Correlation of local failure with measures of dose insufficiency in the high-dose single-fraction treatment of bony metastases. Academic Article uri icon

Overview

abstract

  • PURPOSE: In the setting of high-dose single-fraction image-guided radiotherapy of spine metastases, the delivered dose is hypothesized to be a significant factor in local control. We investigated the dependence of local control on measures of dose insufficiency. METHODS AND MATERIALS: The minimum doses received by the hottest 100%, 98%, and 95% (D(min), D(98), and D(95)) of the gross target volume (GTV) were computed for 91 consecutively treated lesions observed in 79 patients. Prescribed doses of 18-24 Gy were delivered in a single fraction. The spinal cord and cauda equina were constrained to a maximum dose of 12-14 Gy and 16 Gy, respectively. A rank-sum test was used to assess the differences between radiographic local failure and local control. RESULTS: With a median follow-up of 18 months, seven local failures have occurred. The distributions of GTV D(min), D(98), and D(95) for treatments resulting in local failure were found to be statistically different from the corresponding distributions of the patient group as a whole. Taking no account of histology, p values calculated for D(min), D(98), and D(95) were 0.004, 0.012, and 0.031, respectively. No correlations between local failure and target volume or between local failure and anatomic location were found. CONCLUSIONS: The results indicate that D(min), D(98), and D(95) may be important risk factors for local failure. No local failures in any histology were observed when D(min) was >15 Gy, suggesting that this metric may be an important predictor of local control.

publication date

  • March 28, 2010

Research

keywords

  • Bone Neoplasms
  • Pelvic Bones
  • Spinal Neoplasms

Identity

PubMed Central ID

  • PMC3319455

Scopus Document Identifier

  • 77953620618

Digital Object Identifier (DOI)

  • 10.1016/j.ijrobp.2009.10.003

PubMed ID

  • 20350795

Additional Document Info

volume

  • 77

issue

  • 4