Dose-escalation using intensity-modulated radiotherapy for prostate cancer – Evaluation of the dose distribution with and without 18F-choline PET-CT detected simultaneous integrated boost

Pinkawa, Michael; Attieh, Charbel; Piroth, Marc D.; Holy, Richard; Nussen, Sandra; Klotz, Jens; Hawickhorst, Robert; Schäfer, Wolfgang; Eble, Michael J.

doi:10.1016/j.radonc.2009.07.014

« Previous Next »Radiotherapy & Oncology
Volume 93, Issue 2 , Pages 213-219, November 2009

Dose-escalation using intensity-modulated radiotherapy for prostate cancer – Evaluation of the dose distribution with and without ¹⁸F-choline PET-CT detected simultaneous integrated boost

Michael Pinkawa
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
- Corresponding author. Address: Department of Radiation Oncology, RWTH Aachen University, Pauwelsstrasse 30, 52057 Aachen, Germany.
Charbel Attieh
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Marc D. Piroth
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Richard Holy
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Sandra Nussen
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Jens Klotz
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany
Robert Hawickhorst
- Department of Nuclear Medicine, RWTH Aachen University, Aachen, Germany
Wolfgang Schäfer
- Department of Nuclear Medicine, RWTH Aachen University, Aachen, Germany
Michael J. Eble
- Department of Radiation Oncology, RWTH Aachen University, Aachen, Germany

Received 12 March 2009; received in revised form 24 July 2009; accepted 25 July 2009. published online 01 September 2009.

Abstract

Background and purpose

The aim of the study was to evaluate the impact of a dose escalation to an ¹⁸F-choline PET-CT defined simultaneous integrated boost (IB) on the dose distribution and changes of the equivalent uniform dose (EUD).

Materials and methods

PET-CT was performed in 12 consecutive patients for treatment planning. An intraprostatic lesion was defined by a tumour-to-background uptake value ratio >2 (GTV_PET). Dose escalation was focused only on the intraprostatic lesion. Two comparisons were evaluated: whole prostate irradiation to 76Gy±boost to 80Gy (C1) and whole prostate irradiation to 66.6Gy±boost to 83.25Gy (C2).

Results

PTV/GTV_PET+margins were covered by a mean EUD of 75.9/76.1Gy vs. 77.1/80.1Gy (C1) and 66.5/66.2Gy vs. 71.1/82.9Gy (C2) (p<0.01, respectively). Concerning the organs at risk, EUD increased slightly with an additional boost (mean EUD for bladder: C1 53.2Gy vs. 53.8Gy; C2 43.0Gy vs. 45.1Gy; for rectum: C1 52.0Gy vs. 52.6Gy; C2 43.0Gy vs. 45.4Gy; p<0.01, respectively). The distance to the organs at risk had a significant impact on the respective maximum doses in the treatment plans with IB.

Conclusions

Treatment planning with IB allows an individually adapted dose escalation. The therapeutic ratio can be improved by a considerable dose escalation to the macroscopic tumour, but only minor EUD changes to the bladder and rectum.

Keywords: Prostate neoplasm, Intensity-modulated radiotherapy, Simultaneous integrated boost, Dose escalation, Choline PET