TY - JOUR
T1 - Dose escalation for locally advanced pancreatic cancer
T2 - How high can we go?
AU - Colbert, Lauren E.
AU - Rebueno, Neal
AU - Moningi, Shalini
AU - Beddar, Sam
AU - Sawakuchi, Gabriel O.
AU - Herman, Joseph M.
AU - Koong, Albert C.
AU - Das, Prajnan
AU - Holliday, Emma B.
AU - Koay, Eugene J.
AU - Taniguchi, Cullen M.
N1 - Publisher Copyright:
© 2018 The Authors on behalf of the American Society for Radiation Oncology
PY - 2018/10/1
Y1 - 2018/10/1
N2 - Purpose: There are limited treatment options for locally advanced, unresectable pancreatic cancer (LAPC) and no likelihood of cure without surgery. Radiation offers an option for local control, but radiation dose has previously been limited by nearby bowel toxicity. Advances in on-board imaging and treatment planning may allow for dose escalation not previously feasible and improve local control. In preparation for development of clinical trials of dose escalation in LAPC, we undertook a dosimetric study to determine the maximum possible dose escalation while maintaining known normal tissue constraints. Methods and Materials: Twenty patients treated at our institution with either SBRT or dose-escalated hypofractionated IMRT (DE-IMRT) were re-planned using dose escalated SBRT to 70 Gy in 5 fractions to the GTV and 40 Gy in 5 fractions to the PTV. Standard accepted organ at risk (OAR) constraints were used for planning. Descriptive statistics were generated for homogeneity, conformality, OAR's and GTV/PTV. Results: Mean iGTV coverage by 50 Gy was 91% (±0.07%), by 60 Gy was 61.3% (±0.08%) and by 70 Gy was 24.4% (±0.05%). Maximum PTV coverage by 70 Gy was 33%. Maximum PTV coverage by 60 Gy was 77.5%. The following organ at risk (OAR) constraints were achieved for 90% of generated plans: Duodenum V20 < 30 cc, V30 < 3 cc, V35 < 1 cc; Small Bowel V20 < 15 cc, V30 < 1 cc, V35 < 0.1 cc; Stomach V20 < 20 cc, V30 < 2 cc, V35 < 1 cc. V40 < 0.5 cc was achieved for all OAR. Conclusions: Dose escalation to 60 Gy is dosimetrically feasible with adequate GTV coverage. The identified constraints for OAR's will be used in ongoing clinical trials.
AB - Purpose: There are limited treatment options for locally advanced, unresectable pancreatic cancer (LAPC) and no likelihood of cure without surgery. Radiation offers an option for local control, but radiation dose has previously been limited by nearby bowel toxicity. Advances in on-board imaging and treatment planning may allow for dose escalation not previously feasible and improve local control. In preparation for development of clinical trials of dose escalation in LAPC, we undertook a dosimetric study to determine the maximum possible dose escalation while maintaining known normal tissue constraints. Methods and Materials: Twenty patients treated at our institution with either SBRT or dose-escalated hypofractionated IMRT (DE-IMRT) were re-planned using dose escalated SBRT to 70 Gy in 5 fractions to the GTV and 40 Gy in 5 fractions to the PTV. Standard accepted organ at risk (OAR) constraints were used for planning. Descriptive statistics were generated for homogeneity, conformality, OAR's and GTV/PTV. Results: Mean iGTV coverage by 50 Gy was 91% (±0.07%), by 60 Gy was 61.3% (±0.08%) and by 70 Gy was 24.4% (±0.05%). Maximum PTV coverage by 70 Gy was 33%. Maximum PTV coverage by 60 Gy was 77.5%. The following organ at risk (OAR) constraints were achieved for 90% of generated plans: Duodenum V20 < 30 cc, V30 < 3 cc, V35 < 1 cc; Small Bowel V20 < 15 cc, V30 < 1 cc, V35 < 0.1 cc; Stomach V20 < 20 cc, V30 < 2 cc, V35 < 1 cc. V40 < 0.5 cc was achieved for all OAR. Conclusions: Dose escalation to 60 Gy is dosimetrically feasible with adequate GTV coverage. The identified constraints for OAR's will be used in ongoing clinical trials.
UR - http://www.scopus.com/inward/record.url?scp=85052937115&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85052937115&partnerID=8YFLogxK
U2 - 10.1016/j.adro.2018.07.008
DO - 10.1016/j.adro.2018.07.008
M3 - Article
C2 - 30370371
AN - SCOPUS:85052937115
SN - 2452-1094
VL - 3
SP - 693
EP - 700
JO - Advances in Radiation Oncology
JF - Advances in Radiation Oncology
IS - 4
ER -