Evaluation of the Possibility of Dose Realignment Adaptation by Shifting the Isocenter in Proton Beam Therapy for Pancreatic Cancer

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, a tumor is surrounded by the gastrointestinal (GI) tract, which is subject to changes in location, shape, and contents. Due to these inter-fractional changes, proton beam therapy (PBT) for pancreatic cancer may result in unintentionally high doses to the GI tract. Daily adaptive re-planning can solve this problem, but is not yet established with PBT due to its resource intensive characteristics. This study aims to evaluate the GI tract dose using weekly computed tomography (CTw) and the possibility of dose realignment adaptation by shifting the isocenter (IC) of the PBT plan, which does not require re-planning.

MATERIALS/METHODS

We retrospectively analyzed 6 consecutive patients with unresectable pancreatic cancer treated with real-time-image gated PBT using a fiducial marker. The planning CT was scanned at the natural expiration of respiration and a PBT plan of 60 GyE in 25 fractions (baseline plan, PLANbase) was created. The CTw images were acquired the day before start of PBT and once a week during the PBT course thereafter. The PLANbase was rigidly transferred to the CTw based on the relationship between the three-dimensional coordinates of the fiducial marker and those of the IC in the PLANbase. The PLANeval was created by recalculating the PLANbase on the CTw. We evaluated the doses to the stomach, duodenum, and intestines in the PLANeval according to the following criteria: Dmax of the stomach < 60 GyE, duodenum and intestines < 55 GyE, and D1cc of the stomach < 55 GyE, duodenum and intestines < 54 GyE. In addition, we investigated the GI tract dose realignment adaptation for the PLANeval with its IC shifted 2mm, 4mm, and 6mm in each of 6 directions (right, left, ventral, dorsal, cranial, and caudal), respectively.

RESULTS

A total of 35 PLANeval were created for the CTw. In the PLANbase of the 6 patients, the average of Dmax and D1cc of the stomach, duodenum and intestines were 50.7 GyE (range, 46.7-53.6) and 50.0 GyE (45.0-53.2), 49.2 GyE (44.3-51.7) and 48.8 GyE (43.7-51.5), and 49.2 GyE (44.8-52.0) and 48.9 GyE (44.6-51.8), respectively. In the PLANeval, the average of Dmax and D1cc of the stomach, duodenum, and intestines were 53.3GyE (43.8-61.4) and 52.8 GyE (43.2-61.1), 51.0 GyE (36.1-60.0) and 50.3 GyE (35.4-59.8), and 52.5 GyE (36.6-61.0) and 51.9 (34.4-60.9) GyE, respectively. Twenty-two of the 35 PLANeval (63 %) did not meet at least one of the GI tract dose criteria. In 11 of 22 PLANeval with higher doses to the GI tract, the IC shift resulted in GI dose reductions and all dose criteria were met. The minimum amount of the IC shift required to meet the criteria was 2 mm for 8 plans and 4 mm for 3 plans. The remaining 11 PLANeval did not meet the criteria using dose realignment adaptation by shifting the isocenter.

CONCLUSION

Adaptive replanning is necessary for PBT for pancreatic cancers due to excessive GI tract doses in more than 60% of the plans. Dose realignment adaptation by shifting the IC, which does not require re-planning, may be an option in adaptive treatment strategies.

A Risk Prediction Model for Severe Radiation Induced Lymphopenia in Patients with Pancreatic Cancer Treated with Concurrent Chemoradiotherapy

PURPOSE/OBJECTIVE(S)

In pancreatic cancer, radiation induced lymphopenia (RIL) is associated with a poor prognosis. However, normal tissue complication probability (NTCP) models predicting RIL in pancreatic cancer treated with concurrent chemoradiotherapy (CCRT) have yet to be developed. This study aims to develop a least absolute shrinkage and selection operator (LASSO)-based multivariate NTCP model to predict severe RIL in patients with pancreatic cancer during CCRT and to validate the model internally.

