Elective irradiation of pelvic lymph nodes during postprostatectomy salvage radiotherapy.
BACKGROUND
Success rates with salvage radiotherapy (SRT) in men who have a postprostatectomy biochemical relapse are suboptimal. One treatment-intensification strategy includes elective irradiation of the pelvic lymph nodes with whole pelvis radiotherapy (WPRT).


METHODS
An inter-institutional retrospective cohort study compared outcomes for patients who received SRT at 2 separate academic institutions with disparate treatment paradigms: almost exclusively favoring WPRT (n = 112) versus limiting treatment to the prostate bed (PBRT) (n = 135). Patients were excluded if they had lymph node involvement or if they received androgen-deprivation therapy. The Cox proportional hazards model was used to adjust for potential confounders.


RESULTS
In total, 247 patients were analyzed with a median follow-up of 4 years. The pre-SRT prostate-specific antigen (PSA) level (adjusted hazard ratio [HR], 1.58; P < .0001) and a Gleason score of 8 to 10 (adjusted HR, 3.21; P < .0001) were identified as independent predictors of increased risk of biochemical PSA progression after SRT. However, WPRT was not independently associated with biochemical progression-free survival in the multivariate model (adjusted HR, 0.79; P = .20). Neither low-risk patients nor high-risk patients (defined a priori by a preoperative PSA level ≥20 ng/mL, a pathologic Gleason score between 8 and 10, or pathologic T3 tumor classification) benefited from WPRT. Overall survival was similar between treatment groups. When restricting the analysis to patients with pre-SRT PSA levels ≥0.4 ng/mL (n = 139), WPRT was independently associated with a 53% reduction in the risk of biochemical progression (adjusted HR, 0.47; P = .031).


CONCLUSIONS
WPRT did not improve outcomes among the entire group but was independently associated with improved biochemical control among patients with pre-SRT PSA levels ≥0.4 ng/mL.
Department of Radiation Oncology, Virginia Commonwealth University, Richmond, USA. dmoghanaki@vcu.edu
Drew
D
Moghanaki
Bridget F
BF
Koontz
Jeremy D
JD
Karlin
Wen
W
Wan
Nitai
N
Mukhopadhay
Michael P
MP
Hagan
Mitchell S
MS
Anscher
D000328:Adult; D000368:Aged; D006801:Humans; D008198:Lymph Nodes / Q000528:radiation effects*; D008297:Male; D008875:Middle Aged; D010388:Pelvis; D017430:Prostate-Specific Antigen / Q000032:analysis; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000473:pathology / Q000532:radiotherapy* / Q000601:surgery; D012008:Recurrence; D016879:Salvage Therapy; D016896:Treatment Outcome
D017430:Prostate-Specific Antigen