Treatment outcomes of three-dimensional conformal radiotherapy for localized prostate carcinoma

Urinary toxicity after high dose intensity modulated radiotherapy as primary therapy for prostate cancer

BACKGROUND AND PURPOSE

Urinary toxicity plays a major role in the quality of life (QOL) of patients treated with external beam radiotherapy as primary therapy for prostate cancer. In this study we report on: (1) Incidence of acute and late GU toxicity after intensity modulated radiotherapy (IMRT) for prostate cancer at Ghent University Hospital (GUH). (2) Time evolution of pre-IMRT and IMRT-induced acute and late GU toxicity.

MATERIALS AND METHODS

At GUH, 260 patients with a follow-up of > or = 12 months were treated with IMRT for prostate cancer. The incidence and evolution of GU toxicity were recorded.

RESULTS

Acute grades 3, 2 and 1 GU toxicity occurred in 8%, 42% and 42% of the patients, respectively. Late grades 3, 2 and 1 GU toxicity occurred in 3%, 19% and 40% of the patients, respectively. During therapy baseline grade 1 symptoms increased into grade 2 acute GU toxicity in 48%. After 1 and 2 years, 60% and 70% of the patients, respectively, had less GU symptoms when compared to the pre-treatment status.

CONCLUSION

IMRT induces mild GU toxicity. There is an improvement in pre-IMRT obstructive miction disorders.

Intensity-modulated radiation therapy for prostate cancer: Late morbidity and results on biochemical control

PURPOSE

To report on late morbidity and biochemical relapse-free survival (bRFS) after intensity-modulated radiation therapy (IMRT) for prostate cancer.

METHODS

Between 1998 and 2005 133 patients were treated with IMRT for T(1-4) N0 M0 prostate cancer. The median follow-up time was 36 months. In a first cohort, patients received a median planning target volume (PTV) dose of 74 Gy with a hard constraint on maximum rectum dose of 72 Gy (74R72, n=51). Later, median PTV and maximum rectum dose were increased to 76 and 74 Gy, respectively (76R74; n=82). We defined low-risk (n=20), intermediate-risk (n=70) and high-risk (n=43) groups. Androgen deprivation was given to patients in the intermediate- and high-risk group. Late gastro-intestinal (GI) and genito-urinary (GU) morbidity and biochemical relapse, in accordance with the ASTRO consensus, were recorded.

RESULTS

We observed grade 2 GI (17%) and GU (19%), grade 3 GI (1%) and GU (3%) late toxicities. Except for hematuria, the median duration of side-effects was 6 months. Biochemical relapse-free survival (bRFS) at 3 and 5 years was 88% and 83%, respectively, with a significantly better 3-year bRSF for the 76R74 than for the 74R72 group (p=0.01). Five-year bRFS for patients in the low-risk, intermediate-risk and high-risk group was 100%, 94% and 74%, respectively (p<0.01).

CONCLUSION

IMRT for localized or locally advanced prostate cancer combines low morbidity with excellent biochemical control.

Prediagnosis Prostate Specific Antigen Velocity is Associated With Risk of Prostate Cancer Progression Following Brachytherapy and External Beam Radiation Therapy

PURPOSE

Prostate specific antigen velocity 2.0 ng/ml per year or greater in the year before prostate cancer diagnosis is associated with cancer specific survival following radical prostatectomy and radiation therapy. We evaluated the relationship between prediagnosis prostate specific antigen velocity and cancer progression following primary radiation therapy.

MATERIALS AND METHODS

We analyzed the records of 24,893 men from a community based prostate cancer screening study and identified 237 with clinically localized prostate cancer who elected primary radiation therapy. Our final cohort consisted of 130 men, including 83 treated with external beam radiation and 47 treated with brachytherapy. Patient specific variables at diagnosis were analyzed for their value in predicting biochemical progression using American Society for Therapeutic and Radiation Oncology criteria.

RESULTS

Mean followup +/- SD was 64 +/- 35 months. Prostate specific antigen at diagnosis, family history of prostate cancer and prediagnosis prostate specific antigen velocity 2.0 ng/ml per year or greater were associated with cancer progression following brachytherapy or external beam radiation. Of men with prostate specific antigen velocity 2.0 ng/ml per year or greater 38% had cancer progression compared to 12% with prostate specific antigen velocity less than 2.0 ng/ml per year (OR 4.3, p = 0.003). The 6-year progression-free survival estimate was 57% in men with prostate specific antigen velocity 2.0 ng/ml per year or greater and 82% in men with prostate specific antigen velocity less than 2.0 ng/ml per year (p < 0.001). On multivariate analysis absolute prostate specific antigen at diagnosis and prostate specific antigen velocity 2.0 ng/ml per year or greater were independently associated with cancer progression in men treated with external beam radiation therapy or brachytherapy.

CONCLUSIONS

Men with a prediagnosis prostate specific antigen velocity of 2.0 ng/ml per year or greater are at increased risk for cancer progression following brachytherapy or external beam radiation compared to men with a prostate specific antigen velocity of less than 2.0 ng/ml per year.