Long-term outcomes of whole-pelvis radiation therapy using volumetric modulated arc therapy for high-risk prostate cancer†.

This study investigated the outcomes of whole-pelvis radiation therapy (WPRT) using volumetric modulated arc therapy (VMAT) for high-risk prostate cancer. We retrospectively analysed 112 patients with high-risk prostate cancer who started WPRT at our hospital between August 2011 and August 2015. The prescribed dose was 78 Gy in 39 fractions to the prostate and 46.8 Gy in 26 fractions to the pelvic lymph node (LN) area. All patients received long-term androgen deprivation therapy. We evaluated late gastrointestinal (GI) and genitourinary (GU) toxicities using the Common Terminology Criteria for Adverse Events version 4.0. The median follow-up period for censored cases was 97 (interquartile range [IQR] = 85-108) months. The median age was 72 (IQR = 67-75) years. The high-risk and very-high-risk groups included 41 (36.6%) and 71 patients (63.4%), respectively. The median risk of LN invasion calculated by the Roach formula was 36.9 (IQR = 26.6-56.3) %. The 8-year overall survival, biochemical failure-free survival, disease-free survival and distant metastasis-free survival rates were 88.4, 91.9, 83.8 and 98.0%, respectively. Only one patient experienced common iliac LN recurrence, which was outside the pelvic irradiation area. All patients with recurrent disease were categorized into the very-high-risk group. The 8-year cumulative rates of ≥Grade 2 late GI and GU toxicities were 12.8 and 11.8%, respectively. No patients experienced Grade 4 or higher toxicities. WPRT using VMAT for high-risk prostate cancer was well tolerated and effective.

Comparison of Late Toxicity After Whole-pelvis Versus Prostate-only VMAT for Prostate Cancer.

BACKGROUND/AIM: To evaluate whether whole-pelvis (WP) volumetric modulated arc therapy (VMAT) is associated with increased late toxicity compared with prostate-only (PO) VMAT in patients with localized prostate cancer. PATIENTS AND METHODS: Participants comprised 384 consecutive patients treated with definitive VMAT to 78 Gy in 39 fractions from July 2011 to August 2016. Of these, 183 patients received PO-VMAT and 201 patients received initial WP-VMAT to 46.8 Gy in 26 fractions using a simultaneous integrated boost technique. Gastrointestinal (GI) and genitourinary (GU) toxicities were prospectively scored using Common Terminology Criteria for Adverse Events version 4.0. RESULTS: Median follow-up was 49 months (range=16-88 months) in the PO-VMAT group and 52 months (range=10-85 months) in the WP-VMAT group. Frequencies of Grade 3 late GI and GU toxicities were ≤3% across both groups. No patients experienced Grade 4+ toxicity. Cumulative incidences of Grade 2+ late GI and GU toxicities were similar between PO- and WP-VMAT groups (p=0.508 and p=0.838, respectively). Five-year cumulative incidences of Grade 2+ late GI and GU toxicities were 12.2% and 6.6% for the PO-VMAT group and 12.3% and 8.9% for the WP-VMAT group, respectively. CONCLUSION: WP-VMAT did not increase late GI and GU toxicities. This suggests that concerns about increasing toxicity profile are insufficient reason for omitting WPRT for patients with high-risk prostate cancer.

Thermal behavior and microstructures of cathodes for liquid electrolyte-based lithium batteries.

Lithium-ion batteries are widely used as a power source for portable equipment. However, the use of highly flammable organic solvents in the liquid electrolyte component in these batteries presents a serious safety concern. In this study, the thermal stability of battery cathodes comprising LiNi1/3Mn1/3Co1/3O2 (NMC) and LiPF6-based electrolyte solutions have been investigated using transmission electron microscopy (TEM) and differential scanning calorimetry (DSC) methods. Ex situ TEM measurements revealed that significant structural change occurred in the charged NMC composite after heating at a temperature above the exothermal peaks. It was found that LiF nanocrystallites precipitated in LiPF6 and that a number of nanoscale stacking faults developed in the [Formula: see text] layered structure of NMC. The results suggested that the decomposition reaction of LiPF6 and the structural change of NMC were directly associated with the exothermic reaction in the liquid electrolyte-based NMC electrode composite.

Treatment results of neoadjuvant chemoradiotherapy followed by radical esophagectomy in patients with initially inoperable thoracic esophageal cancer.

