Pretreatment clinical mediastinal nodal bulk and extent do not influence survival in N2-positive stage IIIA non-small cell lung cancer patients treated with trimodality therapy.

BACKGROUND: Treatment for patients with N2-positive stage IIIA non-small cell lung cancer has been a controversial issue. The current study evaluated the outcomes in patients treated with trimodality therapy, which consisted of neoadjuvant radiation therapy concurrent with chemotherapy followed by surgical resection, with emphasis on clinical and pathologic nodal status. METHODS: We reviewed the records of 355 patients who were treated with trimodality therapy between 1997 and 2011. RESULTS: After completion of neoadjuvant chemoradiation, overall down-staging and complete response rates were 50.4 % (179 patients), and 13.2 % (47 patients), respectively. With median follow-up of 35.3 months, median times of progression-free survival (PFS) and overall survival (OS) were 16.3 months and 45.5 months, respectively. Seventeen patients (4.8 %) died of postoperative complications, and the remaining 338 patients were analyzed on prognostic factors. Old age (p = 0.032), pneumonectomy (p < 0.001), and ypN+ (p < 0.001) were found to be the significant prognosticators for worse PFS, and old age (p = 0.013), pneumonectomy (p < 0.001), and ypN+ (p < 0.001) were related to worse OS. Clinical N2 status did not influence either OS or PFS: the number of involved stations (single station vs. multi-station; p = 0.187 for PFS; p = 0.492 for OS), and bulk (clinically evident vs. microscopic; p = 0.902 for PFS; p = 0.915 for OS). CONCLUSION: ypN stage was the most important prognosticator for both PFS and OS; however, neither initial bulk nor extent of cN2 disease influenced prognosis. Surgery following neoadjuvant chemoradiation should have contributed to improved clinical outcomes regardless of clinical nodal bulk and extent.

Fibrotic airway stenosis following radiotherapy in patients with adenoid cystic carcinoma.

BACKGROUND AND OBJECTIVE: Radiotherapy is usually administered to the central airway in patients with unresectable adenoid cystic carcinoma (ACC). The purpose of this study was to describe the outcomes of endobronchial intervention in patients with airway stenosis following radiotherapy for ACC. Moreover, we investigated the incidence and contributing factors for airway stenosis following radiotherapy for ACC. METHODS: Forty-seven patients with ACC, who underwent radiotherapy of the tracheobronchial tree from January 1995 to December 2011, were reviewed retrospectively. Fibrotic airway stenoses were diagnosed using three-dimensional computed tomography, flexible bronchoscopy or both. RESULTS: Eleven (23%) of the 47 patients with ACC suffered fibrotic airway stenosis following radiotherapy and received bronchoscopic intervention. The median interval from radiotherapy to diagnosis of fibrotic airway stenosis was 7 months. Low forced expiratory volume in 1 s (FEV1), FEV1 /forced vital capacity and brachytherapy were verified as factors contributing to radiotherapy-induced airway stenosis. Bronchoscopic intervention provided both symptomatic relief and improvement of lung function, and no procedure-related death or major complication was observed. Insertion of a straight silicone stent was required in 10 patients (91%), and 4 (36%) eventually received Y-shaped silicone stents. The stents, once implanted, could not be removed in any of the patients; stents were well-tolerated for a prolonged period in all patients. CONCLUSIONS: Fibrotic airway stenosis following radiotherapy in patients with ACC is often found. Bronchoscopic intervention, including silicone airway stenting, was a safe and useful method for treating radiotherapy-induced fibrotic airway stenosis in patients with ACC.

Combination therapy of cilengitide with belotecan against experimental glioblastoma.

