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PIONEERS IN THE FIGHT AGAINST ‘THE BIG ONE’: PROTON THERAPY FOR LUNG CANCER
Lung cancer is the number one cancer killer in the U.S., causing more deaths than the next three most common
cancers – colon, breast and prostate – combined. Worldwide, lung cancer accounts for 1.3 million deaths annually. An
estimated $10.3 billion per year is spent in the U.S. on lung cancer treatment alone, yet those diagnosed with the
disease have just a 15 percent survival rate.1
Physicians at The University of Texas MD Anderson Proton Therapy Center are leaders in the
research and treatment of lung cancer and pioneers in developing proton therapy for lung
cancer patients. With its advanced image guidance and ability to precisely target tumors in
the lungs, the powerful radiation of protons can be delivered with optimal accuracy –
sparing critical nearby structures, such as the esophagus, heart and spinal cord. Because the
tumor can be treated with a higher dose of radiation, benefits may include better local
control of the disease, higher survival rates and improved quality of life.
By combining proton therapy with
chemotherapy, targeted
molecular therapies and other
promising modalities, the Proton
Therapy Center is leading the next
generation of lung cancer care,
research, education and
prevention.
James Cox, M.D.
“MD Anderson is at the forefront of the most advanced lung cancer treatments available. It is part of our mission to
raise awareness of proton therapy as a potential option for people fighting for their lives,” says James D. Cox, M.D.,
former head of Radiation Oncology at MD Anderson. “When the Proton Therapy Center was established in 2006, for
example, it was the first to treat lung cancer with protons and chemotherapy.”
Proton Therapy at MD Anderson
Roughly 15 to 20 percent of lung cancer patients have tumors that can be treated with surgery combined with other
therapies such as radiation. Another 30 to 50 percent of patients have locally advanced tumors that require a
combined treatment regimen that includes chemo or targeted therapy in addition to radiation therapy. However, it is
challenging to deliver an adequate dose of radiation to a cancerous tumor while sparing nearby normal tissues.
What is Proton Therapy and How is it Different?
Proton therapy is a form of external beam
radiation using particles (protons) instead of
photons (X-rays) to treat tumors. Both forms of
radiation destroy cancer cells by causing their DNA
to malfunction.
Photons deposit the majority of their dose within
the first inch after they reach the skin, and
continue to deposit doses beyond the tumor.
Hitting a deep tumor with just one or two X-ray
beams is difficult and often requires many
different beams – resulting in more radiation
exposure to healthy tissues and organs, such as
the heart.
Proton therapy deposits most of the dose at the
tumor and stop traveling after hitting the target.
This allows the use of fewer beams and greater
sparing of normal tissues and organs.
Proton therapy’s advantage for many lung cancer patients is based on
this feature. Further, by minimizing the exposure of normal tissues,
proton treatment may also reduce some of the side effects of traditional
radiation and help patients maintain good quality of life.
Proton therapy is currently available at only 11 centers in North America
(13 centers are in development). MD Anderson has one of the largest
and most technically advanced centers in the world. The 96,000-square
foot Proton Therapy Center – the first proton center in the world within
a comprehensive cancer center – offers a range of proton treatment
options. These include pencil beam proton therapy, a highly precise
form of proton radiation also known as scanning beam, and intensitymodulated proton therapy (IMPT) – the most advanced form of proton
radiation. For patients with recurrent lung cancer, who have already
received full doses of traditional radiation, pencil beam and intensitymodulated therapies may further limit or eliminate radiation to sensitive
areas.
The Proton Therapy Center treats as many as 900 patients annually. Nearly 5,000 patients have been treated to date,
accounting for 15 percent of the total number of patients who have received proton treatment nationally.
Approximately 1,000 of these patients have been treated for lung cancer. The best lung cancer candidates for proton
radiation are those whose cancer is localized in the chest and can’t be removed surgically, notes Cox.
