Interfraktionelle Bewegung der Prostataloge anhand von RTOG-Definitionen und täglichen CT-„on-Rails“: Unterscheidet sich die Zielbewegung der superioren und inferioren Anteile des klinischen Zielvolumens?

Translated title of the contribution: Prostate bed target interfractional motion using RTOG consensus definitions and daily CT on rails: Does target motion differ between superior and inferior portions of the clinical target volume?

Vivek Verma, Shifeng Chen, Sumin Zhou, Charles A. Enke, Andrew O. Wahl

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Purpose: Using high-quality CT-on-rails imaging, the daily motion of the prostate bed clinical target volume (PB-CTV) based on consensus Radiation Therapy Oncology Group (RTOG) definitions (instead of surgical clips/fiducials) was studied. It was assessed whether PB motion in the superior portion of PB-CTV (SUP-CTV) differed from the inferior PB-CTV (INF-CTV). Patients and methods: Eight pT2-3bN0-1M0 patients underwent postprostatectomy intensity-modulated radiotherapy, totaling 300 fractions. INF-CTV and SUP-CTV were defined as PB-CTV located inferior and superior to the superior border of the pubic symphysis, respectively. Daily pretreatment CT-on-rails images were compared to the planning CT in the left–right (LR), superoinferior (SI), and anteroposterior (AP) directions. Two parameters were defined: “total PB-CTV motion” represented total shifts from skin tattoos to RTOG-defined anatomic areas; “PB-CTV target motion” (performed for both SUP-CTV and INF-CTV) represented shifts from bone to RTOG-defined anatomic areas (i. e., subtracting shifts from skin tattoos to bone). Results: Mean (± standard deviation, SD) total PB-CTV motion was −1.5 (± 6.0), 1.3 (± 4.5), and 3.7 (± 5.7) mm in LR, SI, and AP directions, respectively. Mean (± SD) PB-CTV target motion was 0.2 (±1.4), 0.3 (±2.4), and 0 (±3.1) mm in the LR, SI, and AP directions, respectively. Mean (± SD) INF-CTV target motion was 0.1 (± 2.8), 0.5 (± 2.2), and 0.2 (± 2.5) mm, and SUP-CTV target motion was 0.3 (± 1.8), 0.5 (± 2.3), and 0 (± 5.0) mm in LR, SI, and AP directions, respectively. No statistically significant differences between INF-CTV and SUP-CTV motion were present in any direction. Conclusion: There are no statistically apparent motion differences between SUP-CTV and INF-CTV. Current uniform planning target volume (PTV) margins are adequate to cover both portions of the CTV.

Translated title of the contributionProstate bed target interfractional motion using RTOG consensus definitions and daily CT on rails: Does target motion differ between superior and inferior portions of the clinical target volume?
Original languageGerman
Pages (from-to)38-45
Number of pages8
JournalStrahlentherapie und Onkologie
Volume193
Issue number1
DOIs
StatePublished - Jan 1 2017

Keywords

  • Computed tomography
  • Prostate cancer
  • Prostatectomy
  • Radiotherapy, intensity modulated
  • Toxicity

ASJC Scopus subject areas

  • Radiology Nuclear Medicine and imaging
  • Oncology

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