No abstract available

[en] The installation of a computerized tomography (CT) scanner which can be used with the patient in an upright position is described. This technique will enhance precise location of tumor position relative to critical structures for accurate charged particle dose delivery during fixed horizontal beam radiotherapy. Pixel-by-pixel treatment planning programs have been developed to calculate the dose distribution from multi-port charged particle beams. The plan includes CT scans, data interpretation, and dose calculations. The treatment planning computer is discussed. Treatment planning for irradiation of ocular melanomas is described

[en] An essential element of the heavy-ion radiotherapy program is the development of a computerized treatment planning system. A computerized tomographic (CT) based system is currently in operation, where sequential scans are first displayed on a dedicated raster graphics display unit. Target contours in appropriate slices are then entered via cursor by the radiotherapist. After the entry angle and ion type are chosen, the treatment planning program uses CT data on a pixel-by-pixel basis to (1) design appropriate compensators to contour the stopping region of the therapy beams, (2) select an appropriate spread Bragg peak for the irradiation, (3) design a collimator aperture for each entry portal, and (4) generate isoeffect and physical dose distributions overlayed on the CT image. In this section, we review progress in the area of clinical physics, and outline future lines of investigation

[en] The Radiotherapy Physics Group is involved in clinical physics in support of the heavy ion radiotherapy program. Activities include research and development in the technical aspects of optimal heavy charged particle therapy, and clinical physics service for patients under treatment. Highlights of these activities during the past year are described

[en] The Radiotherapy Physics Group works on the physical and biophysical aspects of charged particle radiotherapy. Our activities include the development of isosurvival beams (beams of uniform biological effect), computerized treatment planning development for charged particle radiotherapy, design of compensation to shape dose distributions, and development of dosimetry techniques to verify planned irradiations in both phantoms and patients

[en] During the past year three new elements have been introduced into the beam line at the Bevatron to improve patient treatment. These are the wobbler magnets, the bar-ridged filters, and the binary absorber. The wobbler consists of a pair of orthogonal dipole magnets that sweep the beam in concentric circles up to 30 cm in diameter. This device replaces the lead scattering-foil system for spreading the beam laterally. This change allows the reduction of the beam energy from 670 MeV/amu to 585 MeV/amu while maintaining the same depth of penetration in the patient. The binary absorber is a set of copper and aluminium plates of binary increments in thickness. Like the variable thickness water column, which it replaces, the binary range absorber sets the residual range of the particles as they enter the final patient compensating filtering. 6 refs., 3 figs., 1 tab

[en] Sixty-five patients with squamous carcinoma of the esophagus (32 patients), carcinoma of the stomach (18 patients) and carcinoma of the biliary tract (15 patients) received from 6000 to 7000 equivalent rad (60-70 Gray equivalents) of helium radiotherapy at 2.0 GyE per fraction, four fractions per day, using multiportal, spread-out Bragg peak therapy. All patients had locally advanced disease without evidence of distant metastases. Partial compensation for tissue inhomogeneities was accomplished. Although palliation of symptoms and regression of tumor was commonly seen, local failure occurred in most patients (77%). The median survival was 8 months. It does not appear that an increase in tumor dose relative to normal tissues can be achieved that would be high enough to increase locoregional control rates over historical control rates with low-LET irradiation. Further studies will be carried out with heavier particles such as neon or silicon in hopes of achieving greater biological effect on these difficult-to-control tumors. 22 references, 6 figures, 1 table

[en] The authors have shown an image correlation technique well suited for the analysis of intracranial lesions above the base of the skull, where surgical burr holes serve as landmarks to define the transformation between initial and subsequent CT scans. The technique is a valuable tool to relate dose distributions from the initial therapy with clinical findings imaged on subsequent CT studies. Beyond this clinical example, the authors envision a number of important applications of image correlation techniques in radiology and radiation therapy. Multiple imaging studies are a reality in the complex management of patients. Techniques in image correlation which provide accurate spatial relationships among these studies will be of great value to both diagnostic radiologists and radiation therapists

[en] The Radiotherapy Physics Group is involved in research and development related to the technical aspects of charged particle radiotherapy, such as the development of treatment planning programs and dosimetry techniques. It also provides clinical physics for patients undergoing heavy-ion radiotherapy

[en] The chapter presents an overview of the use of heavy particles in human cancer radiotherapy. The biophysical characteristics and rationale for using heavy charged particle therapy are explored. The clinical experience with carbon, neon, argon and helium are summarized for various types of tumors including carcinomas of the uterine cervix and lung, skin melanomas and metastatic sarcomas. No obvious normal tissue complications have appeared