Focal or whole-gland salvage prostate brachytherapy with iodine seeds with or without a rectal spacer for postradiotherapy local failure: How best to spare the rectum?
Salvage prostate permanent implant (sPPI) for postradiation local failure provides high rates of biochemical control. The cumulative dose delivered to the prostate and the rectum is still unknown.



We reviewed the postimplant CT-based dosimetry of 18 selected patients who underwent sPPI with (125)I seeds for isolated biopsy-proven local failure several years after external beam radiation therapy. Ten patients had whole-prostate sPPI, and 8 patients had multiparametric MRI-based focal sPPI. In 8 patients, hyaluronic acid (HA) gel was injected into the prostate-rectum space.



The median cumulative biological effective dose after EBRT + sPPI for the prostate and the rectum was higher in patients treated with whole-gland sPPI than in patients treated with focal sPPI (313.5 Gy2 vs. 174.4 Gy2; p = 0.06 and 258.1 Gy3 vs. 172.6 Gy3; p < 0.01, respectively). The median D0.1cc for the rectum was significantly lower in patients who had HA gel: 63.3 Gy (29.0-78.3) vs. 83.9 Gy (34.9-180.0) (p = 0.04).



Cumulative prostate and rectum biological effective doses were lower with focal sPPI. D0.1cc delivered to the rectum was significantly lower with HA gel, while there was no difference between focal or whole-gland plans.
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France.
Valentine
V
Guimas
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France; Medical Imaging Group, IMAC CNRS 6306, University of Burgundy, Dijon, Burgundy, France.
Magali
M
Quivrin
Department of Biostatistics, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France.
Aurélie
A
Bertaut
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France.
Etienne
E
Martin
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France.
Damien
D
Chambade
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France.
Philippe
P
Maingon
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France.
Frédéric
F
Mazoyer
Department of Urology, University Hospital François Mitterand, Dijon, France.
Luc
L
Cormier
Department of Radiation Oncology, Centre Georges François Leclerc, University of Burgundy, Dijon, Burgundy, France; Medical Imaging Group, IMAC CNRS 6306, University of Burgundy, Dijon, Burgundy, France. Electronic address: gcrehange@cgfl.fr.
Gilles
G
Créhange
D000368:Aged; D001918:Brachytherapy / Q000379:methods*; D005782:Gels; D006801:Humans; D006820:Hyaluronic Acid / Q000627:therapeutic use*; D007457:Iodine Radioisotopes / Q000627:therapeutic use*; D008297:Male; D008875:Middle Aged; D009364:Neoplasm Recurrence, Local / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D058958:Organs at Risk / Q000000981:diagnostic imaging; D000072078:Positron Emission Tomography Computed Tomography; D011349:Proctitis / Q000517:prevention & control*; D011471:Prostatic Neoplasms / Q000000981:diagnostic imaging / Q000532:radiotherapy*; D011829:Radiation Dosage; D011832:Radiation Injuries / Q000517:prevention & control*; D011879:Radiotherapy Dosage; D011880:Radiotherapy Planning, Computer-Assisted; D012007:Rectum / Q000000981:diagnostic imaging; D016879:Salvage Therapy / Q000379:methods*; D014057:Tomography, X-Ray Computed
D005782:Gels; D007457:Iodine Radioisotopes; D006820:Hyaluronic Acid
Biologically effective dose; Local failure; Low dose rate; Prostate cancer; Salvage brachytherapy