The prognosis of patients diagnosed with glioblastoma remains dismal in spite of the current concomitant chemoradiotherapy with temozolomide. In particular, the resistance to temozolomide appears to be the greatest obstacle to the treatment of glioblastoma. In the present study, we evaluated in vitro and in vivo the antitumor effects of combination therapy of cilengitide with belotecan, a camptothecin derivate, to treat experimental glioblastoma. The therapeutic effects of the drugs on the U87MG and U251MG human glioblastoma cell lines were assessed using in vitro cell viability and apoptosis assays. The combination treatment group with cilengitide and belotecan enhanced the cytotoxic effects to the glioblastoma cell lines and increased the apoptosis of the tumor cells compared to monotherapy with either drug alone in vitro. Nude mice with established U87MG glioblastoma were assigned to the following four groups: control, cilengitide, belotecan and combination treatment. The volume of tumors and length of survival were also measured. Animals in the combination therapy group demonstrated a significant reduction of tumor volume and an increase in survival (p < 0.05). Immunohistochemistry revealed a decrease in angiogenesis by cilengitide and an increase in apoptosis by cilengitide and belotecan in vivo. The combination therapy of cilengitide with belotecan presented more cytotoxic effects compared to the monotherapy of either drug in vitro and in vivo. This combination protocol may serve as an alternative treatment option for glioblastoma.

Identification and characterization of triamcinolone acetonide, a microglial-activation inhibitor.

Recent studies show that necrotic neuronal cells (NNC) activate microglia, thereby leading to neuronal cell death. This suggests that chemicals that inhibit microglia activation may be used as neuroprotective drugs. In this context, we screened a chemical library for inhibitors of microglia activation. Using a screening system based on a nitrite assay, we isolated two chemicals that inhibit nitric oxide (NO) release from activated microglia: triamcinolone acetonide (TA) and amcinonide. The half-maximal inhibitory concentrations (IC50) of TA and amcinonide for NO release inhibition were 1.78 nM and 3.38 nM, respectively. These chemicals also inhibited NNC-induced expression of the proinflammatory genes iNOS, TNF-α, and IL-1ß in glial cells. A study based on a luciferase assay revealed that TA attenuated NNC-induced microglia activation by blocking the NF-κB signaling pathway. In addition, TA protected cortical neurons in coculture with microglia from LPS/IFN-γ-induced neuronal cell death. In conclusion, TA may inhibit microglia activation and may protect neuronal cells from death induced by microglial activation.

Clinical adoption patterns of 0.35 Tesla MR-guided radiation therapy in Europe and Asia.

BACKGROUND: Magnetic resonance-guided radiotherapy (MRgRT) utilization is rapidly expanding, driven by advanced capabilities including better soft tissue imaging, continuous intrafraction target visualization, automatic triggered beam delivery, and the availability of on-table adaptive replanning. Our objective was to describe patterns of 0.35 Tesla (T)-MRgRT utilization in Europe and Asia among early adopters of this novel technology. METHODS: Anonymized administrative data from all 0.35T-MRgRT treatment systems in Europe and Asia were extracted for patients who completed treatment from 2015 to 2020. Detailed treatment information was analyzed for all MR-linear accelerators (linac) and -cobalt systems. RESULTS: From 2015 through the end of 2020, there were 5796 completed treatment courses delivered in 46,389 individual fractions. 23.5% of fractions were adapted. Ultra-hypofractionated (UHfx) dose schedules (1-5 fractions) were delivered for 63.5% of courses, with 57.8% of UHfx fractions adapted on-table. The most commonly treated tumor types were prostate (23.5%), liver (14.5%), lung (12.3%), pancreas (11.2%), and breast (8.0%), with increasing compound annual growth rates (CAGRs) in numbers of courses from 2015 through 2020 (pancreas: 157.1%; prostate: 120.9%; lung: 136.0%; liver: 134.2%). CONCLUSIONS: This is the first comprehensive study reporting patterns of utilization among early adopters of a 0.35T-MRgRT system in Europe and Asia. Intrafraction MR image-guidance, advanced motion management, and increasing adoption of on-table adaptive RT have accelerated a transition to UHfx regimens. MRgRT has been predominantly used to treat tumors in the upper abdomen, pelvis and lungs, and increasingly with adaptive replanning, which is a radical departure from legacy radiotherapy practices.

Reduction of nitrate using biochar synthesized by Co-Pyrolyzing sawdust and iron oxide.

