The potential of integrating stereotactic ablative radiotherapy techniques with hyperfractionation for lung cancer.

BACKGROUND: Limited literature exists on the feasibility and effectiveness of integrating stereotactic ablative radiotherapy (SABR) techniques with hyperfractionated regimens for patients with lung cancer. This study aims to assess whether the SABR technique with hyperfractionation can potentially reduce lung toxicity. METHODS: We utilized the linear-quadratic model to find the optimal fraction to maximize the tumor biological equivalent dose (BED) to normal-tissue BED ratio. Validation was performed by comparing the SABR plans with 50 Gy/5 fractions and hyperfractionationed plans with 88.8 Gy/74 fractions with the same tumor BED and planning criteria for 10 patients with early-stage lung cancer. Mean lung BED, Lyman-Kutcher-Burman (LKB) normal tissue complication probability (NTCP), critical volume (CV) criteria (volume below BED of 22.92 and 25.65 Gy, and mean BED for lowest 1000 and 1500 cc) and the percentage of the lung receiving 20Gy or more (V20) were compared using the Wilcoxon signed-rank test. RESULTS: The transition point occurs when the tumor-to-normal tissue ratio (TNR) of the physical dose equals the TNR of α/ß in the BED dose-volume histogram of the lung. Compared with the hypofractionated regimen, the hyperfractionated regimen is superior in the dose range above but inferior below the transition point. The hyperfractionated regimen showed a lower mean lung BED (6.40 Gy vs. 7.73 Gy) and NTCP (3.50% vs. 4.21%), with inferior results concerning CV criteria and higher V20 (7.37% vs. 7.03%) in comparison with the hypofractionated regimen (p < 0.01 for all). CONCLUSIONS: The hyperfractionated regimen has an advantage in the high-dose region of the lung but a disadvantage in the low-dose region. Further research is needed to determine the superiority between hypo- and hyperfractionation.

Lymphocytopenia and survival after whole-brain radiotherapy in patients with small-cell lung cancer.

BACKGROUND: To investigate whether whole-brain radiotherapy (WBRT) decreases lymphocyte counts and evaluate the impact of treatment-related lymphopenia on survival in patients with brain metastasis. METHODS: Medical records from 60 small-cell lung cancer patients treated with WBRT from January 2010 to December 2018 were included in the study. Total lymphocyte count (TLC) was obtained pre and post treatment (within 1 month). We performed linear and logistic regression analyses to identify predictors of lymphopenia. The association between lymphopenia and survival was analyzed using Cox regression analysis. RESULTS: Thirty-nine patients (65%) developed treatment-related lymphopenia. The median TLC decrease was -374 cells/µL (interquartile range -50 to -722, p < 0.001). Baseline lymphocyte count was a significant predictor of TLC difference and percentage change in TLC. Logistic regression analysis found male sex (odds ratio [OR] 0.11, 95% confidence interval [CI] 0.00-0.79, p = 0.033) and higher baseline lymphocyte count (OR 0.91, 95% CI 0.82-0.99, p = 0.005) were associated with a lower risk of developing ≥grade 2 treatment-related lymphopenia. Cox regression analysis showed that age at brain metastasis (hazard ratio [HR] 1.03, 95% CI 1.01-1.05, p = 0.013), ≥grade 2 treatment-related lymphopenia, and percentage change in TLC (per 10%, HR 0.94, 95% CI 0.89-0.99, p = 0.032) were prognostic factors of survival. CONCLUSIONS: WBRT decreases TLC and the magnitude of treatment-related lymphopenia is an independent predictor of survival in small-cell lung cancer patients.

Old age and EGFR mutation status in inoperable early-stage non-small cell lung cancer patients receiving stereotactic ablative radiotherapy: A single institute experience of 71 patients in Taiwan.

