Vestibular Vertigo and Disparities in Healthcare Access Among Adults in the United States.

OBJECTIVE: Vertigo and dizziness have a high lifetime prevalence with significant impacts on daily life. We sought to explore differences in access to and ability to afford care among adults with vestibular vertigo by race/ethnicity, income, and insurance type. DESIGN: This is a cross-sectional study using the 2016 National Health Interview Survey. A total of 32,047 adults who completed the 2016 National Health Interview Survey Balance Supplement were analyzed. We used a previously validated definition of vertigo defined as (1) positional vertigo, (2) rotational vertigo, or (3) recurrent dizziness with nausea and either oscillopsia or imbalance. We examined several self-reported measures of healthcare utilization and access. RESULTS: Among adults with vestibular vertigo, African Americans had significantly increased odds of delayed care due to lack of transportation; Hispanic ethnicity was associated with decreased odds of skipping medication doses and asking a doctor for a lower-cost medication. Adults with public insurance had significantly lower odds of reporting delayed care due to worry about cost, not receiving medical care due to cost, and delayed filling of a prescription, but had greater odds of reporting delayed care due to lack of transportation. Lack of insurance and lower income were associated with increased odds of delaying and not receiving care due to cost. CONCLUSION: These findings demonstrate significant differences in access to care among adults with vestibular vertigo in the United States based on race, income, and health insurance status.

Liquid biopsy using cfDNA to predict radiation therapy response in solid tumors

Purpose@#This study explored the potential feasibility of cell-free DNA (cfDNA) in monitoring treatment response through the measurement of chromosomal instabilities using I-scores in the context of radiation therapy (RT) for other solid tumors. @*Materials and Methods@#This study enrolled 23 patients treated with RT for lung, esophageal, and head and neck cancer. Serial cfDNA monitoring was performed before RT, 1 week after RT, and 1 month after RT. Low-depth whole-genome sequencing was done using Nano kit and NextSeq 500 (Illumina Inc.). To measure the extent of genome-wide copy number instability, I-score was calculated. @*Results@#Pretreatment I-score was elevated to more than 5.09 in 17 patients (73.9%). There was a significant positive correlation between the gross tumor volume and the baseline I-score (Spearman rho = 0.419, p = 0.047). The median I-scores at baseline, post-RT 1 week (P1W), and post-RT 1 month (P1M) were 5.27, 5.13, and 4.79, respectively. The I-score at P1M was significantly lower than that at baseline (p = 0.002), while the difference between baseline and P1W was not significant (p = 0.244). @*Conclusion@#We have shown the feasibility of cfDNA I-score to detect minimal residual disease after RT in patients with lung cancer, esophageal cancer, and head and neck cancer. Additional studies are ongoing to optimize the measurement and analysis of I-scores to predict the radiation response in cancer patients.

Direct Air Capture of CO2 Using Poly(ethyleneimine)-Functionalized Expanded Poly(tetrafluoroethylene)/Silica Composite Structured Sorbents.