Nitrate is the most common contaminant in groundwater in Korea, as well as across the world. Reduction of nitrate to ammonia is one of the options available to remediate groundwater. In this study, nitrate in groundwater was removed using a zero-valent iron (ZVI) containing biochar synthesized by co-pyrolyzing iron oxide and sawdust biomass. Among the various biogases generated during the pyrolysis of biomass, CO and H2 act as reducing agents to transform iron oxides to ZVI. Approximately 71% of nitrate was reduced to ammonium by ZVI-biochar at initial pH 2.0, and the reduction decreased sharply by the increase in pH. The mass of nitrate-N decreased is exactly same with the mass of ammonia-N formed. However, ammonium remained in the aqueous phase after reduction by ZVI-biochar, and the total nitrogen was not lowered. Acid-washed zeolite adsorbed most ammonium reduced by the ZVI-biochar and maintained the pH to acidic condition to facilitate the reduction of nitrate. The results of this study imply that nitrate-contaminated groundwater can be properly treated within the guidelines of water quality by synthesized ZVI-containing biochar.

Layered Double Hydroxide Quantum Dots for Use in a Bifunctional Separator of Lithium-Sulfur Batteries.

Functional separators, which are chemically modified and coated with nanostructured materials, are considered an effective and economical approach to suppressing the shuttle effect of lithium polysulfide (LiPS) and promoting the conversion kinetics of sulfur cathodes. Herein, we report cobalt-aluminum-layered double hydroxide quantum dots (LDH-QDs) deposited with nitrogen-doped graphene (NG) as a bifunctional separator for lithium-sulfur batteries (LSBs). The mesoporous LDH-QDs/NG hybrids possess abundant active sites of Co2+ and hydroxide groups, which result in capturing LiPSs through strong chemical interactions and accelerating the redox kinetics of the conversion reaction, as confirmed through X-ray photoelectron spectroscopy, adsorption tests, Li2S nucleation tests, and electrokinetic analyses of the LiPS conversion. The resulting LDH-QDs/NG hybrid-coated polypropylene (LDH-QDs/NG/PP) separator, with an average thickness of ∼17 µm, has a high ionic conductivity of 2.67 mS cm-1. Consequently, the LSB cells with the LDH-QDs/NG/PP separator can deliver a high discharge capacity of 1227.48 mAh g-1 at 0.1C along with a low capacity decay rate of 0.041% per cycle over 1200 cycles at 1.0C.

High-dose thoracic radiation therapy at 3.0 Gy/fraction in inoperable stage I/II non-small cell lung cancer.

OBJECTIVE: High-dose thoracic radiation therapy (HDTRT) alone has been an alternative to surgery in stage I/II non-small cell lung cancer patients with medical co-morbidities and/or poor performance status. Here, we report on the outcome and safety of HDTRT at 3.0 Gy per fraction for reduced treatment duration. METHODS: HDTRT alone at 3.0 Gy per fraction was given to 35 patients (22 at stage I and 13 at stage II). The median age was 73 years old and 14 patients had ECOG performance above 2. The median radiation dose to the primary lesion was 60 (54-66) Gy over 27 (23-38) days, and the dose to the mediastinum was individualized. RESULTS: After the median follow-up of 24 (3-72) months, local in-field progression developed in 11 patients (31.4%) and distant metastases in 14 (40.0%). The median survival period and the 3- and 5-year overall survival (OS) rates for all patients were 24.0 (95% CI: 13.57-34.43) months, 31.4 and 11.2%. Intercurrent deaths were observed in 11 patients. Treatment-related acute and subacute morbidities were observed in 20 patients (57.1%); however, there was neither treatment interruption nor long-term morbidity. CONCLUSIONS: On the basis of the above observations, we achieved treatment outcomes comparable with those of conventional protracted fractionation schedules at considerably shorter duration and lower cost by HDTRT at 3.0 Gy per fraction.

Effect of Radiation Therapy Techniques on Outcome in N3-positive IIIB Non-small Cell Lung Cancer Treated with Concurrent Chemoradiotherapy.