PURPOSE: We evaluated the effectiveness of neoadjuvant chemoradiotherapy (CRT) followed by esophagectomy for cT4 esophageal cancer or lymph node metastases (LNM) invading adjacent structures. MATERIALS AND METHODS: We retrospectively evaluated 42 consecutive patients with thoracic esophageal cancer who underwent CRT followed by esophagectomy between 2008 and 2013. All were initially considered to be unresectable because of cT4 (n = 32) disease or LN invasion (n = 10). Radiotherapy was administered at 41.4 Gy/23 fr with concurrent chemotherapy. At completion of CRT, restaging was performed using computed tomography (CT). RESULTS: All cT4 tumors were downstaged, LNM invading to adjacent structures were considered to be released, and subtotal esophagectomy was performed. The median follow-up period was 42 months. The curative resection (R0) rate was 94% in cT4 group and 70% in LN invasion group. The 3-year overall survival (OS) and 3-year locoregional control (LRC) rates were 65-80% in the cT4 group and 50-67% in LN invasion group, respectively. CONCLUSIONS: The cT4 group showed good rates of R0, OS, and LRC. Surgical resection should be an effective option when downstaging is achieved by CRT for patients with initially inoperable thoracic esophageal cancer.

Direct observation of a non-crystalline state of Li2S-P2S5 solid electrolytes.

There are two types of solid electrolytes which has been recently expected to be applied to all-solid-state batteries. One is the glasses characterized by an amorphous state. The other is the glass ceramics containing crystalline in an amorphous matrix. However, the non-crystalline state of glasses and glass ceramics is still an open question. It has been anticipated that sea-island and core-shell structures including crystalline nanoparticles have been proposed as candidate models for glass ceramics. Nevertheless, no direct observation has been conducted so far. Here we report the non-crystalline state of Li2S-P2S5 glasses and glass ceramics, and the crystallization behavior of the glasses during heating via direct transmission electron microscopy (TEM) observation. High resolution TEM images clearly revealed the presence of crystalline nanoparticles in an amorphous region. Eventually we suggest that the precipitation and connection of crystalline nanoparticles in an amorphous matrix are key to achieving high ionic conductivity.

Correlations of post-implant regional dosimetric parameters at 24 hours and one month, with clinical results of low-dose-rate brachytherapy for localized prostate cancer.

PURPOSE: To evaluate the correlations of post-implant regional dosimetrics at 24 hours (24 h) and 1 month after implant procedures, with clinical outcomes of low-dose-rate (LDR) brachytherapy for localized prostate cancer. MATERIAL AND METHODS: Between January 2008 and December 2014, 130 consecutive patients treated for localized prostate cancer, receiving definitive iodine-125 (125I) brachytherapy treatment were retrospectively analyzed. All patients underwent post-implant CT imaging for dosimetric analysis at 24 h and 1 month after implantation procedure. Prostate contours were divided into quadrants: anterior-superior (ASQ), posterior-superior (PSQ), anterior-inferior (AIQ), and posterior-inferior (PIQ). Predictive factors and cut-off values of biochemical failure-free survival (BFFS) and toxicities of LDR brachytherapy were analyzed. RESULTS: The median follow-up time was 69.5 months. Seven patients (5.4%) had biochemical failure. The 3-year and 5-year BFFS rates were 96.7% and 93.1%, respectively. On multivariate analysis, prostate-specific antigen and Gleason score were significant prognostic factors for biochemical failure. D90 (the minimal dose received by 90% of the volume) of PSQ and PIQ at 24 h, and D90 of PSQ at 1 month were also significant factors. The cut-off values of PSQ D90 were 145 Gy at 24 h and 160 Gy at 1 month. D90 of the whole prostate was not significant at 24 h and at 1 month. D90 of PSQ at 1 month was a significant factor for rectal hemorrhage. CONCLUSIONS: Post-implant D90 of PSQ is significantly associated with BFFS for localized prostate cancer not only at 1 month, but also at 24 hours. D90 of PSQ at 1 month is also a significant factor for rectal hemorrhage.

Results of surgery plus postoperative radiotherapy for patients with malignant parotid tumor.

PURPOSE: The latest version of the World Health Organization (WHO) histologic classification of salivary gland malignancies was published in 2005. To contribute to data accumulation on the basis of this latest version, a retrospective study was performed. MATERIALS AND METHODS: Participants comprised 27 patients who underwent postoperative radiotherapy between 2000 and 2013. Two, eight, and 17 patients were allocated to low, intermediate, and high-grade groups, respectively, in accordance with the latest WHO classification. The radiation field included the tumor bed and ipsilateral regional lymph nodes for 25 patients. The radiation dose was 46-60 Gy (median 56 Gy). RESULTS: Median duration of follow-up was 41 months. Five-year locoregional control was 89 %. Two patients experienced local recurrence and 7 patients developed distant metastases. No patients in the low or intermediate-grade groups developed distant metastases. Overall 3 and 5-year survival for all patients were 81 and 75 %, respectively. Five-year overall survival for patients in the low and intermediate-grade groups was 100 %, compared with 59 % for patients in the high-grade group (p = 0.03). CONCLUSION: Favorable locoregional control was achieved for patients with malignant parotid tumors who underwent surgery plus postoperative radiotherapy. Patients with high-grade tumors frequently experienced distant metastases and prognosis was poor.