108 Radiation Oncology, Biology, Physics Volume 24, Supplement 1

THURSDAY, NOVEMBER 12, 1992

7:15 - 8:45 a.m.

401c

FRACTIONATION IN RADIATION THERAPY - PART I - CLINICAL EMPHASIS, HEAD AND NECK CANCER

Paul M. Harari, M.D. and Jack F. Fowler, Ph.D.

Department of Human Oncology, University of Wisconsin Comprehensive Cancer Center, Madison, WI 53792

This two-part refresher course is designed to review current research activity and treatment results in the field of radiation therapy fractionation. Part I emphasizes clinical research involving altered fractionation schedules, highlighting head and neck cancer as the teaching model. Part II emphasizes the radiobiological rationale for altered fractionation regimens.

A “standard” prescription of 2 Gy x 33 fractions = 66 Gy for patients with squamous cell carcinomas of the head and neck may not fully optimize either primary tumor control nor late normal tissue effects. The last decade has witnessed the treatment of thousands of head and neck cancer patients with curative radiotherapy using altered fractionation schedules designed to improve overall treatment results. Although the number of different fractionation regimens currently being investigated continues to increase, the common guiding principles behind their design are relatively simple (i.e., acceleration, hyperfractionation, overall treatment time).

Common fractionation terminology (i.e., accelerated hyperfractionation) will be reviewed, as well as a brief summary of radiobiological concepts pertaining to tumor doubling time, tumor proliferation kinetics, overall treatment time and fraction size-dependence of acute and late tissue effects. Several well-known head and neck fractionation schedules from around the world (Manchester Christie Hospital - United Kingdom; Princess Margaret Hospital - Canada; Massachusetts General Hospital U.S.A.; M.D. Anderson Hospital - U.S.A.; University of Florida - U.S.A.; Mt. Vernon Hospital CHART - United Kingdom; RTOG and EORTC trials - U.S.A. and Europe) will be summarized with regard to design-rationale, treatment technique and results. The design of several current cooperative group trials (RTOG and EORTC) investigating altered head and neck fractionation will be presented, as well as concepts prompting the pilot evaluation of several brand new treatment regimens.

402

MANAGEMENT OF SUPRATENTORIAL LOW-GRADE GLIOMAS

Edward G. Shaw, M.D

Division of Radiation Oncology, Mayo Clinic, Rochester, MN 55905

I. Introduction A. Epidemiology B. Etiology

II. Pathology A. Grading Systems B. Histology

III. Evaluation A. CT B. MRI C. Pathologic-CT/MI%1 correlates

V. Ongoing Clinical Trials A. Mayo/NCCTG/ECCG/RTOG Trial B EORTC Trial C. BTCG Trial D. POG/CCSG Trial

VI. Toxicity of External Beam Radiation Therapy A. Recurrence vs. radionecrosis B. Neuropsychianic effects

IV. Treatment Options with Literature Review A. Observation B. Surgery C. Postoperative external beam radiation therapy D. Other Outions

1. Int&stitial implants 2. Radioactive colloids 3. Radiosurgery