High-dose and fractionation effects in stereotactic radiation therapy: Analysis of tumor control data from 2965 patients. Issue 3 (June 2015)

• Record Type: Journal Article
• Authors: Shuryak, Igor; Carlson, David J.; Brown, J. Martin; Brenner, David J.
• Is Part Of: Radiotherapy and oncology. Volume 115:Issue 3(2015:Jun.)
• Page Start: 327
• Page End: 334
• Publication Date: 2015-06
• Subjects: Oncology -- Periodicals; Radiotherapy -- Periodicals; Tumors -- Periodicals; Medical Oncology -- Periodicals; Neoplasms -- radiotherapy -- Periodicals; Radiotherapy -- Periodicals; Radiothérapie -- Périodiques; Cancérologie -- Périodiques; Tumeurs -- Périodiques; Electronic journals; 616.9940642
• DOI: 10.1016/j.radonc.2015.05.013
• Languages: English
• ISSNs: 0167-8140

Abstract

<abstract xml:lang="en" abstract-type="author" id="ab005"> <title id="st005">Abstract</title> <sec> <title id="st010">Background and purpose</title> <p id="sp0005">Two aspects of stereotactic radiotherapy (SRT) require clarification: First, are tumoricidal mechanisms at high-doses/fraction the same as at lower doses? Second, is single high-dose SRT treatment advantageous for tumor control (TCP) vs. multi-fraction SRT?</p> </sec> <sec> <title id="st015">Material and methods</title> <p id="sp0010">We analyzed published TCP data for lung tumors or brain metastases from 2965 SRT patients, covering a wide range of doses and fraction numbers. We used: (a) a linear-quadratic model (including heterogeneity), which assumes the same mechanisms at all doses, and (b) alternative models with terms describing distinct tumoricidal mechanisms at high doses.</p> </sec> <sec> <title id="st020">Results</title> <p id="sp0015">Both for lung and brain data, the LQ model provided a significantly better fit over the entire range of treatment doses than did any of the models requiring extra terms at high doses. Analyzing the data as a function of fractionation (1 fraction <italic>vs</italic>. >1 fraction), there was no significant effect on TCP in the lung data, whereas for brain data multi-fraction SRT was associated with higher TCP than single-fraction treatment.</p> </sec> <sec> <title id="st025">Conclusion</title> <p id="sp0020">Our analysis suggests that distinct tumoricidal mechanisms do not determine tumor control at high doses/fraction. In addition, there is evidence suggesting that multi-fraction SRT is superior to single-dose SRT.</p> </sec> </abstract>