Study of prostate-specific antigen levels during salvage radiotherapy after prostate cancer surgery.

"Declarations Ethics approval and consent to participateAll procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study was approved by the institutional review board of Nihon University School of Medicine, and informed consent was obtained from all participants (Trial registration number: Nihon University Itabashi Hospital Clinical Research Center RK-190611-3). Consent for publicationNot applicable. Competing interestsThe authors have no competing interests to disclose. Competing interests The authors have no competing interests to disclose."

"Funding This work received no external funding."

"Declarations: Ethics approval and consent to participateAll procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study was approved by the institutional review board of Nihon University School of Medicine, and informed consent was obtained from all participants (Trial registration number: Nihon University Itabashi Hospital Clinical Research Center RK-190611-3).: Consent for publicationNot applicable.: Competing interestsThe authors have no competing interests to disclose. Ethics approval and consent to participate: All procedures performed were in accordance with the ethical standards of the institutional and/or national research committee and with the 1964 Helsinki declaration and its later amendments or comparable ethical standards. This study was approved by the institutional review board of Nihon University School of Medicine, and informed consent was obtained from all participants (Trial registration number: Nihon University Itabashi Hospital Clinical Research Center RK-190611-3)."