Oyeon Cho

Sustaining Blood Lymphocyte Count during Preoperative Chemoradiotherapy as a Predictive Marker for Pathologic Complete Response in Locally Advanced Rectal Cancer.

Purpose The objective of this study was to explore the relationship between the circulating lymphocyte level during preoperative chemoradiotherapy (CRT) and pathologic complete response (pCR) in locally advanced rectal cancer. Materials and Methods From May 2010 to May 2013, 52 patients treated with preoperative CRT followed by surgery, were analysed. Patients received conventional fractionated radiotherapy (50-54 Gy) with fluorouracil-based chemotherapy. Surgical resection was performed at 4 to 8 weeks after the completion of preoperative CRT. Absolute blood lymphocyte counts and their relative percentage in total white blood cell counts were obtained from complete blood count tests performed prior to and after 4, 8, and 12 weeks of CRT. We analysed the association between achieving pCR and change in blood lymphocyte level during CRT, as well as clinical parameters. Results Among 52 patients, 14 (26.9%) had evidence of pCR. Sustaining the blood lymphocyte count during CRT (lymphocyte count at 4 weeks/baseline lymphocyte count > 0.35; odds ratio, 8.33; p=0.02) and initial carcinoembryonic antigen < 4.4 ng/mL (odds ratio, 6.71; p=0.03) were significantly associated with pCR in multivariate analyses. Conclusion Sustaining blood lymphocyte count during preoperative CRT was predictive for pCR in rectal cancer. Further studies are warranted to investigate the association between pathologic responses and circulating lymphocyte count with its subpopulation during preoperative CRT.

Minimum absolute lymphocyte count during radiotherapy as a new prognostic factor for nasopharyngeal cancer

The purpose of this study was to investigate whether the minimum absolute lymphocyte count (ALC) during radiotherapy (RT) could predict clinical outcome in patients with nasopharyngeal cancer (NPC).

Prophylactic Antiemetic Efficacy of Granisetron or Ramosetron in Patients Undergoing Thyroidectomy

OBJECTIVE Thyroidectomy is associated with a high incidence of postoperative nausea and vomiting (PONV), ranging from 60% to 84%. We conducted this study to compare the antiemetic effects and safety of granisetron 20 micro g/kg and ramosetron 4 micro g/kg in patients undergoing elective thyroidectomy under standard anaesthetic technique. METHODS One hundred and thirteen patients were randomized to receive placebo (n = 41), granisetron 20 nug/kg (n = 36) or ramosetron 4 micro g/kg (n = 36) intravenously over 2-5 minutes immediately before the induction of anaesthesia. The incidence of PONV, nausea severity score (NSS), adverse events and the need for rescue antiemetics were assessed during the first 1 hour (0-1 h) and following 23 hours (1-24 h) after anaesthesia. RESULTS During the first hour after anaesthesia, the incidence of PONV was 36.6% for placebo, 11.1% for granisetron (p = 0.012 vs placebo) and 25.0% for ramosetron. During 1 hour to 23 hours after anaesthesia, the incidence of PONV was 51.2% for placebo, 30.6% for granisetron and 41.7% for ramosetron. There were no significant differences between the three groups. Overall (0-24 h), the corresponding incidence of PONV were 61.0%, 30.6% and 50.0%, respectively, showing a significantly lower value in the granisetron group than in the placebo group (p = 0.008). The incidence of vomiting and rescue antiemetic requirement during the first 24 hours after anaesthesia was significantly lower with the granisetron group than with placebo (p = 0.021 and 0.030, respectively). The most common adverse events in the three groups were headache and dizziness. CONCLUSION Only granisetron 20 micro g/kg was superior to placebo for the prevention of PONV after thyroidectomy.

Prognostic factors and treatment outcome after radiotherapy in cervical cancer patients with isolated para-aortic lymph node metastases

Objective The purpose of the present study was to evaluate treatment outcomes and prognostic factors in cervical cancer patients with isolated para-aortic lymph node (PALN) metastases. We especially tried to evaluate PALN factors such as size, site and number. Methods From August 1994 to December 2009, 40 cervical cancer patients with isolated PALN node metastases at initial diagnosis were selected for analysis. Patients underwent both extended field external beam and intracavitary brachytherapy. Fourteen patients received 5-fluorouracil and cisplatin (FP) and 16 patients received weekly concurrent cisplatin. Information of PALN, such as size, site, and number, was founded before PALN radiotherapy. Results The median follow-up time after primary treatment was 28.5 months (range, 2 to 213 months). The 3-year overall and progression-free survival rate after primary treatment was 44.3% and 31.3%, respectively. In multivariate analysis including tumor stage, performance status, and chemotherapy, FP regimen concurrent chemoradiotherapy was more effective than radiotherapy alone (p=0.030). The 3-year progression-free survival rate was 41.9% and 11.1% in patients with PALN numbers of ≤1 and ≥2, respectively (p=0.008). The 3-year progression-free survival rate was 42.1% and 19.2% in patients with PALN size of <1.5 cm and ≥1.5 cm, respectively (p=0.031). Conclusion The radiologic features of PALN, such as number or size, can be used to determine prognosis in PALN metastatic cervical cancer patients. Furthermore, FP regimen concurrent chemoradiotherapy was associated with better patient survival than radiotherapy alone. However, more studies are required to confirm possible different treatment outcomes between FP and weekly cisplatin regimens.