The rapidly increasing atmospheric CO2 concentration has driven research into the development of cost- and energy-efficient materials and processes for the direct air capture of CO2 (DAC). Solid-supported amine materials can give high CO2 uptakes and acceptable sorption kinetics, but they are generally prepared in powder forms that are likely not practically deployable in large-scale operations due to significant pressure drops associated with packed-bed gas-solid contactors. To this end, the development of effective gas-solid contactors for CO2 capture technologies is important to allow processing high flow rates of gas with low-pressure drops and high mass transfer rates. In this study, we demonstrate new laminate-supported amine CO2 sorbents based on the impregnation of low-molecular-weight, branched poly(ethyleneimine) (PEI) into an expanded poly(tetrafluoroethylene) (ePTFE) sheet matrix containing embedded silica particles to form free-standing sheets amenable to incorporation into structured gas-solid contactors. The free-standing sheets are functionalized with PEI using a highly scalable wet impregnation method. This method allowed controllable PEI distribution and enough porosity retained inside the sheets to enable practical CO2 capacities ranging from 0.4 to 1.6 mmol CO2/gsorbent under dry conditions. Reversible CO2 capacities are achieved under both dry and humid temperature swing cycles, indicating promising material stability. The specific thermal energy requirement for the regeneration based on the measured CO2 and water capacities is 287 kJ/mol CO2, where the molar ratio of water to CO2 of 3.1 is achieved using hydrophobic materials. This is the lowest molar ratio among published DAC sorbents. A larger laminate module is tested under conditions closer to larger-scale operations (linear velocities 0.03, 0.05, and 0.1 m/sec) and demonstrates a stable capacity of 0.80 CO2/gsorbent over five cycles of CO2 adsorption and steam regeneration. The PEI-impregnated ePTFE/silica composite sorbent/contactors demonstrate promising DAC performance derived from the amine-filled silica particles contained in hydrophobic ePTFE domains to reduce water sorption and its concomitant regeneration energy penalty.

Perspective - the need and prospects for negative emission technologies - direct air capture through the lens of current sorption process development.

We provide a perspective on the development of direct air capture (DAC) as a leading candidate for implementing negative emissions technology (NET). We introduce DAC based on sorption, both liquid and solid, and draw attention to challenges that these technologies will face. We provide an analysis of the limiting mass transfer in the liquid and solid systems and highlight the differences.

A Case of Sporadic Suprasellar Hemangioblastoma Mimicking Meningioma

Hemangioblastoma (HBL) in the suprasellar region is very rare and a few cases have been reported. Suprasellar HBL without von Hippel-Lindau disease is much rarer. A 76-year old male patient presented progressively deteriorating visual disturbance. MRI demonstrated solid suprasellar mass of 20 mm in diameter, broadly based to planum sphenoidale and diaphragm sella and dural tail sign after the administration of gadolinium diethylene triamine penta-acetic acid (Gd-DTPA). Preoperative diagnosis was meningioma. Total resection of the tumor was not accomplished because of massive hemorrhage, and the histopathologic examination revealed the tumor to be HBL. The visual disturbance of the patient was not improved. The authors reviewed the literature and considered a differential diagnosis of suprasellar tumors and treatment of suprasellar HBL.

Current Clinical Features of Febrile Seizures in a Pediatric Emergency Room / 이화의대지

OBJECTIVES: To expand current knowledge on febrile seizures (FSs), the most common childhood seizure disorder, we investigated clinical features and risk factors of FS in the pediatric emergency department of a center in western Seoul. METHODS: Children with FS that visited the pediatric emergency room of the Ewha Womans University Medical Center from January to December 2014 were included in this study. A retrospective medical record review was conducted for a total of 404 seizure events relative to 265 patients. RESULTS: A total of 150 boys and 115 girls were enrolled. Children presenting their first FSs were 70.9% (n=188). Average age of FS onset was 28.9 months. Family history was reported in 95 children (36.8%) with higher relevance of paternal inheritance (44.2%, n=42/95). More than half of the seizures (56.4%, n=228/404) occurred on the first day of fever. The most common cause of fever was upper respiratory tract infection (65.8%, n=266/404). Children attending a daycare center had higher incidence of multiple FS compared to those cared for at home. Approximately one third of seizure events (31.7%, n=128/404) were admission cases, mainly because of prolonged fever. CONCLUSION: FS is a common neurologic disorder with relatively high admission rate among pediatric emergency department visits. Daycare attendance is associated with current increased incidence of multiple FS. Further study with long-term follow up is necessary to expand knowledge on improving clinical care strategy in FS.