PURPOSE: This study was conducted to evaluate clinical outcomes following definitive concurrent chemoradiotherapy (CCRT) for patients with N3-positive stage IIIB (N3-IIIB) non-small cell lung cancer (NSCLC), with a focus on radiation therapy (RT) techniques. MATERIALS AND METHODS: From May 2010 to November 2012, 77 patients with N3-IIIB NSCLC received definitive CCRT (median, 66 Gy). RT techniques were selected individually based on estimated lung toxicity, with 3-dimensional conformal RT (3D-CRT) and intensity-modulated RT (IMRT) delivered to 48 (62.3%) and 29 (37.7%) patients, respectively. Weekly docetaxel/paclitaxel plus cisplatin (67, 87.0%) was the most common concurrent chemotherapy regimen. RESULTS: The median age and clinical target volume (CTV) were 60 years and 288.0 cm(3), respectively. Patients receiving IMRT had greater disease extent in terms of supraclavicular lymph node (SCN) involvement and CTV ≥ 300 cm(3). The median follow-up time was 21.7 months. Fortyfive patients (58.4%) experienced disease progression, most frequently distant metastasis (39, 50.6%). In-field locoregional control, progression-free survival (PFS), and overall survival (OS) rates at 2 years were 87.9%, 38.7%, and 75.2%, respectively. Although locoregional control was similar between RT techniques, patients receiving IMRT had worse PFS and OS, and SCN metastases from the lower lobe primary tumor and CTV ≥ 300 cm(3)were associated with worse OS. The incidence and severity of toxicities did not differ significantly between RT techniques. CONCLUSION: IMRT could lead to similar locoregional control and toxicity, while encompassing a greater disease extent than 3D-CRT. The decision to apply IMRT should be made carefully after considering oncologic outcomes associated with greater disease extent and cost.

Tissue expander placement and adjuvant radiotherapy after surgical resection of retroperitoneal liposarcoma offers improved local control.

Given that retroperitoneal liposarcoma (LPS) is extremely difficult to completely resect, and has a relatively high rate of recurrence, radiotherapy (RT) is the treatment of choice after surgical resection. However, it is difficult to obtain a sufficient radiation field because of the close proximity of surrounding organs. We introduce the use of tissue expanders (TEs) after LPS resection in an attempt to secure a sufficient radiation field and to improve recurrence-free survival.This study is a retrospective review of 53 patients who underwent surgical resection of LPS at Samsung Medical Center between January 1, 2005, and December 31, 2012, and had no residual tumor detected 2 months postoperatively. The median follow-up period was 38.9 months.Patients were divided into 3 groups. Those in group 1 (n = 17) had TE inserted and received postoperative RT. The patients in group 2 (n = 9) did not have TE inserted and received postoperative RT. Finally, those in group 3 (n = 27) did not receive postoperative RT. Multivariate analysis was performed to identify the risk factors associated with recurrence-free survival within 3 years. Younger age, history of LPS treatment, and RT after TE insertion (group 1 vs group 2 or 3) were significantly favorable factors influencing 3-year recurrence-free survival.TE insertion after LPS resection is associated with increased 3-year recurrence-free survival, most likely because it allows effective delivery of postoperative RT.

Humic substance-enhanced ultrafiltration for removal of cobalt.

It is well known that the membrane separation process combined with surfactant micelle (micellar-enhanced ultrafiltration) or polyelectrolyte (polyelectrolyte-enhanced ultrafiltration) can remove heavy metal ions or radionuclides effectively. However, the complexing agent, surfactant or polyelectrolyte remained in effluent is a serious disadvantage of these methods. In this study, humic substances (HS) were used as complexing agents instead of synthetic chemicals. The HS are sorts of natural organic matters and their functional groups such as carboxyl and phenyl groups can bind with the cation and form complexes. The effects of HS concentration and pH on the removal of cobalt were investigated. At the HS concentration of 3g/L and pH of 6, over 95% of cobalt was removed by regenerated cellulose membrane with molecular weight cut-off (MWCO) of 3000. As the HS concentration increased, the removal of cobalt was also enhanced because of the increase in binding sites (functional groups). The removal of cobalt increased from 72.5% to 97.5% as pH increased from 4 to 8 at the HS concentration of 3g/L. It resulted from the more deprotonation of functional groups in humic acid at higher pH.

