Table 2.

Characteristics of included studies

Study Author (Year) Countries	№ participants IG vs CG	№ centers	Follow-up time in months; median	Imaging modalities	Age in years; median	Metastases № (Categories)	Controlled primary tumor	Castration-resistant disease	State(s) of OMDa	Intervention Total radiation dose (Fractionation)	Control
STOMP [77–79] Ost (2017, 2020), Deek (2022) Belgium	25 (subsetb) vs 31	6	NI	Choline PET-CT	NI	1–3 (Node, bone, or both)	Yes	No	Metachronous oligorecurrence	SBRT 30 Gy (10 Gy × 3) EQD23 78 Gy	Surveillance
SABR-COMET [80, 83] Palma (2019, 2020), Olson (2019), Harrow (2022) Canada, the Netherlands, UK, Australia	14 vs 2 (both subsetsc)	10	NI	CT and bone scan or PET-CTd Spine MRI if vertebral metastases	NI	1–5; ≤ 3 per organ (Node, bone, lung, liver, adrenal, pararenal)	Yes	MixedP	AnyP	SBRT added to SOC 16–60 Gy (5–20 Gy × 1–12)P EQD23 range 61–227 Gy	SOC
ORIOLE [79, 84] Phillips (2020), Deek (2022) USA	36 vs 18	3	18.8 (range 5.8–35.0)	CT, MRI, and/or bone scan	IG: 68 (range 61–70) CG: 68 (64–76)	1–3 (Node, bone, or both)	NI	No	Metachronous oligorecurrence	SBRT 19.5–48.0 Gy (5–12 Gy × 3–5) EQD23 37–144 Gy	Observation
ARTO [85–90] Francolini (2020, 2021, 2022a, 2022b, 2023a, 2023b) Italy	75 vs 82	16	24.9 (IQR 17.1–35.8)	CT and/or bone scan or choline, fluciclovine, or PSMA PET-CT	IG: 74 (IQR 68–79) CG: 74 (68–79)	1–3 (Node, bone, or both)	9% withoute	Yes	Any with castration-resistance	SBRT 16–40 Gy (6.5–16 Gy × 1–5) EQD23 61–108 Gy Abiraterone acetate + prednisone, ADT	Abiraterone acetate + prednisone, ADT
EXTEND [91] Tang (2023) USA	43 vs 44	3	22.0 (range 11.6–39.2)	CT and bone scan or fluciclovine PET-CT	IG: 67 (IQR 63–72) CG: 67 (63–72)	1–5 metastases (Node, bone ± node, other sites ± bone, node)	Yesf	Mixed IG: 9% CG: 7%	Any	SBRT (MDTg) Recommended, 12–70 Gy (2.3–27 Gy × 1–28)P EQD23 17–162 Gy Intermittent hormone therapy	Intermittent hormone therapy
CORE [92, 115] Khoo (2023) UK, Australia	Total 180 (subsets in both armsh)	30	NI	CT and bone scan or choline/PSMA PET-CT or WBMRIP	NI	1–3 in 1–2 organsP	YesP	MixedP	Metachronous oligorecurrence	SBRT added to SOC Recommended, 24–60 Gy (7.5–18 Gy × 3–8)P EQD23 53–227 Gy	SOC
STOP [93, 116] Schellenberg (2023) Canada	7 vs 2 (both subsetse,i)	8	NI	NI	NI	1–5 progressing; ≤ 3 per organP	NI	33% hormone-sensitivee	Oligoprogression	SBRT to all progressing metastases added to SOC	SOC

Reported in table as described by the study authors and denoted by superscript P if only reported in protocol. Equivalent dose in 2-Gy fractions (EQD2) for α/β = 3 Gy

ADT androgen deprivation therapy, CG control group, CT computed tomography, EORTC European Organization for Research and Treatment of Cancer, ESTRO European Society for Radiation Oncology, Gy Gray, IG intervention group, IQR interquartile range, MDT metastasis-directed therapy, MRI magnetic resonance imaging, NI no information, OMD oligometastatic disease, PET positron emission tomography, PSMA prostate-specific membrane antigen, SBRT stereotactic body radiotherapy, SOC standard of care, vs versus, WBMRI whole body magnetic resonance imaging

^aAccording to ESTRO–EORTC consensus recommendation

^bSix additional participants in the IG were treated with surgery only as decided by the multidisciplinary team

^cEighty-three additional participants with other primary cancer types were included in the study

^dPET-CT was required for solitary pulmonary nodules not pathologically verified, or could be done as decided by the treating oncologists

^eInformation provided by personal correspondence with study authors

^fParticipants with untreated primary tumors received prostate radiotherapy on trial

^gSome participants may have received conventional fractionation only, e.g., due to regional nodal disease

^hSixty-five additional participants with other primary cancer types were included in the study

ⁱEighty-one additional participants with other primary cancer types were included in the study