ESTRO 2022

Session Item

Sunday

May 08

16:55 - 17:55

Room D3

Oligometastatic disease

Co-Chair: , Austria;

Chair: Jonas Willmann, Switzerland

Session Type: Proffered Papers

Track: Clinical

Journey:

16:55 - 17:05

Factors associated with SBRT doses in oligometastatic disease: an EORTC/ESTRO OligoCare analysis

, Switzerland

Presentation Number: OC-0599

Abstract

Abstract Title:

Factors associated with SBRT doses in oligometastatic disease: an EORTC/ESTRO OligoCare analysis

Authors:

Matthias Guckenberger¹, Filippo Alongi², Umberto Ricardi³, Marta Scorsetti⁴, Panagiotis Balermpas¹, Lorenzo Livi⁵, Yolande Lievens⁶, Pètra Braam⁷, Barbara Alicja Jereczek-Fossa⁸, Karin Stellamans⁹, Ivica Ratosa¹⁰, Heike Peulen¹¹, Joachim Widder¹², Sara Ramella¹³, Luc Verbeke¹⁴, Piet Dirix¹⁵, Kaouthar Khanfir¹⁶, Thomas Zilli¹⁷, Hossein Hemmatazad¹⁸, Paul Jeene¹⁹, Giovanni Battista Ivaldi²⁰, Enrico Clementel²¹, Beatrice Fournier²¹, Catherine Fortpied²¹, Piet Ost¹⁵

¹University Hospital Zürich, University of Zürich , Department of Radiation Oncology, Zurich, Switzerland; ²University of Brescia and IRCCS Sacro Cuore Don Calabria Hospital, Radiation Oncology, Negrar, Italy; ³University of Turin, Oncology Department, Turin, Italy; ⁴Humanitas University, Pieve Emanuele (Milan) , IRCCS Humanitas Research Hospital, Milan, Italy; ⁵University of Florence, Department of Experimental and Clinical Biomedical Sciences, Florence, Italy; ⁶Ghent University Hospital and Ghent University, Radiation Oncology Department, Ghent , Belgium; ⁷Radboud University Medical Center Nijmegen, Radiation Oncology, Nijmegen, The Netherlands; ⁸University of Milan, Department of Oncology and Hemato-oncology, Milan, Italy; ⁹Campus Kennedylaan, AZ Groeninge Kortrijk , Kortrijk, Belgium; ¹⁰University of Ljubljana, Division of Radiation Oncology, Institute of Oncology, Ljubljana, Slovenia; ¹¹Catharina Ziekenhuis, Radiation Oncology, Eindhoven, The Netherlands; ¹²Medical University of Vienna, Department of Radiation Oncology, Comprehensive Cancer Center Vienna, Vienna, Austria; ¹³Campus Bio-Medico University, Radiation Oncology, Rome, Italy; ¹⁴Radiation Oncology, Onze-Lieve-Vrouw Ziekenhuis, Aalst, Belgium; ¹⁵Iridium Network, GasthuisZusters Antwerpen - Sint-Augustinus, Radiation Oncology, Wilrijk, Belgium; ¹⁶Hopital de Sion, Hopital du Valais , Radiation Oncology, Sion, Switzerland; ¹⁷Hôpitaux universitaires de Genève - HUG - site de Cluse-Roseraie, Radiation Oncology, Radiation Oncology, Switzerland; ¹⁸Bern University Hospital and University of Bern, Department for Radiation Oncology, Bern, Switzerland; ¹⁹Radiotherapiegroep, ., Deventer, The Netherlands; ²⁰Istituti Clinici Scientifici Maugeri, Radiation Oncology, Pavia, Italy; ²¹European Organisation for Research and Treatment of Cancer (EORTC) , Headquarters, Brussels, Belgium

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Purpose or Objective

Several randomized phase II trials have reported improved outcome if local ablative therapies were added to standard-of-care treatment of oligometastatic cancer patients. Stereotactic body radiotherapy (SBRT) has been the most frequently used local treatment modality and is preferred in international guidelines. However, there is no consensus about the optimal SBRT regime with respect to fractionation and total dose. In this analysis, based on the first patients included in the ongoing ESTRO/EORTC E²-RADIatE OligoCare cohort, we investigate the association of patient and disease characteristics with SBRT doses in oligometastatic cancer patients

Material and Methods

The analysis is based on a snapshot of the database on October 1st 2021; results of this abstract are not definitive and updated results will be presented at the conference. A total of n=984 patients were registered of which n=891 were eligible; n=714 were included into this analysis after exclusion of patients with missing data.

Results

Patients were treated at 31 international centers for oligometastatic breast (n=127), colorectal (n=142), non-small cell lung (n=127) or prostate cancer (n=318). In most patients, oligometastatic disease was characterized by involvement of n=1 organ site (89%) and one solitary metastasis (68.6%). Oligometastatic state was de-novo, repeat or induced oligometastatic disease in 59.9%, 28.7% and 11.4%, respectively. Details of SBRT were available in 612/714 patients for a total of 862 treatments (median 1 per patient, maximum 5). Dose calculation algorithm was Pencil beam in only 6.5%, with all other type B or C. SBRT was performed most often with 5 fractions (40.1%), followed by 3-fraction SBRT (33.9%). Median biological effective dose (BED; a/b ratio 10Gy) prescribed to the CTV/ITV was 72.8Gy with an Q1-Q3 range of 59.5Gy - 107.1Gy. BED doses varied across organ sites with lower doses delivered for spine (median 55.5Gy) and non-vertebral bones (median 60.6Gy) metastases and highest doses delivered for lung (median 134.7Gy) and liver (median 113.1Gy) metastases. Median SBRT doses were 71.5, 79.7 and 87.2 Gy for patients treated for de-novo, repeat or induced oligometastatic disease, respectively. For patients with oligometastatic breast, colorectal, non-small cell lung and prostate cancer, median SBRT doses were 70.3, 120.2, 97.9 and 60.5 Gy respectively.

Conclusion

A large variation of SBRT doses with respect to fractionation and especially total doses has been observed across primary disease, type of oligometastatic disease and lesion`s organ site. A comprehensive analysis will be presented at the ESTRO conference.