303C Hodgkin's Disease — part I: Epidemiology, pathology, staging, and management of early stage disease

Proceedings of the 39th Annual ASTRO Meeting 214 Endobronchial and Endoesophageal High Dose Rate Brachytherapy for Malignant Airway and Digestive Tract Obstructions Minesh P. Mehta, M.D. Dept. of Human Oncology, University of Wisconsin Hospital, Madison, WI With an annual incidence of more than 160,000 cases and a local failure rate between 30-50%, endobronchial occlusion seen with lung cancer is a common and potentially life-threatening complication. Several methods of managing this exist and recently endobronchial brachytherapy has been used extensively as a consequence of the development of fiberoptic bronchoscopy and high dose rate remote afterloading technology. Procedurally, one or more afterloading catheters are inserted in the involved portions of the tracheobronchial tree through fiberoptic guidance. Treatment techniques range from l4 applications fractionated over several weeks or given over 2 days with a single insertion procedure. Almost all procedures are currently performed in the outpatient setting. The major application of this technology is in the palliation of occlusive symptomatology. Clinical improvement ranges from 50-lOO%, radiographic reaeration ranges from 46-88% and bronchoscopic responses ranges from 59-100%. Symptomatic relief is usually quite durable with more than 70% of the patients’ remaining life-time rendered symptom-free and symptom-improved. Recently, this modality has been explored for its curative potential as a boost following external beam radiotherapy. It is clear from these series, that in selected patients, endobronchial boost produces significant reaeration and sparing of lung volume from subsequent external radiation, and a few cases may even become resectable. Demonstration of the survival advantage will, however, require larger clinical trials with adequate controls. Some reports have suggested an unacceptably high rate of fatal hemoptysis following HDR endobronchial brachytherapy. Review of the world literature suggests that fatal hemoptysis rates range from O-50% with an average of about 8%, comparable to an average of 5% with low dose rate brachytherapy. Other recognized complications include fist&e and radiation bronchitis. Because the majority of patients with cancer of the esophagus die with local recurrence and esophageal obstruction, preliminary brachytherapy efforts were limited to the recurrent disease setting. These data suggest that brief symptomatic relief results in two-thirds to threequarters of patients. Subsequent trials in Vancouver and Japan established that in patients with advanced disease, a combination of external beam and endoesophageal brachytherapy was feasible with acceptable morbidity and no mortality. Quality of life analysis suggested improved swallowing ability and reduction in dysphagia in these patients. In a series of almost 300 patients, a small subset were treated with curative intent with planned resection after brachytherapy and external beam radiotherapy, resulting in a median survival of 43 months. Such data led to the incorporation of brachytherapy boost, into RTOG 9207, a Phase I/II trial for localized cancer of the esophagus combining external beam radiation and esophageal brachytherapy in combination with chemotherapy. Complete response to therapy was seen at the primary site in 73% of patients, suggesting that endoesophageal boost could be incorporated in the current standard of care which utilizes combination chemoradiotherapy. Two prospective trials from China and India have validated survival benefit with this approach.

301 Radiation Resistance: What An&y Dritschilo, M.D. Georgetown Medical Center,

is it? How Washington,

Objective: To provide the clinical radiation cellular radiation resistance and to identify

Can We Overcome

It?

DC oncologist strategies

with an overview of molecular studies underlying the basis for tumor currently under investigation to overcome this resistance.

302c 3-D Conformal Radiation Therapy-Part III: Clinical Aspects Bahman Emami, M.D. Loyola University, Maywood, IL PurposeiObiective: The objectives of this course are: (1) present clinical rationale for 3D conformal radiotherapy: (2) site and disease selection for 3D CRT clinical trials: (3) practical utilization of the tools available on 3D CRT systems for clinicians: (4) clinical results of patients treated with 3D conformal radiotherapy, and (5) the potential of 3D conformal radiotherapy for studying radiation-induced normal tissue complications. Significant progress has been made in recent years in clinical implementation of 3D RTP, leading to the realization of conformal radiotherapy. This progress has been due to advancements in computer hardware and software and major research efforts in the areas of physics and computer science. Although clinical implementation of this new technology has been in full use at a few institutions that have invested a significant amount of resources, this is not so in the majority of radiation oncology departments. There is a significant amount of skepticism, as well as interest and caution, among radiation oncologists regarding the true clinical usefulness of this new technology. Caution has also been intensified by recent changes in the health care system. In this refresher course we will demonstrate use of clinical conformal radiotherapy by physicians, describe which disease sites have a higher potential to benefit from this methodology, and take a realistic look at the time and effort required from the radiation oncologist and nonmedical personnel in order to treat patients with 3D conformal radiotherapy. Available clinical results with this modality will be analyzed, and the enormous potential to gain knowledge on volumetric normal tissue tolerance to radiation in using this technology and finally current national collaborative effort on this issue will be reviewed.

303c Hodgkin’s Disease - Part I: Epidemiology, Pathology, Staging, and Management of Early Stage Disease Peter M. Much, M.D.1 Joachim Yahalom, M.D.2 Joint Center for Radiation Therapy, Boston, MA1 Memorial Sloan-Kettering Cancer Center, New York, NY 2 Part I of the refresher course on Hodgkin’s disease (HD) will: 1. Update the epidemiology, review the theories regarding the etiology and discuss new development in the histologic classification of HD. 2. Review the modifications of staging system and discuss the role of staging laparotomy and the implications of modern imaging inforrniltion. 3. Review the alternatives for treatment of early-stage HD and results of recent clinical trials. 4. Review principles and techniques of radiation therapy that are relevant to the management of HD.

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