Simultaneously integrated boost to multiple brain metastases during whole brain radiation therapy-hippocampal avoidance

Alonso N. Gutiérrez, Wolfgang A. Tomé, Amol Ghia, Sayana Thomas, George Cannon, Deepak Khuntia, John S. Kuo, Minesh Mehta

Research output: Chapter in Book/Report/Conference proceedingChapter

1 Scopus citations

Abstract

Purpose: To evaluate the feasibility of delivering a radiosurgery-quality integrated boost to visible brain metastases combined with hippocampal sparing whole brain radiotherapy using helical tomotherapy. Materials and Methods: Ten patients were planned on helical tomotherapy using MR-CT fusion-defined target and normal structure contours. Individually contoured hippocampi were used as conformal avoidance structures and limited to a mean-NTD2 of 6 Gy, where NTD2 denotes the normalized total dose delivered in 2 Gy fractions assuming an α/β-ratio of 2 Gy. A whole brain dose of 32.25 Gy and simultaneous boost doses to brain metastases of either 63.0 Gy (> 2.0 cm) or 70.8 Gy (< 2.0 cm) to be delivered in 15 fractions were prescribed. Plans were generated for a 2.5- and 1.0-cm field width (FW). To assess plan quality, the prescription isodose to target volume (PITV) ratio, target coverage, conformation number, and homogeneity index were computed. Results: Comparing treatment plans using a 1.0-cm FW to those using a 2.5-cm FW, the mean PITV ratio improved from 1.75 ± 0.61 to 1.48 ± 0.37, the whole brain homogeneity improved by 32% (p < 0.0004), and the mean dose in 2.0-Gy fraction equivalents received by the hippocampi varied from 5.8 ± 1.9 to 5.9 ± 1.3 Gy2. Conclusions: Delivery of radiosurgery-quality dose distributions to multiple brain metastases using helical tomotherapy is possible even when combined with whole brain radiation therapy and conformal avoidance of the hippocampi.

Original languageEnglish (US)
Title of host publicationRadiosurgery
Subtitle of host publication8th International Stereotactic Radiosurgery Society Meeting, San Francisco, June 2007
Pages247-257
Number of pages11
DOIs
Publication statusPublished - Mar 19 2010
Externally publishedYes

Publication series

NameRadiosurgery
Volume7
ISSN (Print)1024-2651
ISSN (Electronic)1662-3940

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ASJC Scopus subject areas

  • Surgery
  • Radiology Nuclear Medicine and imaging

Cite this

Gutiérrez, A. N., Tomé, W. A., Ghia, A., Thomas, S., Cannon, G., Khuntia, D., ... Mehta, M. (2010). Simultaneously integrated boost to multiple brain metastases during whole brain radiation therapy-hippocampal avoidance. In Radiosurgery: 8th International Stereotactic Radiosurgery Society Meeting, San Francisco, June 2007 (pp. 247-257). (Radiosurgery; Vol. 7). https://doi.org/10.1159/000288736