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Northeast Florida Medicine
Vol. 67, No. 1 2016
19
Palliative Care
Radiation Oncology is an Essential Component of
Effective Palliative Care for Patients with Cancer
By
Corey Hobbs, MD
1
, Jamie Cesaretti, MD, MS
2
, Mitchell Terk, MD
2
and Michael Olson, MD, PhD
3
1
Department of Radiation Oncology, Mayo Clinic, Jacksonville, FL
2
Terk Oncology, Jacksonville, FL
3
Chief of Radiation Oncology, Baptist MD Anderson Cancer Center, Jacksonville, FL; Adjunct Assistant Professor, Mayo Clinic, Jacksonville, FL
Introduction
Radiation oncologists play an important role in the
palliative management of malignancies involving all organ
systems. Each patient referred for palliative radiation must
have many factors considered before determining whether
radiation is indicated and how it should be administered.
Themost common factors considered include life expectancy,
performance status, age, primary tumor histology, number
of metastases, cost to the patient and expected side effects
of treatment.
1
Traditional radiation doses and fractionations vary based
upon multiple factors. Typical curative doses of radiation
for gross disease range from 60-80 gray (Gy), given in daily
1.8 to 2-Gy fractions. Adjuvant radiation following surgery
typically consists of 45-70 Gy, also given in 1.8 to 2-Gy
fractions. When a high total dose is administered with a
goal of complete tumor eradication, the inadvertent injury
to normal organs is partially mitigated by giving low daily
doses. This allows for interfraction normal tissue repair. The
last several fractions of a curative radiation regimen aremeant
to address the final few surviving cancer cells in a tumor bed.
It is from these last several radiation fractions in a curative
regimen that the risk arises of a late normal tissue effect of
radiation. Therefore, in the palliative setting, one can give
a markedly lower total dose. This can significantly reduce
tumor burdenwithout approaching significant risk to normal
tissue. This is similar to the goals of systemic chemotherapy.
The only difference is that radiation is localized to a focal
region rather than putting the entire body at risk. Common
palliative doses are 40 Gy in 2.67-Gy fractions, 30 Gy in
3-Gy fractions, 20 Gy in 4-Gy fractions and 8 Gy in a single
fraction.
2
These regimens allow a shorter radiation course and
have a relatively low risk of causing significant side effects.
Advances in radiotherapy techniques have increased con-
formality of the radiation dose to the target, allowing better
sparing of normal structures. Stereotactic radiosurgery (SRS)
and stereotactic bo
dy rad
iotherapy (SBRT) are increasingly
being utilized in one to five large fractions with curative in-
tent. These techniques are being investigated in palliation to
obtain quicker relief of symptoms
3
or more durable control
of metastatic lesions.
4
In addition, the SBRT has become a
muchmore valid option for the historically palliative patient,
because understanding of the natural history of patients
with metastatic disease has evolved considerably over the
past decade. Hellman and Weichselbaum described a new
paradigm for evaluating the patient with metastatic disease
simply based on the number of metastatic deposits found
on extent of disease evaluation studies. A recent SBRT trial
of multisite extracranial oligometastases found that 18.3
percent of patients treated with SBRT had no progression
at a median follow-up of 20.9 months. In addition, the one
and two year progression free survival and overall survival
were 33.3 percent and 22.0 percent and 81.5 percent and
Address correspondence to:
Jamie Cesaretti, MD, MS
7017 AC Skinner Parkway
Jacksonville, FL 32256
Abstract:
Radiation therapy is an important component of
multi-disciplinary oncological care for patients with a limited
prognosis. Historically, radiation oncologists have focused on
symptom management in an effort to improve quality of life. This
is accomplished by providing focal short-duration low complexity
radiation to both metastatic and locally advanced cancers arising
in multiple sites throughout the body. In addition to improvements
in quality of life, palliation with radiation has been shown to
increase length of life in patients with stage IV disease. A new
concept termed the “oligo” metastatic disease state and the use of
very focal radiosurgery have allowed for patients to have not only
few symptoms associated with their cancers, but also longer lives.