Cancer Program Annual Report - Eisenhower Medical Center

E I S E N H O W E R M E D I C A L C E N T E R
treating physician chooses the technique that is most
appropriate for the patient. Treatment is then delivered with
Intensity-Modulated Radiation Therapy (IMRT). This advanced
modality of treatment delivery maximizes radiation dose to
the target while minimizing dose to the surrounding normal
structures. Eisenhower BIGHORN Radiation Oncology Center
utilizes RapidArc ® technology, which allows for these complex
treatments to be given in a matter of minutes.
During the course of treatment, most patients experience few
if any side effects. The main long-term side effect of SBRT is
injury to the lung, called radiation pneumonitis. This occurs in
approximately 15 percent of patients and is mild in most cases.
Additional long-term side effects, including injury to the ribs,
heart, and nerves, are rare with careful treatment planning.
Patient selection is key to successful implementation of SBRT.
Each of the three to six treatments delivers a large dose of
radiation, which results in considerably more tissue damage
than conventional doses of radiation. This higher level of
tissue damage is the foundation for why SBRT results in higher
cure rates. However, significant side effects may occur if large
volumes of normal tissues are subjected to these large doses
of radiation. Consequently, SBRT should be reserved for small
tumors (< 4 cm), which limits radiation exposure to the
surrounding lung. Additionally, tumors should be located at
least 2 cm from the main airway, heart, and mediastinal vessels
to avoid excess radiation of these structures. When these
principles are followed, outcomes are excellent and side
effects are tolerable.
In summary, patients with early-stage NSCLC is a localized
disease process, which can be cured with local therapy.
Surgical resection remains the standard of care for management
of this disease. However, SBRT is an effective option for
medically inoperable patients or patients who do not wish to
undergo surgery.
Tumor Immunology:
Breaking through the
Cancer Barrier
Davood Vafai, MD
Medical Oncology
For years,
researchers
have been
perplexed by
a cancer cell’s
ability to elude
an effective
immune
system
response. They understood complex
abnormality of the cancer cells and
how the body’s white blood cells
should destroy them. And, in the
laboratory, their theory proved
correct. The question became why
can cancer cells survive in the body
Recently, researchers discovered the
answer. Cancer cells actually blanket
themselves with a shield — an invisible
barrier — to protect against an
immune system attack. To understand
the pathophysiology of an immune
system attack of a tumor’s antigenic
structure we first need to understand
the mechanism of antigenic presentation
to immune system cells.
The antigenic recognition starts with
both antigen presenting cells (APC
cells) which would capture some of
the membranous and cytoplasmic
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