Clinical factors predicting late severe urinary toxicity after postoperative radiotherapy for prostate carcinoma: a single-institute analysis of 742 patients.
OBJECTIVE
To investigate the clinical factors independently predictive of long-term severe urinary sequelae after postprostatectomy radiotherapy.


METHODS
Between 1993 and 2005, 742 consecutive patients underwent postoperative radiotherapy with either adjuvant (n = 556; median radiation dose, 70.2 Gy) or salvage (n = 186; median radiation dose, 72 Gy) intent.


RESULTS
After a median follow-up of 99 months, the 8-year risk of Grade 2 or greater and Grade 3 late urinary toxicity was almost identical (23.9% vs. 23.7% and 12% vs. 10%) in the adjuvant and salvage cohorts, respectively. On univariate analysis, acute toxicity was significantly predictive of late Grade 2 or greater sequelae in both subgroups (p <.0001 in both cases), and hypertension (p = .02) and whole-pelvis radiotherapy (p = .02) correlated significantly in the adjuvant cohort only. The variables predictive of late Grade 3 sequelae were acute Grade 2 or greater toxicity in both groups and whole-pelvis radiotherapy (8-year risk of Grade 3 events, 21% vs. 11%, p = .007), hypertension (8-year risk, 18% vs. 10%, p = .005), age ≤ 62 years at RT (8-year risk, 16% vs. 11%, p = .04) in the adjuvant subset, and radiation dose >72 Gy (8-year risk, 19% vs. 6%, p = .007) and age >71 years (8-year risk, 16% vs. 6%, p = .006) in the salvage subgroup. Multivariate analysis confirmed the independent predictive role of all the covariates indicated as statistically significant on univariate analysis.


CONCLUSIONS
The risk of late Grade 2 or greater and Grade 3 urinary toxicity was almost identical, regardless of the RT intent. In the salvage cohort, older age and greater radiation doses resulted in a worse toxicity profile, and younger, hypertensive patients experienced a greater rate of severe late sequelae in the adjuvant setting. The causes of this latter correlation and apparently different etiopathogenesis of chronic damage in the two subgroups were unclear and deserve additional investigation.
Department of Radiotherapy, San Raffaele Scientific Institute, Milan, Italy. cozzarini.cesare@hsr.it
Cesare
C
Cozzarini
Claudio
C
Fiorino
Luigi Filippo
LF
Da Pozzo
Filippo
F
Alongi
Genoveffa
G
Berardi
Angelo
A
Bolognesi
Alberto
A
Briganti
Sara
S
Broggi
Aniko
A
Deli
Giorgio
G
Guazzoni
Lucia
L
Perna
Marcella
M
Pasetti
Giovannella
G
Salvadori
Francesco
F
Montorsi
Patrizio
P
Rigatti
Nadia
N
Di Muzio
D000368:Aged; D000704:Analysis of Variance; D005500:Follow-Up Studies; D006470:Hemorrhage / Q000209:etiology*; D006801:Humans; D006973:Hypertension / Q000150:complications; D008297:Male; D008875:Middle Aged; D011468:Prostatectomy; D011471:Prostatic Neoplasms / Q000532:radiotherapy* / Q000601:surgery; D012372:ROC Curve; D011832:Radiation Injuries / Q000150:complications; D011879:Radiotherapy Dosage; D018714:Radiotherapy, Adjuvant / Q000009:adverse effects; D050397:Radiotherapy, Intensity-Modulated / Q000009:adverse effects*; D012306:Risk; D016879:Salvage Therapy / Q000009:adverse effects / Q000379:methods; D012680:Sensitivity and Specificity; D014525:Urethral Stricture / Q000209:etiology*; D001743:Urinary Bladder / Q000528:radiation effects*; D014549:Urinary Incontinence / Q000209:etiology*