1
American Lung Association
“We’re just beginning to see the potential benefits of proton therapy and as we move forward it looks more and
more like an excellent treatment modality,” says Anne S. Tsao, M.D., associate professor in Thoracic/Head and Neck
Medical Oncology. “As we learn more and gather evidence of these benefits, proton therapy will likely be extended to
a broader patient population.”
Research
The Proton Therapy Center is advancing the science of proton therapy by providing
answers to critical knowledge gaps, confirming the effectiveness of proton therapy and
evaluating its use in combination with chemotherapy, targeted molecular therapies
and conventional radiation therapy.
Every patient treated at the Proton Therapy Center is offered the opportunity to
participate in one of more than 25 clinical protocols, which allow for the capture,
analysis and reporting on treatment results related to tissue toxicity, dose
optimization, and quality of life.
Lung cancer patients, for example, may take part in a phase II randomized
clinical trial comparing high-dose traditional intensity-modulated radiation
therapy (IMRT) with high-dose proton therapy. MD Anderson researchers
are also investigating such areas as long-term outcomes for patients with
locally advanced lung cancer treated with proton therapy and survival rates
among proton lung patients versus those treated with traditional radiation
and chemotherapy.
Since 2005, MD Anderson has published more than 175 studies focused on
proton therapy for lung cancer. Recent findings include:
Concurrent chemoradiation therapy, the standard of care for locally
advanced non-small-cell lung cancer (NSCLC), can cause esophagitis and
pneumonia, and X-ray-based radiation often cannot be given at doses
high enough to destroy tumor cells without toxicity to nearby normal
tissues. In a study published in the journal Cancer, researchers showed
that higher doses of proton radiation can be delivered to lung tumors
with lower risk of these life-threatening conditions.
Comparing toxicity and tumor coverage delivered to stage 1 NSCLC
patients via traditional stereotactic body radiation therapy, passively
scattered proton therapy and intensity-modulated proton therapy,
researchers found that: the proton radiation approaches were better in
terms of target volume coverage; significantly reduced the mean total
lung dose; and reduced mean maximal dose to other nearby critical
structures, including the aorta, heart, pulmonary vessels and spinal cord.
The study was published in the International Journal of Radiation
Oncology, Biology, Physics.
Cox explains the outcomes of proton therapy with
concurrent chemotherapy, how lung cancer
patients typically tolerate treatment and what the
future holds for lung cancer patients being treated
with proton therapy at MD Anderson.
Lung Cancer Types
Lung cancer is classified into two main groups by
the type of cells within the tumor. Each type grows
and is treated in differently.
Non-small cell lung cancer (NSCLC): the most
common type; categories of NSCLC are named for
the type of cells in the cancer:



Adenocarcinoma begins in cells that line the
alveoli and make mucus; found more often in
nonsmokers, women and younger people.
Squamous cell/epidermoid cancer begins in
thin, flat cells in the lungs; tobacco is most
often the cause.
Large cell carcinoma begins in certain types of
large cells in the lungs.
Small cell lung cancer (oat-cell cancer): makes up
less than 20 percent of cases and is almost always
caused by tobacco; often starts in the bronchi,
then grows and spreads to other parts of the body.
Proton Therapy Center researchers have completed phase I of a study, published in the International Journal of
Radiation Oncology, Biology, Physics, examining the effect of shorter courses of proton beam therapy in patients
that have locally advanced NSCLC but that cannot receive chemotherapy with radiation. Using higher doses of
proton beam therapy, treatment was typically completed in approximately three weeks.
“Advances are rapidly occurring in the field of proton therapy for lung cancer. Consider the ability to precisely target a
tumor that moves with every breath or radiating a recurrent cancer that previously we wouldn’t have because of the
toxic effects of earlier treatments,” says Daniel Gomez, M.D., assistant professor in Radiation Oncology. “Evidencebased innovations in proton therapy are making it possible to treat complicated tumors that traditional forms of
radiation can’t target as effectively. As more patients are treated, the technology will continue to improve.”