Can initial diagnostic PET-CT aid to localize tumor bed in breast cancer radiotherapy: feasibility study using deformable image registration

BackgroundLocalization of the tumor bed of breast cancer is crucial for accurate planning of boost irradiation. Lumpectomy cavity and surgical clips provide localizing information about tumor bed. However, defining the tumor bed is often difficult because of presence of unclear lumpectomy cavity and lack of certain information such as absence of surgical clips. In the present study, we evaluated the feasibility of initial diagnostic PET-CT in localization of the tumor bed using deformable image registration (DIR).MethodsWe selected twenty-five patients who had an initial diagnostic PET-CT performed and underwent breast-conserving surgery with surgical clips in tumor bed. In every individual patient, two target volumes were separately delineated on planning CT; 1) target volume based on surgical clips with a margin of 1 cm (TVclip) and 2) tumor volume based on 90% of maximum SUV on PET-CT registered by DIR (TVPET). The percent of TVPET in TVclip (Vin) was calculated and distance between center points of two volumes (Dcenter) was also measured.ResultsMean Dcenter between two volumes was 1.4 cm (range, 0.33 – 2.53). Mean Vin was 94.8% (range, 60.9-100) and 100% in 18 out of 25 patients. When compared to the center of TVclip, the center of TVPET tended to be located posteriorly (mean 0.3 cm, standard deviation 0.6), laterally (mean 0.3 cm, standard deviation 0.8) and inferiorly (mean 0.4 cm, standard deviation 0.9).ConclusionInitial diagnostic PET-CT can be one of the possible references to localize the tumor bed in breast cancer radiotherapy.

Met inactivation by S-allylcysteine suppresses the migration and invasion of nasopharyngeal cancer cells induced by hepatocyte growth factor

Purpose Past studies have reported that S-allylcysteine (SAC) inhibits the migration and invasion of cancer cells through the restoration of E-cadherin, the reduction of matrix metalloproteinase (MMP) and Slug protein expression, and inhibition of the production of reactive oxygen species (ROS). Furthermore, evidence is emerging that shows that ROS induced by radiation could increase Met activation. Following on these reports of SAC and Met, we investigated whether SAC could suppress Met activation. Materials and Methods Wound healing, invasion, 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium (MTT), soft agar colony forming, western blotting, and gelatin zymography assays were performed in the human nasopharyngeal cancer cell lines HNE1 and HONE1 treated with SAC (0, 10, 20, or 40 mM) and hepatocyte growth factor (HGF). Results This study showed that SAC could suppress the migration and invasion of HNE1 and HONE1 cell lines by inhibiting p-Met. An increase of migration and invasion induced by HGF and its decrease in a dose dependent manner by SAC in wound healing and invasion assays was observed. The reduction of p-Met by SAC was positively correlated with p-focal adhesion kinase (p-FAK) and p-extracellular related kinase (p-ERK in both cell lines). SAC reduced Slug, MMP2, and MMP9 involved in migration and invasion with the inhibition of Met-FAK signaling. Conclusion These results suggest that SAC inhibited not only Met activation but also the downstream FAK, Slug, and MMP expression. Finally, SAC may be a potent anticancer compound for nasopharyngeal cancer treated with radiotherapy.

Parotid gland sparing effect by computed tomography-based modified lower field margin in whole brain radiotherapy

Purpose Parotid gland can be considered as a risk organ in whole brain radiotherapy (WBRT). The purpose of this study is to evaluate the parotid gland sparing effect of computed tomography (CT)-based WBRT compared to 2-dimensional plan with conventional field margin. Materials and Methods From January 2008 to April 2011, 53 patients underwent WBRT using CT-based simulation. Bilateral two-field arrangement was used and the prescribed dose was 30 Gy in 10 fractions. We compared the parotid dose between 2 radiotherapy plans using different lower field margins: conventional field to the lower level of the atlas (CF) and modified field fitted to the brain tissue (MF). Results Averages of mean parotid dose of the 2 protocols with CF and MF were 17.4 Gy and 8.7 Gy, respectively (p < 0.001). Mean parotid dose of both glands ≥20 Gy were observed in 15 (28.3%) for CF and in 0 (0.0%) for MF. The whole brain percentage volumes receiving >98% of prescribed dose were 99.7% for CF and 99.5% for MF. Conclusion Compared to WBRT with CF, CT-based lower field margin modification is a simple and effective technique for sparing the parotid gland, while providing similar dose coverage of the whole brain.

