Yuri Jeong

Comparison of the effects of sevoflurane and propofol anaesthesia on regional cerebral glucose metabolism in humans using positron emission tomography

This study compared brain glucose metabolism during sevoflurane anaesthesia and propofol anaesthesia using positron emission tomography (PET) in the same eight human volunteers. All the volunteers were anaesthetized twice, with a 1-week interval. Half of the volunteers received sevoflurane on the first occasion and propofol on the second; the other half received the two anaesthetics in the reverse order. PET scans using 18F-fluorodeoxyglucose were performed after sevoflurane or propofol anaesthesia. The relative glucose metabolic rate (rGMR) in the brain was assessed with statistical parametric mapping. Propofol suppressed the rGMR of the neocortex area more than sevoflurane, and sevoflurane suppressed the rGMR of the paleocortex and telencephalon more than propofol. These findings suggest that these two anaesthetics act via different mechanisms and may provide an important clue to the relationship between anaesthesia and the brain.

Whole pelvic intensity-modulated radiotherapy for high-risk prostate cancer: a preliminary report.

Purpose To assess the clinical efficacy and toxicity of whole pelvic intensity-modulated radiotherapy (WP-IMRT) for high-risk prostate cancer. Materials and Methods Patients with high-risk prostate cancer treated between 2008 and 2013 were reviewed. The study included patients who had undergone WP-IMRT with image guidance using electronic portal imaging devices and/or cone-beam computed tomography. The endorectal balloon was used in 93% of patients. Patients received either 46 Gy to the whole pelvis plus a boost of up to 76 Gy to the prostate in 2 Gy daily fractions, or 44 Gy to the whole pelvis plus a boost of up to 72.6 Gy to the prostate in 2.2 Gy fractions. Results The study cohort included 70 patients, of whom 55 (78%) had a Gleason score of 8 to 10 and 50 (71%) had a prostate-specific antigen level > 20 ng/mL. The androgen deprivation therapy was combined in 62 patients. The biochemical failure-free survival rate was 86.7% at 2 years. Acute any grade gastrointestinal (GI) and genitourinary (GU) toxicity rates were 47% and 73%, respectively. The actuarial rate of late grade 2 or worse toxicity at 2 years was 12.9% for GI, and 5.7% for GU with no late grade 4 toxicity. Conclusion WP-IMRT was well tolerated with no severe acute or late toxicities, resulting in at least similar biochemical control to that of the historic control group with a small field. The long-term efficacy and toxicity will be assessed in the future, and a prospective randomized trial is needed to verify these findings.

Treatment results of breast cancer patients with locoregional recurrence after mastectomy

Purpose To analyze the results of locoregional and systemic therapy in the breast cancer patients with locoregional recurrence (LRR) after mastectomy. Materials and Methods Seventy-one patients who received radiotherapy for isolated LRR after mastectomy between January 1999 and December 2009 were retrospectively reviewed. Among the 71 patients, 59 (83.1%) underwent wide excision and radiotherapy and 12 (16.9%) received radiotherapy alone. Adjuvant hormonal therapy was given to 45 patients (63.4%). Oncologic outcomes including locoregional recurrence-free survival, disease-free survival (DFS), and overall survival (OS) and prognostic factors were analyzed. Results Median follow-up time was 49.2 months. Of the 71 patients, 5 (7%) experienced second isolated LRR, and 40 (56%) underwent distant metastasis (DM). The median DFS was 35.6 months, and the 3- and 5-year DFS were 49.1% and 28.6%, respectively. The median OS was 86.7 months, and the 5-year OS was 62.3%. Patients who received hormone therapy together showed better 5-year DFS and OS than the patients treated with locoregional therapy only (31.6% vs. 22.1%, p = 0.036; 66.5% vs. 55.2%, p = 0.022). In multivariate analysis, higher N stage at recurrence was a significant prognostic factor for DFS and OS. Disease free interval (≤30 months vs. >30 months) from mastectomy to LRR was also significant for OS. The patients who received hormone therapy showed superior DFS and showed trend to better OS. Conclusion DM was a major pattern of failure after the treatment of LRR after mastectomy. The role of systemic treatment for LRR after mastectomy should be investigated at prospective trials.