MATERIALS/METHODS

We retrospectively reviewed patients with localized pancreatic cancer who underwent CCRT using three-dimensional conformal radiation therapy from 2013 to 2021. The exclusion criteria were patients with distant metastasis; patients who did not complete RT due to tumor progression; patients who did not have absolute lymphocyte count (ALC) data available before or during RT. An ALC of < 0.5 K/μL during CCRT was defined as severe RIL. A NTCP model of severe RIL was developed by LASSO-based multivariate analysis. We used age, sex, Karnofsky performance status, maximum tumor size, carbohydrate antigen 19-9 level before RT, ALC before RT, volume of planning target volume (PTV), and dosimetric parameters for surrounding organs (including spleen, vertebrae, liver, bilateral kidneys, gastrointestinal tracts) as variables for LASSO. In addition, internal validation was performed by the bootstrap method. The predictive performance of the model was evaluated by the area under the curve (AUC) of the receiver operating characteristic curve and scaled Brier score.

RESULTS

Of the 131 patients included in the study, the median age was 68 years (range, 42-84), and 55% were male. The median ALC before RT was 1.37 K/µL (0.52-3.50). The median PTV volume was 315.4 ml (86.3-1079.3). The median dose of radiotherapy was 50.4 Gy (16.2-50.4), with 1.8 Gy per fraction. Combination chemotherapy was S-1 in 99 cases (75.6%) and gemcitabine in 32 cases (24.4%). Induction chemotherapy before CCRT was performed in 39 patients (29.8%). Severe RIL was observed in 84 (63.6%) patients. The LASSO showed that low baseline ALC (p = 0.0002), large PTV volume (p < 0.0001), and a large kidney V5 defined as the percentage of bilateral kidneys receiving 5 Gy or more (p = 0.0338) were selected as parameters of the prediction model for severe RIL (AUC = 0.917) and scaled Brier score was 0.511. As a result of internal validation by the bootstrap method, the average AUC was 0.918 (95% confidence interval, 0.849-0.954).

CONCLUSION

Severe RIL occurred frequently during CCRT for pancreatic cancer, and a NTCP model for severe RIL developed and validated internally in this study showed good predictive performance. External validation is needed before this NTCP model can be used as a benchmark for treatment planning to reduce the risk of severe RIL and for considering future treatment approaches.

Prognostic significance of nutritional indices in patients with head and neck squamous cell carcinoma treated with immune checkpoint inhibitors

BACKGROUND

Although patients with head and neck squamous cell cancer (HNSCC) often show malnutrition, its effects on immune checkpoint inhibitor (ICI) treatment outcomes in these patients are unclear.

OBJECTIVES

To investigate the prognostic influence of nutritional indices in patients with HNSCC treated with ICIs and determine the optimal indices.

METHODS

This retrospective study included 106 patients with HNSCC treated with ICIs between 2017 and 2022. The prognostic influences of body mass index (BMI), geriatric nutritional risk index (GNRI), and prognostic nutritional index (PNI) on overall survival (OS) and progression-free survival (PFS) were analysed using the Kaplan-Meier method and Cox-regression models.

RESULTS

The 1-year PFS rates in the groups with high and low BMI, GNRI, and PNI were, respectively, 24.2% and 28.4% (p = .731), 29.7% and 14.4% (p = .024), and 30.3% and 13.9% (p = .015). PNI was an independent prognostic factor for both PFS (hazard ratio (HR) = 1.89; 95% confidence interval (CI), 1.08-3.29) and OS (HR = 3.26; 95% CI, 1.66-6.40).

CONCLUSIONS

PNI can predict ICI outcomes and should be assessed when ICI treatment is considered.

Identification of patients with Graves' disease who benefit from high-dose radioactive iodine therapy

OBJECTIVE

Radioactive iodine (RAI) therapy is a useful treatment for Graves' disease (GD). Most RAI sessions administer ≤ 500 MBq of iodine (I)-131. Sometimes patients require repeated RAI, often for longer periods of remission. We investigated the characteristics of patients for whom high dose (mostly 1110 MBq of I-131) RAI was effective as RAI therapy for GD.

METHODS

We retrospectively analyzed the cases of 79 patients who underwent RAI for GD in a multicenter setting. We divided the patients into two groups based on the I-131 dose administered: the low dose (LD) group who received ≤ 500 MBq (n = 44) and the high dose (HD) group who received > 500 MBq (n = 35). The therapeutic effect was defined as achieving remission and reaching the point of participating in thyroid hormone replacement therapy within 1 year after RAI. We compared the LD and HD groups' remission rates and conducted a multivariate logistic regression analysis of predictive factors for remission. In a simulation, using the formula for predicting the probability of remission obtained from the analysis results, we estimated how much the remission rate would change if the I-131 dose is increased from 500 to 1110 MBq.

