Higher-Than-Conventional Radiation Doses in Localized Prostate Cancer Treatment: A Meta-analysis of Randomized, Controlled Trials

      Purpose

      To determine in a meta-analysis whether the outcomes in men with localized prostate cancer treated with high-dose radiotherapy (HDRT) are better than those in men treated with conventional-dose radiotherapy (CDRT), by quantifying the effect of the total dose of radiotherapy on biochemical control (BC).

      Methods and Materials

      The MEDLINE, EMBASE, CANCERLIT, and Cochrane Library databases, as well as the proceedings of annual meetings, were systematically searched to identify randomized, controlled studies comparing HDRT with CDRT for localized prostate cancer. To evaluate the dose–response relationship, we conducted a meta-regression analysis of BC ratios by means of weighted linear regression.

      Results

      Seven RCTs with a total patient population of 2812 were identified that met the study criteria. Pooled results from these RCTs showed a significant reduction in the incidence of biochemical failure in those patients with prostate cancer treated with HDRT (p < 0.0001). However, there was no difference in the mortality rate (p = 0.38) and specific prostate cancer mortality rates (p = 0.45) between the groups receiving HDRT and CDRT. However, there were more cases of late Grade >2 gastrointestinal toxicity after HDRT than after CDRT. In the subgroup analysis, patients classified as being at low (p = 0.007), intermediate (p < 0.0001), and high risk (p < 0.0001) of biochemical failure all showed a benefit from HDRT. The meta-regression analysis also detected a linear correlation between the total dose of radiotherapy and biochemical failure (BC = −67.3 + [1.8 × radiotherapy total dose in Gy]; p = 0.04).

      Conclusions

      Our meta-analysis showed that HDRT is superior to CDRT in preventing biochemical failure in low-, intermediate-, and high-risk prostate cancer patients, suggesting that this should be offered as a treatment for all patients, regardless of their risk status.
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      Linked Article

      • In Regard to Viani et al
        International Journal of Radiation Oncology • Biology • PhysicsVol. 95Issue 3
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          To the Editor: During the review process of another article that referenced an article by Viani et al (1), we noted an error with one of their equations—specifically, the equation for biochemical control (BC) for intermediate-risk patients noted in Figure 12 on page 1416. Using the equation BC = (1.78 × RTTD) − 53.8 and using the radiation therapy total dose (RTTD) of 90.4 Gy given on page 1415, the BC rate equals 107.1%. Could the authors please clarify the accuracy of the equation as written and perhaps help us correct a typographical or similar error?
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