TY - JOUR
T1 - Phase I trial of stereotactic MR-guided online adaptive radiation therapy (SMART) for the treatment of oligometastatic or unresectable primary malignancies of the abdomen
AU - Henke, Lauren
AU - Kashani, Rojano
AU - Robinson, Clifford
AU - Curcuru, Austen
AU - DeWees, Todd
AU - Bradley, Jeffrey
AU - Green, Olga
AU - Michalski, Jeff
AU - Mutic, Sasa
AU - Parikh, Parag
AU - Olsen, Jeffrey
N1 - Publisher Copyright:
© 2017 The Authors
PY - 2018/3
Y1 - 2018/3
N2 - Purpose/objectives: SBRT is used to treat oligometastatic or unresectable primary abdominal malignancies, although ablative dose delivery is limited by proximity of organs-at-risk (OAR). Stereotactic, magnetic resonance (MR)-guided online-adaptive radiotherapy (SMART) may improve SBRT's therapeutic ratio. This prospective Phase I trial assessed feasibility and potential advantages of SMART to treat abdominal malignancies. Materials/methods: Twenty patients with oligometastatic or unresectable primary liver (n = 10) and non-liver (n = 10) abdominal malignancies underwent SMART. Initial plans prescribed 50 Gy/5 fractions (BED 100 Gy) with goal 95% PTV coverage by 95% of prescription, subject to hard OAR constraints. Daily real-time online-adaptive plans were created as needed, based on daily setup MR-image-set tumor/OAR “anatomy-of-the-day” to preserve hard OAR constraints, escalate PTV dose, or both. Treatment times, patient outcomes, and dosimetric comparisons between initial and adaptive plans were prospectively recorded. Results: Online adaptive plans were created at time of treatment for 81/97 fractions, due to initial plan violation of OAR constraints (61/97) or observed opportunity for PTV dose escalation (20/97). Plan adaptation increased PTV coverage in 64/97 fractions. Zero Grade ≥ 3 acute (<6 months) treatment-related toxicities were observed. Discussion: SMART is clinically deliverable and safe, allowing PTV dose escalation and/or simultaneous OAR sparing compared to non-adaptive abdominal SBRT.
AB - Purpose/objectives: SBRT is used to treat oligometastatic or unresectable primary abdominal malignancies, although ablative dose delivery is limited by proximity of organs-at-risk (OAR). Stereotactic, magnetic resonance (MR)-guided online-adaptive radiotherapy (SMART) may improve SBRT's therapeutic ratio. This prospective Phase I trial assessed feasibility and potential advantages of SMART to treat abdominal malignancies. Materials/methods: Twenty patients with oligometastatic or unresectable primary liver (n = 10) and non-liver (n = 10) abdominal malignancies underwent SMART. Initial plans prescribed 50 Gy/5 fractions (BED 100 Gy) with goal 95% PTV coverage by 95% of prescription, subject to hard OAR constraints. Daily real-time online-adaptive plans were created as needed, based on daily setup MR-image-set tumor/OAR “anatomy-of-the-day” to preserve hard OAR constraints, escalate PTV dose, or both. Treatment times, patient outcomes, and dosimetric comparisons between initial and adaptive plans were prospectively recorded. Results: Online adaptive plans were created at time of treatment for 81/97 fractions, due to initial plan violation of OAR constraints (61/97) or observed opportunity for PTV dose escalation (20/97). Plan adaptation increased PTV coverage in 64/97 fractions. Zero Grade ≥ 3 acute (<6 months) treatment-related toxicities were observed. Discussion: SMART is clinically deliverable and safe, allowing PTV dose escalation and/or simultaneous OAR sparing compared to non-adaptive abdominal SBRT.
KW - ART
KW - MR-IGRT
KW - MRI-guided radiation therapy
KW - Online-adaptive radiation therapy
KW - SBRT
KW - SMART
UR - http://www.scopus.com/inward/record.url?scp=85038821694&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85038821694&partnerID=8YFLogxK
U2 - 10.1016/j.radonc.2017.11.032
DO - 10.1016/j.radonc.2017.11.032
M3 - Article
C2 - 29277446
AN - SCOPUS:85038821694
SN - 0167-8140
VL - 126
SP - 519
EP - 526
JO - Radiotherapy and Oncology
JF - Radiotherapy and Oncology
IS - 3
ER -