Pulse frequency in pulsed brachytherapy based on tissue repair kinetics

P. Sminia; C. J. Schneider; K. Koedooder; G. van Tienhoven; L. E. Blank; D. G. González

doi:10.1016/S0360-3016(98)00023-6

Pulse frequency in pulsed brachytherapy based on tissue repair kinetics

P. Sminia
, C. J. Schneider
, K. Koedooder
, G. van Tienhoven
, L. E. Blank
, D. G. González

Research output: Contribution to journal › Article › Academic › peer-review

Abstract

PURPOSE: Investigation of normal tissue sparing in pulsed brachytherapy (PB) relative to continuous low-dose rate irradiation (CLDR) by adjusting pulse frequency based on tissue repair characteristics. METHOD: Using the linear quadratic model, the relative effectiveness (RE) of a 20 Gy boost was calculated for tissue with an alpha/beta ratio ranging from 2 to 10 Gy and a half-time of sublethal damage repair between 0.1 and 3 h. The boost dose was considered to be delivered either in a number of pulses varying from 2 to 25, or continuously at a dose rate of 0.50, 0.80, or 1.20 Gy/h. RESULTS: The RE of 20 Gy was found to be identical for PB in 25 pulses of 0.80 Gy each h and CLDR delivered at 0.80 Gy/h for any alpha/beta value and for a repair half-time > 0.75 h. When normal tissue repair half-times are assumed to be longer than tumor repair half-times, normal tissue sparing can be obtained, within the restriction of a fixed overall treatment time, with higher dose per pulse and longer period time (time elapsed between start of pulse n and start of pulse n + 1). An optimum relative normal tissue sparing larger than 10% was found with 4 pulses of 5 Gy every 8 h. Hence, a therapeutic gain might be obtained when changing from CLDR to PB by adjusting the physical dose in such a way that the biological dose on the tumor is maintained. The normal tissue-sparing phenomenon can be explained by an increase in RE with longer period time for tissue with high alpha/beta ratio and fast or intermediate repair half-time, and the RE for tissue with low alpha/beta ratio and long repair half-time remains almost constant. CONCLUSION: Within the benchmark of the LQ model, advantage in normal tissue-sparing is expected when matching the pulse frequency to the repair kinetics of the normal tissue exposed. A period time longer than 1 h may lead to a reduction of late normal tissue complications. This theoretical advantage emphasizes the need for better knowledge of human tissue-repair kinetics

Original language	English
Pages (from-to)	139-150
Journal	International journal of radiation oncology, biology, physics
Volume	41
Issue number	1
DOIs	https://doi.org/10.1016/S0360-3016(98)00023-6
Publication status	Published - 1998

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title = "Pulse frequency in pulsed brachytherapy based on tissue repair kinetics",

abstract = "PURPOSE: Investigation of normal tissue sparing in pulsed brachytherapy (PB) relative to continuous low-dose rate irradiation (CLDR) by adjusting pulse frequency based on tissue repair characteristics. METHOD: Using the linear quadratic model, the relative effectiveness (RE) of a 20 Gy boost was calculated for tissue with an alpha/beta ratio ranging from 2 to 10 Gy and a half-time of sublethal damage repair between 0.1 and 3 h. The boost dose was considered to be delivered either in a number of pulses varying from 2 to 25, or continuously at a dose rate of 0.50, 0.80, or 1.20 Gy/h. RESULTS: The RE of 20 Gy was found to be identical for PB in 25 pulses of 0.80 Gy each h and CLDR delivered at 0.80 Gy/h for any alpha/beta value and for a repair half-time > 0.75 h. When normal tissue repair half-times are assumed to be longer than tumor repair half-times, normal tissue sparing can be obtained, within the restriction of a fixed overall treatment time, with higher dose per pulse and longer period time (time elapsed between start of pulse n and start of pulse n + 1). An optimum relative normal tissue sparing larger than 10\% was found with 4 pulses of 5 Gy every 8 h. Hence, a therapeutic gain might be obtained when changing from CLDR to PB by adjusting the physical dose in such a way that the biological dose on the tumor is maintained. The normal tissue-sparing phenomenon can be explained by an increase in RE with longer period time for tissue with high alpha/beta ratio and fast or intermediate repair half-time, and the RE for tissue with low alpha/beta ratio and long repair half-time remains almost constant. CONCLUSION: Within the benchmark of the LQ model, advantage in normal tissue-sparing is expected when matching the pulse frequency to the repair kinetics of the normal tissue exposed. A period time longer than 1 h may lead to a reduction of late normal tissue complications. This theoretical advantage emphasizes the need for better knowledge of human tissue-repair kinetics",

author = "P. Sminia and Schneider, \{C. J.\} and K. Koedooder and \{van Tienhoven\}, G. and Blank, \{L. E.\} and Gonz{\'a}lez, \{D. G.\}",

year = "1998",

doi = "10.1016/S0360-3016(98)00023-6",

language = "English",

volume = "41",

pages = "139--150",

journal = "International journal of radiation oncology, biology, physics",

issn = "0360-3016",

publisher = "Elsevier Inc.",

number = "1",

}

TY - JOUR

T1 - Pulse frequency in pulsed brachytherapy based on tissue repair kinetics

AU - Sminia, P.