Lymph node standardized uptake values at pre-treatment 18F-fluorodeoxyglucose positron emission tomography as a valuable prognostic factor for distant metastasis in nasopharyngeal carcinoma

Objective: The aim of the present study was to evaluate prognostic values of pre-treatment fluorine-18 fludeoxyglucose (18F-FDG) positron emission tomography (PET) parameters for predicting the distant metastasis (DM) of nasopharyngeal cancer. Methods: 73 patients diagnosed with nasopharyngeal cancer with regional lymph node (LN) involvement, who underwent pre-treatment 18F-FDG PET evaluation between January 2005 and December 2012, were retrospectively reviewed. We assessed the 18F-FDG PET parameters of the primary tumours (T–) and regional LNs (N–). For patients with bilateral retropharyngeal, bilateral neck and/or supraclavicular LN involvement, we also assessed the 18F-FDG PET parameters of the farthest LN station [N(f)–]. The following 18F-FDG PET parameters were evaluated: maximum standardized uptake value (SUVmax), mean standardized uptake value (SUVmean), peak standardized uptake value (SUVpeak), metabolic tumour volumes (MTVs) (MTV30–MTV70, which were calculated as the tumour volume with 30%, 40%, 50%, 60% and 70% of the SUVmax as the threshold, respectively) and total lesion glycolysis (TLG) (TLG30–TLG70, which were determined by the product of each MTV and the corresponding SUVmean within that MTV). Distant metastasis-free survival (DMFS) rates were estimated from the date of the start of radiotherapy to the date of DM or last follow-up by the Kaplan–Meier method. Univariate and multivariate analyses were performed to identify prognostic factors for DMFS. The median follow-up period was 53 months (range 12–110 months). Results: Most patients (95%) received concurrent chemoradiotherapy. The major failure pattern was DM (15 of all patients, 21%) and the 5-year DMFS was 79%. In univariate analysis, the T–SUVmax, T–SUVmean, T–SUVpeak, N–SUVmax, N–SUVpeak, N(f)–SUVmax and N(f)–SUVpeak were significant prognostic factors for DMFS. In multivariate analysis, the T–SUVmax, T–SUVpeak, N(f)–SUVmax and N(f)–SUVpeak were significant prognostic factors for DMFS. Of these parameters, the N(f)–SUVmax (hazard ratio = 6.524; p = 0.001) and N(f)–SUVpeak (hazard ratio = 5.399; p = 0.001) were the strongest prognostic factors for DMFS. Conclusion: In patients with nasopharyngeal cancer with LN involvement, the standardized uptake value parameter of the farthest LN station seems to be an important 18F-FDG PET parameter for predicting DM. Further studies are needed to validate its clinical significance. Advances in knowledge: We found that pre-treatment 18F-FDG PET parameters of primary tumours and regional LNs (the SUVmax and SUVpeak of the primary tumour and the farthest LN station) were significant prognostic factors for DMFS in patients with nasopharyngeal carcinoma with LN involvement.

Propensity Score Matching Analysis of Changes in Alpha-Fetoprotein Levels after Combined Radiotherapy and Transarterial Chemoembolization for Hepatocellular Carcinoma with Portal Vein Tumor Thrombus.

Background and Aim To investigate the value of changes in alpha-fetoprotein (AFP) levels for the prediction of radiologic response and survival outcomes in hepatocellular carcinoma (HCC) patients with portal vein tumor thrombus (PVTT) who received combined treatment of 3-dimensional conformal radiotherapy (3D-CRT) and transarterial chemoembolization (TACE). Methods A database of 154 HCC patients with PVTT and elevated AFP levels (>20 ng/mL) treated with 3D-CRT and TACE as an initial treatment between August 2002 and August 2008 was retrospectively reviewed. AFP levels were determined 1 month after radiotherapy, and AFP response was defined as an AFP level reduction of >20% from the initial level. Radiologic response, overall survival (OS), and progression-free survival (PFS) rates were compared between AFP responders and non-responders. Propensity-score based matching analysis was performed to minimize the effect of potential confounding bias. Results The median follow-up period was 11.1 months (range, 3.1–82.7 months). In the propensity-score matching cohort (92 pairs), a best radiologic response of CR or PR occurred in more AFP responders than AFP non-responders (41.3% vs. 10.9%, p < 0.001). OS and PFS were also longer in AFP responders than in non-responders (median OS 13.2 months vs. 5.6 months, p < 0.001; median PFS 8.7 months vs. 3.5 months, p < 0.001). Conclusions AFP response is a significant predictive factor for radiologic response. Furthermore, AFP response is significant for OS and PFS outcomes. AFP evaluation after combined radiotherapy and TACE appears to be a useful predictor of clinical outcomes in HCC patients with PVTT.

