PARENT SESSION
1:30 PM to 3:30 PM
Tuesday, April 23, 2002
Poster Session 17 Induced Gene Expression
Room: Nevada Exhibition Center
(P22-238) Absorbed integral dose and plasma cytokine expression in patients receiving pelvic radiotherapy.
Daly, Barbara1, Evans, Mark1, Johnke, Roberta1, Biggs, Lisa1, Lee, T1, Evans, Scott1, Kovacs, Charles*,1, 1 Division of Radiation Biology & Oncology, Greenville, North Carolina
ABSTRACT-
Proinflammatory and profibrotic cytokines were measured in the plasma of 37 patients treated for adenocarcinoma of the prostate with wide-field + boost radiotherapy (xRT)according to RTOG protocols 9408 and 9413. Using the RTOG protocols, the experimental group was well-defined (patients staged as T1-2CN0M0with eligible Gleason and PSA values) and received a uniform course of xRT (fraction size, total dose, and field size). Plasma level of IL-1
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, TNF/, M-CSF, GM-CSF, and TGF were determined prior to initiating xRT, and at 24 hr after patients had received xRT in accumulating doses of 9.0 Gy throughout the course of treatment. Of the 7 cytokines, only IL-1, M-CSF, and TGF were significantly enhanced prior to treatment. Moreover, during xRT, expression of the same three cytokines were signficantly enhanced in the majority of patients with IL-1 and M-CSF appearing as cyclic waves after accumulated doses of 9 and 45 Gy, and enhanced waves of TGF observed after 18 and 54 Gy. To establish whether these enhanced cytokine waves were related to the amount of energy absorbed during xRT, integral xRT doses (ID) were calculated and correlations established between the (ID) and cytokine levels for individual patients over the course of treatment. A significant correlation between the absorbed ID and plasma cytokine levels of individual patients was observed for an accumulated treatment dose of up to 9.0 Gy (18 Gy for TGF). Thereafter, this correlation was dampened such that after 45 Gy, the correlation between absorbed integral dose and cytokine level were negative or non-existent.
KEYWORDS: absorbed integral dose, cytokines, pelvic radiotherapy, prostate disease