Focal dose escalation for prostate cancer using  68 Ga-HBED-CC PSMA PET/CT and MRI: a planning study based on histology reference

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Abstract

Background

Focal radiation therapy has gained of interest in treatment of patients with primary prostate cancer (PCa). The question of how to define the intraprostatic boost volume is still open. Previous studies showed that multiparametric MRI (mpMRI) or PSMA PET alone could be used for boost volume definition. However, other studies proposed that the combined usage of both has the highest sensitivity in detection of intraprostatic lesions. The aim of this study was to demonstrate the feasibility and to evaluate the tumour control probability (TCP) and normal tissue complication probability (NTCP) of radiation therapy dose painting using ⁶⁸Ga-HBED-CC PSMA PET/CT, mpMRI or the combination of both in primary PCa.

Methods

Ten patients underwent PSMA PET/CT and mpMRI followed by prostatectomy. Three gross tumour volumes (GTVs) were created based on PET (GTV-PET), mpMRI (GTV-MRI) and the union of both (GTV-union). Two plans were generated for each GTV. Plan95 consisted of whole-prostate IMRT to 77 Gy in 35 fractions and a simultaneous boost to 95 Gy (Plan95 ^PET/Plan95 ^MRI/Plan95 ^union). Plan80 consisted of whole-prostate IMRT to 76 Gy in 38 fractions and a simultaneous boost to 80 Gy (Plan80 ^PET/Plan80 ^MRI/Plan80 ^union). TCPs were calculated for GTV-histo (TCP-histo), which was delineated based on PCa distribution in co-registered histology slices. NTCPs were assessed for bladder and rectum.

Results

Dose constraints of published protocols were reached in every treatment plan. Mean TCP-histo were 99.7% (range: 97%–100%) and 75.5% (range: 33%–95%) for Plan95 ^union and Plan80 ^union, respectively. Plan95 ^union had significantly higher TCP-histo values than Plan95 ^MRI ( p = 0.008) and Plan95 ^PET ( p = 0.008). Plan80 ^union had significantly higher TCP-histo values than Plan80 ^MRI ( p = 0.012), but not than Plan80 ^PET ( p = 0.472).

Plan95 ^MRI had significantly lower NTCP-rectum than Plan95 ^union ( p = 0.012). No significant differences in NTCP-rectum and NTCP-bladder were observed for all other plans ( p > 0.05).

Conclusions

IMRT dose escalation on GTVs based on mpMRI, PSMA PET/CT and the combination of both was feasible. Boosting GTV-union resulted in significantly higher TCP-histo with no or minimal increase of NTCPs compared to the other plans.

Electronic supplementary material

The online version of this article (10.1186/s13014-018-1036-8) contains supplementary material, which is available to authorized users.

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Author and article information

Contributors

Constantinos Zamboglou:

ORCID: http://orcid.org/0000-0002-7849-7550

+4976127094610 , constantinos.zamboglou@uniklinik-freiburg.de

Benedikt Thomann: benedikt.thomann@uniklinik-freiburg.de

Khodor Koubar: khodor.koubar@uniklinik-freiburg.de

Peter Bronsert: peter.brondert@uniklinik-freiburg.de

Tobias Krauss: tobias.krauss@uniklinik-freiburg.de

Hans C. Rischke: hans.christian.rischke@uniklinik-freiburg.de

Ilias Sachpazidis: ilias.sachpazidis@uniklinik-freiburg.de

Vanessa Drendel: vanessa.drendel@uniklinik-freiburg.de

Nasr Salman: nasr.salman@uniklinik-freiburg.de

Kathrin Reichel: kathrin.reichel@uniklinik-freiburg.de

Cordula A. Jilg: cordula.jilg@uniklinik-freiburg.de

Martin Werner: martin.werner@uniklinik-freiburg.de

Philipp T. Meyer: philipp.meyer@uniklinik-freiburg.de

Michael Bock: michael.boch@uniklinik-freiburg.de

Dimos Baltas: dimos.baltas@uniklinik-freiburg.de

Anca L. Grosu: anca.grosu@uniklinik-freiburg.de

Journal

Journal ID (nlm-ta): Radiat Oncol

Journal ID (iso-abbrev): Radiat Oncol

Title: Radiation Oncology (London, England)

Publisher: BioMed Central (London )

ISSN (Electronic): 1748-717X

Publication date (Electronic): 2 May 2018

Publication date PMC-release: 2 May 2018

Publication date Collection: 2018

Volume: 13

Electronic Location Identifier: 81

Affiliations

[1 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Department of Radiation Oncology, Medical Center – University of Freiburg, Faculty of Medicine, ; Robert-Koch Straße 3, 79106 Freiburg, Germany

[2 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Division of Medical Physics, Department of Radiation Oncology, , Medical Center – University of Freiburg, Faculty of Medicine, ; Freiburg, Germany

[3 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Department of Pathology, , Medical Center – University of Freiburg, Faculty of Medicine, ; Freiburg, Germany

[4 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Department of Nuclear Medicine, , Medical Center – University of Freiburg, Faculty of Medicine, ; Freiburg, Germany

[5 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Department of Radiology, , Medical Center – University of Freiburg, Faculty of Medicine, ; Freiburg, Germany

[6 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Department of Urology, , Medical Center – University of Freiburg, Faculty of Medicine, ; Freiburg, Germany

[7 ]ISNI 0000 0000 9428 7911, GRID grid.7708.8, Division of Medical Physics, Department of Radiology, , Medical Center – University of Freiburg, Faculty of Medicine, ; Freiburg, Germany

[8 ]German Cancer Consortium (DKTK), Partner Site Freiburg, Freiburg, Germany

[9 ]GRID grid.5963.9, Berta-Ottenstein-Programme, , Faculty of Medicine, University of Freiburg, ; Freiburg, Germany

Author information

Constantinos Zamboglou http://orcid.org/0000-0002-7849-7550

Article

Publisher ID: 1036

DOI: 10.1186/s13014-018-1036-8

PMC ID: 5930745

PubMed ID: 29716617

SO-VID: ab53b4ab-3b9d-42bb-817d-aacd04a425a4

License:

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License ( http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver ( http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.

History

Date received : 7 March 2018

Date accepted : 26 April 2018

Custom metadata

ScienceOpen disciplines: Oncology & Radiotherapy

Keywords: prostate cancer,focal therapy,mri,psma pet/ct

Data availability:

ScienceOpen disciplines: Oncology & Radiotherapy

Keywords: prostate cancer, focal therapy, mri, psma pet/ct

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