Impact of Metastasis-directed Therapy Guided by Different PET/CT Radiotracers on Distant and Local Disease Control in Oligorecurrent Hormone-sensitive Prostate Cancer: A Secondary Analysis of the PRECISE-MDT Study

Abstract

Prospective trials suggest that metastasis-directed therapy (MDT) is an effective treatment for patients with oligometastatic prostate cancer (PCa). Gallium 68 (⁶⁸Ga) prostate-specific membrane antigen (PSMA)-11 PET/CT-guided MDT seems to improve the oncologic outcome in these patients compared with fluorine 18 (¹⁸F)-fluorocholine and ¹⁸F-PSMA-1007 PET/CT-guided MDT, but the effects in terms of local or distant disease control remain unclear. Thus, the present subanalysis of the PRECISE-MDT study analyzed patients with hormone-sensitive PCa who underwent MDT guided by PET/CT for nodal or bone oligorecurrent disease and were restaged with the same imaging modality in case of biochemical recurrence after MDT. Among 340 lesions detected in 241 male patients (median age, 74 [IQR, 9] years), ¹⁸F-fluorocholine, ⁶⁸Ga-PSMA-11, and ¹⁸F-PSMA-1007 PET/CT-guided MDT was performed in 179, 81, and 80 lesions, respectively. At restaging imaging, the PET/CT imaging modality used to guide MDT was not significantly associated with local recurrence-free survival (LRFS), with median LRFS not reached for ⁶⁸Ga-PSMA-11 PET/CT, ¹⁸F-PSMA-11 PET/CT, and ¹⁸F-fluorocholine PET/CT (P = .73). However, the detection rate of a new metastasis was significantly higher if MDT was guided by ¹⁸F-fluorocholine PET/CT (119 of 179 lesions, 66.5%) compared with ⁶⁸Ga-PSMA-11 or ¹⁸F-PSMA-1007 PET/CT (23 of 81 lesions, 28%, and 27 of 80, 34%, respectively; P < .001 for both). Moreover, MDT guided by ⁶⁸Ga-PSMA-11 PET/CT led to an improved median metastasis-free survival (MFS) (not reached) compared with ¹⁸F-PSMA-1007 (median MFS, 24.9 months; P < .001) or ¹⁸F-fluorocholine PET/CT (median MFS, 18 months; P < .001). These findings suggest that using different PET/CT imaging modalities to guide MDT might impact the distant disease control in this clinical scenario. Keywords: Radiation Therapy, Oncology, Urinary, Prostate, PET/CT Supplemental material is available for this article. Published under a CC BY 4.0 license.

Keywords: Oncology; PET/CT; Prostate; Radiation Therapy; Urinary.

Figure 1:

Kaplan-Meier curves (log-rank test) show local recurrence-free survival according to the PET/CT radiopharmaceutical used to guide metastasis-directed therapy in (A) all lesions and (B) nodal or (C) bone metastases. ¹⁸F = fluorine 18, ⁶⁸Ga = gallium 68, PSMA = prostate-specific membrane antigen.

Figure 2:

Kaplan-Meier curves (log-rank test) show metastasis-free survival according to the PET/CT radiopharmaceutical used to guide metastasis-directed therapy in (A) all lesions and (B) nodal or (C) bone metastases. ¹⁸F = fluorine 18, ⁶⁸Ga = gallium 68, PSMA = prostate-specific membrane antigen.

Figure 3:

Representative maximum-intensity projections of PET/CT scans obtained with different radiopharmaceuticals before metastasis-directed therapy (MDT) and at the time of imaging recurrence. Scans obtained before MDT (left) show lesions that underwent MDT (yellow), while follow-up images (right) display both local recurrences (yellow) and new metastases (red). ¹⁸F = fluorine 18, ⁶⁸Ga = gallium 68, PSMA = prostate-specific membrane antigen.