RESULTS

The mean ± standard deviation I-131 dose administered in the LD group was 480 ± 6 MBq, and that of the HD group was 1054 ± 265 MBq. Thirty-five patients (80%) in the LD group and 26 patients (74%) in the HD group achieved remission; this difference in the remission rate was not significant. The multivariate analysis results demonstrated that the absorbed dose and thyroid-stimulating antibody (TSAb) were independent predictors of remission. Seven patients (8.9%) showed an increased probability of remission from < 50% to > 50% when the higher RAI dose was applied (1110 MBq instead of 500 MBq). The thyroid volume and TSAb values in these patients were relatively large at 54.7 ± 34.2 mL and 1378.4 ± 586.3%, respectively.

CONCLUSION

Although the overall remission rate was not significantly different between the patients who received high- or low-dose I-131, treatment with high-dose RAI may improve the probability of remission in patients with a massive thyroid volume and/or high-TSAb Graves' disease.

Combination Therapy by Transarterial Injection of Miriplatin-Iodized Oil Suspension with Microwave Ablation for Medium-Sized Hepatocellular Carcinoma: the Preliminary Experience

PURPOSE

To evaluate the feasibility and safety of transarterial injection of a miriplatin-iodized oil suspension combined with Emprint miriplatin-iodized oil suspension-microwave ablation in patients with medium-sized (3-5 cm) hepatocellular carcinomas.

MATERIALS AND METHODS

This retrospective study included a total of 11 patients with 12 hepatocellular carcinomas (mean size, 3.6 ± 0.6 cm) underwent miriplatin-iodized oil suspension-microwave ablation. Microwave ablation was performed under the guidance of computed tomography fluoroscopy following transarterial miriplatin-iodized oil suspension injection on the same day. Technical success, complications, and local tumor progression were assessed.

RESULTS

The primary and secondary technical success rates were 75.0% and 100%, respectively. The number of treatment sessions per nodule was 1.25 ± 0.45. A total 15 sessions were required to achieve technical success (one session in nine lesions, two sessions in three lesions). Two major complications (pneumothorax [n = 1] and hemorrhage [n = 1]) occurred (2/15, 13.3%). No local tumor progression was observed during the follow-up period (mean 12.0 ± 2.0 months, range 2.7-23.9 months).

CONCLUSIONS

Miriplatin-iodized oil suspension-microwave ablation for medium-sized hepatocellular carcinomas can be safely performed with good local control.

Single-Session Intranodal Glue Embolization for Postsurgical Refractory Groin Lymphorrhea: A Case Report

A 90-year-old female presented with poor right groin wound healing due to lymphorrhea and infection following a surgical cutdown procedure for arterial revascularization. Although negative pressure wound therapy (NPWT) and inguinal lymphadenectomy were performed, infection and lymphorrhea did not heal. Lymphangiography via a right inguinal lymph node revealed lymphatic leakage in the wound. Intranodal glue embolization (IGE) was performed by injecting 0.6 mL of 33% n-butyl-2 cyanoacrylate (NBCA)-lipiodol mixture. Additionally, the presence of glue in an open wound was directly confirmed in this case. After embolization, lymphorrhea ceased, and the wound healed completely. No lymphorrhea recurrence or complications were observed for 6 months. This case suggests that IGE could be an effective treatment for groin lymphorrhea.

Improvements to healthcare waste management at regional referral hospitals in Tanzania using the KAIZEN approach

Purpose

The purpose of this study is to see how the 5S-KAIZEN-TQM approach can contribute to improve the management of healthcare waste (HCW) in the regional level public hospitals in Tanzania.

Design/methodology/approach

This study employed an explanatory case study framework and focused on improvement of HCW management by assessing the information obtained through the direct observation and systematic interviewing during the consultation visits and external hospital performance assessment (EHPA) and the self-administrated questionnaires as sources of evidence.

Findings

Based on the observations, 100% adoption of the 5S approach was observed in 25 of 28 regional referral hospitals (RRHs). At these RRHs, segregation of HCW management has been improved by applying color codes and symbols for establishing self-explanatory system on proper segregation. In addition, seven out of 28 RRHs applied the KAIZEN process and reduced occurrences of improper waste segregation.

Research limitations/implications

This study has the following limitations in terms of the information. The data were collected through the direct observation. Moreover, areas for the implementation of the KAIZEN vary from hospital to hospital, and only 25% of RRHs completed the KAIZEN processes for improvement of HCW management. Caveats are, therefore, needed in extrapolating the study results to other settings. Despite these caveats, the findings will provide important insights for implementing the 5S-KAIZEN approach in Tanzania and other African countries for improvement of HCW management.

