Incidence and dose-volume analysis of acute bladder toxicity following pelvic radiotherapy.
OBJECTIVE
The authors performed this prospective study to evaluate the incidence of acute bladder toxicity following pelvic radiation therapy and to determine any dosimetric predictors for the toxicity.


METHODS
Acute bladder toxicity was evaluated weekly by physicians using the Common Terminology Criteria for Adverse Events (CTCAE version 4.0). At the same time, the International Prostate Symptom Score (IPSS) and Overactive Bladder Symptom Score (OABSS) were also assessed by each patient during radiation therapy. We contoured the bladder wall, solid bladder and trigone on the planning computed tomography and analyzed dose-volume histograms to determine which of these could be the most suitable dosimetric predictor.


RESULTS
Of 92 eligible patients, 27 (29%) demonstrated CTCAE grade 2 acute bladder toxicity, with nocturia as the most frequently observed symptom. IPSS demonstrated better agreement with CTCAE than OABSS. In receiver-operating characteristic curve analysis, the largest area under the curve was observed for V20 of both the bladder wall and the bladder.


CONCLUSIONS
Acute bladder toxicity during pelvic radiation therapy is not a trivial complication and should be actively investigated. Dose-volume relationships demonstrate that both bladder wall V20 and bladder solid V20 are useful surrogates for identifying patients at high risk of toxicity. The roles of IPSS and OABSS need to be validated in a larger study.
Jin-Hong
JH
Park
Young Seok
YS
Kim
Jongmoo
J
Park
Hanjong
H
Ahn
Choung-Soo
CS
Kim
Minju
M
Kim
Jong Hoon
JH
Kim
Seung Do
SD
Ahn
D000208:Acute Disease; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D059248:Chemoradiotherapy / Q000009:adverse effects; D004307:Dose-Response Relationship, Radiation; D005260:Female; D005833:Genital Neoplasms, Female / Q000532:radiotherapy; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D010386:Pelvic Neoplasms / Q000532:radiotherapy*; D011237:Predictive Value of Tests; D011446:Prospective Studies; D011471:Prostatic Neoplasms / Q000532:radiotherapy; D012372:ROC Curve; D011832:Radiation Injuries / Q000453:epidemiology* / Q000209:etiology*; D011878:Radiotherapy / Q000009:adverse effects; D012004:Rectal Neoplasms / Q000532:radiotherapy; D056910:Republic of Korea / Q000453:epidemiology; D018570:Risk Assessment; D012307:Risk Factors; D012720:Severity of Illness Index; D001743:Urinary Bladder / Q000528:radiation effects*; D014555:Urination Disorders / Q000453:epidemiology* / Q000209:etiology*