Survey of the Patterns of Using Stereotactic Ablative Radiotherapy for Early-Stage Non-small Cell Lung Cancer in Korea / Journal of the Korean Cancer Association, 대한암학회지

PURPOSE: Stereotactic ablative radiotherapy (SABR) is an effective emerging technique for early-stage non-small cell lung cancer (NSCLC). We investigated the current practice of SABR for early-stage NSCLC in Korea. MATERIALS AND METHODS: We conducted a nationwide survey of SABR for NSCLC by sending e-mails to all board-certified members of the Korean Society for Radiation Oncology. The survey included 23 questions focusing on the technical aspects of SABR and 18 questions seeking the participants' opinions on specific clinical scenarios in the use of SABR for early-stage NSCLC. Overall, 79 radiation oncologists at 61/85 specialist hospitals in Korea (71.8%) responded to the survey. RESULTS: SABR was used at 33 institutions (54%) to treat NSCLC. Regarding technical aspects, the most common planning methods were the rotational intensity-modulated technique (59%) and the static intensity-modulated technique (49%). Respiratory motion was managed by gating (54%) or abdominal compression (51%), and 86% of the planning scans were obtained using 4-dimensional computed tomography. In the clinical scenarios, the most commonly chosen fractionation schedule for peripherally located T1 NSCLC was 60 Gy in four fractions. For centrally located tumors and T2 NSCLC, the oncologists tended to avoid SABR for radiotherapy, and extended the fractionation schedule. CONCLUSION: The results of our survey indicated that SABR is increasingly being used to treat NSCLC in Korea. However, there were wide variations in the technical protocols and fractionation schedules of SABR for early-stage NSCLC among institutions. Standardization of SABR is necessary before implementing nationwide, multicenter, randomized studies.

Clinical Characteristics and Epidemiology of Enteroviral Meningitis Compared to Non-Enteroviral Meningitis in Infants under 3 Months of Age / 이화의대지

OBJECTIVES: To compare the epidemiology, clinical presentation, laboratory findings, seasonality and hospital course of enteroviral meningitis (EM) and non-enteroviral meningitis (NEM) cases in infants under 3 months of age. METHODS: A retrospective chart review was performed of infants under 3 months of age or less with viral meningitis admitted to Ewha Womans University Mokdong Hospital between January 2010 and December 2016. RESULTS: EM patients were more likely to have siblings compared with NEM. Most of EM was diagnosed during the summer season. Almost 80% of EM was diagnosed between July and September. Fever lasted longer in EM patients compared to NEM. White blood cell count (WBC) from the cerebrospinal fluid was higher in EM patients compared with NEM patients. WBC in blood were lower in EM patients compared with NEM patients. C-reactive protein was lower in EM patients compared with NEM patients. Most of the patients were initially started on antibiotics therapy to rule out bacterial meningitis. EM patients received shorter duration of antibiotic treatment compared with NEM patients. CONCLUSION: This study was conducted to augment the understanding of the incidence, epidemiology, transmission in infants, clinical presentation, laboratory findings, seasonality and hospital courses of enteroviral meningitis compared to NEM. Early recognition, rapid diagnosis and proper clinical management can reduce duration of antibiotic treatment.

The Effect of Perioperative Radiation Therapy on Spinal Bone Fusion Following Spine Tumor Surgery

INTRODUCTION: Perioperative irradiation is often combined with spine tumor surgery. Radiation is known to be detrimental to healing process of bone fusion. We tried to investigate bone fusion rate in spine tumor surgery cases with perioperative radiation therapy (RT) and to analyze significant factors affecting successful bone fusion. METHODS: Study cohort was 33 patients who underwent spinal tumor resection and bone graft surgery combined with perioperative RT. Their medical records and radiological data were analyzed retrospectively. The analyzed factors were surgical approach, location of bone graft (anterior vs. posterior), kind of graft (autologous graft vs. allograft), timing of RT (preoperative vs. postoperative), interval of RT from operation in cases of postoperative RT (within 1 month vs. after 1 month) radiation dose (above 38 Gy vs. below 38 Gy) and type of radiation therapy (conventional RT vs. stereotactic radiosurgery). The bone fusion was determined on computed tomography images. RESULT: Bone fusion was identified in 19 cases (57%). The only significant factors to affect bony fusion was the kind of graft (75% in autograft vs. 41 in allograft, p=0.049). Other factors proved to be insignificant relating to postoperative bone fusion. Regarding time interval of RT and operation in cases of postoperative RT, the time interval was not significant (p=0.101). CONCLUSION: Spinal fusion surgery which was combined with perioperative RT showed relatively low bone fusion rate (57%). For successful bone fusion, the selection of bone graft was the most important.

