Intermediate-term outcome after PSMA-PET guided high-dose radiotherapy of recurrent high-risk prostate cancer patients.

Abstract

BACKGROUND:

By the use of PSMA positron emission tomography (PET) detection of prostate cancer lesions with a high sensitivity and specificity combined with a favorable lesion to background contrast is feasible. Therefore, PSMA-PET is increasingly used for planning of radiotherapy treatment; however, any data on intermediate-term outcome is missing so far.

METHODS:

Patients with high-risk or very high risk prostate cancer, referred for salvage radiotherapy (SRT, n = 22) between 2013 and 2015, underwent PSMA-PET prior to therapy. Irradiation was planned on PET data with boost to macroscopic tumors/metastases. Treatment related toxicity was measured using Common Terminology Criteria for Adverse Events (CTCAE, v4.0).

RESULT:

Findings in PSMA-PET led to treatment modifications in 77% of SRT patients compared to available CT information. One patient did not receive irradiation due to disseminated disease, the other patients received increased boost doses to macroscopic disease and/or inclusion of additional target volumes. Toxicity was low as only 2 patients reported toxicities > grade 1. With a Median follow-up time of 29 in patients that were not lost to follow-up, prolonged PSA responses below baseline were observed in the majority of patients (14 of 20). In hormone-naïve SRT patients (n = 11), radiotherapy led to prolonged PSA decrease in 8/11 patients, however with 3 of these 8 patients receiving repeated PSMA based irradiation of novel lesions during follow-up.

CONCLUSION:

PSMA-PET guided planning of radiotherapy led to change of treatment in the majority of patients. Treatment related toxicity was well tolerated and promising results regarding intermediate-term PSA decrease were observed.

TRIAL REGISTRATION:

No trial registration was performed due to retrospective evaluation.

• Authors: Sebastian Zschaeck, Peter Wust, Marcus Beck, Waldemar Wlodarczyk, David Kaul, Julian Rogasch, Volker Budach, Christian Furth, Pirus Ghadjar
• Journal: Radiation oncology (London, England) (Radiat Oncol) Vol. 12 Issue 1 Pg. 140 (Aug 23 2017) ISSN: 1748-717X [Electronic] England
• PMID: 28830532 (Publication Type: Journal Article)

Topics

• Aged
• Humans
• Male
• Middle Aged
• Positron-Emission Tomography (methods)
• Prostatic Neoplasms (radiotherapy)
• Radiotherapy Planning, Computer-Assisted (methods)
• Radiotherapy, Image-Guided (methods)
• Retrospective Studies
• Treatment Outcome