Impact of Staging 68Ga-PSMA-11 PET Scans on Radiation Treatment Plansin Patients With Prostate Cancer

Susan Y Wu; Lauren Boreta; Katsuto Shinohara; Hao Nguyen; Alexander R Gottschalk; I-Chow Hsu; Mack Roach 3rd; Antonio C Westphalen; Felix Y Feng; Peter R Carroll; Albert J Chang; Thomas A Hope

doi:10.1016/j.urology.2018.09.038

Impact of Staging ⁶⁸Ga-PSMA-11 PET Scans on Radiation Treatment Plansin Patients With Prostate Cancer

Urology. 2019 Mar:125:154-162. doi: 10.1016/j.urology.2018.09.038. Epub 2018 Dec 21.

Authors

Affiliations

¹ Department of Radiation Oncology, University of California, San Francisco, CA.
² Department of Urology, University of California, San Francisco, CA; University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA.
³ Department of Urology, University of California, San Francisco, CA.
⁴ Department of Radiation Oncology, University of California, San Francisco, CA; University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA.
⁵ Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA.
⁶ Department of Radiation Oncology, University of California, San Francisco, CA; Department of Urology, University of California, San Francisco, CA; University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA; Department of Medicine, University of California, San Francisco, CA.
⁷ Department of Radiation Oncology, David Geffen School of Medicine, University of California, Los Angeles, CA.
⁸ University of California San Francisco Helen Diller Family Comprehensive Cancer Center, San Francisco, CA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA; Department of Radiology, San Francisco VA Medical Center, San Francisco, CA. Electronic address: Thomas.Hope@ucsf.edu.

PMID: 30580002
DOI: 10.1016/j.urology.2018.09.038

Abstract

Objective: To evaluate the impact of staging ⁶⁸Ga-PSMA-11 PET imaging on radiotherapy (RT) dose and volumes in patients with prostate cancer.

Methods: Forty-five patients (89% high or very high risk by NCCN criteria) who underwent ⁶⁸Ga-PSMA-11 PET imaging prior to definitive treatment for prostate cancer between December 2015 and December 2016 were included. Locations of ⁶⁸Ga-PSMA-11-avid lesions were compared to Radiation Therapy Oncology Group consensus pelvic nodal volumes (clinical target volume [CTV]); coverage of lesions outside the consensus CTV was considered a major change, while dose-escalation to lesions within the consensus CTV was considered a minor change.

Results: All patients had ⁶⁸Ga-PSMA-11 PET uptake in the prostate. Twenty-five patients (56%) had N1/M1a disease on ⁶⁸Ga-PSMA-11 PET scan, of whom 21 (47%) were previously N0. Six patients (13%) had bone metastases on ⁶⁸Ga-PSMA-11 PET scan, of whom 4 had prior negative bone scans. Eight patients (18%) had lymph node metastases outside the consensus CTV. Twelve patients (27%) received a RT boost to nodes within the consensus CTV. Six patients (13%) had limited bone metastases treated with focal RT. Overall PSMA PET imaging resulted in major and/or minor changes to RT plans in 24 patients (53%).

Conclusion: ⁶⁸Ga-PSMA-11 PET imaging resulted in RT changes in 53% of patients. Prospective investigation is needed to evaluate the clinical benefit of RT changes based on staging ⁶⁸Ga-PSMA-11 PET imaging.

Published by Elsevier Inc.

Publication types

Comparative Study
Research Support, Non-U.S. Gov't

MeSH terms

Aged
Edetic Acid / analogs & derivatives*
Gallium Isotopes
Gallium Radioisotopes
Humans
Male
Neoplasm Staging
Oligopeptides*
Positron-Emission Tomography* / methods
Prostatic Neoplasms / diagnostic imaging*
Prostatic Neoplasms / pathology
Prostatic Neoplasms / radiotherapy*
Radiotherapy Dosage

Substances

Gallium Isotopes
Gallium Radioisotopes
Oligopeptides
gallium 68 PSMA-11
Edetic Acid