摘要:

We designed a questionnaire to be filled out by the physicist at the time of planning treatment with the aid of a computer in order to assess what was learned during the course of the planning session. We analyzed the results to gauge the impact of the 70 treatment planning sessions conducted during the one month period in our department in which questionnaires were completed (about 72% of all external beam plans made in that period). In 65 instances (93%) an initial judgment as to how treatment would be delivered had already been made and in 56 of these cases the patient's treatment had already been simulated by the time the computer calculation was made. Changes in the intended plan were made in eight of the 65 cases (12%). In 38% of the cases, more than one plan was developed and, when this was the case, on average records of 2.6 plans were made. Those performing the plans were asked to judge their value to the overall treatment of the patient, and the results were as follows: essential–19 cases (27%); very helpful–22 cases (31%); and somewhat helpful–29 cases (41%).

ISSN:0269-3127    

DOI:10.1118/1.596302

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

摘要:

The relative percent dose reduction by lead(Pb) of 6‐MeV electrons produced by Clinac 1800 for 6×6, 10×10, 15×15, 20×20, and 25×25 cm2cones both with and without buildup is measured. The thickness of Pb required to attenuate the intensity of the primary electron beam to 95% and 98% depends upon the cone size and upon the depth in phantom at which transmission measurements are made.

ISSN:0269-3127    

DOI:10.1118/1.596257

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

摘要:

An improved scheme has been developed for measuring the coincidence of the light field and radiation fields of a radiotherapy accelerator. Scans of the light and radiation fields are made sequentially using a photodiode on standard field plotting apparatus. By superimposing the two plots, differences between the two fields’ boundaries can be accurately determined. The technique is simple and avoids uncertainties inherent in common techniques employing film.

ISSN:0269-3127    

DOI:10.1118/1.596258

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

摘要:

Using the AAPM Task Group 21 protocol, photon and electron doses were compared in polystyrene and acrylic phantoms. The ionization chambers used were a Farmer graphite chamber, a PTW acrylic chamber, a homemade polystyrene chamber, and an Exradin air‐equivalent chamber, all being of cylindrical type. A Memorial parallel‐plate polystyrene chamber was also included.60Co, 4‐, 6‐, and 18‐MV x rays as well as 9‐ and 20‐MeV electron beams were investigated.

ISSN:0269-3127    

DOI:10.1118/1.596269

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1118/1.596260

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1118/1.596263

出版商:American Association of Physicists in Medicine    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1988.tb36274.x

出版商:Wiley    

年代:1998

数据来源: WILEY

ISSN:0269-3127    

DOI:10.1002/j.2473-4209.1988.tb36276.x

出版商:Wiley    

年代:1998

数据来源: WILEY