PURPOSE: To evaluate three-dimensional conformal (3D-CRT), intensity-modulated (IMRT) and respiration-gated radiotherapy (RGRT) techniques for gastric irradiation for target coverage and minimization of renal doses. All techniques were four-dimensional (4D)-CT based, incorporating the intrafractional mobility of the target volume and organs at risk (OAR). METHODS AND MATERIALS: The stomach, duodenal C-loop, and OAR (kidneys, liver, and heart) were contoured in all 10 phases of planning 4D-CT scans for five patients who underwent abdominal radiotherapy. Planning target volumes (PTVs) encompassing all positions of the stomach (PTV(all phases)) were generated. Three respiratory phases for RGRT in inspiration and expiration were identified, and corresponding PTV(inspiration) and PTV(expiration) and OAR volumes were created. Landmark-based fields recommended for the Radiation Therapy Oncology Group (RTOG) 99-04 study protocol were simulated to assess PTV coverage. IMRT and 3D-CRT planning with and without additional RGRT planning were performed for all PTVs, and corresponding dose volume histograms were analyzed. RESULTS: Use of landmark-based fields did not result in full geometric coverage of the PTV(all phases) in any patient. IMRT significantly reduced mean renal doses compared with 3D-CRT (15.0 Gy +/- 0.9 Gy vs. 20.1 Gy +/- 9.3 Gy and 16.6 Gy +/- 1.5 Gy vs. 32.6 Gy +/- 7.1 Gy for the left and right kidneys, respectively; p = 0.04). No significant increase in renal sparing was seen when adding RGRT to either 3D-CRT or IMRT. Tolerance doses to the other OAR were not exceeded. CONCLUSIONS: Individualized field margins are essential for gastric irradiation. IMRT plans significantly reduce renal doses, but the benefits of RGRT in gastric irradiation appear to be limited.
PURPOSE: To evaluate three-dimensional conformal (3D-CRT), intensity-modulated (IMRT) and respiration-gated radiotherapy (RGRT) techniques for gastric irradiation for target coverage and minimization of renal doses. All techniques were four-dimensional (4D)-CT based, incorporating the intrafractional mobility of the target volume and organs at risk (OAR). METHODS AND MATERIALS: The stomach, duodenal C-loop, and OAR (kidneys, liver, and heart) were contoured in all 10 phases of planning 4D-CT scans for five patients who underwent abdominal radiotherapy. Planning target volumes (PTVs) encompassing all positions of the stomach (PTV(all phases)) were generated. Three respiratory phases for RGRT in inspiration and expiration were identified, and corresponding PTV(inspiration) and PTV(expiration) and OAR volumes were created. Landmark-based fields recommended for the Radiation Therapy Oncology Group (RTOG) 99-04 study protocol were simulated to assess PTV coverage. IMRT and 3D-CRT planning with and without additional RGRT planning were performed for all PTVs, and corresponding dose volume histograms were analyzed. RESULTS: Use of landmark-based fields did not result in full geometric coverage of the PTV(all phases) in any patient. IMRT significantly reduced mean renal doses compared with 3D-CRT (15.0 Gy +/- 0.9 Gy vs. 20.1 Gy +/- 9.3 Gy and 16.6 Gy +/- 1.5 Gy vs. 32.6 Gy +/- 7.1 Gy for the left and right kidneys, respectively; p = 0.04). No significant increase in renal sparing was seen when adding RGRT to either 3D-CRT or IMRT. Tolerance doses to the other OAR were not exceeded. CONCLUSIONS: Individualized field margins are essential for gastric irradiation. IMRT plans significantly reduce renal doses, but the benefits of RGRT in gastric irradiation appear to be limited.
Authors: Neil C Estabrook; Jonathan B Corn; Marvene M Ewing; Higinia R Cardenes; Indra J Das Journal: Br J Radiol Date: 2017-12-22 Impact factor: 3.039
Authors: James Welsh; Matthew B Palmer; Jaffer A Ajani; Zhongxing Liao; Steven G Swisher; Wayne L Hofstetter; Pamela K Allen; Steven H Settle; Daniel Gomez; Anna Likhacheva; James D Cox; Ritsuko Komaki Journal: Int J Radiat Oncol Biol Phys Date: 2010-12-01 Impact factor: 7.038
Authors: Greg Knight; Craig C Earle; Roxanne Cosby; Natalie Coburn; Youssef Youssef; Richard Malthaner; Rebecca K S Wong Journal: Gastric Cancer Date: 2012-03-31 Impact factor: 7.370
Authors: James Welsh; Daniel Gomez; Matthew B Palmer; Beverly A Riley; Amin V Mayankkumar; Ritsuko Komaki; Lei Dong; X Ronald Zhu; Anna Likhacheva; Zhongxing Liao; Wayne L Hofstetter; Jaffer A Ajani; James D Cox Journal: Int J Radiat Oncol Biol Phys Date: 2011-04-04 Impact factor: 7.038
Authors: James Welsh; Stephen H Settle; Arya Amini; Lianchun Xiao; Akihiro Suzuki; Yuki Hayashi; Wayne Hofstetter; Ritsuko Komaki; Zhongxing Liao; Jaffer A Ajani Journal: Cancer Date: 2011-10-05 Impact factor: 6.860