Late toxicity after conformal and intensity‐modulated radiation therapy for prostate cancer: Impact of previous surgery for benign prostatic hyperplasia

Abstract

Objectives:To retrospectively compare late toxicity of conventional-dose three-dimensional conformal radiation therapy (3D-CRT) and high-dose intensity-modulated radiation therapy (IMRT) for prostate cancer. Methods: A total of 340 patients with T1-3 prostate cancer were treated with 3D-CRT (n = 228) and IMRT (n = 112). The median follow-up time was 5.9 years and 3.0 years, respectively. The prescription dose was 70 Gy for 3D-CRT and 78 Gy for IMRT. Late gastrointestinal (GI) and genitourinary (GU) toxicities were graded according to the Fox Chase modification of the Radiation Therapy Oncology Group and Late Effects Normal Tissue Task Force criteria. Results: There was no difference between 3D-CRT and IMRT in the incidence of GI and GU toxicity at 3 years. On multivariate analysis, transurethral resection of prostate/open transvesical prostatectomy (TURP/TVPE) for benign prostatic hyperplasia, carried out before radiotherapy, significantly increased the risk of Grade Ն2 GU toxicity (risk ratio 1.88). Among patients who experienced TURP/TVPE, the 5-year actuarial likelihood of Grade 2-3 urinary incontinence was 23%, compared with 9% for those without prostate surgery (P = 0.01). Conclusions: Tolerance of 3D-CRT and IMRT was similar, despite the use of high radiation dose with IMRT. Previous TURP/TVPE increased the risk of GU toxicity.

Prospective evaluation of quality of life 54 months after high-dose intensity-modulated radiotherapy for localized prostate cancer

“…Dose escalation without enhancing toxicity is thus possible if IMRT is used instead of 3D-CRT. The results of several other studies support this conclusion: a 16% incidence of urinary toxicity and 3% incidence of GI toxicity (grade 2+) 10 years after 81 Gy IMRT, a 9% incidence of grade 2 urinary toxicity and a 5% incidence of grade 2 GI toxicity 3 years after 76 Gy IMRT, and no difference in urinary or GI toxicity between 78 Gy IMRT and 70 Gy 3D-CRT [31-33]. …”

Outcomes After Intensity-Modulated Versus Conformal Radiotherapy in Older Men With Nonmetastatic Prostate Cancer

“…A recent systematic review of IMRT identified five published studies in which late toxicity data was compared between IMRT and CRT, and we identified one additional study based on a comprehensive search (7, 41–46). Table 5 summarizes these studies and compares results to our findings.…”

Five-Year Results of IMRT for Prostate Cancer – Toxicity

“…Použití radioterapie s modulovanou intenzitou umožňuje eskalovat dávku při Významným faktorem ovlivňujícím míru chronické toxicity je rovněž čas [26][27][28][29]. Naprostá většina symptomů pozdní postradiační gastrointestinální toxicity je pozorována v prvních třech letech po ukončení radioterapie.…”