BACKGROUND: Stereotactic ablative radiotherapy (SABR) is now the standard of care for patients with inoperable early-stage lung cancer. Many of these patients are elderly. EGFR (epidermal growth factor receptor) mutation is also common in the Asian population. METHODS: To evaluate the effects of old age and EGFR mutation on treatment outcomes and toxicity, we reviewed the medical records of 71 consecutive patients with inoperable early-stage non-small cell lung cancer (NSCLC) who received SABR at Taipei Veterans General Hospital between 2015 and 2021. RESULTS: The study revealed that median age, follow-up, Charlson comorbidity index, and ECOG score were 80 years, 2.48 years, 3, and 1, respectively. Of these patients, 37 (52.1%) were 80 years or older, and 50 (70.4%) and 21 (29.6%) had T1 and T2 diseases, respectively. EGFR mutation status was available for 33 (46.5%) patients, of whom 16 (51.5%) had a mutation. The overall survival rates at 1, 3, and 5 years were 97.2, 74.9, and 58.3%, respectively. The local control rate at 1, 3, and 5 years was 97.1, 92.5, and 92.5%, respectively. Using Cox proportional hazards regression we found that male sex was a risk factor for overall survival (p = 0.036, 95% CI: 1.118-26.188). Two patients had grade 2 pneumonitis, but no other grade 2 or higher toxicity was observed. We did not find any significant differences in treatment outcomes or toxicity between patients aged 80 or older and those with EGFR mutations in this cohort. CONCLUSION: These findings indicate that age and EGFR mutation status do not significantly affect the effectiveness or toxicity of SABR for patients with inoperable early-stage NSCLC.

The clinical relative biological effectiveness and prostate-specific antigen kinetics of carbon-ion radiotherapy in low-risk prostate cancer.

BACKGROUND: To evaluate the clinical relative biological effectiveness (RBE) of carbon-ion radiotherapy (C-ion RT) for prostate cancer. METHODS: The records of 262 patients with low-risk prostate cancer (median age, 65 [47-80] years) treated with C-ion RT at QST Hospital, National Institutes for Quantum Science and Technology in Japan during 2000-2018 were reviewed retrospectively. Four different protocol outcomes and prostate-specific antigen (PSA) responses were evaluated. The median follow-up was 8.4 years. The Kaplan-Meier method was used to estimate the biochemical or clinical failure-free rate (BCFFR). Clinical RBE was calculated using the tumor control probability model. RESULTS: The 5-, 7-, and 10-year BCFFRs were 91.7%, 83.8%, and 73.2%, respectively. The 10-year BCFFRs of patients who received C-ion RT at 66 Gy (RBE) in 20 fractions, 63 Gy (RBE) in 20 fractions, and 57.6 Gy (RBE) in 16 fractions were 81.4%, 70.9%, and 68.9%, respectively. The PSA level and density during follow-up were better in the patients treated with the lower fraction size. A higher PSA nadir and shorter time to PSA nadir were risk factors for biochemical or clinical failure by multivariate Cox regression. The tumor control probability analysis showed that the estimated clinical RBE values to achieve an 80% BCFFR at 10 years for 20, 16, and 12 fractions were 2.19 (2.18-2.24), 2.16 (2.14-2.23), and 2.12 (2.09-2.21), respectively. CONCLUSIONS: Using clinical data from low-risk prostate cancer patients, we showed the clinical RBE of C-ion RT decreased with increasing dose per fraction.

Compassionate Treatment of Brainstem Tumors with Boron Neutron Capture Therapy: A Case Series.

Brainstem tumors are heterogenous and cancerous glioma tumors arising from the midbrain, pons, and the medulla that are relatively common in children, accounting for 10% to 20% of all pediatric brain tumors. However, the prognosis of aggressive brainstem gliomas remains extremely poor despite aggressive treatment with chemotherapy and radiotherapy. That means there are many life-threatening patients who have exhausted all available treatment options and are beginning to face end-of-life stage. Therefore, the unique properties of highly selective heavy particle irradiation with boron neutron capture therapy (BNCT) may be well suited to prolong the lives of patients with end-stage brainstem gliomas. Herein, we report a case series of life-threatening patients with end-stage brainstem glioma who eligible for Emergency and Compassionate Use, in whom we performed a scheduled two fractions of salvage BNCT strategy with low treatment dosage each time. No patients experienced acute or late adverse events related to BNCT. There were 3 patients who relapsed after two fractionated BNCT treatment, characterized by younger age, lower T/N ratio, and receiving lower treatment dose. Therefore, two fractionated low-dose BNCT may be a promising treatment for end-stage brainstem tumors. For younger patients with low T/N ratios, more fractionated low-dose BNCT should be considered.

