A prototype beam delivery system for the proton medical accelerator at Loma Linda.

A variable energy proton accelerator was commissioned at Fermi National Accelerator Laboratory for use in cancer treatment at the Loma Linda University Medical Center. The advantages of precise dose localization by proton therapy, while sparing nearby healthy tissue, are well documented [R. R. Wilson, Radiology 47, 487 (1946); M. Wagner, Med. Phys. 9, 749 (1982); M. Goitein and F. Chen, Med. Phys. 10, 831 (1983)]. One of the components of the proton therapy facility is a beam delivery system capable of delivering precise dose distributions to the target volume in the patient. To this end, a prototype beam delivery system was tested during the accelerator's commissioning period. The beam delivery system consisted of a beam spreading device to produce a large, uniform field, a range modulator to generate a spread out Bragg peak (SOBP), and various beam detectors to measure intensity, beam centering, and dose distributions. The beam delivery system provided a uniform proton dose distribution in a cylindrical volume of 20-cm-diam area and 9-cm depth. The dose variations throughout the target volume were found to be less than +/- 5%. Modifications in the range modulator should reduce this considerably. The central axis dose rate in the region of the SOBP was found to be 0.4 cGy/spill with an incident beam intensity of 6.7 x 10(9) protons/spill. With an accelerator repetition rate of 30 spills/min and expected intensity of 2.5 x 10(10) protons/spill for patient treatment, this system can provide 50 cGy/min for a 20-cm-diam field and 9-cm range modulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Inpatient survey of nursing care measures for treatment of patients with anorexia nervosa.

This study identifies and describes the inpatient nursing treatment and rationale for patients with anorexia nervosa in nationally recognized psychiatric inpatient settings. The study was undertaken to guide planned change in the nursing protocol on the authors' unit. Sixteen units were surveyed in an extensive telephone interview using structured interview guides. Findings indicated that behavioral management with contingency plans was the mainstay of treatment for the patients regardless of the identified unit treatment philosophy. This approach is effective for patient weight gain within an inpatient setting. Based on these data, the authors concluded that the program which was ongoing at their site was more restrictive than that in most other settings. Changes were made in the unit program to lessen the controls. Objective measures of weight and length of stay indicated that patients do as well with the revised plan as they did with the more controlled plan.

Modification of articulation error using a multiple-context, distinctive-feature treatment program.

This study describes a distinctive feature approach to remediating articulation disorders which, rather than relying upon across-phoneme generalization, incorporates all phonemes exhibiting a specific feature. Comparison is made to an approach which relies upon generalization. Clinical implications are discussed.