Evaluation of Prognostic Factors and Validation of Tumor Response Ratios after Neoadjuvant Chemotherapy in Patients with Breast Cancer

PURPOSE: In the treatment of breast cancer, neoadjuvant chemotherapy (NAC) is useful to reduce breast cancer size before surgical intervention. Patients who achieve a pathologic complete response (pCR) to NAC have improved overall survival (OS). However, the relationship between prognosis and partial response is yet unclear. In this study, we evaluated prognostic factors and the tumor response ratio (TRR) method among patients who received NAC. METHODS: Clinicopathologic factors were evaluated to predict OS. The TRR was calculated by dividing pathologic tumor size by clinical tumor size. TRRs were then categorized into four groups, and the survival times for the different TRR groups were compared using statistical evaluation. RESULTS: Clinical N stage (p=0.02), overall stage (p=0.04), pathologic N stage (p=0.03), hormone receptor status (p=0.01), and lymphovascular invasion (p=0.02) were significantly associated with OS. Pathologic overall stage and TRR did not correlate with OS. Patients with a pCR exhibited the best survival rates using the current staging system and the TRR method. CONCLUSION: Clinicopathologic factors can be easily applied to predict OS, and clinicians could use these parameters until an accurate, simple, and highly discriminatory methods is developed to assess breast cancer patients with a partial.

The Molecular Subtype Dependent Effect of Concurrent Radiotherapy and Systemic Therapy on Breast Cancer: Analysis of a Human In Vivo Model of Metastatic Brain Lesions

PURPOSE: The molecular subtype of breast cancer is an important predictive factor. Therefore, we investigated the effects of concurrent or serial radiotherapy and systemic therapy on metastatic brain lesions according to the molecular subtype of breast cancer. METHODS: The present retrospective study examined data from 66 patients with breast cancer and metastatic brain lesions, who were treated using radiotherapy between January 1990 and July 2014. Patients were classified into the following three subtypes based on their hormone receptor (HR) and human epidermal growth factor receptor 2 (HER2) status: HR+/HER2− (luminal A, 13 patients), HR+/HER2+ (luminal B, 21 patients), HR−/HER2+ (HER2, 22 patients), or HR−/HER2− (triple negative, 10 patients). The brain lesions and their responses to treatment were evaluated using brain computed tomography or magnetic resonance imaging. Progression of brain disease was defined by a ≥20% increase in the sum of the lesion's diameters or the development of a new brain lesion. Progression-free survival was calculated from the initiation of radiotherapy to the first instance of brain disease progression or last follow-up. RESULTS: Patients in the HER2 group who had received concur-rent radiotherapy and systemic therapy (mainly HER2-targeted therapy) exhibited significantly better progression-free survival than did patients who had received radiotherapy followed by systemic therapy (p=0.037). However, concurrent radiotherapy and systemic therapy did not significantly improve progression-free survival in the luminal A (p=0.527), luminal B (p=0.462), or triple negative (p=0.558) groups. CONCLUSION: Concurrent radiotherapy and mainly HER2-targeted systemic therapy significantly prolonged progression-free survival in the HER2 group.