Comparison of concurrent chemoradiotherapy versus sequential radiochemotherapy in patients with completely resected non-small cell lung cancer

Purpose Our institution has implemented two different adjuvant protocols in treating patients with non-small cell lung cancer (NSCLC): chemotherapy followed by concurrent chemoradiotherapy (CT-CCRT) and sequential postoperative radiotherapy (PORT) followed by postoperative chemotherapy (POCT). We aimed to compare the clinical outcomes between the two adjuvant protocols. Materials and Methods From March 1997 to October 2012, 68 patients were treated with CT-CCRT (n = 25) and sequential PORT followed by POCT (RT-CT; n = 43). The CT-CCRT protocol consisted of 2 cycles of cisplatin-based POCT followed by PORT concurrently with 2 cycles of POCT. The RT-CT protocol consisted of PORT followed by 4 cycles of cisplatin-based POCT. PORT was administered using conventional fractionation with a dose of 50.4–60 Gy. We compared the outcomes between the two adjuvant protocols and analyzed the clinical factors affecting survivals. Results Median follow-up time was 43.9 months (range, 3.2 to 74.0 months), and the 5-year overall survival (OS), locoregional recurrence-free survival (LRFS), and distant metastasis-free survival (DMFS) were 53.9%, 68.2%, and 51.0%, respectively. There were no significant differences in OS (p = 0.074), LRFS (p = 0.094), and DMFS (p = 0.490) between the two protocols. In multivariable analyses, adjuvant protocol remained as a significant prognostic factor for LRFS, favouring CT-CCRT (hazard ratio [HR] = 3.506, p = 0.046) over RT-CT, not for OS (HR = 0.647, p = 0.229). Conclusion CT-CCRT protocol increased LRFS more than RT-CT protocol in patients with completely resected NSCLC, but not in OS. Further studies are warranted to evaluate the benefit of CCRT strategy compared with sequential strategy.

CT-based quantitative evaluation of radiation-induced lung fibrosis: a study of interobserver and intraobserver variations

Purpose The degree of radiation-induced lung fibrosis (RILF) can be measured quantitatively by fibrosis volume (VF) on chest computed tomography (CT) scan. The purpose of this study was to investigate the interobserver and intraobserver variability in CT-based measurement of VF. Materials and Methods We selected 10 non-small cell lung cancer patients developed with RILF after postoperative radiation therapy (PORT) and delineated VF on the follow-up chest CT scanned at more than 6 months after radiotherapy. Three radiation oncologists independently delineated VF to investigate the interobserver variability. Three times of delineation of VF was performed by two radiation oncologists for the analysis of intraobserver variability. We analysed the concordance index (CI) and inter/intraclass correlation coefficient (ICC). Results The median CI was 0.61 (range, 0.44 to 0.68) for interobserver variability and the median CIs for intraobserver variability were 0.69 (range, 0.65 to 0.79) and 0.61(range, 0.55 to 0.65) by two observers. The ICC for interobserver variability was 0.974 (p < 0.001) and ICCs for intraobserver variability were 0.996 (p < 0.001) and 0.991 (p < 0.001), respectively. Conclusion CT-based measurement of VF with patients who received PORT was a highly consistent and reproducible quantitative method between and within observers.

Hematological parameters during concurrent chemoradiotherapy as potential prognosticators in patients with stage IIB cervical cancer

We hypothesized that hemoglobin levels, absolute neutrophil count, and absolute lymphocyte count were associated with radiotherapy response and cancer progression and that they might reflect tumor repopulation during concurrent chemoradiotherapy. This study aimed to investigate these hematological parameters as prognosticators of cervical cancer. We analyzed 105 stage IIB cervical cancer patients treated with concurrent chemoradiotherapy, using log-rank tests and multivariate analyses. Hazard ratios were calculated weekly to evaluate changes in hemoglobin, absolute neutrophil count, and absolute lymphocyte count that were associated with disease-specific survival. Patients were categorized into the high hematological risk (patients with low hemoglobin plus high absolute neutrophil count and/or low absolute lymphocyte count) and the low hematological risk (others) groups according to the median cutoff values. During the second week of concurrent chemoradiotherapy, hematological factors were significantly associated with survival. In multivariate analysis, hematological risk was independently associated with disease-specific survival and progression-free survival. The 5-year disease-specific survival and progression-free survival rates in the high hematological risk group were significantly lower compared with those in the low hematological risk group (81.6% vs 92.6%, p = 0.0297; 73.7% vs 89.3%, p = 0.0163, respectively). During the second week of concurrent chemoradiotherapy, the hematological parameters could predict treatment outcome in stage IIB cervical cancer.