Bifocal lesions have a poorer treatment outcome than a single lesion in adult patients with intracranial germinoma.

Intracranial germinoma (IG) rarely occurs in adults. Its optimal treatment strategy is unclear. We evaluated the outcomes of radiotherapy in adults with intracranial germinoma. Data of 29 adult patients (age, 18-52 years; median age, 24.3 years) with IG treated with radiotherapy at Taipei Veterans General Hospital were retrospectively reviewed. They were followed up for a median time of 5.9 years (range, 1.0-12.8 years). We used the Kaplan-Meier method to estimate the progression-free survival (PFS) and overall survival (OS), and univariate and multivariate Cox proportional hazards regression models to identify the factors affecting PFS. PFS and OS were compared between adult and pediatric patients with IG. The 1-, 3-, and 5-year PFS rates were 96.6%, 85.8%, and 77.8%, respectively, in the adult patients, and the OS rate were all 100%. Seven patients (24.1%) experienced recurrence, and in six of them, salvage therapy successfully controlled the disease. Two patients (6.9%) died after 5 years of follow-up due to disease progression and central pontine myelinolysis. In the univariate and multivariate Cox analysis, bifocal lesions had a significantly lower PFS than those with single lesions (p = 0.008). Kaplan-Meier survival analysis showed that adult patients had a poorer PFS (p = 0.06) and OS (p = 0.025) than pediatric patients. Our study showed bifocal lesions were associated with lower PFS than a single lesion among adult IG patients, and adult IG patients tended to have poorer PFS and OS compared to pediatric IG patients. For adult patients with bifocal IG, we recommend treatment with craniospinal irradiation, whole ventricle irradiation (WVI) with chemotherapy, or frequent spine images follow-up for patients who received only WVI.

Correlation between drug sensitivity profiles of circulating tumour cell-derived organoids and clinical treatment response in patients with pancreatic ductal adenocarcinoma.

INTRODUCTION: Pancreatic ductal adenocarcinoma (PDAC) is highly aggressive and has poor prognosis. There are few biomarkers to inform treatment decisions, and collecting tumour samples for testing is challenging. METHODS: Circulating tumour cells (CTCs) from patients with PDAC liquid biopsies were expanded ex vivo to form CTC-derived organoid cultures, using a laboratory-developed biomimetic cell culture system. CTC-derived organoids were tested for sensitivity to a PDAC panel of nine drugs, with tests conducted in triplicate, and a weighted cytotoxicity score (CTS) was calculated from the results. Clinical response to treatment in patients was evaluated using Response Evaluation Criteria in Solid Tumours (RECIST) version 1.1 criteria at the time of blood sampling and 3 months later. The correlation between CTS and clinical response was then assessed. RESULTS: A total of 41 liquid biopsies (87.8% from patients with Stage 4 disease) were collected from 31 patients. The CTC-derived organoid expansion was achieved in 3 weeks, with 87.8% culture efficiency. CTC-derived organoid cultures were positive for EpCAM staining and negative for CD45 staining in the surface marker analysis. All patients had received a median of two lines of treatment prior to enrolment and prospective utility analysis indicated significant correlation of CTS with clinical treatment response. Two representative case studies are also presented to illustrate the relevant clinical contexts. CONCLUSIONS: CTCs were expanded from patients with PDAC liquid biopsies with a high success rate. Drug sensitivity profiles from CTC-derived organoid cultures correlated meaningfully with treatment response. Further studies are warranted to validate the predictive potential for this approach.

Outcomes of intracranial germinoma-A retrospective multinational Asian study on effect of clinical presentation and differential treatment strategies.

