TY - JOUR
T1 - Dose escalation for locally advanced lung cancer using adaptive radiation therapy with simultaneous integrated volume-adapted boost
AU - Weiss, Elisabeth
AU - Fatyga, Mirek
AU - Wu, Yan
AU - Dogan, Nesrin
AU - Balik, Salim
AU - Sleeman IV, William
AU - Hugo, Geoffrey
PY - 2013/7/1
Y1 - 2013/7/1
N2 - In a planning study, the feasibility of dose intensification with image-guided adaptive radiation therapy for locally advanced lung cancer was tested using simultaneous integrated boost, and deformable image and dose summation including nonrigid clinical target volume warping. The results show the ability to safely increase the biologically equivalent-to-2 Gy dose by 13.4 Gy/13.9 Gy and the expected tumor control probability by 22.1%/23.4% at lung isotoxicity/normal tissue tolerance, respectively. Purpose: To test the feasibility of a planned phase 1 study of image-guided adaptive radiation therapy in locally advanced lung cancer. Methods and Materials: Weekly 4-dimensional fan beam computed tomographs (4D FBCT) of 10 lung cancer patients undergoing concurrent chemoradiation therapy were used to simulate adaptive radiation therapy: After an initial intensity modulated radiation therapy plan (0-30 Gy/2 Gy), adaptive replanning was performed on week 2 (30-50 Gy/2 Gy) and week 4 scans (50-66 Gy/2 Gy) to adjust for volume and shape changes of primary tumors and lymph nodes. Week 2 and 4 clinical target volumes (CTV) were deformably warped from the initial planning scan to adjust for anatomical changes. On the week 4 scan, a simultaneous integrated volumeadapted boost was created to the shrunken primary tumor with dose increases in 5 0.4-Gy steps from 66 Gy to 82 Gy in 2 scenarios: plan A, lung isotoxicity; plan B, normal tissue tolerance. Cumulative dose was assessed by deformably mapping and accumulating biologically equivalent dose normalized to 2 Gy-fractions (EQD2). Results: The 82-Gy level was achieved in 1 in 10 patients in scenario A, resulting in a 13.4-Gy EQD2 increase and a 22.1% increase in tumor control probability (TCP) compared to the 66-Gy plan. In scenario B, 2 patients reached the 82-Gy level with a 13.9 Gy EQD2 and 23.4% TCP increase. Conclusions: The tested image-guided adaptive radiation therapy strategy enabled relevant increases in EQD2 and TCP. Normal tissue was often dose limiting, indicating a need to modify the present study design before clinical implementation.
AB - In a planning study, the feasibility of dose intensification with image-guided adaptive radiation therapy for locally advanced lung cancer was tested using simultaneous integrated boost, and deformable image and dose summation including nonrigid clinical target volume warping. The results show the ability to safely increase the biologically equivalent-to-2 Gy dose by 13.4 Gy/13.9 Gy and the expected tumor control probability by 22.1%/23.4% at lung isotoxicity/normal tissue tolerance, respectively. Purpose: To test the feasibility of a planned phase 1 study of image-guided adaptive radiation therapy in locally advanced lung cancer. Methods and Materials: Weekly 4-dimensional fan beam computed tomographs (4D FBCT) of 10 lung cancer patients undergoing concurrent chemoradiation therapy were used to simulate adaptive radiation therapy: After an initial intensity modulated radiation therapy plan (0-30 Gy/2 Gy), adaptive replanning was performed on week 2 (30-50 Gy/2 Gy) and week 4 scans (50-66 Gy/2 Gy) to adjust for volume and shape changes of primary tumors and lymph nodes. Week 2 and 4 clinical target volumes (CTV) were deformably warped from the initial planning scan to adjust for anatomical changes. On the week 4 scan, a simultaneous integrated volumeadapted boost was created to the shrunken primary tumor with dose increases in 5 0.4-Gy steps from 66 Gy to 82 Gy in 2 scenarios: plan A, lung isotoxicity; plan B, normal tissue tolerance. Cumulative dose was assessed by deformably mapping and accumulating biologically equivalent dose normalized to 2 Gy-fractions (EQD2). Results: The 82-Gy level was achieved in 1 in 10 patients in scenario A, resulting in a 13.4-Gy EQD2 increase and a 22.1% increase in tumor control probability (TCP) compared to the 66-Gy plan. In scenario B, 2 patients reached the 82-Gy level with a 13.9 Gy EQD2 and 23.4% TCP increase. Conclusions: The tested image-guided adaptive radiation therapy strategy enabled relevant increases in EQD2 and TCP. Normal tissue was often dose limiting, indicating a need to modify the present study design before clinical implementation.
UR - http://www.scopus.com/inward/record.url?scp=84880596251&partnerID=8YFLogxK
U2 - 10.1016/j.ijrobp.2012.12.027
DO - 10.1016/j.ijrobp.2012.12.027
M3 - Article
C2 - 23523321
AN - SCOPUS:84880596251
SN - 0360-3016
VL - 86
SP - 414
EP - 419
JO - International Journal of Radiation Oncology Biology Physics
JF - International Journal of Radiation Oncology Biology Physics
IS - 3
ER -