The new prognostic staging system has a better accuracy of prognosis of survival than the routinely used AJCC TNM staging system and thus is more useful in identifying high-risk patients for more intense treatment and care.

Background: Whole pelvic radiotherapy (WPRT) with stereotactic body radiotherapy (SBRT) boost has been shown to be effective in patients with high-risk prostate cancer (PC). However, no study has directly compared the efficacy of WPRT with SBRT boost with that of conventionally fractionated radiotherapy (CFRT). We compared the clinical outcomes between CFRT and WPRT with SBRT boost in patients with high or very high-risk PC (National Comprehensive Cancer Network definition). Methods: In total, 132 patients treated with CFRT and 121 patients treated with WPRT followed by SBRT boost were retrospectively analyzed. For the CFRT group, the prescribed dose range was 74-79.2 Gray (Gy) administered at 1.8-2 Gy per fraction. For WPRT with SBRT boost, the prescribed doses were 45 Gy administered in 25 fractions to the whole pelvis followed by 21 Gy boost (3 fractions of 7 Gy each) to prostate and seminal vesicles. The overall survival (OS) and biochemical failure (Phoenix definition) free survival (bFFS) were assessed by using the Kaplan-Meier method or the Cox proportional hazards regression model. The gastrointestinal (GI) and genitourinary (GU) tract toxicity were assessed using the National Cancer Institute Common Terminology Criteria for Adverse Events (CTCAE) v3.0. Results: The estimated 4-years overall survival in the CFRT and WPRT with SBRT boost groups was 91.6 and 97.7%, respectively (P = 0.18). The estimated 4-years biochemical failure-free survival in the CFRT and WPRT with SBRT boost groups was 89.1 and 93.9%, respectively (P = 0.41). No acute grade 3 or higher GI and GU toxicity was observed in both groups. Late grade 3 GI and GU toxicity occurred in 2.3 and 2.3% in the CFRT group, and in 1.7 and 0.8% in the WPRT with SBRT boost group, respectively. There was no significant between-group difference with respect to acute or late toxicity. Wang et al. SBRT Boost for Prostate Cancer Conclusions: In patients with high or very high-risk localized PC, compared with CFRT, WPRT with SBRT boost resulted in similar biochemical-free and overall survival rate with minimal toxicity. WPRT with SBRT boost is a feasible option for patients with high or very high-risk PC.

An expectation–maximization (EM) likelihood estimation procedure is proposed to obtain the maximum likelihood estimates of the parameters in a mixture distributions model based on type-I hybrid censored samples when the mixture proportions are unknown. Three bootstrap methods are applied to construct the confidence intervals of the model parameters. Monte Carlo simulations are conducted to evaluate the performance of the proposed methods. Simulation results show that the proposed methods can perform well to obtain reliable point and interval estimation results. Three examples are used to illustrate the applications of the proposed methods.

Background This study evaluates the feasibility of HyperArc (HA) for trigeminal neuralgia (TN) by comparing dose distribution with CyberKnife (CK). Methods Contour sets from twenty patients who had undergone CK for TN were used to generate HA treatment plans for comparison. Two different TN target delineation settings were used: the whole segment of the trigeminal nerve root entry zone (REZ) group and the 5-mm spherical target group. The prescribed dose was 65 Gy in a single fraction, prescribed to the 80% isodose line. The CK and HA treatment plans were compared for target coverage, sparing of organs at risk (OARs), and dose distribution metrics. Results In the whole segment of the REZ group, the HA plans showed statistically significant differences with higher target coverage than the CK plans. The mean brain doses for HA and CK were 0.83 Gy and 1.15 Gy, respectively (P < 0.001). The brain V12 was significantly smaller for HA plans (5.9 cm3) than CK plans (6.9 cm3). Significant achievement in the doses of the ipsilateral/contralateral cranial nerve (CN) VII/VIII were observed in the HA plans than the CK plans. The conformity index was significantly greater in the HA plans compared to the CK plans. The dose gradient radius was similar for the CK and HA plans. In the 5mm-spherical target group, both plans showed good target coverage, with the CK plans exhibiting better brain sparing and higher CN VII/VIII dose. The dose distribution metrics were similar for both plans. Conclusions The HA technique is a feasible alternative for TN treatment, offering excellent organ-at-risk sparing and favorable dosimetric distribution.