Clinical Outcome of Treatment for Patients with Giant Cell Tumor in Spine

OBJECTIVE: The treatment of giant cell tumor (GCT) is mainly performed surgically. However, GCT in spine seems difficult to treat because of the limited surgical accessibility and proximity. In this report, we analyzed the outcome of GCT treatment in spine. METHODS: Between 2000 and 2012, 19 patients received treatment for GCT in spine. Median age at their first diagnosis was 31 years, 10 patients were male, and 9 female. Fourteen tumors were located in the sacrum, 1 in cervical, 1 in thoracic and 3 in lumbar spine. As primary treatment, gross total removal (GTR) was done in 6 patients, and subtotal removal (STR) in 13 patients. Radiation therapy (RT) as an adjuvant therapy was performed in 2 cases in GTR group and 10 cases in STR group. RESULTS: During the follow-up, 7 patients had local recurrence (36.8%). The average period until recurrence after primary treatment was 14 months. No recurrence was detected in GTR group. Recurrence was noted in 7 out of 13 patients who underwent STR. These differences were statistically significant (p=0.024). A median of recurrence free period (RFP) was 84 months. Also average RFP of the RT group was 112 months, and non-RT group was 65 months. These differences were statistically significant (p=0.041). CONCLUSION: Treatment of choice for GCT in spine is a complete removal of tumor without neurological deficits. In case of incomplete removal, radiation therapy may be a useful adjuvant treatment modality.

Two Cases of Dedifferentiated Chordoma in the Sacrum

Dedifferentiated chordoma (DC) is defined as a chordoma containing sarcoma components. DC is distinguished from conventional chordoma by the rapidity of tumor growth and the potential for distant metastasis. We report two cases of DC, which are developed in the sacrum. We reviewed the medical records and imaging studies of 2 patients diagnosed with DC and the literature published. In the first case, percutaneous biopsy revealed that it was conventional chordoma in the sacrum. Patient underwent radiation therapy (RT). Six years after the RT, the tumor recurred. Surgical removal was performed and the recurrent tumor was diagnosed as DC in histopathologic examination. In the second case, a patient underwent gross total resection of sacral tumor, which was diagnosed with conventional chordoma. Aggravated tumor was detected after 4 months, and patient underwent reoperation. The second operation revealed the transformation of the tumor into DC. The survival time of the patients after the diagnosis was 10 and 31 months. Dedifferentiated chordoma is a rare and highly aggressive tumor. De novo type exists, but it usually transformed from recurrent chordoma after surgical resection or radiation.

Intracavitary Radiation Therapy for Recurrent Cystic Brain Tumors with Holmium-166-Chico : A Pilot Study

OBJECTIVE: Intracavitary injection of beta-emitting radiation source for control of cystic tumors has been tried with a benefit of localized internal radiation. The authors treated cystic brain tumor patients with Holmium-166-chitosan complex (Ho-166-chico), composed of a beta-emitting radionuclide Holmium-166 and biodegradable chit polymer, and evaluated the safety and effective measurement for response. METHODS: Twenty-two patients with recurrent cystic brain tumor and/or located in a deep or eloquent area were enrolled in this pilot study. The cyst volume and wall thickness were determined on CT or MRI to assess radiological response. The activity of Ho-166-chico injected via Ommaya reservoir was prescribed to be 10-25 Gy to the cyst wall in a depth of 4 mm. RESULTS: There was neither complications related to systemic absorption nor leakage of Ho-166-chico in all 22 patients. But, two cases of oculomotor paresis were observed in patients with recurrent craniopharyngioma. Radiological response was seen in 14 of 20 available follow-up images (70%). Seven patients of 'evident' radiological response experienced more than 25% decrease of both cyst volume and wall thickness. Another 7 patients with 'suggestive' response showed decrease of cyst volume without definitive change of the wall thickness or vice versa. All patients with benign tumors or low grade gliomas experienced symptomatic improvement. CONCLUSION: Ho-166-chico intracavitary radiation therapy for cystic tumor is a safe method of palliation without serious complications. The determination of both minimal effective dosage and time interval of repeated injection through phase 1 trial could improve the results in the future.

