Objectives. To retrospectively determine the outcome of patients treated wi
th salvage three-dimensional conformal radiotherapy (RT) for prostate cance
r recurrence after cryosurgical ablation of the prostate (CSAP). Biochemica
l control rates and morbidity were analyzed.
Methods. Between January 1990 and November 1999, a total of 49 patients ini
tially treated with CSAP were later irradiated because of a rising prostate
-specific antigen (PSA) level and/or a positive biopsy at Allegheny General
Hospital. The clinical stage before cryosurgery was Tie in 7 patients; T2a
in 7 patients; T2b in 10 patients; T3 in 17 patients; and T4 and/or N1 in
8 patients. The Gleason score was 6 or lower in 29 patients, 7 in 11 patien
ts, and 8 or higher in 9 patients. The mean pre-CSAP PSA level was 15.7 ng/
mL (range 2.4 to 45). One patient had a PSA level less than 4 ng/mL, 16 had
a PSA level of 4 to 10 ng/mL, 21 had a PSA level of 10 to 20 ng/mL, and 11
had a PSA level greater than 20 ng/ml. Before the start of RT, a complete
restaging workup was performed and was negative for distant metastatic dise
ase in all 49 patients. The mean interval to recurrence after CSAP was 19 m
onths (range 3 to 78). The mean RT dose to the planning target volume was 6
2.9 Gy (range 50.4 to 68.4).
Results. The mean pre-RT PSA level was 2.4 ng/ml(range 0.1 to 7.4). After R
T, the mean nadir PSA level was 0.4 ng/ml (range 0 to 4.2). The mean time t
o PSA nadir was 5.8 months (range 1 to 15). In 42 patients, the PSA nadir w
as less than 1.0 ng/ml, in 5 patients the PSA nadir was greater than 1 ng/m
L, and in 2 patients the PSA level remained stable. With a median follow-up
time of 32 months (range 12 to 85), the overall biochemical control rate w
as 61%. The mean time to biochemical failure was 14.5 months (range 1 to 47
). Of 30 patients with a pre-RT PSA level of 2.5 ng/mL or less, the disease
of 22 (73%) was controlled compared with only 8 (42%) of 19 with a pre-RT
PSA level greater than 2.5 ng/ml (P = 0.040). Biochemical control occurred
in 18 (69%) of 26 patients with a dose of 64 Cy or greater compared with on
ly 12 (52%) of 23 patients with a dose of less than 64 Gy (P = 0.024). The
disease of 20 (70%) of 29 patients with a Gleason score of 6 or lower was c
ontrolled versus 10 (50%) of 20 patients with a Gleason score of 7 or great
er (P = 0.064), Only 2 patients developed subacute morbidity (proctitis and
a urethral stricture). All complications resolved with conservative measur
es.
Conclusions. Salvage RT for prostate cancer recurrence after CSAP appears f
easible. Our preliminary experience revealed that post-CSAP RT in patients
with prostate cancer appears to effectively diminish the post-RT PSA level
to a nadir of 1.0 ng/ml or less in most patients. The pre-RT PSA level and
radiation dose may be important predictors of biochemical control in the sa
lvage setting. RT as described was associated with minimal toxicity to the
gastrointestinal/genitourinary systems. Additional prospective randomized s
tudies are necessary to better assess the role of RT in the treatment of th
ese patients. UROLOGY 56: 833-838, 2000. (C) 2000, Elsevier Science Inc.