Adjuvant radiotherapy for gastric cancer: A dosimetric comparison of 3-dimensional conformal radiotherapy, tomotherapy® and conventional intensity modulated radiotherapy treatment plans

Max Dahele, Matthew Skinner, Brenda Schultz, Marlene Cardoso, Chris Bell, Yee C. Ung*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

Abstract

Some patients with gastric cancer benefit from post-operative chemo-radiotherapy, but adequately irradiating the planning target volume (PTV) whilst avoiding organs at risk (OAR) can be difficult. We evaluate 3-dimensional conformal radiotherapy (CRT), conventional intensity-modulated radiotherapy (IMRT) and helical tomotherapy (TT). TT, 2 and 5-field (F) CRT and IMRT treatment plans with the same PTV coverage were generated for 5 patients and compared. Median values are reported. The volume of left/right kidney receiving at least 20Gy (V20) was 57/51% and 51/60% for 2 and 5F-CRT, and 28/14% for TT and 27/19% for IMRT. The volume of liver receiving at least 30Gy (V30) was 45% and 62% for 2 and 5F-CRT, and 37% for TT and 35% for IMRT. With TT, 98% of the PTV received 95-105% of the prescribed dose, compared with 45%, 34% and 28% for 2F-CRT, 5F-CRT and IMRT respectively. Using conventional metrics, conventional IMRT can achieve comparable PTV coverage and OAR sparing to TT, but at the expense of PTV dose heterogeneity. Both irradiate large volumes of normal tissue to low doses. Additional studies are needed to demonstrate the clinical impact of these technologies.

Original languageEnglish
Pages (from-to)115-121
Number of pages7
JournalMedical Dosimetry
Volume35
Issue number2
DOIs
Publication statusPublished - 2010

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