Evaluation of computed tomography numbers for treatment planning of lung cancer

Journal Article · Wed Sep 01 00:00:00 EDT 1982 · Int. J. Radiat. Oncol., Biol. Phys.; (United States)

DOI:https://doi.org/10.1016/0360-3016(82)90627-7· OSTI ID:6579582

Mira, J G; Fullerton, G D; Ezekiel, J; Potter, J L

Computerized tomography numbers (CTN) were evaluated in 32 computerized tomography scans performed on patients with carcinoma of the lung, with the aim of evaluating CTN in normal (lung, blood, muscle, etc) and pathologic tissues (tumor, atelectasis, effusion, post-radiation fibrosis). Our main findings are: 1. Large individual CTN variations are encountered in both normal and pathologic tissues, above and below mean values. Hence, absolute numbers are meaningless. Measurements of any abnormal intrathoracic structure should be compared in relation to normal tissue CTN values in the same scan. 2. Tumor and complete atelectasis have CTN basically similar to soft tissue. Hence, these numbers are not useful for differential diagnosis. 3. Effusions usually have lower CTN and can be distinguished from previous situations. 4. Dosimetry based on uniform lung density assumptions (i.e., 300 mg/cm/sup 3/) might produce substantial dose errors as lung CTN exhibit variations indicating densities well above and below this value. 5. Preliminary information indicates that partial atelectasis and incipient post-radiation fibrosis can have very low CTN. Hence, they can be differentiated from solid tumors in certain cases, and help in differential diagnosis of post radiation recurrence within the radiotherapy field versus fibrosis.

• Research Organization: Univ. of Texas, San Antonio
• OSTI ID: 6579582
• Journal Information: Int. J. Radiat. Oncol., Biol. Phys.; (United States), Vol. 8:9
• Country of Publication: United States
• Language: English

Related Subjects

62 RADIOLOGY AND NUCLEAR MEDICINE
COMPUTERIZED TOMOGRAPHY
DIAGNOSTIC USES
RADIOTHERAPY
PLANNING
ATTENUATION
CARCINOMAS
FIBROSIS
LUNGS
BODY
DIAGNOSTIC TECHNIQUES
DISEASES
MEDICINE
NEOPLASMS
NUCLEAR MEDICINE
ORGANS
PATHOLOGICAL CHANGES
RADIOLOGY
RESPIRATORY SYSTEM
THERAPY
TOMOGRAPHY
USES
550603* - Medicine- External Radiation in Therapy- (1980-)
550601 - Medicine- Unsealed Radionuclides in Diagnostics