A new power law for determination of total 125I seed activity for ultrasound-guided prostate implants

Clinical evaluations

Andrew Wu, Chen Chiao Lee, Mark Johnson, Douglas Brown, Ronald Benoit, Ralph Miler, Jeffery Cohen, Paul Geis, Alex S J Chen, Shalom Kalnicki

Research output: Contribution to journalArticle

17 Citations (Scopus)

Abstract

Purpose: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total 125I activity required to deliver a prescription dose to a given prostate volume. Methods and Materials: Dose calculations were based on the new standards for 125I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of 125I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)2.00 where A is apparent activity in mCi, or A (U) = 1.69 d (cm)2.00 where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. Results: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D90 of these 40 patients was 172.0 Gy (SD ± 29 Gy). This means that on the average, 90% of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD ± 4.7). As a result, 94.7% of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD ± 0.21). Conclusion: This new and simple power law or a new mCi-volume look-up table for 125I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D90, CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach. Copyright (C) 2000 Elsevier Science Inc.

Original languageEnglish (US)
Pages (from-to)1397-1403
Number of pages7
JournalInternational Journal of Radiation Oncology Biology Physics
Volume47
Issue number5
DOIs
StatePublished - Jul 15 2000
Externally publishedYes

Fingerprint

seeds
Prostate
Seeds
dosage
evaluation
Prescriptions
Air
homogeneity
air currents
prostate gland
Iodine
positioning
iodine
planning
Technology
implantation
inhomogeneity
air

Keywords

  • Brachytherapy
  • Implant
  • Iodine-125
  • Prostate

ASJC Scopus subject areas

  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Radiation

Cite this

A new power law for determination of total 125I seed activity for ultrasound-guided prostate implants : Clinical evaluations. / Wu, Andrew; Lee, Chen Chiao; Johnson, Mark; Brown, Douglas; Benoit, Ronald; Miler, Ralph; Cohen, Jeffery; Geis, Paul; Chen, Alex S J; Kalnicki, Shalom.

In: International Journal of Radiation Oncology Biology Physics, Vol. 47, No. 5, 15.07.2000, p. 1397-1403.

Research output: Contribution to journalArticle

Wu, Andrew ; Lee, Chen Chiao ; Johnson, Mark ; Brown, Douglas ; Benoit, Ronald ; Miler, Ralph ; Cohen, Jeffery ; Geis, Paul ; Chen, Alex S J ; Kalnicki, Shalom. / A new power law for determination of total 125I seed activity for ultrasound-guided prostate implants : Clinical evaluations. In: International Journal of Radiation Oncology Biology Physics. 2000 ; Vol. 47, No. 5. pp. 1397-1403.
@article{f2631890e18f4ccea8d91ca5bb75cb05,
title = "A new power law for determination of total 125I seed activity for ultrasound-guided prostate implants: Clinical evaluations",
abstract = "Purpose: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total 125I activity required to deliver a prescription dose to a given prostate volume. Methods and Materials: Dose calculations were based on the new standards for 125I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of 125I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)2.00 where A is apparent activity in mCi, or A (U) = 1.69 d (cm)2.00 where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. Results: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D90 of these 40 patients was 172.0 Gy (SD ± 29 Gy). This means that on the average, 90{\%} of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD ± 4.7). As a result, 94.7{\%} of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD ± 0.21). Conclusion: This new and simple power law or a new mCi-volume look-up table for 125I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D90, CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach. Copyright (C) 2000 Elsevier Science Inc.",
keywords = "Brachytherapy, Implant, Iodine-125, Prostate",
author = "Andrew Wu and Lee, {Chen Chiao} and Mark Johnson and Douglas Brown and Ronald Benoit and Ralph Miler and Jeffery Cohen and Paul Geis and Chen, {Alex S J} and Shalom Kalnicki",
year = "2000",
month = "7",
day = "15",
doi = "10.1016/S0360-3016(00)00552-6",
language = "English (US)",
volume = "47",
pages = "1397--1403",
journal = "International Journal of Radiation Oncology Biology Physics",
issn = "0360-3016",
publisher = "Elsevier Inc.",
number = "5",

}

TY - JOUR

T1 - A new power law for determination of total 125I seed activity for ultrasound-guided prostate implants

T2 - Clinical evaluations

AU - Wu, Andrew

AU - Lee, Chen Chiao

AU - Johnson, Mark

AU - Brown, Douglas

AU - Benoit, Ronald

AU - Miler, Ralph

AU - Cohen, Jeffery

AU - Geis, Paul

AU - Chen, Alex S J

AU - Kalnicki, Shalom

PY - 2000/7/15

Y1 - 2000/7/15

N2 - Purpose: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total 125I activity required to deliver a prescription dose to a given prostate volume. Methods and Materials: Dose calculations were based on the new standards for 125I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of 125I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)2.00 where A is apparent activity in mCi, or A (U) = 1.69 d (cm)2.00 where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. Results: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D90 of these 40 patients was 172.0 Gy (SD ± 29 Gy). This means that on the average, 90% of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD ± 4.7). As a result, 94.7% of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD ± 0.21). Conclusion: This new and simple power law or a new mCi-volume look-up table for 125I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D90, CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach. Copyright (C) 2000 Elsevier Science Inc.

AB - Purpose: The intraoperative planning with peripheral loading approach is an important technique for ultrasound-guided transperineal prostate implant. In this paper a sphero-cylindrical dose model is described to generate a new power law or a look-up table for determination of the total 125I activity required to deliver a prescription dose to a given prostate volume. Methods and Materials: Dose calculations were based on the new standards for 125I seeds (model 6711) implemented by the National Institute of Standards and Technology (NIST) in 1999. Using the sphero-cylindrical dose model with peripheral loading approach, a new power law for calculating total activity of radioactive iodine required to deliver a prescribed dose for the target volume was developed. Accounting for random variation of the seed positioning in the prostate and the current air-kerma strength standard of 125I seeds, this new power law is formulated as follows: A (mCi) = 2.15 d (cm)2.00 where A is apparent activity in mCi, or A (U) = 1.69 d (cm)2.00 where A is air-kerma strength in U, required to deliver a cumulative dose of 145 Gy to a prostate gland with an average dimension, d, in centimeters. Results: The efficacy of using the new power law in prostate implants was demonstrated. For clinical evaluations of this new power law, 40 patients were chosen in 1998. The average D90 of these 40 patients was 172.0 Gy (SD ± 29 Gy). This means that on the average, 90% of the target volume received was 172.0 Gy. The average coverage index (CI) in this study was 94.7 (SD ± 4.7). As a result, 94.7% of the target volume received the prescription dose. The dose homogeneity index (HI) which measured the degree of the dose inhomogeneity was 0.38 (SD ± 0.21). Conclusion: This new and simple power law or a new mCi-volume look-up table for 125I seed prostate implantation has been developed and formulated for clinical use. Clinical evaluations expressed in quantitative parameters such as D90, CI, and HI in prostate implants have been thoroughly analyzed and clearly demonstrated the efficacy of this approach. Copyright (C) 2000 Elsevier Science Inc.

KW - Brachytherapy

KW - Implant

KW - Iodine-125

KW - Prostate

UR - http://www.scopus.com/inward/record.url?scp=0034662014&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034662014&partnerID=8YFLogxK

U2 - 10.1016/S0360-3016(00)00552-6

DO - 10.1016/S0360-3016(00)00552-6

M3 - Article

VL - 47

SP - 1397

EP - 1403

JO - International Journal of Radiation Oncology Biology Physics

JF - International Journal of Radiation Oncology Biology Physics

SN - 0360-3016

IS - 5

ER -