Stereotactic Radiotherapy Versus Palliative Conventional Radiotherapy for Oligoprogressive Metastatic Cancers

Inclusion Criteria

• •1. Age 19 or older
• •2. Able to provide informed consent
• •3. Histologically confirmed solid malignancy (excluding lymphoma or myeloma) with metastatic disease detected on imaging
• •4. Biopsy of metastasis at some time prior to enrollment is preferred, but not required
• •5. ECOG performance status 0-2
• •6. Life expectancy ≥ 6 months
• •7. Progression meeting RECIST criteria in up to 5 individual lesions. Progression may be defined as:
• •1. Progression of an individual metastasis according to RECIST 1.1 criteria (≥ 20% enlargement of the tumour vs. baseline or nadir, taking as reference the smallest diameter seen prior to starting or during systemic therapy, and associated with a 5 mm minimum increase in size) OR
• •2. Unambiguous development of a new metastatic lesion at least 5 mm in size OR
• •3. Progressive enlargement of a known metastasis on 2 consecutive imaging studies 2-3 months apart with a minimum 5 mm increase in size from baseline.
• •4. A progressing primary tumor is eligible as per the criteria above
• •8. If the participant is on systemic therapy at the time of oligoprogression:
• •The most recent systemic therapy agent must have been delivered for a total of at least 3 months, with an initial partial response (PR), complete response (CR) or stable disease (SD) prior to the development of oligoprogressive lesions
• •9. If the participant is not on systemic therapy at the time of oligoprogression:
• •(i.e., "oligorecurrence"(1), however, included as "oligoprogression" for the purpose of this study protocol):
• •10. There must be PR, CR or SD persisting for at least 3 months prior to the development of oligoprogressive lesions
• •11. Participants who are not on systemic therapy at the time of oligoprogression must have other site(s) of disease (metastases or primary tumor) that are stable or resolved and have not received definitive treatment (inclusive of surgery, radical doses of radiotherapy including SABR, or ablation) and are not going to receive SABR.
• •12. All sites of oligoprogression can be safely treated
• •13. Restaging completed within 12 weeks prior to randomization (see section 5.1)
• •14. Negative urine pregnancy test for People of Child-Bearing Potential (POCBP) within 4 weeks of radiotherapy start date.
• •6. Brain metastasis \> 3.5 cm in size or a total volume of brain metastases greater than 30 cc.
• •8. Participants with spine instability as judged by a Spinal Instability Neoplastic Score (SINS) of \>12.
• •9. Dominant brain metastasis requiring surgical decompression
• •10. For participants with liver metastases; moderate/severe liver dysfunction (Child Pugh B or C)
• •11. Liver metastases located in the "Biliary no fly zone" defined for this trial as common biliary track, cystic duct and distal branches (1 cm) + 5 mm
• •12. Surgical resection of all oligoprogression metastases (i.e. no lesion available to be treated with SABR)
• •13. Pregnant or lactating individuals