Originality/value

This is an original study to provide evidence about the usefulness of the 5S-KAIZEN-TQM approach for improving HCW management in a low-income country in Africa.

Combination therapy by transarterial injection of miriplatin-iodized oil suspension with radiofrequency ablation (RFA) versus microwave ablation (MWA) for small hepatocellular carcinoma: a comparison of therapeutic efficacy

PURPOSE

To compare the technical efficacy and complications of the transarterial injection of a miriplatin-iodized oil suspension combined with radiofrequency ablation (RFA) or microwave ablation (MWA) in the treatment of small hepatocellular carcinomas (HCCs).

MATERIALS AND METHODS

This retrospective study included 123 HCCs in 101 patients treated with the transarterial injection of a miriplatin-iodized oil suspension and RFA (MPT-RFA) (maximum diameter: 1.5 [Formula: see text] 0.5 cm, range: 0.6-3.0 cm) and 68 HCCs in 49 patients treated with the transarterial injection of a miriplatin-iodized oil suspension and MWA (MPT-MWA) (maximum diameter: 1.6 [Formula: see text] 0.7 cm, range: 0.5-3.0 cm). Technical success was defined as the achievement of an ablative margin of at least 5 mm for each tumor. Technical success, complications, and local tumor progression were compared between the two groups.

RESULTS

The initial technical success rate was significantly higher with MPT-MWA (94.1%) than with MPT-RFA (76.4%; P = 0.003). The number of treatment sessions per nodule was significantly lower with MPT-MWA (1.1) than with MPT-RFA (1.3) (P = 0.004). The major complication rates were similar with MPT-RFA (5.8%) and MPT-MWA (2.7%) (P = 0.391). The one-year local tumor progression rate was similar between MPT-RFA (0%) and MPT-MWA (0%) (P = 0.73).

CONCLUSION

MPT-MWA may have improved therapeutic efficiency in the treatment of small HCCs.

[Infected Thoracic Aortic Aneurysm Secondary to the Purulent Pericarditis;Report of a Case]

A 69-year-old man was hospitalized urgently to the department of cardiology, with the progressive general malaise. On admission, his blood pressure was 80/42 mmHg, his white cell count 13,700/µl, and C-reactive protein 25.55 mg/dl suggesting existence of aggressive infection with impaired circulation. Massive pericardial effusion was detected in echocardiography. Pericardial drainage was undergone promptly. There was drainage of 700 ml and the property was purulent. Pneumococcus was detected by the culture test of the pericardial fluid. Antibiotic administration was started by a diagnosis of the purulent pericarditis. His general condition was improved. However, a rapidly expanding saccular aneurysm was found in a descending thoracic aorta by computed tomography( CT). As an infected thoracic aortic aneurysm secondary to the purulent pericarditis, we performed thoracic endovascular aneurysm repair (TEVAR). The intravenous administration of antibiotics was continued for 2 weeks after TEVAR, which was followed by oral antibiotic administration for 1 year. The aneurysm completely disappeared by CT, 10 months after TEVAR. In case with an infected thoracic aortic aneurysm, TEVAR can be a 1st choice of treatment, depending on a causative organism and the morphology of the aneurysm.

Intratumoral artery on contrast-enhanced computed tomography imaging: differentiating intrahepatic cholangiocarcinoma from poorly differentiated hepatocellular carcinoma

AIM

Differentiating intrahepatic cholangiocarcinoma (ICC) from poorly differentiated hepatocellular carcinoma (p-HCC) is often difficult, but it is important for providing appropriate treatments. The purpose of this study was to examine the features differentiating ICC from p-HCC on contrast-enhanced dynamic-computed tomography (CT).

METHODS

This study examined 42 patients with pathologically confirmed ICC (n = 19) or p-HCC (n = 23) for which contrast-enhanced dynamic CT data were available. CT images were analyzed for enhancement patterns during the arterial phase, washout pattern, delayed enhancement, satellite nodules, capsular retraction, lesion shape, and presence of an intratumoral hepatic artery, intratumoral hepatic vein, intratumoral portal vein, and bile duct dilation around the tumor, portal vein tumor thrombus, lobar atrophy, or lymphadenopathy.