Role of Adjuvant Radiotherapy in Left-Sided Pancreatic Cancer-Population-Based Analysis with Propensity Score Matching.

This population-based study evaluated the survival impact of postoperative radiotherapy (PORT) in left-sided pancreatic cancer. The Surveillance, Epidemiology, and End Results (SEER) database was used to identify patients with surgically resected left-sided pancreatic adenocarcinoma from 2004 to 2010. Propensity score matching was conducted to compare PORT and non-PORT groups. A total of 445 patients were identified, and PORT was performed in 180 (40 %) patients. In the unmatched population, there were no significant differences in overall survival (OS) (P = 0.197) and cause-specific survival (CSS) (P = 0.379) between the PORT and non-PORT groups. After propensity score matching, the patients treated with PORT had longer median OS (P = 0.012) and CSS (P = 0.039) than the non-PORT group. In propensity-adjusted multivariate analysis, non-receipt of PORT was a poor prognostic factor in OS (hazard ratio [HR] 1.39, 95 % confidence interval [CI] 1.08-1.79), and CSS (HR 1.31, 95 % CI 1.01-1.71). The log odds of positive lymph nodes (LOODS) (≥-0.73) was also associated with worse OS (P = 0.003) and CSS (P = 0.001). In left-sided pancreatic cancer, considering the addition of PORT is a reasonable option as in pancreatic head cancer. The LOODS was suggested as a strong predictive indicator of the patients' prognoses.

High ratio of programmed cell death protein 1 (PD-1)(+)/CD8(+) tumor-infiltrating lymphocytes identifies a poor prognostic subset of extrahepatic bile duct cancer undergoing surgery plus adjuvant chemoradiotherapy.

BACKGROUND AND PURPOSE: This study investigated the prognostic role of PD-L1 expression, PD-1(+) tumor-infiltrating lymphocytes (TILs), and the ratio of PD-1(+)/CD8(+) TILs in extrahepatic bile duct (EHBD) cancer. MATERIALS AND METHODS: We analyzed 83 patients with EHBD cancer who underwent curative surgery plus fluoropyrimidine-based chemoradiotherapy (CRT). Expressions of PD-L1, PD-1, and CD8 were assessed by immunohistochemistry. RESULTS: Fifty-six (68%) patients were PD-L1-positive, and its lower expression level was associated with hilar tumor location (P=0.044). A higher ratio of PD-1(+)/CD8(+) TILs was associated with poorer overall survival (OS) (P=0.032), relapse-free survival (RFS) (P=0.024), and distant metastasis-free survival (DMFS) (P=0.039) in Kaplan-Meier analyses, but survival differences were not observed according to the PD-L1 expression level. With Cox proportional hazards models, the ratio of PD-1(+)/CD8(+) TILs was the independent prognostic factor in OS (HR 2.47, 95% CI 1.04-5.86), RFS (HR 2.41, 95% CI 1.08-5.41), and DMFS (HR 2.67, 95% CI 1.00-7.11) after adjusting for other significant clinicopathologic variables. CONCLUSION: A strong survival impact of the ratio of PD-1(+)/CD8(+) TILs was observed in EHBD cancer. In the poor prognostic subgroup, the blockade of the immune checkpoint in combination with conventional multimodality treatment needs to be considered.

Definitive Bimodality Concurrent Chemoradiotherapy in Patients with Inoperable N2-positive Stage IIIA Non-small Cell Lung Cancer.

