Early changes in tumor metabolism after treatment: The effects of stereotactic radiotherapy

• Published in: International journal of radiation oncology, biology, physics Vol. 20; no. 5; pp. 1053 - 1060
• Main Authors: Rozental, Jack M., Levine, Ross L., Mehta, Minesh P., Kinsella, Timothy J., Levin, Allan B., Allan, Ozer, Mendoza, Manuel, Hanson, Joan M., Schrader, Debra A., Nickles, Robert J.
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.1991; Elsevier
• Subjects: Biological and medical sciences; Brain Neoplasms - metabolism; Brain Neoplasms - radiotherapy; Brain Neoplasms - secondary; Brain tumor; Carcinoma, Renal Cell - metabolism; Carcinoma, Renal Cell - radiotherapy; Carcinoma, Renal Cell - secondary; Deoxyglucose - analogs & derivatives; Fluorine Radioisotopes; Fluorodeoxyglucose F18; Glioma - diagnostic imaging; Glioma - metabolism; Glioma - radiotherapy; Glucose - metabolism; Humans; Kidney Neoplasms - diagnostic imaging; Kidney Neoplasms - metabolism; Kidney Neoplasms - radiotherapy; Medical sciences; Melanoma - metabolism; Melanoma - radiotherapy; Melanoma - secondary; PET; Radiotherapy. Instrumental treatment. Physiotherapy. Reeducation. Rehabilitation, orthophony, crenotherapy. Diet therapy and various other treatments (general aspects); Stereotactic radiotherapy; Stereotaxic Techniques; Tomography, Emission-Computed; Brain tumor; Glioma metabolism; Stereotactic radiotherapy; PET; Stereotaxia; Tumor; Glioma; Radiotherapy; Brain (invertebrata)
• DOI: 10.1016/0360-3016(91)90204-H
• ISSN: 0360-3016

Four patients with intracranial neoplasms, two with malignant gliomas and two with brain metastases, were treated with stereotactic radiotherapy. Patients received between 15 and 27.5 Gray of photon irradiation to the central tumor target point; the 80% isodose line covered the periphery of the tumor as determined by contrast enhanced computed tomography. Patients underwent a sequence of three Positron Emission Tomographic scans using [ 18F]-fluorodeoxyglucose (PET-FDG)—a baseline scan the day before treatment, and follow-up scans 1 and 7 days after treatment. Ratios between the maximal tumor regional cerebral metabolic rate for glucose (rCMRGlu) (T ∗) and the contralateral remote white matter rCMRGlu (RW), that is, the glucose uptake ratio (T ∗/RW), were calculated. The percent change in ratios relative to each patient's baseline scan were calculated. Ratios increased 25% to 42% 1 day post-radiotherapy, then decreased to between 10% above and 12% below the baseline value 7 days postradiotherapy. The T ∗/RW increased acutely after stereotactic radiotherapy in a fashion similar to that previously described following chemotherapy with a complex multi-drug regimen. A common metabolic pathway may underlie the increase in T ∗/RW after these different treatments.