“We always knew he would do something important,” Dyer says.

Although the two were in different programs, they had a couple of classes together and hung out with the same crowd.

“I always had the sinful hope that he wouldn’t do so well on tests,” Dyer says, jokingly. “He scored almost perfect and the professor would not give a curve.”

After college, the two went their separate ways—Dyer going to work for DuPont and retiring a few years ago to the family farm, Douglass going to a position at Oak Ridge National Laboratory, the first in a series of steps toward the launch of CTI. They had not seen each other since.

When he was diagnosed with prostate cancer, it was Dyer’s primary care doctor who suggested proton therapy. He found Provision online, set up an appointment and was duly impressed with the responsiveness of the staff and, especially, Dr. Marcio Fagundes, who called his doctor and then Dyer personally as he was considering whether to choose proton therapy. In the end, Dyer and his wife decided to travel the 380 round trip miles each day to Provision for treatment.

The Friday before Dyer’s graduation, he and Douglass were reunited, posing for a photo and chatting for a few minutes about old times.

“I am so blessed that people like Terry have had ideas like PET and proton therapy and that, somehow, he has pulled all this together and made it a world-class facility,” Dyer says.

For Douglass, it was a gratifying reconnection.

“It is very rewarding and humbling to know that something of which I have been a part is impacting the lives of those whom I knew decades ago,” he says. “We never know how what we do impacts others, and we should all be thankful and blessed that we can be a part of something unique that changes lives and patient care for the better.”

French doctor high on Provision, ProNova

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Georges Noël’s interest in proton therapy hearkens back to the time when he met Provision Chief Medical Physicist Niek Schreuder in 1997 at a conference in Paris.

Georges, a radiation oncologist and widely published author, wrote a paper in 2005 declaring, “proton is the future.”

“That is not a new idea for me,” said Noël, director of the radiobiological lab at Centre Paul Strauss, a cancer treatment and research facility, in Strasbourg, France. Last year, he took a sabbatical from his position, to research proton therapy with plans to set up a center there.

He came to the U.S. to research protons, starting with a six month stint in Boston. He then decided to expand his experiences to other centers, taking jaunts to Jacksonville, Philadelphia, New York, Chicago, Shreveport and San Diego. He spent the last two months of his year-long tour observing and writing his report at Provision Center for Proton Therapy.

He already was familiar with Provision. In addition to his long-time relationship with Schreuder, journal articles by Medical Director Dr. Marcio Fagundes were regular reference points. He also came to learn about ProNova Solutions and the new proton therapy machines being developed here.

“I came to compare machines from different companies and show in my report what is the best one,” he says.

After his time here, Noël says he is absolutely sold on the ProNova product.

“It’s a device to treat patients and to treat patients better,” he said. “I think ProNova is at least five years ahead of the competition. I think this company is the future of protons.”

Noël said he appreciated the close collaboration among clinicians and ProNova development staff as well as the attention paid to the comfort of both the patients and the technicians in the proton therapy equipment’s design.

And, at Provision and ProNova, everyone has the same goal, he said.

“To think that what the physician wants, the physicist wants, what the technician wants is for proton therapy to work better,” he said.

That mindset makes ProNova machines attractive for an institution that is focused on innovation as well as treatment. Noël said he believes the equipment will be most compatible with whatever research track he might want to take, whether testing better treatments, developing databases or coming up with a dose calculation system. ProNova’s entrepreneurial approach to making a new and better machine makes it ideal for making advancements in the field of proton therapy.

“To create a company from nothing,” he said, “that’s always marvelous to me.”