Summary of Prospective Studies Integrating RLT with External-Beam Radiotherapy in Oligorecurrent Disease
| Trial | Inclusion | n | RLT and dosage | Timing of RLT | Primary endpoint |
|---|---|---|---|---|---|
| Randomized evaluating addition of RLT to SBRT | |||||
| LUNAR (NCT05496959) | ≤5 lesions outside prostate/prostate bed on PSMA PET/CT | 90 | 177Lu-PNT2002 (6.8 GBq per cycle, 2 cycles given 6–8 wk apart) | Neoadjuvant | PFS: progression defined on basis of PSMA PET/CT scans obtained at 12 mo or at time of PSA-based biochemical progression; initiation of salvage therapy |
| POPSTAR II (NCT05560659) | ≤5 sites of nodal or bony metastases, with at least 1 site with SUVmax 2× SUVmax liver | 92 | 177Lu-PNT2002 (6 GBq (±10%) per cycle, 2 cycles 6–8 wk apart) | SABR between cycles 1 and 2 | PFS: progression defined as biochemical or clinical |
| RAVENS (NCT04037358) | ≤3 metastases with at least 1 bone (on CT or bone scan) or ≤5 metastases with at 1 least 1 bone (on PET/CT); PSADT < 15 mo; PSA ≥ 0.5 | 64 | 223Ra (55 kBq per cycle, 6 cycles 4 wk apart) | SABR concurrent with cycle 1 | PFS: progression defined as biochemical (PSA increased by ≥2 ng/mL from nadir) or clinical (based on conventional imaging or initiation of ADT) |
| PSMA-DC (NCT05939414) | ≤5 metastases by PSMA PET only with none on CT or bone scan | 450 | 177Lu-PSMA-617 (6.8 GBq per cycle, 4 cycles given 6 wk apart) | Neoadjuvant | Metastasis-free survival: defined as lack of metastasis identifiable on bone scan, CT, or MRI |
| Phase II single arm evaluating adding radiotherapy to RLT | |||||
| ProstACT target (NCT05146973) | Recurrent after prostatectomy; ≤5 nodal lesions, all at or below aortic bifurcation with SUVmax > 5; radiotherapy here is conventionally fractionated salvage radiotherapy | 50 | 177Lu-DOTA-TLX591-CHO (2.8 GBq per cycle, 2 cycles given 2 wk apart) | Adjuvant | PSA-based PFS: time from enrollment to time of PSA increase > 25% |
| NCT03361735 | ≤4 metastases with at least 1 bone lesion and ≤1 visceral or nodal lesions | 24 | 223Ra 5 (55 kBq per cycle, 6 cycles 4 wk apart) | 9 mo of ADT, with SBRT starting on day 1 of ADT and radium starting on day 31 of ADT | Time to treatment failure: time from initiation of ADT for metastatic disease until PSA increase to >pre-ADT level or PSA > 10 (whichever is smaller) or radiographic or clinical progression or resumption of ADT by physician’s choice |
PSADT = PSA doubling time; RCT = randomized controlled trial.