PURPOSE: This study was conducted to evaluate the treatment outcomes following definitive bimodality concurrent chemoradiotherapy (CCRT) in patients with inoperable N2-positive stage IIIA (N2-IIIA) non-small cell lung cancer (NSCLC). MATERIALS AND METHODS: From May 1997 to December 2012, 65 out of 633 patients with N2-IIIA NSCLC received bimodality therapy. The treatment modality was selected during/after neoadjuvant CCRT in 21 patients or primarily at diagnosis in 44 through a multidisciplinary consensus meeting. The median age was 65 years (range, 36 to 76 years). Sixty patients (92.3%) had clinically evident N2 disease, while 22 (33.8%) had multi-station N2 involvement. The median radiation therapy dose was 66 Gy in 33 fractions, while the dose was elevated to 72 Gy in 13 patients who had a treatment break due to delayed decision regarding resectability. The most frequent chemotherapy regimen was weekly paclitaxel or docetaxel plus cisplatin or carboplatin (54, 83.1%). RESULTS: During the median follow-up of 18.8 months (range, 1.6 to 173.1 months), 34 patients (52.3%) experienced disease progression, with distant metastasis being the most common first treatment failure pattern (23, 34.8%). The median and 2-year rates of progression-free survival were 18.8 months and 45.9%, respectively. The median and 2-year rates of overall survival were 28.6 months and 50.1%, respectively. CONCLUSION: Definitive bimodality therapy in patients with N2-IIIA NSCLC demonstrated favorable outcomes, while trimodality therapy could be considered for candidates for less than pneumonectomy.

Removal characteristics of anionic metals by micellar-enhanced ultrafiltration.

Surfactant-based separation of Fe(CN)(6)(3-) and CrO(4)(2-) using regenerated cellulose membrane was studied in order to assess the potential of micellar-enhanced ultrafiltration for the remediation of wastewater or groundwater polluted with ferriccyanide and chromate. In the ferriccyanide/octadecylamine acetate (ODA) and chromate/ODA systems, removal of ferriccyanide increased from 73 to 92% and to 98%, and that of chromate from 64 to 97% and to >99.9% as the molar ratio of ODA to ferriccyanide and to chromate increased from 1 to 2 and to 3, respectively. In the ferriccyanide/chromate/ODA system, while the removal of ferriccyanide increased from 62 to 72% and to 93%, the removal of chromate from 20 to 38% and to 68% as the molar ratio of ferriccyanide:chromate:ODA increased from 1:1:1 to 1:1:2 and to 1:1:4, respectively. With the molar ratio of 1:1:6, the removal was >99.9 and 98% for chromate and ferriccyanide, respectively. Ferriccyanide ions were more easily bound to ODA micelles because the binding power of ferriccyanide was greater than that of chromate.

Hypofractionated three-dimensional conformal radiation therapy alone for centrally located cT1-3N0 non-small-cell lung cancer.

PURPOSE: We retrospectively analyzed the treatment outcomes and toxicities by hypofractionated three-dimensional conformal radiation therapy (RT) alone in the patients with centrally located cT1-3N0 non-small-cell lung cancer (NSCLC). METHODS: Sixty patients with centrally located cT1-3N0 NSCLC received definitive RT alone at 3.0 Gy per fraction for either medical comorbidity or refusal of surgery, between January 2001 and December 2010. The central tumor was defined as being within 2 cm around the proximal bronchial tree. The median total dose was 60 (39-60) Gy. RESULTS: The local control (LC), overall survival (OS), and cause-specific survival rates at 2 and 5 years were 57.9%, 59.6%, 61.7%, and 50.1%, 33.5%, and 40.5%, respectively. Multivariate analyses showed that high cT stage (p = 0.007) and histology with NSCLC-not otherwise specified (p = 0.008) were the significantly unfavorable prognostic factors for OS, and that high cT stage (p = 0.031) and poor performance state (p = 0.007) were for LC. The LC rate at 2 years was 100% for cT1 tumor, 56.5% for cT2 tumor, and 28.6% for cT3 tumor, respectively. No patients experienced grade 3 or higher esophagitis, and three experienced grade 3 or higher pneumonitis. CONCLUSION: Hypofractionated RT regimen for centrally located cT1-3N0 NSCLC proved safe with minimal toxicity, and, based on the excellent clinical outcomes in cT1 tumors, might serve as an alternative option for the patients who might not tolerate stereotactic body radiation therapy. As the clinical outcomes in cT2-3 tumors were still unsatisfactory, further dose intensifying regimen coupled with the use of concurrent systemic chemotherapy might be warranted.

Port site metastasis after robotic-assisted laparoscopic hysterectomy for uterine cervical cancer: a case report and literature review.