BACKGROUND: This multinational study was conducted to report clinical presentations and treatment strategies in patients with intracranial germinomas across selected Asian centers, including failure patterns, risk factors, and outcomes. METHODS: A retrospective data collection and analysis of these patients, treated between 1995 and 2015 from eight healthcare institutions across four countries was undertaken. RESULTS: From the results, 418 patients were analyzed, with a median follow-up of 8.9 years; 79.9% of the patients were M0, and 87.6% had ß-human chorionic gonadotropin values <50 mIU/mL. The 5/10-year overall survival (OS) and recurrence-free survival (RFS) rates were 97.2%/96.2% and 89.9%/86.9%, respectively. RFS was predicted by the radiotherapy (RT) field, with focal RT having the worst outcome, whereas chemotherapy usage had no impact on survival. Among patients who received chemotherapy, response to chemotherapy did not predict survival outcomes. In M0 patients, primary basal ganglia tumors predicted a worse RFS. In patients with bifocal tumors, an extended field RT was associated with better outcomes. In multivariable analysis, only RT fields were associated with RFS. In relapsed patients, salvage rates were high at 85.7%. Additionally, patients who received salvage RT had a better outcome (91.6% vs. 66.7%). CONCLUSIONS: Survival outcomes of patients with germinoma were excellent. Thus, the focus of treatment for intracranial germinoma should be on survivorship. Further studies are warranted to find the optimal intensity and volume of radiation, including the role of chemotherapy in the survival of patients with intracranial germinomas, considering age, primary tumor location, and extent of disease.

Salvage Boron Neutron Capture Therapy for Malignant Brain Tumor Patients in Compliance with Emergency and Compassionate Use: Evaluation of 34 Cases in Taiwan.

Although boron neutron capture therapy (BNCT) is a promising treatment option for malignant brain tumors, the optimal BNCT parameters for patients with immediately life-threatening, end-stage brain tumors remain unclear. We performed BNCT on 34 patients with life-threatening, end-stage brain tumors and analyzed the relationship between survival outcomes and BNCT parameters. Before BNCT, MRI and 18F-BPA-PET analyses were conducted to identify the tumor location/distribution and the tumor-to-normal tissue uptake ratio (T/N ratio) of 18F-BPA. No severe adverse events were observed (grade ≥ 3). The objective response rate and disease control rate were 50.0% and 85.3%, respectively. The mean overall survival (OS), cancer-specific survival (CSS), and relapse-free survival (RFS) times were 7.25, 7.80, and 4.18 months, respectively. Remarkably, the mean OS, CSS, and RFS of patients who achieved a complete response were 17.66, 22.5, and 7.50 months, respectively. Kaplan-Meier analysis identified the optimal BNCT parameters and tumor characteristics of these patients, including a T/N ratio ≥ 4, tumor volume < 20 mL, mean tumor dose ≥ 25 Gy-E, MIB-1 ≤ 40, and a lower recursive partitioning analysis (RPA) class. In conclusion, for malignant brain tumor patients who have exhausted all available treatment options and who are in an immediately life-threatening condition, BNCT may be considered as a therapeutic approach to prolong survival.

Identification of key genes and pathways associated with topotecan treatment using multiple bioinformatics tools.

