Local recurrences after radiotherapy for prostate cancer (PCa) often originate at the location of the macroscopic tumour(s). Since PCa cells are known to be sensitive to high fraction doses, hypofractionated whole gland stereotactic body radiotherapy (SBRT) in conjunction with a simultaneous ablative microboost to the macroscopic tumour(s) within the prostate could be a way to reduce the risk of local failure.
We investigated the safety of this treatment strategy.
Patients with intermediate or high risk PCa were enrolled in a prospective phase II trial, called hypo-FLAME. All patients were treated with extreme hypofractionated doses of 35 Gy in 5 weekly fractions to the whole prostate gland with an integrated boost up to 50 Gy to the multiparametric (mp) MRI-defined tumour(s). Treatment-related toxicity was measured using the CTCAE v4.0. The primary endpoint of the trial was treatment-related acute toxicity.
Between April 2016 and December 2018, 100 men were treated in 4 academic centres. All patients were followed up for a minimum of 6 months. The median mean dose delivered to the visible tumour nodule(s) on mpMRI was 44.7 Gy in this trial. No grade ≥3 acute genitourinary (GU) or gastrointestinal (GI) toxicity was observed. Furthermore, 90 days after start of treatment, the cumulative acute grade 2 GU and GI toxicity rates were 34.0% and 5.0%, respectively.
Simultaneous focal boosting to the macroscopic tumour(s) in addition to whole gland prostate SBRT is associated with acceptable acute GU and GI toxicity.
Radiotherapy and oncology : journal of the European Society for Therapeutic Radiology and Oncology. 2020 Apr 01 [Epub ahead of print]
Cédric Draulans, Uulke A van der Heide, Karin Haustermans, Floris J Pos, Jochem van der Voort van Zyp, Hans De Boer, Veerle H Groen, Evelyn M Monninkhof, Robert J Smeenk, Martina Kunze-Busch, Robin De Roover, Tom Depuydt, Sofie Isebaert, Linda G W Kerkmeijer
Department of Radiation Oncology, University Hospitals Leuven, Belgium; Department of Oncology, KU Leuven, Belgium. Electronic address: ., Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. Electronic address: ., Department of Radiation Oncology, University Hospitals Leuven, Belgium; Department of Oncology, KU Leuven, Belgium. Electronic address: ., Department of Radiation Oncology, The Netherlands Cancer Institute, Amsterdam, The Netherlands. Electronic address: ., Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands. Electronic address: ., Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands. Electronic address: ., Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands. Electronic address: ., Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands; Julius Centre for Health Sciences and Primary Care, University Medical Centre Utrecht, The Netherlands. Electronic address: ., Department of Radiation Oncology, Radboud University Medical Centre, Nijmegen, the Netherlands. Electronic address: ., Department of Radiation Oncology, Radboud University Medical Centre, Nijmegen, the Netherlands. Electronic address: ., Department of Radiation Oncology, University Hospitals Leuven, Belgium; Department of Oncology, KU Leuven, Belgium. Electronic address: ., Department of Radiation Oncology, University Hospitals Leuven, Belgium; Department of Oncology, KU Leuven, Belgium. Electronic address: ., Department of Radiation Oncology, University Hospitals Leuven, Belgium; Department of Oncology, KU Leuven, Belgium. Electronic address: ., Department of Radiation Oncology, University Medical Centre Utrecht, The Netherlands; Department of Radiation Oncology, Radboud University Medical Centre, Nijmegen, the Netherlands. Electronic address: .
PubMed http://www.ncbi.nlm.nih.gov/pubmed/32247206