RESULTS

Univariate analysis revealed the presence of rim enhancement (p = 0.037), lobulated shape (p = 0.004), intratumoral artery (p < 0.001), and bile duct dilation (p = 0.006) as parameters significantly favoring ICC, while a washout pattern significantly favored p-HCC (p < 0.001). Multivariate analysis revealed intratumoral artery as a significant, independent variable predictive of ICC (p = 0.037), and 15 ICCs (78.9%) showed this feature. Washout pattern was a significant, independent variable favoring p-HCC (p = 0.049), with 15 p-HCCs (65.2%) showing this feature.

CONCLUSION

The presence of an intratumoral artery in the arterial phase on contrast-enhanced dynamic CT was a predictable finding for ICC, and the presence of a washout pattern was a predictable finding for p-HCC, differentiating between ICC and p-HCC.

Development of a long-slot microwave plasma source

A 20 cm long 10 cm wide microwave plasma source was realized by inserting two 20 cm long 1.5 mm diameter rod antennas into the plasma. Plasma luminous distributions around the antennas were changed by magnetic field arrangement created by permanent magnets attached to the source. The distributions appeared homogeneous in one direction along the antenna when the spacing between the antenna and the source wall was 7.5 mm for the input microwave frequency of 2.45 GHz. Plasma density and temperature at a plane 20 cm downstream from the microwave shield were measured by a Langmuir probe array at 150 W microwave power input. The measured electron density and temperature varied over space from 3.0 × 10(9) cm(-3) to 5.8 × 10(9) cm(-3), and from 1.1 eV to 2.1 eV, respectively.

Observational cohort study of first-line bevacizumab with oxaliplatin or irinotecan and fluoropyrimidines in metastatic colorectal cancer: HGCSG0802—Analysis of early tumor shrinkage (ETS)

753

Background: It was reported that early tumor shrinkage (ETS) was associated with better overall survival (OS) in patients (pts) with metastatic colorectal cancer (mCRC) receiving first line chemotherapy. We investigated association of ETS with progression-free survival (PFS) and OS in pts with mCRC treated with first-line bevacizumab (BV)-based chemotherapy (HGCSG0802). Methods: The objective of HGCSG0802 was to evaluate PFS, OS, response rate (RR), safety and so on. The key eligibility criteria were evaluable lesions, older than 20 years old, ECOG PS 0-2. This analysis evaluated the association of ETS at 8 weeks from the start of chemotherapy with pts characteristics, PFS and OS. To identify factors associated with ETS, if there were clinical variables with p < 0.2 in univariate analysis, we planned a multivariate analysis using the logistic regression model. To identify predictive and prognostic factors, a multivariate analysis was performed using Cox proportional hazard model with backward elimination for variables with p < 0.2 in univariate analysis. Results: Of 108 pts (the full analysis set), 99 pts were evaluable for ETS. Sixty-eight pts (68.7%) had ETS ≥20%. The pts characteristics between ETS ≥20% (ETS) and <20% (Non-ETS) were well balanced. In univariate analysis to identify factors associated with ETS, there were no clinical variables with p < 0.2. The median PFS and OS were 7.3/18.3 months in Non-ETS versus 10.0/25.2 months in ETS (HR 0.529; p=0.006 and HR 0.627; p=0.107). In multivariate analysis for PFS and OS, although there was no significant difference between ETS and Non-ETS for OS (HR 0.709; p=0.186), there was significant difference for PFS (HR 0.524; p=0.006). Conclusions: ETS was observed in 68.7% (68/99) and non-ETS in 31.3% (31/99) of patients with metastatic colorectal cancer received bevacizumab combined first line chemotherapy. In univariate analysis, it could not identify any factors associated with ETS. In the results of multivariate analysis, ETS showed an independent predictive impact, but not prognostic impact. Clinical trial information: UMIN000018935.

Dust particle diffusion in ion beam transport region

Dust particles of μm size produced by a monoplasmatron ion source are observed by a laser light scattering. The scattered light signal from an incident laser at 532 nm wavelength indicates when and where a particle passes through the ion beam transport region. As the result, dusts with the size more than 10 μm are found to be distributed in the center of the ion beam, while dusts with the size less than 10 μm size are distributed along the edge of the ion beam. Floating potential and electron temperature at beam transport region are measured by an electrostatic probe. This observation can be explained by a charge up model of the dust in the plasma boundary region.

Sandwich organization of non-ionic surfactant liquid crystalline phases as induced by large inorganic K4Nb6O17 nanosheets

While retaining its lamellar liquid crystal phase, K4Nb6O17 nanosheets were used as a template to sandwich and stabilize an alkylpoly(ethylene oxide) nonionic surfactant-water system showing monodomain (lamella) formation within the inorganic niobate sheets that appears to be not dependent on the surfactant liquid crystalline state in solution but more its concentration.

Association of morphologic response with progression free survival in patients with metastatic colorectal cancer treated with bevacizumab-based chemotherapy: HGCSG0802

743

Background: It was reported that an optimal morphologic response to preoperative chemotherapy was associated with better overall survival (OS) in patients (pts) with colorectal liver metastases (CLM). We investigated association of morphologic response with progression free survival (PFS) in pts with unresectable CLM from HGCSG0802 observational cohort study in pts with mCRC treated with first-line bevacizumab (BV)-based chemotherapy. Methods: The objective of HGCSG0802 was to evaluate PFS, OS, time to treatment failure (TTF), response rate (RR), safety, etc. The key eligibility criteria were evaluable lesions, older than 20 years old, ECOG PS 0-2. Pts with CLM underwent contrast-enhanced CT at the start and every 8-weeks of BV-based chemotherapy. In this analysis, three blinded, independent radiologists evaluated images for morphologic response, based on metastases changing from heterogeneous masses with ill-defined margins into homogeneous hypoattenuating lesions with sharp borders. Association of morphologic response and pts characteristics, RR, and PFS were evaluated. PFS was analyzed with Kaplan-Meier method, log-rank test, and Cox proportional hazards model. Results: Of 108 pts (the full analysis set), 73 pts with CLM were evaluable for morphologic criteria. Eighteen pts (24.7%) had optimal morphologic response (OR), 31 (42.5%) had incomplete (IR), and 24 (32.9%) had no response (NR). The pts characteristics between those with OR, IR and NR were generally balanced. The median TTF was 7.2 months in NR versus 7.2 months in IR versus 6.8 months in OR (HR (OR/NR) = 0.91, HR (OR/IR) = 0.90; p = 0.93). RR was 77.8% in OR versus 64.5% in IR and 58.3% in NR (p = 0.528). The median PFS was 8.3 months in NR versus 8.5 months in IR versus 9.1 months in OR (HR (OR/NR) = 0.72, HR (OR/IR) = 1.04; p = 0.420). Conclusions: In this analysis, morphologic response might not be a prognostic marker in first-line BV-based chemotherapy in pts with CLM.

Association of early tumor shrinkage with progression-free survival in patients with metastatic colorectal cancer treated with bevacizumab-based chemotherapy: HGCSG0802

749

Background: It was reported that early tumor shrinkage (ETS) was associated with better overall survival (OS) in patients (pts) with metastatic colorectal cancer (mCRC) receiving cetuximab. We investigated association of ETS with progression free survival (PFS) in pts with unresectable colorectal liver metastases (CLM) from HGCSG0802 observational cohort study in pts with mCRC treated with first-line bevacizumab (BV)-based chemotherapy. Methods: The objective of HGCSG0802 was to evaluate PFS, OS, time to treatment failure (TTF), response rate (RR), safety and so on. The key eligibility criteria were evaluable lesions, older than 20 years old, ECOG PS 0-2. In this analysis, association of ETS at 8 weeks from the start of chemotherapy with pts characteristics, PFS and TTF was evaluated. Pts characteristics were compared using Student-t test, chi-square test and Fisher’s exact test. PFS and TTF were analyzed with Kaplan-Meier method and compared using log-rank test. Univariate analysis for the association of pts characteristics with PFS and TTF was performed using log-rank test, and multivariate analysis was performed using Cox proportional hazards model. Results: Of 108 pts (the full analysis set), 74 pts with CLM were evaluable for ETS. Forty-nine pts (66.2%) had ETS ≥20%. The pts characteristics between ETS ≥20% and <20% were well balanced. The median PFS was 7.3 months in ETS <20% versus 10.0 months in ETS ≥20% (HR 0.55; p=0.025). In multivariate analysis for PFS, there was no significant difference between ETS ≥20% and <20% (HR 0.585; p=0.066). The median TTF (ETS <20% v ≥20%) was 5,1 months vs. 7.7 months (HR 0.46; p=0.003). In multivariate analysis for TTF, there was significant difference between ETS ≥20% and <20% (HR 0.509; p=0.017). Conclusions: In this analysis, ETS ≥20% might be positive predictive marker for PFS and TTF in pts with CLM receiving first-line BV-based chemotherapy.

Type 2 diabetes reduces the proliferation and survival of oligodendrocyte progenitor cells in ishchemic white matter lesions

Diabetes mellitus (DM) is a major risk factor for stroke and it exacerbates tissue damage after ischemic insult. Diabetes is one of the important causes of the progression of white matter lesion, however, the pathological mechanisms remain unclear. The present study evaluated the influences of type 2 DM on ischemic subcortical white matter injury and the recruitment of oligodendrocyte progenitor cells (OPCs) under chronic cerebral hypoperfusion using type 2 diabetic (db/db) mice. After bilateral common carotid artery stenosis (BCAS), the rarefaction in the white matter was more severe in db/db mice than in db/+ mice, and the number of glutathione S-transferase-pi (GST-pi)-positive mature oligodendrocytes (OLG) was lower in db/db mice than in db/+ mice at 4 and 8 weeks after ischemia. There were no significant differences in the number of single-stranded DNA (ssDNA)-positive apoptotic cells in the deep white matter between the db/db and db/+ mice. We found a transient increase in the platelet-derived growth factor receptor-α (PDGFRα)-positive OPCs in white matter lesions after ischemia. However, significantly fewer PDGFRα-positive OPCs were detected in db/db than db/+ mice from 4weeks after BCAS. The number of Ki67-positive proliferating cells in the deep white matter was significantly lower in db/db mice than in db/+ mice from 4 to 8weeks after BCAS. Most of the Ki67-positive cells were PDGFRα-positive OPCs. Finally, we assessed the survival of 5-bromo-2'-deoxyuridine (BrdU)-positive proliferating cells in ischemic white matter, and found significantly poorer survival of BrdU/PDGFRα-positive OPCs or BrdU/GST-pi-positive OLGs in the db/db mice compared to the db/+ mice in the white matter after BCAS. Our findings suggest that the type 2 DM mice exhibited more severe white matter injury 8 weeks after chronic ischemia. Decreased proliferation and survival of OPCs may play an important role in the progression of white matter lesions after ischemia in diabetics.

No graduated pressure profile in compression stockings still reduces muscle fatigue

Most sporting compression stockings possess a graduated pressure profile. However, it remains unclear whether the graduated pressure profile is an essential feature for reducing the development of muscle fatigue. This study sought to examine the effect of the pressure profile of compression stockings on the degree of muscle fatigue of lower leg muscles induced by submaximal running exercise. 15 male subjects performed 30-min treadmill running in 1 control and 4 compression stocking conditions with the following profiles; 1) graduated low pressure, 2) graduated high pressure, 3) uniform pressure distribution, and 4) localized pressure just over the gastrocnemius muscle belly. Before and immediately after the exercise, T2-weighted magnetic resonance images of the right lower leg were obtained without testing garments. T2 values of the triceps surae and tibialis anterior were calculated from the images. T2 was significantly increased after the running in all conditions. The magnitude of T2 increase was significantly greater in the control than in other 3 conditions except for the one with graduated low pressure, whereas there were no significant differences among the latter 3 conditions. The findings suggest that a graduated pressure profile is not an essential feature of compression stockings for reducing the development of muscle fatigue during submaximal running exercise.

Factors influencing national rollout of quality improvement approaches to public hospitals in Tanzania

Purpose

– The purpose of this paper is to identify factors that influence the implementation of the rollout of the 5S approach in public hospitals in Tanzania, and share the way to scale this up for similar setting in developing countries.

Design/methodology/approach

– The effect size was calculated from pre- and post-assessment results of Training of Trainers (ToT) to examine the effectiveness of ToT. A questionnaire with 14 explanatory variables was developed and completed based on information collected during Consultation visits (CVs) and progress report meetings (PRMs). Then, data were analysed to identify the influencing factors in relation to outcome variables (CV average score).

Findings

– Among 14 explanatory variables, five explanatory variables showed statistical significant association with the CV average score. Those are: “Feedback and information sharing,” (p=0.031), “Quality Improvement Team roles and responsibility” (p=0.002), “5S knowledge,” “Involvement and commitment,” and “5S guidelines use and availability,” (p=0.000). When the explanatory variables were controlled by levels of hospitals; “involvement and commitment” was the only explanatory variable for national level hospitals. For regional referral hospitals, “QIT roles and responsibility” (p=0.02) and “5S knowledge” (p=0.03) were statistically significant. For district hospitals, “involvement and commitment” (p=0.01) and “availability of guideline (p=0.001)” were statistically significant.

