Dataset Information

Dose escalation for locally advanced pancreatic cancer: How high can we go?

ABSTRACT: 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.

SUBMITTER: Colbert LE

PROVIDER: S-EPMC6200902 | biostudies-literature | 2018 Oct-Dec

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Dose escalation for locally advanced pancreatic cancer: How high can we go?

Colbert Lauren E LE Rebueno Neal N Moningi Shalini S Beddar Sam S Sawakuchi Gabriel O GO Herman Joseph M JM Koong Albert C AC Das Prajnan P Holliday Emma B EB Koay Eugene J EJ Taniguchi Cullen M CM

Advances in radiation oncology 20181023 4

<h4>Purpose</h4>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 ...[more]

PMID: 30370371

Similar Datasets

Project description:ObjectiveThis study aims to compare recurrence patterns and outcomes of biologically effective dose (BED10, α/β = 10) of 60-70 Gy with those of a BED10 >70 Gy for locally advanced pancreatic cancer (LAPC).MethodsPatients from three centers with a biopsy and a radiographically proven LAPC were retrospectively included and data were prospectively collected from June 2012 to June 2019. Radiotherapy was delivered by stereotactic body radiation therapy. Recurrences were categorized as in-field, marginal, and outside-the-field recurrence. Patients in two groups were required to receive abdominal enhanced contrast CT or MRI every 2-3 months and CA19-9 examinations every month during follow-up. Treatment-related toxicities were evaluated every month. Overall survival (OS) and progression-free survival (PFS) were estimated using the Kaplan-Meier method.ResultsAfter propensity score matching, there were 486 patients in each group. The median prescription dose of the two groups was 37 Gy/5-8 f (range: 36-40.8 Gy/5-8 f) and 42 Gy/5-8 f (range: 40-49.6 Gy/5-8 f), respectively. The median OS of patients with a BED10 >70 Gy and a BED10 60-70 Gy was 20.3 months (95% CI: 19.1-21.5 months) and 18.2 months (95% CI: 17.8-18.6 months) respectively (p < 0.001). The median PFS of the two cohorts was 15.4 months (95% CI: 14.2-16.6 months) and 13.3 months (95% CI: 12.9-13.7 months) respectively (p < 0.001). A higher incidence of in-field and marginal recurrence was found in patients with BED10 of 60-70 Gy (in-field: 97/486 versus 72/486, p = 0.034; marginal: 109/486 versus 84/486, p = 0.044). However, more patients with BED10 >70 Gy had grade 2 or 3 acute (87/486 versus 64/486, p = 0.042) and late gastrointestinal toxicities (77/486 versus 55/486, p = 0.039) than those with BED10 of 60-70 Gy.ConclusionBED10 >70 Gy was found to have the best survival benefits along with a higher incidence of acute and late gastrointestinal toxicities. Therefore, a higher dose may be required in the case of patients' good tolerance.

Dataset Information

Dose escalation for locally advanced pancreatic cancer: How high can we go?

Publications

Dose escalation for locally advanced pancreatic cancer: How high can we go?

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets