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Freudenberg R, Hartmann H, Andreeff M, Oehme L, Leichtner T, Fischer A, Paulus T, Krause M, Kotzerke J. [Treatment Planning and Dose Verification for Combined Internal and External Radiotherapy (CIERT)]. Nuklearmedizin 2021; 61:49-57. [PMID: 34844272 DOI: 10.1055/a-1650-9428] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
AIM The combined internal and external radiotherapy (CIERT) take advantage of the benefits from radionuclide therapy and external beam irradiation. These include steep dose gradients and a low toxicity to normal tissue due to the use of unsealed radioisotopes as well as homogeneous dose distribution within the tumor due to external beam irradiation. For a combined irradiation planning, an infrastructure has to be developed that takes into account the dose contributions from both modalities. A physical verification of the absorbed dose distribution should follow by measurements using OSL detectors. METHOD Internal irradiation was performed using Re-188 in a cylindrical phantom with three inserts. SPECT images were acquired to calculate the internal dose using the software STRATOS. The dose distribution was exported as DICOM-RT data and imported in the software Pinnacle. Based on the internal dose distribution the external irradiation using 6 MV photons was planned. The dose contributions of both modalities separately as well as for combined irradiation was measured using OSL detectors made out of Beryllium oxide. RESULTS The planed doses of combined irradiation (1 Gy, 2 Gy, 4 Gy) could be verified within the uncertainty of the detectors. The mean energy response to Re-188 was (88.6 ± 2.4) % with respect to the calibration with 200 kV X-ray irradiation. The energy response to 6 MV photons was (146.0 ± 4.9) %. CONCLUSION A workflow for the treatment planning of combined internal and external radiotherapy has been developed and tested. Measurements verified the calculated doses. Therefore, the physical and technical basis for the dosimetry of combined irradiation were worked out.
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Affiliation(s)
- Robert Freudenberg
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Holger Hartmann
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Michael Andreeff
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Liane Oehme
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany
| | - Thomas Leichtner
- Department of Radiation Oncology, University Hospital Carl Gustav Carus, Dresden, Germany
| | | | - Timo Paulus
- Philips Technologie GmbH Innovative Technologies, Aachen, Germany
| | - Mechthild Krause
- Department of Radiation Oncology, University Hospital Carl Gustav Carus, Dresden, Germany.,OncoRay - National Center for Radiation Research in Oncology, Technische Universität Dresden, Dresden, Germany.,partner site Dresden, German Cancer Consortium, Dresden, Germany.,partner site Dresden, National Center for Tumor Diseases Dresden, Dresden, Germany.,German Cancer Research Center (DKFZ), Heidelberg, Germany.,Helmholtz-Zentrum Dresden-Rossendorf, Dresden, Germany
| | - Jörg Kotzerke
- Department of Nuclear Medicine, University Hospital Carl Gustav Carus, Dresden, Germany.,partner site Dresden, German Cancer Consortium, Dresden, Germany.,partner site Dresden, National Center for Tumor Diseases Dresden, Dresden, Germany
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