OBJECTIVE: The incidence of port site metastasis after robotic-assisted laparoscopic surgery for cervical cancer is not well known. According to recent studies of gynecological malignancies, the reported incidence is low and comparable to the results of conventional laparoscopic surgery. Here, we report the case of a patient who suffered port site metastasis after robotic-assisted laparoscopic hysterectomy for stage IB1 uterine cervical cancer. CASE REPORT: The current case is, as we know, only the third episode of port site metastasis after robotic-assisted laparoscopic surgery for cervical cancer documented in the medical literature. Following diagnosis of the port site metastasis, the patient was treated with concurrent chemoradiotherapy (CRT) and experienced a remarkable early response. We reviewed the patient's medical chart and imaging studies, and searched the Medline database to evaluate the incidence, prognosis and treatment outcomes of such cases of port site metastasis in uterine cervical cancer patients. CONCLUSION: CRT resulted in a rapid decrease in tumor size and relief of abdominal pain in our patient. CRT might be considered as a salvage or palliative modality in patients with port site metastasis and/or locoregional recurrence.

Continuous microalgae recovery using electrolysis with polarity exchange.

There is increasing interest in the use of microalgae as a renewable source for the production of fuels and chemicals, but improvements are needed in all steps of this process, including harvesting. A continuous microalgae harvest system was developed based on electrolysis, referred to here as a continuous electrolytic microalgae (CEM) harvest system. This innovative system combines cultivation and harvesting and enables continuous and efficient concentration of microalgae. The electrodes were subject to a polarity exchange (PE) in the middle of the operation to further improve the harvest efficiency. Use of PE, rather than conventional electro-coagulation-flotation (ECF), led to more efficient cell recovery and more uniform recovery over the entire harvest chamber. In addition, PE increased the cell growth rate and the circulated cells remained intact after harvesting.

Continuous microalgae recovery using electrolysis: effect of different electrode pairs and timing of polarity exchange.

Microalgae have great potential as a feedstock for biofuel production. Continuous operation is an important benefit of the continuous electrolytic microalgae (CEM) harvest system, but it is necessary to optimize cultivability and recovery efficiency in order to improve overall performance. Two pairs of best-candidate electrodes for polarity exchange (PE) were examined to improve these two key factors: (i) aluminum and dimensionally stable anode (Al-DSA), and (ii) Al-platinum (Al-Pt). Al-DSA was better than Al-Pt because it led to less cell damage and was less expensive. Moreover, cell viability and recovery were improved by optimizing the timing of PE. A P1:P2 ratio of 1:1.5 at 5min and 1:1.2 at 10min yielded the best results, with greatly reduced electricity consumption and enhanced cell viability and recovery. The CEM harvest system appears to be a well-suited option for the harvest of microalgae for biofuel production.

Development of the DVH management software for the biologically-guided evaluation of radiotherapy plan.

PURPOSE: To develop the dose volume histogram (DVH) management software which guides the evaluation of radiotherapy (RT) plan of a new case according to the biological consequences of the DVHs from the previously treated patients. MATERIALS AND METHODS: We determined the radiation pneumonitis (RP) as an biological response parameter in order to develop DVH management software. We retrospectively reviewed the medical records of lung cancer patients treated with curative 3-dimensional conformal radiation therapy (3D-CRT). The biological event was defined as RP of the Radiation Therapy Oncology Group (RTOG) grade III or more. RESULTS: The DVH management software consisted of three parts (pre-existing DVH database, graphical tool, and Pinnacle(3) script). The pre-existing DVH data were retrieved from 128 patients. RP events were tagged to the specific DVH data through retrospective review of patients' medical records. The graphical tool was developed to present the complication histogram derived from the pre-existing database (DVH and RP) and was implemented into the radiation treatment planning (RTP) system, Pinnacle(3) v8.0 (Phillips Healthcare). The software was designed for the pre-existing database to be updated easily by tagging the specific DVH data with the new incidence of RP events at the time of patients' follow-up. CONCLUSION: We developed the DVH management software as an effective tool to incorporate the phenomenological consequences derived from the pre-existing database in the evaluation of a new RT plan. It can be used not only for lung cancer patients but also for the other disease site with different toxicity parameters.