THE FACES OF LUNG CANCER
Here are three lung cancer patients who credit proton therapy with saving their lives.
Chuck Martinez: From Cancer Survivor to Marathon Runner
In 2007, just a year after surviving bladder cancer, 37-year-old Chuck Martinez began his fight against stage
IIIA non-small-cell lung cancer.
“Chuck was the perfect candidate for proton therapy,” says his physician, Ritsuko Komaki, M.D., director of
MD Anderson’s Thoracic Radiation Program. “With the location of his tumor, it was critical to limit the
radiation dose to surrounding areas, especially since he was on concurrent chemotherapy.”
Cancer-free since 2010, Chuck still wonders what may have caused his lung cancer. “I’ve never been a
smoker, so it has been one of the big mysteries for me.”
“For reasons not fully understood, lung cancer is becoming more frequent in young, healthy individuals,”
says Joe Y. Chang, M.D., Ph.D., professor and clinical section chief of thoracic radiation oncology. “In their
30s and 40s, these patients hopefully have long lives ahead and every effort must be made to provide a
treatment option that will help assure those years are spent with good quality of life.”
Today, Chuck is dedicated to a healthy lifestyle. He lost 30 pounds and has completed five half-marathons.
He recently completed the 2013 Chevron Half Marathon in Houston, finishing in two hours and five minutes.
“Running marathons never crossed my mind. My wife and I used to watch them every year on TV,
wondering ‘What does it take for someone to do that?’ I never thought it would be me,” he says.
Suzan Shughart: Not Taking ‘No’ For an Answer
When Suzan was told she had no more than two years to live at age 59, she refused to accept a death sentence. A
routine checkup had resulted in the discovery of a large tumor in the middle of her chest, but she says, “I didn’t
panic. I remember thinking, calmly, ‘Oh, so this is how it happens, this is how I die.’ And then immediately deciding
I would beat this.”
Her determination led her to MD Anderson, where doctors agreed that she didn’t have to accept the prognosis.
After the tumor was surgically removed, Suzan returned home to Scottsdale for chemotherapy. But five months
later, the cancer came back. She decided to return to MD Anderson, where proton therapy was recommended.
On her 60th birthday Suzan rang the Proton Therapy Center’s ceremonial gong, marking the end of her treatment.
“I never felt sick. I drove myself to proton therapy every day and used my time in Houston to explore and spend
time with my son, daughter-in-law and baby granddaughter.”
Today, seven years after her first diagnosis and also after undergoing treatment at MD Anderson for breast cancer,
Suzan is in remission. She’s thankful for the care she’s been given, but also for having the courage to take charge of
her health and find the best solution.
Billy Walls: The World’s First Lung Cancer Patient Treated with Pencil Beam
Always active, Billy Walls served 20 years in the Army before transitioning to an electronics career in El Paso. He was enjoying
an active second retirement working with Habitat for Humanity when, in 2004, he started coughing up blood.
Diagnosed with lung cancer, Billy underwent surgery, chemotherapy and traditional radiation. Then in 2008, he began coughing
up blood again. Though checkups showed no signs of cancer, the symptoms resurfaced and in 2010 doctors confirmed the
cancer’s recurrence. Billy came to MD Anderson, where he became the first person in the world to receive pencil beam proton
therapy.
“My physician – Dr. Chang – told me that receiving radiation twice for the same cancer is extremely rare – and that because of
my previous levels of radiation exposure, pencil beam would be the best treatment,” he says. He received 33 treatments over a
two-month span while also undergoing chemotherapy.
“It was imperative to target Billy’s tumor with the greatest amount of accuracy while limiting exposure to parts of his lung that
had previously received radiation,” says Chang. “With pencil beam technology, we were able to conform the treatment to the
exact shape and depth of the tumor and deliver the highest dose of radiation possible.”
Before pencil beam, reradiating Billy’s lung would have been impossible. To date, MD Anderson has treated about 30 similar
cases.
Now 78 years old, Billy is enjoying his life at home with his wife.
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