Prognostic Factors for Distant Metastasis in Patients with Locoregional Recurrence after Mastectomy

Purpose The purpose of this study was to identify patients with high risk of distant metastasis (DM) after salvage treatment for postmastectomy locoregional recurrence (LRR). Methods We retrospectively reviewed 142 patients who received salvage radiotherapy with or without wide excision for isolated LRR after mastectomy between January 1999 and December 2012. Distant metastasis-free survival (DMFS) was estimated from the date of diagnosis of isolated LRR to the date of DM or last follow-up using the Kaplan-Meier method, and Cox regression analysis was performed to identify prognostic factors for DM. Results The median follow-up period was 54 months. The major failure pattern was DM (56%) and the 5-year DMFS was 43%. In multivariate analysis, initial N (iN) stage, recurrent N (rN) stage, and hormone receptor (HR) status were significant prognostic factors for DM (5-year DMFS: iN0 vs. iN1-3, 73% vs. 25%, p<0.001; rN0 vs. rN1-3, 61% vs. 29%, p<0.001; HR+ vs. HR-, 49% vs. 21%, p<0.001). Conclusion Patients with lymph node involvement and/or HR- specimens seem to experience more DM than patients with chest wall-only recurrence and HR+ specimens. Further studies are needed to investigate the role of chemotherapy in these patients.

Clinical significance of the post-radiotherapy 18F-fluorodeoxyglucose positron emission tomography response in nasopharyngeal cancer

Objective: The aim of the present study was to evaluate the clinical significance of the post-radiotherapy 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) response for detecting residual disease and predicting survival outcome in patients with nasopharyngeal cancer. Methods: We reviewed 143 patients with nasopharyngeal cancer who underwent 18F-FDG PET within 6 months after completion of radiotherapy between 2001 and 2012. 18F-FDG PET findings at the primary tumor (T–) and regional lymph nodes (N–) were separately assessed and considered negative [PET (–)] or positive [PET (+)] depending on the remaining focal increased uptake of 18F-FDG that was greater than that of the surrounding muscle or blood vessels. The standard of reference was histopathological confirmation or clinical/imaging follow-up. Overall survival (OS), distant metastasis-free survival (DMFS), and locoregional recurrence-free survival (LRRFS) rates were estimated from the date of the start of radiotherapy. Results: The median follow-up period was 73 months (range, 9–182 months). Overall, 83 and 66% of patients achieved T–PET (-) and N–PET (-) responses, and the negative-predictive values (NPVs) for T– and N– were 100 and 99%, respectively. The sensitivity, specificity, and positive-predictive value were 100, 84, and 8% for T–, and 67, 80, and 7% for N–, respectively. The 5-year OS, DMFS, and LRRFS rates were 83, 83, and 87%, respectively, and patients with N–PET (+) with SUVmax >2.5 showed significantly inferior 5-year OS and DMFS rates than patients with N–PET (-) or N–PET (+) with SUVmax ≤2.5 (44 vs 86%, p = 0.004; 36 vs 85%, p < 0.001). Conclusion: In patients that have received definitive (chemo)radiotherapy for nasopharyngeal cancer, 18F-FDG PET within 6 months of completion of treatment has a high NPV for predicting residual disease and is prognostic for long-term treatment outcomes. Patients with remaining focal increased uptake of 18F-FDG at lymph nodes may benefit from more aggressive treatments, and further studies are needed to validate the clinical significance of post-radiotherapy 18F-FDG PET. Advances in knowledge: We found that post-radiotherapy 18F-FDG PET findings have a high NPV for detecting residual disease and are a significant prognostic factor for treatment outcomes.