Thumbnail
Access Restriction
Open

Author Ahmed, Kamran A. ♦ Fulp, William J. ♦ Berglund, Anders E. ♦ Hoffe, Sarah E. ♦ Dilling, Thomas J. ♦ Eschrich, Steven A. ♦ Shridhar, Ravi ♦ Torres-Roca, Javier F.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword RADIOLOGY AND NUCLEAR MEDICINE ♦ ABDOMEN ♦ BRAIN ♦ ESOPHAGUS ♦ HEAD ♦ LIVER ♦ LUNGS ♦ LYMPH NODES ♦ MAMMARY GLANDS ♦ METASTASES ♦ NECK ♦ NEOPLASMS ♦ OVARIES ♦ PATIENTS ♦ RADIOSENSITIVITY ♦ RADIOTHERAPY ♦ RECTUM
Abstract Purpose: We previously developed a multigene expression model of tumor radiation sensitivity index (RSI) with clinical validation in multiple independent cohorts (breast, rectal, esophageal, and head and neck patients). The purpose of this study was to assess differences between RSI scores in primary colon cancer and metastases. Methods and Materials: Patients were identified from our institutional review board–approved prospective observational protocol. A total of 704 metastatic and 1362 primary lesions were obtained from a de-identified metadata pool. RSI was calculated using the previously published rank-based algorithm. An independent cohort of 29 lung or liver colon metastases treated with 60 Gy in 5 fractions stereotactic body radiation therapy (SBRT) was used for validation. Results: The most common sites of metastases included liver (n=374; 53%), lung (n=116; 17%), and lymph nodes (n=40; 6%). Sixty percent of metastatic tumors, compared with 54% of primaries, were in the RSI radiation-resistant peak, suggesting metastatic tumors may be slightly more radiation resistant than primaries (P=.01). In contrast, when we analyzed metastases based on anatomical site, we uncovered large differences in RSI. The median RSIs for metastases in descending order of radiation resistance were ovary (0.48), abdomen (0.47), liver (0.43), brain (0.42), lung (0.32), and lymph nodes (0.31) (P<.0001). These findings were confirmed when the analysis was restricted to lesions from the same patient (n=139). In our independent cohort of treated lung and liver metastases, lung metastases had an improved local control rate compared to that in patients with liver metastases (2-year local control rate of 100% vs 73.0%, respectively; P=.026). Conclusions: Assessment of radiation sensitivity between primary and metastatic tissues of colon cancer histology revealed significant differences based on anatomical location of metastases. These initial results warrant validation in a larger clinical cohort.
ISSN 03603016
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-07-15
Publisher Place United States
Journal International Journal of Radiation Oncology, Biology and Physics
Volume Number 92
Issue Number 4


Open content in new tab

   Open content in new tab