Differences in gross target volumes on contrast vs. Noncontrast CT scans utilized for conformal radiation therapy treatment planning for prostate carcinoma

Su Min Zhou, Gunilla C. Bentel, Catherine G. Lee, Mitchell S. Anscher

Research output: Contribution to journalArticle

21 Citations (Scopus)

Abstract

Purpose: To compare the gross target volumes (GTVs) (prostate and seminal vesicles) defined on noncontrast and contrast-enhanced computed tomography (CT) images used for three-dimensional conformal treatment planning (3DCRT). Methods and Materials: From 1993 to 1996, 39 patients referred for radiation therapy for adenocarcinoma of the prostate underwent pretreatment pelvic CT scanning with and without intravenous (IV) contrast for treatment planning purposes. Seven patients were excluded because of incomplete data sets. The prostate and seminal vesicles were outlined by the same physician on all images of 32 patients. On 18 CT exams, the prostate and seminal vesicles were blindly outlined a second time by the same physician to evaluate intraphysician consistency. Discrepancies between the GTVs outlined with and without contrast and between the first and second outline on the same study were assessed by calculating the projected area in the anterior- to-posterior (AP) and right lateral (RLAT) beam's-eye view (BEV). To assess the magnitude, frequency, and direction of discrepancies between the two GTVs, the extension of the GTVs in six directions (right, left, anterior, posterior, cephalad, and caudal) was determined. Results: The GTV outlined with contrast was larger in all directions, except caudal, in the majority of patients. The change in the GTV with contrast was significant in the cephalad (p = 0.0003) and right (p = 0.0007) directions, but not in the other directions. Although the increase with contrast in any direction was usually small (average ≤5 mm), these changes resulted in a significant increase in GTV area in both the AP and RLAT BEV (9.0%, p = 0.0017 and 8.2%, p = 0.023, respectively). The intraphysician variability in outlining the prostate/seminal vesicles was minimal. Conclusions: The addition of IV contrast does appear to make a significant difference in how the prostate and seminal vesicles are outlined by an experienced observer. The increase in area of the target, found when contrast is used, should be taken into consideration when designing the treatment fields for patients with carcinoma of the prostate.

Original languageEnglish (US)
Pages (from-to)73-78
Number of pages6
JournalInternational Journal of Radiation Oncology Biology Physics
Volume42
Issue number1
DOIs
StatePublished - Aug 1 1998

Fingerprint

planning
Prostate
radiation therapy
Seminal Vesicles
Radiotherapy
tomography
cancer
Tomography
Carcinoma
physicians
Therapeutics
Physicians
Three-Dimensional Imaging
Direction compound
pretreatment
Adenocarcinoma
scanning

Keywords

  • Prostate cancer
  • Radiotherapy
  • Three-dimensional conformal radiotherapy
  • Treatment planning

ASJC Scopus subject areas

  • Radiation
  • Oncology
  • Radiology Nuclear Medicine and imaging
  • Cancer Research

Cite this

Differences in gross target volumes on contrast vs. Noncontrast CT scans utilized for conformal radiation therapy treatment planning for prostate carcinoma. / Zhou, Su Min; Bentel, Gunilla C.; Lee, Catherine G.; Anscher, Mitchell S.

In: International Journal of Radiation Oncology Biology Physics, Vol. 42, No. 1, 01.08.1998, p. 73-78.

Research output: Contribution to journalArticle

@article{bf36f98f2b854726977ed03e8503fd7f,
title = "Differences in gross target volumes on contrast vs. Noncontrast CT scans utilized for conformal radiation therapy treatment planning for prostate carcinoma",
abstract = "Purpose: To compare the gross target volumes (GTVs) (prostate and seminal vesicles) defined on noncontrast and contrast-enhanced computed tomography (CT) images used for three-dimensional conformal treatment planning (3DCRT). Methods and Materials: From 1993 to 1996, 39 patients referred for radiation therapy for adenocarcinoma of the prostate underwent pretreatment pelvic CT scanning with and without intravenous (IV) contrast for treatment planning purposes. Seven patients were excluded because of incomplete data sets. The prostate and seminal vesicles were outlined by the same physician on all images of 32 patients. On 18 CT exams, the prostate and seminal vesicles were blindly outlined a second time by the same physician to evaluate intraphysician consistency. Discrepancies between the GTVs outlined with and without contrast and between the first and second outline on the same study were assessed by calculating the projected area in the anterior- to-posterior (AP) and right lateral (RLAT) beam's-eye view (BEV). To assess the magnitude, frequency, and direction of discrepancies between the two GTVs, the extension of the GTVs in six directions (right, left, anterior, posterior, cephalad, and caudal) was determined. Results: The GTV outlined with contrast was larger in all directions, except caudal, in the majority of patients. The change in the GTV with contrast was significant in the cephalad (p = 0.0003) and right (p = 0.0007) directions, but not in the other directions. Although the increase with contrast in any direction was usually small (average ≤5 mm), these changes resulted in a significant increase in GTV area in both the AP and RLAT BEV (9.0{\%}, p = 0.0017 and 8.2{\%}, p = 0.023, respectively). The intraphysician variability in outlining the prostate/seminal vesicles was minimal. Conclusions: The addition of IV contrast does appear to make a significant difference in how the prostate and seminal vesicles are outlined by an experienced observer. The increase in area of the target, found when contrast is used, should be taken into consideration when designing the treatment fields for patients with carcinoma of the prostate.",
keywords = "Prostate cancer, Radiotherapy, Three-dimensional conformal radiotherapy, Treatment planning",
author = "Zhou, {Su Min} and Bentel, {Gunilla C.} and Lee, {Catherine G.} and Anscher, {Mitchell S.}",
year = "1998",
month = "8",
day = "1",
doi = "10.1016/S0360-3016(98)00190-4",
language = "English (US)",
volume = "42",
pages = "73--78",
journal = "International Journal of Radiation Oncology Biology Physics",
issn = "0360-3016",
publisher = "Elsevier Inc.",
number = "1",

