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Sarcomas are a type of
malignancy that arise from the supporting elements and connective tissues of the
body. Sarcomas may arise from bone, blood vessels, nerves, fat, muscles, or
tendons. Since connective tissues are widespread, sarcomas can affect any part
of the body. They most commonly arise in the extremities, particularly the
thigh. A patient with a sarcoma typically notices a painless swelling that
slowly enlarges. Since there are so many types of connective tissue, there are
an equally large number of specific types, or histologies, of sarcomas. Some of
the more common sarcomas of bone and soft tissue are: liposarcoma (fat),
leiomyosarcoma (smooth muscle), malignant peripheral nerve sheath tumor (nerve
covering) and synovial cell sarcoma (joint space lining).
Sarcomas can affect all age
groups. Muscle sarcomas, such as RMS, and osteosarcomas of bone predominantly
affect children. Other sarcomas arise in adults, particularly between the third
and fifth decade of life.
Under microscopic examination,
sarcomas may appear very much like normal, non-malignant, connective tissue
(low-grade sarcomas) or demonstrate worrisome features (intermediate and
high-grade sarcomas). The latter sarcomas are capable of spreading through the
bloodstream to organs such as the lungs or liver (metastases). Low-grade
sarcomas rarely metastasize.
At UCLA, patients with sarcoma
are managed by a multidisciplinary team of specialized physicians. The team
consists of physicians from surgical oncology, orthopedic surgery, medical
oncology, radiation oncology, pathology, and radiology. The expertise of this
team spans nearly 30 years and has resulted in significant contributions to the
science of managing patients with sarcomas. All patients with sarcomas are
discussed by the multidisciplinary team at a weekly conference designed to
achieve a coordinated plan of treatment. The goal of management is to cure the
patient and preserve the maximum amount of normal tissue and function.
Low-grade ST sarcomas are
generally managed by a combination of surgical tumor removal and a course of
postoperative radiation therapy lasting 5 weeks. Intermediate and high-grade
sarcomas typically are treated with a multimodal combination of chemotherapy,
radiation therapy, and surgery. For patients with extremity soft tissue
sarcomas, preservation of a functional limb can be expected in greater than 90%
of cases.
Radiation therapy for patients
with soft tissue sarcoma at UCLA involves the most sophisticated techniques
available, including conformal radiotherapy (CRT) and intensity-modulated
radiotherapy (IMRT). Treatment is administered with state-of-the-art linear
accelerators. Computerized treatment planning by a staff of specialized
physicists ensures accurate irradiation of tumor and maximum protection of
normal tissue. Patients undergoing preoperative irradiation for intermediate
and high-grade tumors typically receive 8 treatments. Patients undergoing
postoperative irradiation typically receive 28-35 treatments depending upon the
grade and type of sarcoma.
Simulation X-ray for a patient with a sarcoma of the thigh.
Computerized radiation dose planning for soft tissue sarcoma near the knee.
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