Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Simulated dose painting of hypoxic sub-volumes in pancreatic cancer
  stereotactic body radiotherapy   Dose painting of hypoxic tumour sub-volumes using positron-emission
tomography (PET) has been shown to improve tumour control in silico in several
sites. Pancreatic cancer presents a more stringent challenge, given its
proximity to critical organs-at-risk (OARs) and anatomic motion. A
radiobiological model was developed to estimate clonogen survival fraction
(SF), using 18F-fluoroazomycin arabinoside PET (FAZA PET) images from ten
patients with pancreatic cancer to quantify oxygen enhancement effects. For
each patient, four simulated five-fraction stereotactic body radiotherapy
(SBRT) plans were generated: 1) a standard SBRT plan aiming to cover the
planning target volume with 40 Gy, 2) dose painting plans delivering escalated
doses to FAZA-avid hypoxic sub-volumes, 3) dose painting plans with simulated
spacer separating the duodenum and pancreatic head, and 4), plans with
integrated boosts to geometric contractions of the tumour (GTV). All plans
saturated at least one OAR dose limit. SF was calculated for each plan and
sensitivity of SF to simulated hypoxia quantification errors was evaluated.
Dose painting resulted in a 55% reduction in SF as compared to standard SBRT;
78% with spacer. Integrated boosts to hypoxia-blind geometric contractions
resulted in a 41% reduction in SF. The reduction in SF for dose-painting plans
persisted for all hypoxia quantification parameters studied, including
registration and rigid motion errors that resulted in shifts and rotations of
the GTV and hypoxic sub-volumes by as much as 1 cm and 10 degrees. Although
proximity to OARs ultimately limited dose escalation, with estimated SFs
(~10^-5) well above levels required to completely ablate a ~10 cm^3 tumour,
dose painting robustly reduced clonogen survival when accounting for expected
treatment and imaging uncertainties and thus, may improve local response and
associated morbidity.

21
The categories of this paper are: adap-org
17
The categories of this paper are: q-fin
7
The categories of this paper are: hep-th
26
The categories of this paper are: bayes-an
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The categories of this paper are: cmp-lg
34
The categories of this paper are: chem-ph
0
The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: chao-dyn
1
The categories of this paper are: cs
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The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: plasm-ph
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The categories of this paper are: econ