Dose-volume effects in rat thoracolumbar spinal cord: An evaluation of NTCP models

Journal Article · Fri Oct 01 00:00:00 EDT 2004 · International Journal of Radiation Oncology, Biology and Physics

DOI:https://doi.org/10.1016/j.ijrobp.2004.05.029· OSTI ID:20630931

Philippens, Marielle E.P. ^[1]; Pop, Lucas A.M. ^[1]; Visser, Andries G ^[1]; Schellekens, Suzanne ^[1]; Kogel, Albert J. van der ^[1]

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1. Department of Radiation Oncology, University Medical Center, Nijmegen (Netherlands)

Purpose: To evaluate models for normal-tissue-complication probability (NTCP) on describing the dose-volume effect in rat thoracolumbar spinal cord. Methods and materials: Single-dose irradiation of four field lengths (4, 1.5, 1.0, and 0.5 cm) was evaluated by the endpoints paresis and white-matter necrosis. The resulting dose-response data were used to rank phenomenological and tissue architecture NTCP models. Results: The 0.5-cm field length showed a steep increase in radiation tolerance. Statistical analysis of the model fits, which included evaluation of goodness of fit (GOF) and confidence intervals, resulted in the rejection of all the models considered. Excluding the smallest field length, the Schultheiss (D{sub 50} = 21.5 Gy, k = 26.5), the relative seriality (D{sub 50} = 21.4 Gy, s = 1.6, {gamma}{sub 50} = 6.3), and the critical element (D{sub 50,FSU} = 26.6 Gy, {gamma}{sub 50,FSU} = 2.3, n 1.3) model gave the best fit. Conclusion: A thorough statistical analysis resulted in a serial or critical-element behavior for the field lengths of 1.0 cm and greater. Including the 0.5-cm field length, the radiation response markedly diverged from serial properties, but none of the models applied acceptably described this dose-response relationship. This study suggests that the commonly assumed serial behavior of the spinal cord might be valid for daily use in external- beam irradiation.

• OSTI ID: 20630931
• Journal Information: International Journal of Radiation Oncology, Biology and Physics, Vol. 60, Issue 2; Other Information: DOI: 10.1016/j.ijrobp.2004.05.029; PII: S0360-3016(04)00829-6; Copyright (c) 2004 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved; Country of input: International Atomic Energy Agency (IAEA); ISSN 0360-3016
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRONMENTAL POLLUTANT EFFECTS ON LIVING ORGANISMS AND BIOLOGICAL MATERIALS
DOSE-RESPONSE RELATIONSHIPS
EVALUATION
IRRADIATION
MATTER
NECROSIS
RADIATION DOSES
RATS
SPINAL CORD