Radiotherapy management of metastases

68

Radiation

Oncology . Biology

Physics

November

??

1986, Volume 12, Sup. 1

the dose response relationships for early and late responding tissues. (3) The variation of cellular response with the quality of the radiation; the relation between RBE and LET. (4) The age-response function, i.e., the variation of cellular radiosensitivity with the phase of the cell cycle. (5) Fractionation, the repair of sublethal damage and potentially lethal damage and the dose rate effect. (6) The effect of the presence or absence of molecular oxygen on radiation response, and the wider question of the chemical modification of radiation injury by sensitizers and protectors. (7) The kinetics of cells,tisues and tumors; cell cycle growth fraction, cell loss factor and the process of reoxygenationThe result of laboratory research provide a basis for a retrospective understanding of conventional radiotherapy protocols that were developed empirically, and allow an appreciation of the importance of fraction size and overall time as separate variables in the iso-effect relationship. Laboratory research also is the starting point for the newer ideas that include radiosensitizers neutrons, protectors, hyperthermia and altered fractionation patterns. These will be discussed in Part II.

108 PEDIATRIC

RADIATION

THERAPY

J. Robert Cassady, M.D. University of Arizona Medical

Center,

Health

Sciences

Center,

Tucson,

AZ

85724

This refresher course will emphasize current therapeutic approaches to a variety of pediatric solid tumors including rhabdomyosarcoma, Ewings tumor, neuroblastoma, Wilms' tumor, and retinoblastoma. In addition, several pediatric brain tumors will be discussed. Emphasis will be placed on necessary pretreatment evaluation and staging prior to initiation of therapy. Technical aspects of radiation treatment will be covered and the integration of radiation accompanying chemotherapy will also be emphasized. Representative results to be expected, complications, and major areas requiring improvement in treatment approaches will be presented. Available results of several pediatric group studies will be discussed.

109 COMPLICATIONS

IN THE TREATMENT

0~ GYN

(CERVICAL)

Marvin Rotman, M.D. State University of New York, Downstate

Medical

CANCER

Center

While the newer multidisciplinary approach to oncologic disease has brought increasing survival, it has required consistent refinement increasing short and long-term in treatment methods to prevent morbidity. have at other Although at times quite incisive, attempts to evaluate and avoid complications times only underlined our basic inability to quantitate the insults of combined therapy. With this in mind, this course will review and outline those factors related to complications of pelvic and pelvo-abdominal radiation when used as an integral part of the management of gynecologic cancer. Emphasis will be placed on the intracavitary applicator, the use of external and intracavitary radiation and combined radical radiation and surgery.

110 RADIdTHERAPY

MANAGEMENT

OF METASTASES

A. Robert Kagan, M.D., Chief Radiation Therapy Department, Los Angeles, CA 90027

Kaiser

Permanente,

Southern

CA Permanente

Medical

Group,

4950 Sunset

Blvd.,

Few As much as 60% of our time is spent in the consultation and management of incurable disease. Which patients can benefit from guidelines are available for the treatment of metastatic cancer. What dose over how many days? radiation? Should the radiotherapeutic techniques be simple or complex? The concept of staging is not well delineated for patients with metastasis. Which prognostic factors For example, a patient with mammary cancer who recurs are important to remember when examining patients? Whereas the on adjuvant CMF or who has multiple deposits and a short recurrence interval will die soon. patient with a single site of metastasis and a long recurrence interval may live a few years. So-called The use of steroids has revolutionized our management in cerebral epidural metastases. "emergency" radiation therapy can be delayed in favor of determining whether the symptoms of the After a steroid response, radiation metastatic focus to the nervous system will respond to steroids. Most often the onset of nervous system metastasis is a therapy can be given to radiosensitive tumors. The median survival of all patients with nervous system metastases is 2-6 months. dire prognostic sign.

Proceedings

We forget widespread

that the disease.

presence

of

69

of the 28th Annual ASTRO Meeting

metastases

to

the

nervous

system

is

a

pre-terminal

event

because

of

Bone biopsy may be indicated in the patient with a suspected solitary metastasis and a long Treacherous boney areas of metastases because of the morbidity of pathological recurrence-free interval. We should be wary of vertebral fracture are especially the femur and the surgical neck of the humerus. the pain of which can easily mask symptoms of spinal cord compression. No matter how careful metastasis, we are, missing slow paraplegia in a patient chronically complaining of low back-pelvic-thigh pain occurs. In a patient with symptans of radiculopathy, the corresponding vertebrae should be irradiated. Rapid

high fraction

treatment

is recommended

for all metastases.

Exceptions

Metastasis commonly generates a feeling of hopelessness, helplessness psychosocial factors, I have found honesty to be the best policy.

will be discussed.

and distrust.

In discussing