BACKGROUND: The goal of this study is to determine critical genes and pathways associated with topotecan using publicly accessible bioinformatics tools. METHODS: Topotecan signatures were downloaded from the Library of Integrated Network-Based Cellular Signatures (LINCS) database (http://www.ilincs.org/ilincs/). Differentially expressed genes (DEGs) were defined as genes that appeared at least three times with p values <0.05 and a fold change of ≥50% (|log2FC| ≥ 0.58). Hub genes were identified by evaluating the following parameters using a protein-protein interaction network: node degrees, betweenness, and eigenfactor scores. Hub genes and the top-40 DEGs by |log2FC| were used to generate a Venn diagram, and key genes were identified. Functional and pathway enrichment analysis was performed using the Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. Information on ovarian cancer patients derived from The Cancer Genome Atlas (TCGA) database was analyzed, and the effect of topotecan on the protein expression was examined by Western blotting. RESULTS: Eleven topotecan signatures were downloaded, and 65 upregulated and 87 downregulated DEGs were identified. Twenty-one hub genes were identified. We identified eight key genes as upregulated genes, including NFKBIA, IKBKB, GADD45A, CDKN1A, and HIST2H2BE, while EZH2, CDC20, and CDK7 were identified as downregulated genes, which play critical roles in the cell cycle and carcinogenesis in KEGG analysis. In the TCGA analysis, the CDKN1A+/EZH2- group had the longest median survival, while the CDKN1A-/EZH2+ group had the shortest median survival. Topotecan-treated murine ovarian (MOSEC), colorectal (CT26), and lung (LLC) cancer cell lines displayed upregulated CDKN1A encoding p21 and downregulated Ezh2. CONCLUSION: Using publicly accessible bioinformatics tools, we evaluated key genes and pathways related to topotecan and examined the key genes using the TCGA database and in vitro studies.

A single-center study of treatment outcomes of pediatric basal ganglia germinoma in Taiwan.

PURPOSE: A basal ganglia (BG) germinoma is a rare tumor, and the optimal treatment remains unknown. We evaluated the clinical outcomes of treatment of BG germinoma in pediatric patients in Taiwan. METHODS: We retrospectively reviewed the medical records of 34 children with BG germinoma who were treated with radiotherapy (RT) at Taipei Veterans General Hospital between 1989 and 2016. The median follow-up time is 8.3 years (1.8-25.2 years). Survival was analyzed using the Kaplan-Meier estimate. Univariate Cox proportional-hazards models were used to identify the potential risk factors. RESULTS: Only four patients (11.8%) experienced recurrence and all successfully underwent salvage therapy. One patient (2.97%) died due to suspected radiotherapy (RT)-related sarcoma in the scalp. The 2-, 3-, and 5-year DFS rates were 91.2%, 88.2%, and 79.4%, respectively; the 2-, 3-, and 5-year OS rates were 97.1%, 94.1%, and 82.4%, respectively. Focal RT showed low DFS in the Kaplan-Meier survival curves (P = .028) compared with non-focal RT (whole ventricle, whole brain, or cranial spinal area). In the univariate Cox proportional-hazards model, there was a significant difference in DFS between focal and non-focal RT (P = .03). There is no difference in DFS and OS between BG germinoma patients and non-BG germinoma patients. CONCLUSIONS: We found an excellent DFS and OS in pediatric patients with BG germinoma treated with RT. Whole ventricle irradiation is recommended for good tumor control and low treatment-related toxicity. BG germinoma patients showed similar treatment results as germinoma patients in other common sites.

Increased risk of pelvic fracture after radiotherapy in rectal cancer survivors: A propensity matched study.

To determine whether radiotherapy (RT) can increase pelvic fracture risk in rectal cancer survivors. Rectal cancer patients who underwent curative surgery between 1996 and 2011 in Taiwan were retrospectively studied using the National Health Insurance Research Database (NHIRD) of Taiwan. ICD-9 Codes 808, 805.4-805.7, 806.4-806.7, and 820 (including pelvic, sacrum, lumbar, and femoral neck fracture) were defined as pelvic fracture. Propensity scores for RT, age, and sex were used to perform one-to-one matches between the RT and non-RT group. Risks of pelvic and arm fractures were compared by multivariable Cox regression. Of the 32 689 patients, 7807 (23.9%) received RT, and 1616 suffered from a pelvic fracture (incidence rate: 1.17/100 person-years). The median time to pelvic fracture was 2.47 years. After matching, 6952 patients each in the RT and non-RT groups were analyzed. RT was associated with an increased risk of pelvic fractures in the multivariable Cox model (hazard ratio (HR): 1.246, 95% confidence interval (CI): 1.037-1.495, P = 0.019) but not with arm fractures (HR: 1.013, 95% CI: 0.814-1.259, P = 0.911). Subgroup analyses revealed that RT was associated with a higher pelvic fracture rate in women (HR: 1.431, 95% CI: 1.117-1.834) but not in men, and the interaction between sex and RT was significant (P = 0.03). The HR of pelvic fracture increased 2-4 years after RT (HR: 1.707, 95% CI: 1.150-2.534, P = 0.008). An increased risk of pelvic fracture is noted in rectal cancer survivors, especially women, who receive RT.

