Treating Lung Cancer Without Surgery
Even when it’s caught early, some people with lung cancer aren’t healthy or strong enough to undergo surgery to remove the tumor. This was the case for Robert Tumanic, a 69-year-old financial consultant living near Milwaukee, WI. Right after being diagnosed with early-stage lung cancer in 2015 (he had tumors in both of his lungs), doctors also discovered he also had chronic obstructive pulmonary disease (COPD), an illness that interferes with normal breathing.
Because he was too weak and frail for surgery, his treatment options were more limited; as many as a third of people with early non-small cell lung cancer (NSCLC) find themselves in this challenging position, too. Fortunately, there is another option.
What Usually Happens
Normally, when cancer is located only in the lungs and hasn’t spread to the lymph nodes, and the person is otherwise healthy, doctors recommend removing the tumor through surgery, says Rodney Wegner, M.D., a radiation oncologist with Allegheny Health Network in Monroeville, PA.
Depending on the tumor's location, size, and stage, surgery is all a patient might need, though in many cases, doctors also recommend following up with chemotherapy or immunotherapy to make sure all the cancer cells are eliminated.
A Nonsurgical Lung Cancer Treatment
However, when surgery isn't option for people like Tumanic--his doctors at the Mayo Clinic in Rochester, MN, worried the procedure might affect his ability to breathe and function normally afterwards--physicians may turn to non-invasive stereotactic body radiation therapy (SBRT), also known as stereotactic ablative radiotherapy (SABR) and advertised under brand names such as Cyberknife.
Tumanic says this treatment helped save his life.
What Is SBRT?
First developed in the 1990s, SBRT technology surged in popularity in the 2000s when technical refinements allowed it to be used for conditions like lung cancer that require precise, targeted delivery.
SBRT has "revolutionized radiation oncology," says Andrea McKee, M.D., chief of radiation oncology at Lahey Hospital & Medical Center in Burlington, MA. "It's an incredible option for patients. It's really changed what we can do for medically inoperable lung cancer." SBRT is also used to treat small, early-stage pancreatic cancer as well as cancers that have spread to the liver, lung, spine, and adrenal glands.
How SRBT Works
SBRT doesn't involve cutting in to the body, but instead combines finely-tuned imaging and multiple, highly focused beams that precisely target a tumor from different angles, destroying it with intense doses of radiation.
For early stage lung cancer, SBRT typically is done on an outpatient basis in three to five sessions over one to two weeks. The sessions last an hour or less. It doesn't require an extended hospital stay, recovery is usually quick, and it leads to relatively few side effects. Sometimes, when it's used as an initial treatment instead of surgery, SBRT is a definitive treatment to treat the cancer with radiation alone.
Who SRBT Is For
SBRT is best suited for Non-Small Cell Lung Cancer. That said, it is also used for NSCLC (as it was for Tumanic). SBRT may be used in very limited stage Small Cell Lung Cancer (SCLC) that has not spread to lymph nodes, although this is done infrequently given the high risk of spread for SCLC.SBRT is most effective for people whose tumors are under 3 cm in size and usually no more than 5 cm.
"I would say that 90 percent of the time, patients have zero side effects," Dr. Wegner explains.
A Patient's Experience With SRBT
To get his treatments, Tumanic recalls climbing into a specially designed bean-bag style chair that hugged his body, holding him very still as the SBRT unit whirred and rotated around his body to deliver the radiation.
"It was scanning me in real time, so it would find the tumor and position the radiation head to shoot the tumor," Tumanic describes. "It was like rocket science. I did enjoy the science around this thing."
How SRBT Compares to Standard Radiation Therapy
Until SBRT became widely used in 2008, people otherwise too sick have surgery were usually offered traditional radiation therapy, which is delivered over 6-7 weeks with concurrent chemotherapy for lung carcinomas and can cause side effects such as dry and itchy skin, fatigue, as well as damage to healthy tissue near the target site. Some people gave up on getting treated at all, says Dr. McKee. "They felt that if they couldn’t have surgery, they just wouldn't bother with treatment."
Because it's so targeted, SBRT can provide higher doses in far fewer visits without sacrificing impact: the local control rate is approximately 90% with SBRT alone in controlling and killing early lung tumors. Success rates for traditional radiation without chemotherapy is less than half.
SBRT for Other Lung Cancer Patients
When a person gets SBRT for early-stage lung cancer, their risk of recurrence is about the same as it is for people who have surgery. So it's little surprise that studies are underway to see if the technology might be a viable option for all patients with early stage lung cancer—not just those who are too risky to operate on.
Some early analysis of data published in the Annals of Translational Medicine looks promising, showing that SBRT may be more desirable in the sense that it leads to fewer side effects. But more in-depth studies are needed. Researchers are hopeful that studies such as the Veterans Affairs Lung Cancer Surgery Or Stereotactic Radiotherapy (VALOR) trial will provide some answers.
An Immune Boost from SRBT?
In addition to being noninvasive, SBRT may help stimulate the immune system. Much remains to be investigated, but researchers already recognize that radiation can boost the body’s immune response to cancer cells locally as well as systemically, Dr. McKee says. Additional studies are looking at the effectiveness of combining SBRT with immunotherapies.
The Latest Progress
Advances in precision targeting of tumors with SBRT continue. Although a small amount of tissue around the tumor will likely be damaged during the treatment, it's usually so minor that most patients don’t notice it, Dr. Wegner says. “We now can now do a 4-dimensional CT scan, which allows us to look at the motion of the tumor while a patient breathes, and account for that," he says. This means doctors are able to treat a smaller amount of lung tissue without missing their target.
SBRT Drawbacks and Side Effects
SBRT isn't recommended for people in the later stages cancer that may have spread past the lung. And while most people say they don’t have many (if any) side effects from SBRT, chest pain and increased risk for rib fracture are problems for some, in part because the radiation can weaken bones.
"We [also] have to be careful with tumors that are close to central structures, like the heart or esophagus," explains Dr. McKee, as radiation near those areas can damage those organs.
For Tumanic, everything went well during treatment, but several months after the procedure he began noticing that his lungs and breathing had changed. He felt short of breath during exercise or while he was doing pulmonary rehabilitation. Approximately 1 in 10 people develop this kind of radiation pneumonitis; irritation and inflammation of the lung can lead to difficulty breathing. This side effect usually develops six weeks to four months after SBRT treatment has ended and is treated with corticosteroids such as prednisone to lower inflammation.
Tumanic not only developed pneumonitis again, for which he was treated with corticosteroids, but had to go through a second round of SBRT for another tumor that developed in his lungs. That said, the news was good at a recent follow-up visit to the Mayo Clinic, where they told him the tumor was gone. He says he feels healthier than he has in many years—and is grateful for having had the option of SBRT.