Simultaneous boost radiotherapy versus conventional dose radiotherapy for patients with newly diagnosed glioblastoma: a multi-institutional analysis.

We compared survival outcomes of high-dose concomitant boost radiotherapy (HDCBRT) and conventional dose radiotherapy (CRT) for newly diagnosed glioblastoma (GB). Patients treated with intensity-modulated radiation therapy for newly diagnosed GB were included. In HDCBRT, specific targets received 69, 60, and 51 Gy in 30 fractions, while 60 Gy in 30 fractions was administered with a standard radiotherapy method in CRT. Overall survival (OS) and progression-free survival (PFS) were compared using the Log-rank test, followed by multivariate Cox analysis. The inverse probability of treatment weighting (IPTW) method was also applied to each analysis. Among 102 eligible patients, 45 received HDCBRT and 57 received CRT. With a median follow-up of 16 months, the median survival times of OS and PFS were 21 and 9 months, respectively. No significant differences were observed in OS or PFS in the Kaplan-Meier analyses. In the multivariate analysis, HDCBRT correlated with improved OS (hazard ratio, 0.49; 95% confidence interval, 0.27-0.90; P = 0.021), and this result remained consistent after IPTW adjustments (P = 0.028). Conversely, dose suppression due to the proximity of normal tissues and IMRT field correlated with worse OS and PFS (P = 0.008 and 0.049, respectively). A prospective study with a stricter protocol is warranted to validate the efficacy of HDCBRT for GB.

Early salvage radiotherapy in patients with biochemical recurrence after radical prostatectomy: Its impact and optimal candidate.

AIM: We aimed to identify the optimal candidates for early salvage radiotherapy (SRT) among patients with biochemical recurrence (BCR) after radical prostatectomy (RP). METHODS: This multi-institutional retrospective study included 371 patients treated using SRT after RP. The median (range) PSA level at BCR was 0.36 (0.10-2.00) ng/mL. The association between early SRT (ie, starting PSA level < 0.50) and BCR after SRT was tested in each subgroup according to our own risk stratification. RESULTS: The median follow-up time was 51 months. By multivariate analysis, pT3b, Gleason score ≥ 8, negative surgical margins, PSA doubling time < 6 months, and non-early SRT were associated with BCR after SRT. Patients were stratified by four risk factors other than non-early SRT: (1) low risk (0 risk factor), (2) intermediate risk (1 risk factor), and (3) high risk (≥2 risk factors). The BCR-free survival was higher in the early SRT group than the nonearly SRT group in the high-risk subgroup (P = 0.020), whereas that was similar between two groups in the low-risk and intermediate-risk subgroups (P = .79 and .18, respectively). Multivariate analysis revealed that early SRT was beneficial for the high-risk subgroup (P = .032), whereas early SRT was not associated with improved outcomes in the low-risk and intermediate-risk subgroups (P = .92 and 1.0, respectively). CONCLUSIONS: This study suggested that early SRT seemed to contribute to better biochemical control for patients with more adverse features, whereas no benefit was observed in men with no adverse features.

Impact of advanced radiotherapy techniques and dose intensification on toxicity of salvage radiotherapy after radical prostatectomy.

The safety and efficacy of dose-escalated radiotherapy with intensity-modulated radiotherapy (IMRT) and image-guided radiotherapy (IGRT) remain unclear in salvage radiotherapy (SRT) after radical prostatectomy. We examined the impact of these advanced radiotherapy techniques and dose intensification on the toxicity of SRT. This multi-institutional retrospective study included 421 patients who underwent SRT at the median dose of 66 Gy in 2-Gy fractions. IMRT and IGRT were used for 225 (53%) and 321 (76%) patients, respectively. At the median follow-up of 50 months, the cumulative incidence of late grade 2 or higher gastrointestinal (GI) and genitourinary (GU) toxicities was 4.8% and 24%, respectively. Multivariate analysis revealed that the non-use of either IMRT or IGRT, or both (hazard ratio [HR] 3.1, 95% confidence interval [CI] 1.8-5.4, p < 0.001) and use of whole-pelvic radiotherapy (HR 7.6, CI 1.0-56, p = 0.048) were associated with late GI toxicity, whereas a higher dose ≥68 Gy was the only factor associated with GU toxicities (HR 3.1, CI 1.3-7.4, p = 0.012). This study suggested that the incidence of GI toxicities can be reduced by IMRT and IGRT in SRT, whereas dose intensification may increase GU toxicity even with these advanced techniques.