Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2008 Dec 1;72(5):1402-7.
doi: 10.1016/j.ijrobp.2008.03.011. Epub 2008 May 9.

Does treatment duration affect outcome after radiotherapy for prostate cancer?

David J D'Ambrosio  1 , Tianyu Li, Eric M Horwitz, David Y T Chen, Alan Pollack, Mark K Buyyounouski
Affiliations

Does treatment duration affect outcome after radiotherapy for prostate cancer?

David J D'Ambrosio et al. Int J Radiat Oncol Biol Phys. .

Abstract

Purpose: The protraction of external beam radiotherapy (RT) time is detrimental in several disease sites. In prostate cancer, the overall treatment time can be considerable, as can the potential for treatment breaks. We evaluated the effect of elapsed treatment time on outcome after RT for prostate cancer.

Methods and materials: Between April 1989 and November 2004, 1,796 men with prostate cancer were treated with RT alone. The nontreatment day ratio (NTDR) was defined as the number of nontreatment days divided by the total elapsed days of RT. This ratio was used to account for the relationship between treatment duration and total RT dose. Men were stratified into low risk (n = 789), intermediate risk (n = 798), and high risk (n = 209) using a single-factor model.

Results: The 10-year freedom from biochemical failure (FFBF) rate was 68% for a NTDR <33% vs. 58% for NTDR >/=33% (p = 0.02; BF was defined as a prostate-specific antigen nadir + 2 ng/mL). In the low-risk group, the 10-year FFBF rate was 82% for NTDR <33% vs. 57% for NTDR >/=33% (p = 0.0019). The NTDR was independently predictive for FFBF (p = 0.03), in addition to T stage (p = 0.005) and initial prostate-specific antigen level (p < 0.0001) on multivariate analysis, including Gleason score and radiation dose. The NTDR was not a significant predictor of FFBF when examined in the intermediate-risk group, high-risk group, or all risk groups combined.

Conclusions: A proportionally longer treatment duration was identified as an adverse factor in low-risk patients. Treatment breaks resulting in a NTDR of >/=33% (e.g., four or more breaks during a 40-fraction treatment, 5 d/wk) should be avoided.

PubMed Disclaimer

Conflict of interest statement

Conflict of interest: A. Pollack received a departmental Varian research grant; all other authors have no conflicts of interest.

Figures

Fig. 1
Fig. 1
Kaplan-Meier freedom from biochemical failure estimates for all patients according to nontreatment day ratio (NTDR) quartile (n = 1,796).
Fig. 2
Fig. 2
Kaplan-Meier freedom from biochemical failure estimates by nontreatment day ratio (NTDR) of <33% vs. ≥33% for all patients (n = 1,796).
Fig. 3
Fig. 3
Kaplan-Meier freedom from biochemical failure estimates by nontreatment day ratio (NTDR) of <33% vs. ≥33% for low-risk patients (n = 789).
Fig. 4
Fig. 4
Kaplan-Meier freedom from biochemical failure estimates by nontreatment day ratio (NTDR) of <33% vs. ≥33% for intermediate-risk patients (n = 798).
Fig. 5
Fig. 5
Kaplan-Meier freedom from biochemical failure estimates by nontreatment day ratio (NTDR) of <33% vs. ≥33% for high-risk patients (n = 209).
See this image and copyright information in PMC

Comment in

References

    1. Suwinski R, Sowa A, Rutkowski T, et al. Time factor in postoperative radiotherapy: a multivariate locoregional control analysis in 868 patients. Int J Radiat Oncol Biol Phys. 2003;56:399–412. - PubMed
    1. Withers HR, Peters LJ, Taylor JM, et al. Local control of carcinoma of the tonsil by radiation therapy: An analysis of patterns of fractionation in nine institutions. Int J Radiat Oncol Biol Phys. 1995;33:549–562. - PubMed
    1. Taylor JM, Withers HR, Mendenhall WM. Dose-time considerations of head and neck squamous cell carcinomas treated with irradiation. Radiother Oncol. 1990;17:95–102. - PubMed
    1. Maciejewski B, Withers HR, Taylor JM, et al. Dose fraction-ation and regeneration in radiotherapy for cancer of the oral cavity and oropharynx: Tumor dose-response and repopulation. Int J Radiat Oncol Biol Phys. 1989;16:831–843. - PubMed
    1. Lai PP, Perez CA, Shapiro SJ, et al. Carcinoma of the prostate stage B and C: Lack of influence of duration of radiotherapy on tumor control and treatment morbidity. Int J Radiat Oncol Biol Phys. 1990;19:561–568. - PubMed

Publication types