AU - Schneider, C. J.

AU - Koedooder, K.

AU - van Tienhoven, G.

AU - Blank, L. E.

AU - González, D. G.

PY - 1998

Y1 - 1998

N2 - PURPOSE: Investigation of normal tissue sparing in pulsed brachytherapy (PB) relative to continuous low-dose rate irradiation (CLDR) by adjusting pulse frequency based on tissue repair characteristics. METHOD: Using the linear quadratic model, the relative effectiveness (RE) of a 20 Gy boost was calculated for tissue with an alpha/beta ratio ranging from 2 to 10 Gy and a half-time of sublethal damage repair between 0.1 and 3 h. The boost dose was considered to be delivered either in a number of pulses varying from 2 to 25, or continuously at a dose rate of 0.50, 0.80, or 1.20 Gy/h. RESULTS: The RE of 20 Gy was found to be identical for PB in 25 pulses of 0.80 Gy each h and CLDR delivered at 0.80 Gy/h for any alpha/beta value and for a repair half-time > 0.75 h. When normal tissue repair half-times are assumed to be longer than tumor repair half-times, normal tissue sparing can be obtained, within the restriction of a fixed overall treatment time, with higher dose per pulse and longer period time (time elapsed between start of pulse n and start of pulse n + 1). An optimum relative normal tissue sparing larger than 10% was found with 4 pulses of 5 Gy every 8 h. Hence, a therapeutic gain might be obtained when changing from CLDR to PB by adjusting the physical dose in such a way that the biological dose on the tumor is maintained. The normal tissue-sparing phenomenon can be explained by an increase in RE with longer period time for tissue with high alpha/beta ratio and fast or intermediate repair half-time, and the RE for tissue with low alpha/beta ratio and long repair half-time remains almost constant. CONCLUSION: Within the benchmark of the LQ model, advantage in normal tissue-sparing is expected when matching the pulse frequency to the repair kinetics of the normal tissue exposed. A period time longer than 1 h may lead to a reduction of late normal tissue complications. This theoretical advantage emphasizes the need for better knowledge of human tissue-repair kinetics

AB - PURPOSE: Investigation of normal tissue sparing in pulsed brachytherapy (PB) relative to continuous low-dose rate irradiation (CLDR) by adjusting pulse frequency based on tissue repair characteristics. METHOD: Using the linear quadratic model, the relative effectiveness (RE) of a 20 Gy boost was calculated for tissue with an alpha/beta ratio ranging from 2 to 10 Gy and a half-time of sublethal damage repair between 0.1 and 3 h. The boost dose was considered to be delivered either in a number of pulses varying from 2 to 25, or continuously at a dose rate of 0.50, 0.80, or 1.20 Gy/h. RESULTS: The RE of 20 Gy was found to be identical for PB in 25 pulses of 0.80 Gy each h and CLDR delivered at 0.80 Gy/h for any alpha/beta value and for a repair half-time > 0.75 h. When normal tissue repair half-times are assumed to be longer than tumor repair half-times, normal tissue sparing can be obtained, within the restriction of a fixed overall treatment time, with higher dose per pulse and longer period time (time elapsed between start of pulse n and start of pulse n + 1). An optimum relative normal tissue sparing larger than 10% was found with 4 pulses of 5 Gy every 8 h. Hence, a therapeutic gain might be obtained when changing from CLDR to PB by adjusting the physical dose in such a way that the biological dose on the tumor is maintained. The normal tissue-sparing phenomenon can be explained by an increase in RE with longer period time for tissue with high alpha/beta ratio and fast or intermediate repair half-time, and the RE for tissue with low alpha/beta ratio and long repair half-time remains almost constant. CONCLUSION: Within the benchmark of the LQ model, advantage in normal tissue-sparing is expected when matching the pulse frequency to the repair kinetics of the normal tissue exposed. A period time longer than 1 h may lead to a reduction of late normal tissue complications. This theoretical advantage emphasizes the need for better knowledge of human tissue-repair kinetics

U2 - 10.1016/S0360-3016(98)00023-6

DO - 10.1016/S0360-3016(98)00023-6

M3 - Article

C2 - 9588929

SN - 0360-3016

VL - 41

SP - 139

EP - 150

JO - International journal of radiation oncology, biology, physics

JF - International journal of radiation oncology, biology, physics

IS - 1

ER -

Pulse frequency in pulsed brachytherapy based on tissue repair kinetics

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