PMID- 28517338
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20191120
IS  - 2473-4209 (Electronic)
IS  - 0094-2405 (Linking)
VI  - 39
IP  - 6Part13
DP  - 2012 Jun
TI  - SU-E-T-256: Radiation Dose Responses for Chemoradiation Therapy of Pancreatic 
      Cancer: An Analysis of Compiled Clinical Data Using Biophysical Models.
PG  - 3762
LID - 10.1118/1.4735323 [doi]
AB  - PURPOSE: We have analyzed recent clinical data obtained from chemoradiation of 
      unresectable, locally advanced pancreatic cancer in order to examine possible 
      benefits from radiotherapy (RT) dose escalation as well as to propose possible 
      dose escalated fractionation schemes. METHODS: A modified linear quadratic (LQ) 
      model was used to fit clinical tumor response data from chemoradiation treatments 
      using different fractionations. Biophysical radiosensitivy parameters, a and alpha/beta, 
      tumor potential doubling time, Td, and delay time for tumor doubling during 
      treatment, Tk, were extracted from the fits and were used to calculate feasible 
      fractionation schemes for dose escalations. RESULTS: Examination of published 
      data from 20 institutions showed no clear indication of improved survival with 
      raised radiation dose. However, an enhancement in tumor response was observed for 
      higher irradiation doses, an important and promising clinical Result with respect 
      to palliation and quality of life. The radiobiological parameter estimates 
      obtained from the analysis are: alpha/beta = 10 +/- 3 Gy, a = 0.010 +/- 0.003 Gy-1, Td = 56 
      +/- 5 days and Tk = 7 +/- 2 days. Possible dose escalation schemes are proposed based 
      on the calculation of the biologically equivalent dose (BED) required for a 50% 
      tumor response rate. CONCLUSIONS: From the point of view of tumor response, 
      escalation of the administered radiation dose leads to a potential clinical 
      benefit, which when combined with normal tissue complication analyses may Result 
      in improved treatments for certain patients with advanced pancreatic cancer. 
      Based on this analysis, a dose escalation trial with 2.25 Gy/fraction up to 69.75 
      Gy is being initiated for unresectable pancreatic cancer at our institution. 
      Partially supported by MCW Cancer Center Meinerz Foundation.
CI  - (c) 2012 American Association of Physicists in Medicine.
FAU - Moraru, I
AU  - Moraru I
AD  - Medical College of Wisconsin, New Berlin, WI.
FAU - Tai, A
AU  - Tai A
AD  - Medical College of Wisconsin, New Berlin, WI.
FAU - Erickson, B
AU  - Erickson B
AD  - Medical College of Wisconsin, New Berlin, WI.
FAU - Li, X
AU  - Li X
AD  - Medical College of Wisconsin, New Berlin, WI.
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Med Phys
JT  - Medical physics
JID - 0425746
OTO - NOTNLM
OT  - Biomedical modeling
OT  - Cancer
OT  - Data analysis
OT  - Dosimetry
OT  - Radiation therapy
OT  - Radiation treatment
OT  - Therapeutics
OT  - Tissues
EDAT- 2012/06/01 00:00
MHDA- 2012/06/01 00:01
CRDT- 2017/05/19 06:00
PHST- 2017/05/19 06:00 [entrez]
PHST- 2012/06/01 00:00 [pubmed]
PHST- 2012/06/01 00:01 [medline]
AID - 10.1118/1.4735323 [doi]
PST - ppublish
SO  - Med Phys. 2012 Jun;39(6Part13):3762. doi: 10.1118/1.4735323.