Stereotactic body radiation therapy (SBRT) delays the emergence of castration resistance in patients with oligometastatic prostate cancer.
OBJECTIVE
To investigate whether bon e metastases-directed stereotactic body radiation therapy (SBRT) delays the emergence of castration resistance in patients with oligometastatic prostate cancer (OPC).


METHODS
OPC is usually managed with androgen deprivation therapy (ADT). Migration to castration-resistant prostate cancer will inevitably occur in the majority of these patients. There are several strategies aimed to delay the emergence of castration resistance including intermittent ADT, second generation antiandrogens (abiraterone, enzalutamide) or metastases-directed SBRT. The present report describes two cases of patients with OPC that received SBRT 24 Gy/3Rx to the solitary bony lesion after ADT failure.


RESULTS
Both cases showed complete and durable biochemical response for 13 and 17 months, respectively.


CONCLUSIONS
SBRT can be used to delay the emergence of castration resistance and the need for systemic therapy when used after ADT failure.
Department of Oncology, Clínica Universidad de Navarra, University of Navarre, Avda Pío XII s/n, Pamplona, Navarre, Spain. mmartinezf@unav.es.|Instituto de Investigación Biomédica de Navarra (IDISNA), Pamplona, Spain. mmartinezf@unav.es.
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MI
Martínez-Fernández
Department of Oncology, Clínica Universidad de Navarra, University of Navarre, Avda Pío XII s/n, Pamplona, Navarre, Spain.|Instituto de Investigación Biomédica de Navarra (IDISNA), Pamplona, Spain.
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JL
Pérez Gracia
Department of Oncology, Clínica Universidad de Navarra, University of Navarre, Avda Pío XII s/n, Pamplona, Navarre, Spain.|Instituto de Investigación Biomédica de Navarra (IDISNA), Pamplona, Spain.
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I
Gil-Bazo
Department of Oncology, Clínica Universidad de Navarra, University of Navarre, Avda Pío XII s/n, Pamplona, Navarre, Spain.|Instituto de Investigación Biomédica de Navarra (IDISNA), Pamplona, Spain.
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Martínez-Monge
D000230:Adenocarcinoma / Q000532:radiotherapy* / Q000556:secondary; D000726:Androgen Antagonists / Q000627:therapeutic use; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001859:Bone Neoplasms / Q000532:radiotherapy* / Q000556:secondary; D019008:Drug Resistance, Neoplasm / Q000528:radiation effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D064129:Prostatic Neoplasms, Castration-Resistant / Q000473:pathology / Q000532:radiotherapy*; D016634:Radiosurgery / Q000379:methods*; D016879:Salvage Therapy / Q000379:methods
D000726:Androgen Antagonists; D000970:Antineoplastic Agents
Androgen deprivation therapy; Castration resistance; SBRT