Variation of lung density corrections in a typical patient population

Journal Article · Fri Sep 01 04:00:00 EDT 1989 · Medical Dosimetry; (USA)

OSTI ID:7167823

Jayaraman, S; Johnston, S A; Sabina, S A; Baker, A S; Asbell, S O ^[1]

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1. Albert Einstein Medical Center, Philadelphia, PA (USA)

The correction factors to allow for the excess transmission through the lung were worked out for 25 patients who underwent radiation treatment of lesions in thorax. The geometrical arrangements of the beams used for the treatments were reconstructed on the CT scans to identify the amount of lung that intervened. The lung transmission correction factors were worked out for four possible photon energies Cobalt-60, 6 MV, 10 MV, and 20 MV. Isocentric treatment was considered throughout and the isocenter was regarded as the point of dose prescription as is done in normal practice. Correction factors were based on published experimental data for situations that had the isocenter inside the lung. Ratio of TAR (or TMR) method and Batho's power law of TAR (or TMR) method were used if the isocenter was behind the lung. It was observed that the average increase in the total dose after lung corrections were 11.5 {plus minus} 6%, 8.5 {plus minus} 5%, 5.5 {plus minus} 3%, and 4.0 {plus minus} 2% at the energies of Cobalt-60, 6 MV, 10 MV, and 20 MV, respectively. This proves the importance of carrying out the lung transmission corrections to achieve a greater consistency in the doses delivered between groups of patients treated with different photon energies.

• OSTI ID: 7167823
• Journal Information: Medical Dosimetry; (USA), Journal Name: Medical Dosimetry; (USA) Vol. 14:3; ISSN 0739-0211; ISSN MEDOE
• Country of Publication: United States
• Language: English

Related Subjects

550603* -- Medicine-- External Radiation in Therapy-- (1980-)
62 RADIOLOGY AND NUCLEAR MEDICINE
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BODY
BODY AREAS
CHEST
COBALT 60
COBALT ISOTOPES
COMPUTERIZED TOMOGRAPHY
CORRECTIONS
DIAGNOSTIC TECHNIQUES
DISEASES
DOSES
INTERMEDIATE MASS NUCLEI
INTERNAL CONVERSION RADIOISOTOPES
ISOMERIC TRANSITION ISOTOPES
ISOTOPES
LUNGS
MEDICINE
MINUTES LIVING RADIOISOTOPES
NEOPLASMS
NUCLEAR MEDICINE
NUCLEI
ODD-ODD NUCLEI
ORGANS
PATIENTS
RADIATION DOSES
RADIOISOTOPES
RADIOLOGY
RADIOTHERAPY
RESPIRATORY SYSTEM
THERAPY
TOMOGRAPHY
YEARS LIVING RADIOISOT