Research limitations/implications

– This study has the following limitations. The data were collected from existing reports and presentation materials only. There might be reporting bias, as PRM data is self-reported from the hospitals. Caution is therefore needed in extrapolating the study results to other settings. Despite these caveats, the findings will provide important insights for designing and implementing QI programs in Tanzania and in other African countries.

Originality/value

– The authors' conceptual framework is based on the existing literature on the science of diffusion and scale up of innovation in the health sector. Few studies are known from resource constrain settings in Africa which assess the determinants of the process of nationwide scale-up of proven interventions.

Visceral fat accumulation is associated with cerebral small vessel disease

BACKGROUND AND PURPOSE

Obesity is associated with the risk of coronary artery disease and stroke. Visceral fat plays a significant role in the atherogenic effects of obesity. Whether visceral fat accumulation, as measured by computed tomography (CT), is an independent risk factor for the presence of cerebral small vessel disease (SVD) was investigated.

METHODS

This study comprised 506 Japanese subjects 35-74 years of age (mean 55.3 years) without a history of symptomatic cerebrovascular disease who underwent health screening tests, including brain magnetic resonance imaging, carotid echography and measurements of the visceral fat area (VFA) and subcutaneous fat area (SFA) on abdominal CT. Visceral fat accumulation was defined as VFA ≥ 100 cm(2) . Logistic regression analysis was performed to examine the associations between visceral fat accumulation and cerebral SVD such as white matter lesions (WMLs) and silent lacunar infarction (SLI).

RESULTS

The prevalence of WMLs and SLI but not carotid plaque were significantly higher in subjects with VFA ≥ 100 cm(2) than those with VFA < 100 cm(2) . A VFA ≥ 100 cm(2) was associated with WMLs and SLI independent of age, cardiovascular risk factors and other measurements of obesity, such as waist circumference and body mass index. A large waist circumference was independently associated with SLI. SFA, the combination of VFA and SFA, and body mass index were not associated with WMLs or SLI.

CONCLUSIONS

Visceral fat accumulation was independently associated with the presence of cerebral SVD in subjects without a history of symptomatic cerebrovascular disease.

Fluctuation of an ion beam extracted from an AC filament driven Bernas-type ion source

Argon ion beam fluctuation from an AC filament driven Bernas-type ion source is observed. The ion beam was measured by an 8 measurement elements beam profile monitor. The amplitude of the beam current fluctuation stayed in the same level from 100 Hz to 1 kHz of the filament heating frequency. The beam current fluctuation frequency measured by the beam profile monitor was equal to the frequency of the AC filament operation. The fluctuation amplitudes of the beam current by AC operation were less than 7% and were in the same level of the DC operation.

Chronic brain ischemia induces the expression of glial glutamate transporter EAAT2 in subcortical white matter

Glutamate plays a central role in brain physiology and pathology. The involvement of excitatory amino acid transporters (EAATs) in neurodegenerative disorders including acute stroke has been widely studied, but little is known about the role of glial glutamate transporters in white matter injury after chronic cerebral hypoperfusion. The present study evaluated the expression of glial (EAAT1 and EAAT2) and neuronal (EAAT3) glutamate transporters in subcortical white matter and cortex, before and 3-28 days after the ligation of bilateral common carotid arteries (LBCCA) in rat brain. K-B staining showed a gradual increase of demyelination in white matter after ischemia, while there was no cortical involvement. Between 3 and 7 days after LBCCA, a significant increase in EAAT2 protein levels was observed in the ischemic brain and the number of EAAT2-positive cells also significantly increased both in the cortical and white matter lesions. EAAT2 was detected in glial-fibrillary acidic protein (GFAP)-positive astrocytes in both the cortex and white matter, but not in neuronal and oligodendroglial cells. EAAT1 was slightly elevated after ischemia only in the white matter, but EAAT3 was at almost similar levels both in the cortex and white matter after ischemia. A significant increase in EAAT2 expression level was also noted in the deep white matter of chronic human ischemic brain tissue compared to the control group. Our findings suggest important roles for up-regulated EAAT2 in chronic brain ischemia especially in the regulation of high-affinity of extracellular glutamate and minimization of white matter damage.