Lung Cancer: Radiation Oncology
Radiation therapy, also called radiotherapy, is another common treatment
option for some types of lung cancer. With radiation therapy, high-energy
X-rays are used to shrink tumors, relieve pain and pressure, decrease
symptoms, and improve quality of life. Cancer specialists called radiation
oncologists provide this specialized treatment in conjunction with a special
team including physicists, dosimetrists, radiation therapists and nurses.
Radiation is an important treatment modality, used either singularly or
in combination with chemotherapy and/or surgery, for the management of
thoracic malignancies. This therapy can be used as the primary therapy
(often in combination with chemotherapy) and/or adjuvantly to definitive
surgery to reduce the likelihood of recurrence postoperatively. It also
plays an important role in the management or palliation of symptoms due
to advanced thoracic cancers. This is a useful treatment in primary lung,
esophageal and thymic tumors.
What to Expect
Prior to treatment, patient will meet with a radiation oncologist to determine
the role of radiation and the patient’s eligibility. Additional
tests may be required prior to treatment (ie. pulmonary function tests}
to determine if a patient is a candidate. In the curative setting, radiation
maybe combined with chemotherapy and this will be determined by a medical
oncologist. If a patient is a candidate for radiotherapy, they will first
undergo a special CT scan to help plan or “map” the treatment,
known as “simulation”. Permanent tattoos may be required.
A special immobilization cushion may be fabricated at the time of simulation.
Most treatments are delivered daily, 5 days/week, Monday through Friday.
Treatment usually takes less than 15 minutes and is painless. Duration
of treatment may last up to 6 ½ weeks depending on the type of
cancer. In special cases, treatment may be delivered over 3-5 days.
The side effects of treatment usually depend on the part of the body that
is being irradiated. The possible side effects of thoracic radiation include,
but are not limited to:
- Dry cough
- Mild shortness of breath
- Discomfort with swallowing due to irritation of the esophagus
- Skin redness in the treatment field
The Department of Radiation Oncology at St Joseph Hospital uses the latest
radiation techniques utilizing Varian linear accelerators with the Trilogy
platform. We offer
Intensity Modulated RadioTherapy (IMRT) using RapicArc,
Image–Guided RadioTherapy (IGRT),Stereotactic Body Radiotherapy and Radiosurgery (SBRT and SRS respectively).
Radiotherapy for Non-Small Cell Lung Cancer (NSCLC):
Radiation plays and important part in the treatment of stage 3 NSCLC. Patients
who are surgically operable may be offered moderate dose preoperative
radiotherapy in conjunction with chemotherapy to shrink the tumor prior
to surgery. In patients who have undergone surgery initially for stage
3 lung cancer, radiation is often recommended post operatively with chemotherapy,
either concurrently or sequentially to reduce the likelihood of recurrence.
Patients with stage 3 NSCLC who are not surgically operable may be candidates
for definitive chemoradiation with curative intent.
Small Cell Lung Cancer (SCLC):
Small cell lung cancer treatment depends on whether or not the disease
is limited or extensive. Unlike NSCLC, surgery has a more limited role
in SCLC (unless tumors are small and peripheral). Concurrent chemoradiation
is the treatment of choice for limited stage SCLC with a potentially curative
intent. If disease is extensive, short course radiotherapy can be used
to palliate symptoms, such as pain, shortness of breath or brain metastasis.
Prophylactic Cranial Irradiation (PCI):
Patients with SCLC have a 50-80% chance of developing brain metastasis
over the course of their lifetime. Those who have a good response to either
chemotherapy or chemoradiation (based on post treatment imaging) and who
have not yet developed brain metastases, may benefit from low dose whole
brain irradiation to reduce the risk of this happening. There may also
be a benefit to overall survival. The neurocognitive risks and benefits
are discussed with the patient.
Stereotactic Body Radiotherapy (SBRT):
SBRT is a novel form a radiotherapy for treating lung cancers. It involves
precise patient immobilization and targeting of tumors with focused, high
dose radiation over 3-5 days. This can result in very high local control
rates approaching that of surgery while minimizing damage to normal tissue.
It can be used in the following settings:
1. Early stage primary lung cancers in patients who are not good candidates
due to the tumor being surgically inoperable or due to patients not being
medically operable due to other medical conditions. Tumors are ideally
less than 5 cm and are not close to major blood vessels or airways. Patients
who are elderly or considered at too high risk for surgery may also be
appropriate candidates for SBRT.
2. Patients with solitary tumors that have spread to areas of the lung
from other areas of the body.
Stereotactic Radiosurgery (SRS) for Brain Metastasis:
Patients with NSCLC who have 3 or fewer brain metastases can be offered
a single, high-dose precision radiation treatment. This may involve a
multidisciplinary approach with a neurosurgeon. Treatment involves a special
pretreatment MRI, fabrication of an immobilization mask or device and
usually takes less than 15 minutes. Compared to whole brain irradiation,
neurocognitive side effects are limited.