Changes of characterization of Salmonella Typhimurium isolate following sequential exposures to porcine neutrophil / 대한수의학회지

To develop a live vaccine candidate using an attenuated strain of Salmonella Typhimurium (ST), biochemical properties, plasmid profile, PFGE patterns and pathogenic analysis of the ST isolate were carried out after sequential passage of the ST isolate in porcine neutrophils. By the passage, the ability of the neutrophil-adapted isolate to utilize d-xylose was lost, while the ability of the strain to ferment trehalose was delayed after 2 or more days of the culture. Also, changes including deletion of the gene fragments were observed in PFGE analysis of the neutrophil-adapted isolates. Two plasmids, 105kb and 50kb, were cured in the strain passaged over 15 times in porcine neutrophils. The 50% of lethal dose (LD50) of the parent strain was changed from 1 x 10(5) LD50 to 6 x 10(6) LD50 by the passage in intraperitoneal injection of the strains into mice. These results suggested that bacterial genotypic and phenotypic responses might be globally altered depending on the inside environment of neutrophils.

Treatment of Compressive Optic Neuropathy by Recurred Maxillary Cancer Using Stereotactic Radiosurgery: A Case Report

PURPOSE: To report a case of a female patient treated with stereotactic radiosurgery for compressive optic neuropathy by recurred maxillary cancer. CASE SUMMARY: A 51-year-old woman with a history of maxillary cancer presented with decreased visual acuity and visual field and color vision defects in the right eye. The CT scan revealed a wide spread mass along the ethmoid sinus, orbit, optic canal, and skull base. Under the impression of compressive optic neuropathy, stereotactic radiosurgery was performed. A cumulative dose of 39 Gy in 3 daily fractions of 13 Gy was administered to the mass. After 10 days, visual acuity, color vision, and visual field improved and were maintained after a 2 month follow-up. CONCLUSIONS: Stereotactic radiosurgery could be another treatment option for patients with compressive optic neuropathy caused by a malignant tumor.

Quality Assurance of Intensity Modulated Radiation Therapy: Site-Specific Results of Eulji University Hospital / 대한방사선종양학회지

PURPOSE: To analyze our quality assurance (QA) data for intensity modulated radiation therapy (IMRT) according to treatment site and to possibly improve QA for IMRT in Hospital. MATERIALS AND METHODS: We performed QA on 50 patients (head and neck, 28 patients; Breast, 14 patients; Pelvis, 8 patients) for IMRT. The calculated dose from RTP was compared with the measured value film, gamma index, and ionization chamber for dose measurement in each case. RESULTS: The point dose measurement results in 45 of 50 patients showed good agreement with the calculation dose (+/-3%). The largest error measured thus far has been 3.60%, with a mean of only -0.17% (SD, 2.25%). Each treatment site showed an error rate of -0.13% (SD, 1.93%) for head and neck cases, -0.26% (SD, 2.79%) for breast cases, and -0.24% (SD, 2.44%) for pelvis cases. The gamma index verified with the error rate of head and neck cases (6%), breast (10%), and pelvis (6%), which corresponded to a tolerance of 3 mm (3% for the head and neck, 2%, for the breast 1% for the pelvis, and 0% in the region where the isodose curve was greater than 90%. CONCLUSION: We recognize the cause of errors for each treatment site of IMRT QA and so we maximize our efforts to reduce error and increase accuracy.

