Risk Factors for Biochemical Recurrence After PSMA-PET-Guided Definitive Radiotherapy in Patients With De Novo Lymph Node-Positive Prostate Cancer
Introduction The National Comprehensive Cancer Network recommends external beam radiotherapy (EBRT) combined with androgen deprivation therapy (ADT) as the preferred treatment option for newly diagnosed node-positive (cN1) prostate cancer (PCa) patients. However, implementation of positron emission...
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| Published in: | Frontiers in oncology Vol. 12; p. 898774 |
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| Main Authors: | , , , , , , , , , , , , , |
| Format: | Journal Article |
| Language: | English |
| Published: |
Frontiers Media S.A
07-06-2022
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| Subjects: | |
| Online Access: | Get full text |
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| Summary: | Introduction
The National Comprehensive Cancer Network recommends external beam radiotherapy (EBRT) combined with androgen deprivation therapy (ADT) as the preferred treatment option for newly diagnosed node-positive (cN1) prostate cancer (PCa) patients. However, implementation of positron emission tomography targeting prostate-specific membrane antigen (PSMA-PET) in the staging of primary PCa patients has a significant impact on RT treatment concepts. This study aims to evaluate outcomes and their respective risk factors on patients with PSMA-PET-based cN1 and/or cM1a PCa receiving primary RT and ADT.
Methods
Forty-eight patients with cN0 and/or cM1a PCa staged by [
18
F]PSMA-1007-PET (
n
= 19) or [
68
Ga]PSMA-11-PET (
n
= 29) were retrospectively included. All patients received EBRT to the pelvis ± boost to positive nodes, followed by boost to the prostate. The impact of different PET-derived characteristics such as maximum standard uptake value (SUVmax) and number of PET-positive lymph nodes on biochemical recurrence-free survival (BRFS) (Phoenix criteria) and metastasis-free survival (MFS) was determined using Kaplan–Meier and Cox proportional hazard regression analyses.
Results
Median follow-up was 24 months. Median initial serum prostate-specific antigen was 20.2 ng/ml (IQR 10.2–54.2). Most patients had cT stage ≥ 3 (63%) and ISUP grade ≥ 3 (85%). Median dose to the prostate, elective nodes, and PET-positive nodes was 75 Gy, 45 Gy, and 55 Gy, respectively. Ninety percent of patients received ADT with a median duration of 9 months (IQR 6–18). In univariate analysis, cM1a stage (
p
= 0.03), number of >2 pelvic nodes (
p
= 0.01), number of >1 abdominal node (
p
= 0.02), and SUVmax values ≥ median (8.1 g/ml for
68
Ga-PSMA-11 and 7.9 g/ml for
18
F-PSMA-1007) extracted from lymph nodes were significantly associated with unfavorable BRFS, but classical clinicopathological features were not. Number of >2 pelvic nodes (
n
= 0.03), number of >1 abdominal node (
p
= 0.03), and SUVmax values ≥ median extracted from lymph nodes were associated with unfavorable MFS. In multivariate analysis, number of >2 pelvic lymph nodes was significantly associated with unfavorable BRFS (HR 5.2,
p
= 0.01) and SUVmax values ≥ median extracted from lymph nodes had unfavorable MFS (HR 6.3,
p
= 0.02).
Conclusion
More than 2 PET-positive pelvic lymph nodes are associated with unfavorable BRFS, and high SUVmax values are associated with unfavorable MFS. Thus, the number of PET-positive lymph nodes and the SUVmax value might be relevant prognosticators to identify patients with favorable outcomes. |
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| Bibliography: | ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 Reviewed by: Xavier Maldonado, Vall d’Hebron University Hospital, Spain; Ridwan Alam, Johns Hopkins Medicine, United States This article was submitted to Genitourinary Oncology, a section of the journal Frontiers in Oncology Edited by: Hiten D. Patel, Loyola University Medical Center, United States |
| ISSN: | 2234-943X 2234-943X |
| DOI: | 10.3389/fonc.2022.898774 |