Definitive Radiotherapy for Older Patients with Prostate Cancer: Experience of a Medical Center in Taiwan.

Whether age predicts treatment outcome of prostate cancer remains controversial. With the aging of the world population, properly understanding the effect of age may facilitate both treatment decision-making and defining the natural history of prostate cancer. Consecutive 581 patients with locally-confined adenocarcinoma of the prostate who received radical definitive radiotherapy(RT) (76-78 Gy) between 2004 and 2015 at a medical center in Taiwan were reviewed retrospectively. Median age was 78 years. The median follow-up was 66 months. The 5-year biochemical failure-free survival(BFFS), distant metastasis-free survival(DMFS), disease-specific survival(DSS), and overall survival(OS) rates were 84.9%, 93.8%, 97.8%, and 86.6%, respectively, for all patients. Comparing those above and below the age of 80, no difference in 5-year BFFS, DMFS, or DSS was found. Multivariate Cox regression analysis showed that tumor stage, Gleason score, initial PSA, and latency before RT were significant risk factors of BFFS. The latency before RT was significantly longer in the older group than in the under 80 group. Delay to start RT might explain the previous finding of inferior disease control in older patients in other studies. With the exception of OS, no other differences in outcomes or toxicities were observed in older patients.

Arsenic contamination in groundwater and its possible sources in Hanam, Vietnam.

This study investigated the arsenic (As) level in groundwater, and the characteristics of aquifer sediment as related to the occurrence of As in groundwater in Hanam, Vietnam. The deposition and transport of As-containing substances through rivers were also examined. Arsenic concentrations in 88% of the groundwater samples exceeded the As limit for drinking water based on the WHO standards. The dominating form of arsenic was As(III). The maximum total As content in bore core sediment was found in a peat horizon of the profiles and generally, elevated levels of As were also found in other organic matter-rich horizons. Total As contents of the bore core sediments were significantly correlated with crystalline iron oxide, silt and clay contents, suggesting that As in aquifer sediment was mainly associated with iron (hydr)oxides and clay mineral. In the groundwater, As concentration showed significant correlations with the total concentrations of Fe and HCO (3)(-). Significant correlations between HCl-extractable As and non-crystalline Fe oxide, total C, N, and S were also observed in the profiles. The results support the hypothesis that under favorable reductive conditions established by the degradation of organic matter, the dissolution of iron (hydr)oxides releases adsorbed As into the groundwater. The deposition of As in the sediments from the Red River were significantly higher than that in the Chau Giang River, suggesting that the Red River is the main source of As-containing substances deposited in the study area.

Investigation of As, Mn and Fe fixation inside the aquifer during groundwater exploitation in the experimental system imitated natural conditions.

Water-dissolved oxygen was supplied into anaerobic aquifer , which oxidized Fe(II), Mn(II) and trivalent arsenic and changed them into undissolved solid matter through hydrolysis, precipitation, co-precipitation and adsorption processes. The experiment was carried out on the column imitated a bore core of anaerobic aquifer with water phase containing Fe(II), Mn(II), As(III) concentration of 45.12 mg/L, 14.52 mg/L, 219.4 µg/L, respectively and other ions similarly composition in groundwater. After 6 days of air supply, concentration of iron reduced to 0.38 mg/L, manganese to 0.4 mg/L, arsenic to 9.8 µg/L (equivalent 99.16% of iron, 97.25% of manganese and 95.53% of arsenic fixed), and for other ions, the concentration changed almost according to general principles. Ion phosphate and silicate strongly influenced on arsenic removal but supported iron and manganese precipitation from water phase. Based on the experimental results, new model of groundwater exploitation was proposed.