Proceedings of the 31st Annual ASTRO Meeting 85

A large number of physiological, pathological and immunological factors will influence the success of tumor imaging and therapy. Examples will be discussed. Regional as opposed to systemic administration may increase the amount of radiolabeled MoAb uptake in tumors with less toxicity to the host. New approaches in the use of radiolabeled MoAbs for cancer therapy involve a second cytotoxic agent (toxin or drug) on the same antibody molecule, or the use of radiosensitizers with radiolabeled MoAbs. Other areas of active research include genetic and chemical alterations of MoAbs to increase their potential for radiolabeling and tumor localization or to decrease the human anti-mouse antibody response, the use of cocktails of MoAbs, and multimodality strategies lymohokines, or other biological response modifiers.

combining radiolabeled MoAbs with chemotherapy,

105

CANCER OF THE PROSTATE: CLINICAL DECISION MAKING AND TREATMENT TECHNOLOGY

Gerald E. Hanks, M.D.

University of Pennsylvania/Fox Chase Cancer Center

This course will review the natural history of prostate cancer as it relates to treatment decisions, the success and complications of common forms of management and emphasize clinical decision making and technology of treatment delivery. It will also review the status of important ongoing clinical trials, those that need to be done and describe the role of PSA in evaluating and following prostate cancer patients.

106

HEAD AND NECK: TREATMENT OF PRIMARY AND RELAPSED NASOPHARYNGEAL CARCINOMA

Chiu-Chen Wang, M.D.

Dept. of Radiation Medicine, Massachusetts General Hospital, Boston, MA

Nasooharyngeal carcinoma is not a common malignancy of the head and neck in the United States and presents a great challenge to the radiation oncologists in this country. Its management is radio- therapeutic and calls for careful treatment techniques to include the primary and the lymphatic drainage areas to high doses while sparing the neighboring organs such as the spinal cord, eyes, temporal lobe and mid brain.

This refresher course will review radiotherapeutic management of primary and relapsed nasopharyngeal carcinoma. The treatment techniques, placement of irradiation portals, dose levels, complications and treatment results are presented. Special emphasis will be placed on the routine use of intracavitary implant to boost the primary site and its technical aspects will be duscussed.

The control rates for advanced lesions after once-a-day radiotherapy are still quite low and most advanced lesions are treated with the b.i.d. radiotherapy program at the current time. The treatment techniques and results after b.i.d. radiotherapy will be presented in detail.

Because of the unique location of primary lesions of the nasopharynx, a modified b.i.d. program is in progress and its rationale will be discussed.

107

PARTICLE TREATMENT OF THE EYE

John E. Munzenrider, M.D.

Department of Radiation Medicine, Massachusetts General Hospital--Harvard Medical School, Boston, MA 02114

The eye has been treated with high dose fractionated proton beam therapy at the Harvard Cyclotron since 1975, in collaboration with the Retina Service of the Massachusetts Eye and Ear infirmary and the Radiation Medicine Department of the Massachusetts General Hospital. The vast majority of patients treated have had uveal melanomas, but proton therapy has also been employed in a few patients with choroidal angiomas, retinoblastomas, and metastatic disease.

In patients with uveal melanoma, survival and vision after treatment, have been good. in the first 128 patients, 80% + 5% were surviving,

At five years

20/200 (6/600) or better (Gragoudas, E.S., et al, and 69% + 6% of treated eyes had visual acuity of

OPTHALMOLOGY 94:349-353, 1987). Probability of eye

86 Radiation Oncology, Biology, Physics October 1989, Volume 17, Supplement 1

retention has been 89% for all patients, and 97%, 93X, and 78% for patients with small, intermediate, and large tumors, respectively (Munzenrider, J.E., et al, Int. J. Radiat. Oncol. Biol. Phys. 15:553-558, 1988). The probability of local tumor control at 60 months has been 96.3 + 1.5% (Munzenrider, J.E., et al, Int. J. Radiat. Oncol. Biol. Phys. 16:1989, In Press).

The computerized treatment planning system, treatment technique, and updated results in uveal melanoma patients treated at Harvard will be presented. Possible indications for proton beam treatment of other eye conditions will also be discussed.

Particle beam therapy for uveal melanomas has also been employed on large numbers of patients at Lawrence Berkeley Laboratory, in Berkley, California (Lindstadt, D., Int. J. Radiat. Oncol. Biol. Phys. 15:347-352, 1988) and at Paul Scherrer Institute (formerly SIN), in Villigen, Switzerland, generally using techniques and dose schedules similar to those employed at Harvard. Available results from those centers will be presented. Survival data in particle beam treated patients will also be discussed, particularly as it relates to the rationale for an ongoing national prospective clinical trial (Fine, S.S., Arch. Opthalmol. 104:653-65412i986) which randomizes patients with intermediate tumors between enucleation and brachytherapy, using 1 plaques.

108

PHOTODYNAMIC THERAPY: THEORY AND PRACTICE

Thomas F. DeLaney, M.D. and Eli Glatstein, M.D.

Radiation Oncology Branch, National Cancer Institute, Bethesda, MD 20892

Photodynamic therapy is a promising investigative treatment modality that employs photosenitizing agents and light of appropriate energy to eradicate malignant tissue. It has been shown to be effective in both in vitro and in vivo models and is currently being evaluated in a variety of clinical applications. The physical and biological basis for therapy will be reviewed, in an attempt to define a strategy for successful utilization of photodynamic therapy in the clinic.

1. Basic principles a. Photochemistry b. Light and photophysics

2. Pre-clinical studies a. Photodynamic effects on cells in vitro b. Photodynamic effects in experimental tumor models

3. Clinical experience with Photodynamic Therapy a. Clinical results in selected anatomic sites b. Ongoing clinical investigations

109

STATISTICAL APPROACHES TO NON-RANDOMIZED DATA

Marlene J. Egger, Ph.D.

Dept. of Family & Preventive Medicine, Utah Regional Cancer Center, University of Utah, Salt Lake City, UT 84132

Substantial inquiry into new therapies occurs in non-randomized, relatively uncontrolled environments: early experience with new devices and pilot/feasibility studies at single institutions are good examples. A clinic may publish a decade's or more experience with a particular untoward effect of a specific therapy. Several investigators may place in the public domain consensus reports and a uniform database documenting their evaluation of particular therapeutic modalities. Even in a controlled clinical trial, specific parameters of the therapeutic modality may be uncontrolled.

The use and interpretation of data available from such sources requires care and consideration unnecessary when the data derive from a controlled clinical trial. The purpose of this refresher course is to identify statistical concepts and approaches which facilitate the judicious use of uncontrolled sources.

Discussion will include topics such as representativeness of subjects, validity issues such as selection bias, various types of confounding and effect modification. The relevance to clinicians of selected issues arising during the statistical analysis will be explicated. The propriety of hypothesis testing in addition to hypothesis generation using uncontrolled sources will be explored.