I'm Dr. Keith Unger. I'm a radiation oncologist at MedStar Georgetown
University Hospital. I'm director of the Gastrointestinal Cancer Service and
Residency Program director. I see patients to provide recommendations
about radiation therapy. I primarily focus on treating gastrointestinal
cancers, as well as sarcomas, among other sites. The goal with radiation therapy is
to kill cancer, often in conjunction with other cancer therapies including
chemotherapy and surgery. At MedStar Georgetown University Hospital, we have
extensive experience in both proton therapy and experience with other
advanced radiation therapy techniques. So whatever the patient's situation is
or the indication radiation therapy, we choose the best treatment modality for
the individual situation because we have all these techniques available.
Additionally, we have a strong multidisciplinary team in other
departments so we can offer surgical services, oncology services, and other
supportive care services that are necessary for comprehensive cancer
treatment. I'm very excited to be able to offer proton therapy. I think it provides
a very exciting option to patients in which we can improve our results over
traditional radiation therapy techniques. It gives us another tool in our our
armeterium against cancer and allows us to have additional options and choices for
our patients. Over the last ten to twenty years, we've
seen rapid advancements in the technologies that we use for radiation
therapy, as well as drug therapies that are used in oncology. With these
advancements, we've seen real progress and improvements in patient outcomes.
When I speak with patients, it's critical that I understand what they're looking
to get out of their treatment. So when we have a conversation, I focus on trying to
both educate them, provide recommendations, but really to understand
what their goals of therapy are and to work to the best of my ability to meet
those goals.
Proton therapy is an advanced form of radiation therapy that uses protons, a
charged particle, to deliver radiation therapy to treat cancer. Protons travel
through tissue and release their energy at the end of their range, thus sparing
tissue behind your target. This is as opposed to X-rays which is a more
traditional form of radiation therapy that is used widely to treat cancer
which travels through the target and out the back end, resulting in additional
exposure of normal tissues to radiation as opposed to protons.
Proton therapy is, oftentimes, a more precise form of radiation therapy.
Because there's less normal tissue exposed to the effects of radiation with
proton therapy, it's possible to increase the dose of radiation thus potentially
being a more effective therapy. Or, it's possible to decrease the normal tissue
exposed to the effects of radiation thus reducing the side effects, both acutely
in the short term or long term following radiation treatment.
Proton therapy can be used throughout the body. In the gastrointestinal tract,
the strongest evidence for using proton therapy is treating liver cancers.
There's evidence to indicate vast improvements over traditional radiation
techniques using proton therapy to treat cancers that start within the liver or
even metastatic cancers in highly selected cases. Liver cancers include
cholangiocarcinomas, which are bile duct cancers, or
hepatocellular carcinomas, cancers that develop in the primary liver cells.
So there are many GI cancers that can be treated with proton therapy including
pancreas cancer. So in certain scenarios, proton therapy can offer a benefit in
treating pancreas cancer as compared to traditional radiation techniques. At
MedStar Georgetown University Hospital, we have a variety of options to treat
pancreas cancer including proton therapy. We also have the option of CyberKnife. So
we have a number of treatment modalities, and we would consider which modality
would be best for each individual patient.
We think about protons therapy as an option in three general scenarios in
treating esophageal cancer. Firstly, in what we call the preoperative setting,
that means before surgery. It's been shown that proton therapy results in
significantly less radiation dose going to the heart the lungs and the
gastrointestinal tract as compared to what we see with traditional radiation
therapy techniques. There's some evidence that this can decrease side effects as
well as decreasing complications from surgery.
Additionally, proton therapy can be used to provide additional dose to the tumor
in situations where surgery is not possible for esophageal cancer.
Potentially, this could result in improved outcomes.
Finally, proton therapy can be used in the situation where a patient has had
prior radiation therapy, and we would use proton therapy to retreat the patient. A
scenario which is very complex and is often not amenable to other treatment
options.
Proton therapy can be a good treatment for primary liver cancer, meaning cancers
that start within the liver. However, in certain circumstances, proton
therapy can be used for limited metastatic cancer in the liver, which is
cancer starting on another organ and spreading to the liver. The liver is very
sensitive to the effects of radiation therapy, so it's critical that we spare
as much of the liver from the effects of radiation therapy as possible when
treating liver tumors. We believe that proton therapy is a ideal option for
many liver tumors because it allows maximal sparing of normal liver and
allows us to add additional radiation therapy to the tumor thus increasing the
control rates or improving outcomes with treatment.
The most common reason someone is not a candidate for proton therapy is if the
cancer is not localized, meaning if the cancer has spread widely throughout the
body. Proton therapy like other forms of radiation therapy is a local treatment,
meaning we treat a specific anatomic region of the body. So if the cancer has
spread widely, the benefits of proton therapy or even any form of radiation
therapy may be less.
In certain situations, we would consider radiation therapy, even in the setting of
metastatic disease meaning it's spread outside of the area it started. Typically,
those situations are when the sites of metastases are limited, so a few in
number, or in the case where the sites of metastatic disease are causing a
specific symptom or are at risk of causing the patient a problem or symptom.
From a patient's perspective, proton therapy is very similar to traditional
radiation therapy techniques in that it's a noninvasive treatment. Patients
would come in for daily radiation treatments, lie on a table, and the proton
therapy machine would move around the patient deliver the radiation. They don't
see or feel anything, and then once the machine is turned off, radiation leaves
their body.
The side effects from treatment depend on where we're treating in the body and
which organs are exposed to the effects of the radiation treatment. Side effects
for treating gastrointestinal cancers typically include side effects such as
loss of appetite, nausea, or fatigue. However, again, the side effects are
really dependent on the side of the body we're treating.
So oftentimes, we combine proton therapy with other cancer treatments including
chemotherapy, systemic treatments, or surgery.
Proton therapy, just like other forms of radiation therapy, can be combined
seamlessly with these other treatments.
Even in the setting of prior radiation therapy, proton therapy is a option for
retreatment, something we call reirradiation. The reason we consider a proton
therapy for retreatment is because it results in less exposure of the normal
tissues that have had prior radiation exposure.
We often work with other cancer specialists throughout the community, so
it's possible to receive your cancer treatment in the community and receive
proton therapy at MedStar Georgetown University Hospital.
The reason to come to MedStar Georgetown University Hospital is that we offer a
wide array of radiation therapy options. We have extensive experience in advanced
radiation therapy modalities including proton therapy as well as other
modalities like CyberKnife. Additionally, we are a Comprehensive Cancer Center, and
we offer services with expertise in medical oncology, surgery, and it's you
can have your cancer team under one roof. Our proton center is on-site within our
Cancer Center offering easy access to the other services.