Chemotherapy for Malignant Gliomas Based on Histoculture Drug Response Assay : A Pilot Study

OBJECTIVE: The Histoculture Drug Response Assay (HDRA), which measures chemosensitivity using minced tumor tissue on drug-soaked gelfoam, has been expected to overcome the limitations of in vitro chemosensitivity test in part. We analyzed interim results of HDRA in malignant gliomas to see if the test can deserve further clinical trials. METHODS: Thirty-three patients with malignant gliomas were operated and their tumor samples were examined for the chemosensitivity to 10 chosen drugs by HDRA. The most sensitive chemotherapy regimen among those pre-established was chosen based on the number of sensitive drugs or total inhibition rate (IR) of the regimen. The response was evaluated by 3 month magnetic resonance image. RESULTS: Among 13 patients who underwent total resection of the tumor, 12 showed no evidence of disease and one patient revealed progression. The response rate in 20 patients with residual tumors was 55% (3 complete and 8 partial responses). HDRA sensitivity at the cut-off value of more than one sensitive drug in the applied regimen showed a sensitivity of 100%, specificity of 60% and predictability of 70%. Another cut-off value of >80% of total IR revealed a sensitivity of 100%, specificity of 69%, and predictability of 80%. For 12 newly diagnosed glioblastoma patients, median progression-free survival of the HDRA sensitive group was 21 months, while that of the non-sensitive group was 6 months (p=0.07). CONCLUSION: HDRA for malignant glioma was inferred as a feasible method to predict the chemotherapy response. We are encouraged to launch phase 2 clinical trial with chemosensitivity on HDRA.

Multiple Myeloma with Biclonal Gammopathy Accompanied by Prostate Cancer / 대한진단검사의학회지

We report a rare case of multiple myeloma with biclonal gammopathy (IgG kappa and IgA lambda type) in a 58-year-old man with prostate cancer who presented with lower back pain. Through computed tomography (CT) imaging, an osteolytic lesion at the L3 vertebra and an enhancing lesion of the prostate gland with multiple lymphadenopathies were found. In the whole body positron emission tomography-computed tomography (PET-CT), an additional osteoblastic bone lesion was found in the left ischial bone. A prostate biopsy was performed, and adenocarcinoma was confirmed. Decompression surgery of the L3 vertebra was conducted, and the pathologic result indicated that the lesion was a plasma cell neoplasm. Immunofixation electrophoresis showed the presence of biclonal gammopathy (IgG kappa and IgA lambda). Bone marrow plasma cells (CD138 positive cells) comprised 7.2% of nucleated cells and showed kappa positivity. We started radiation therapy for the L3 vertebra lesion, with a total dose of 3,940 cGy, and androgen deprivation therapy as treatment for the prostate cancer.

Comparative Outcome after Treatment for Synchronous vs. Metachronous Colorectal Cancer Liver Metastasis

PURPOSE: This study was designed to compare outcomes in patients who underwent hepatectomy or radiofrequency thermal ablation (RFA) for synchronous or metachronous colorectal liver metastases (CLM). METHODS: One hundred twenty-two patients who underwent hepatectomy or RFA for their first CLM between 2001 and 2004 were enrolled in this study. The patients were divided into two groups (synchronous [N=77] and metachronous [N=45] CLM). Patient characteristics, clinicopathologic features, long-term outcomes, and prognostic factors were analyzed retrospectively. RESULTS: There were no significant differences in the 5-year disease-free and overall survival rates between the synchronous and metachronous CLM groups (36.2% vs. 37.2%, p=0.78; and 53.0% vs. 54.4%, p=0.82, respectively). Patients in the synchronous CLM group underwent more bilobar hepatic resections, intra-operative RFA, or co-modality treatments than the metachronous CLM group (p=0.035). The surgical resection group had a longer disease-free survival, but not overall survival than the RFA group. Greater N stage and female gender were associated with a worse prognosis in overall survival; N0 stage and surgical resection were good prognostic factors for disease-free survival. N stage and surgical resection were also statistically significant prognostic factors based on multivariate analysis. CONCLUSION: The synchronicity of CLM is not a significant prognostic factor, but the clinicopathologic characteristics that reflect more disseminated disease than metachronous metastasis are significant prognostic factors. Tumor characteristics and aggressiveness may be more important for prognosis than chronology.