}

TY - JOUR

T1 - Differences in gross target volumes on contrast vs. Noncontrast CT scans utilized for conformal radiation therapy treatment planning for prostate carcinoma

AU - Zhou, Su Min

AU - Bentel, Gunilla C.

AU - Lee, Catherine G.

AU - Anscher, Mitchell S.

PY - 1998/8/1

Y1 - 1998/8/1

N2 - Purpose: To compare the gross target volumes (GTVs) (prostate and seminal vesicles) defined on noncontrast and contrast-enhanced computed tomography (CT) images used for three-dimensional conformal treatment planning (3DCRT). Methods and Materials: From 1993 to 1996, 39 patients referred for radiation therapy for adenocarcinoma of the prostate underwent pretreatment pelvic CT scanning with and without intravenous (IV) contrast for treatment planning purposes. Seven patients were excluded because of incomplete data sets. The prostate and seminal vesicles were outlined by the same physician on all images of 32 patients. On 18 CT exams, the prostate and seminal vesicles were blindly outlined a second time by the same physician to evaluate intraphysician consistency. Discrepancies between the GTVs outlined with and without contrast and between the first and second outline on the same study were assessed by calculating the projected area in the anterior- to-posterior (AP) and right lateral (RLAT) beam's-eye view (BEV). To assess the magnitude, frequency, and direction of discrepancies between the two GTVs, the extension of the GTVs in six directions (right, left, anterior, posterior, cephalad, and caudal) was determined. Results: The GTV outlined with contrast was larger in all directions, except caudal, in the majority of patients. The change in the GTV with contrast was significant in the cephalad (p = 0.0003) and right (p = 0.0007) directions, but not in the other directions. Although the increase with contrast in any direction was usually small (average ≤5 mm), these changes resulted in a significant increase in GTV area in both the AP and RLAT BEV (9.0%, p = 0.0017 and 8.2%, p = 0.023, respectively). The intraphysician variability in outlining the prostate/seminal vesicles was minimal. Conclusions: The addition of IV contrast does appear to make a significant difference in how the prostate and seminal vesicles are outlined by an experienced observer. The increase in area of the target, found when contrast is used, should be taken into consideration when designing the treatment fields for patients with carcinoma of the prostate.

AB - Purpose: To compare the gross target volumes (GTVs) (prostate and seminal vesicles) defined on noncontrast and contrast-enhanced computed tomography (CT) images used for three-dimensional conformal treatment planning (3DCRT). Methods and Materials: From 1993 to 1996, 39 patients referred for radiation therapy for adenocarcinoma of the prostate underwent pretreatment pelvic CT scanning with and without intravenous (IV) contrast for treatment planning purposes. Seven patients were excluded because of incomplete data sets. The prostate and seminal vesicles were outlined by the same physician on all images of 32 patients. On 18 CT exams, the prostate and seminal vesicles were blindly outlined a second time by the same physician to evaluate intraphysician consistency. Discrepancies between the GTVs outlined with and without contrast and between the first and second outline on the same study were assessed by calculating the projected area in the anterior- to-posterior (AP) and right lateral (RLAT) beam's-eye view (BEV). To assess the magnitude, frequency, and direction of discrepancies between the two GTVs, the extension of the GTVs in six directions (right, left, anterior, posterior, cephalad, and caudal) was determined. Results: The GTV outlined with contrast was larger in all directions, except caudal, in the majority of patients. The change in the GTV with contrast was significant in the cephalad (p = 0.0003) and right (p = 0.0007) directions, but not in the other directions. Although the increase with contrast in any direction was usually small (average ≤5 mm), these changes resulted in a significant increase in GTV area in both the AP and RLAT BEV (9.0%, p = 0.0017 and 8.2%, p = 0.023, respectively). The intraphysician variability in outlining the prostate/seminal vesicles was minimal. Conclusions: The addition of IV contrast does appear to make a significant difference in how the prostate and seminal vesicles are outlined by an experienced observer. The increase in area of the target, found when contrast is used, should be taken into consideration when designing the treatment fields for patients with carcinoma of the prostate.

KW - Prostate cancer

KW - Radiotherapy

KW - Three-dimensional conformal radiotherapy

KW - Treatment planning

UR - http://www.scopus.com/inward/record.url?scp=0031690493&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031690493&partnerID=8YFLogxK

U2 - 10.1016/S0360-3016(98)00190-4

DO - 10.1016/S0360-3016(98)00190-4

M3 - Article

C2 - 9747822

AN - SCOPUS:0031690493

VL - 42

SP - 73

EP - 78

JO - International Journal of Radiation Oncology Biology Physics

JF - International Journal of Radiation Oncology Biology Physics

SN - 0360-3016

IS - 1

ER -