Man Ki Chung

Metabolic Tumor Volume of [18F]-Fluorodeoxyglucose Positron Emission Tomography/Computed Tomography Predicts Short-Term Outcome to Radiotherapy With or Without Chemotherapy in Pharyngeal Cancer

Purpose: This study aimed to investigate whether metabolic tumor volume (MTV) measured from [18F]-fluorodeoxyglucose positron emission tomography/computed tomography (FDG-PET/CT) predicts short-term outcome to radiotherapy with or without chemotherapy and disease-free survival (DFS) in patients with pharyngeal cancers. Experimental Design: The MTVs of primary sites with or without neck nodes were measured in 82 patients. Short-term outcome was assessed using the treatment response evaluation by the Response Evaluation Criteria in Solid Tumors and recurrence events during follow-up (complete response/no recurrence or residual disease/recurrence). Results: A total of 64 patients had complete response/no recurrence as of the last follow-up. A cutoff of 40 mL for the MTV was the best discriminative value for predicting treatment response. By univariate analyses, patients with MTV >40 mL showed a significantly lower number of complete response/no recurrence than did patients with MTV ≤40 mL [68.2% versus 87.8%; hazard ratio (HR), 3.34; 95% confidence interval (95% CI), 1.09-10.08; P = 0.03], as is the same in tumor-node-metastasis stage (87.5% for I-II versus 90% for III versus 63.8% for IV; P = 0.02). However, MTV was only a significant predictor of short-term outcome by multivariate analyses (HR, 4.09; 95% CI, 1.02-16.43; P = 0.04). MTV >40 mL indicated a significantly worse DFS than MTV ≤40 mL (HR, 3.42; 95% CI, 1.04-11.26;P = 0.04). The standardized uptake value for the primary tumor did not show any correlation with treatment outcome or DFS. Conclusion: MTV has a potential value in predicting short-term outcome and DFS in patients with pharyngeal cancers. (Clin Cancer Res 2009;15(18):5861–8)

Subclinical lymph node metastasis in papillary thyroid microcarcinoma: A study of 551 resections

BACKGROUND In clinically node-negative papillary thyroid microcarcinoma (PTMC), the frequency of subclinical lymph node metastasis (LNM) in the central cervical compartment (subclinical central LNM) has been reported to be as great as 65%. Routine prophylactic central compartment lymph node dissection (CLND) has been debated, because the risk of operative complications might outweigh its prognostic benefit. We aimed to study clinicopathologic factors associated with subclinical central LNM to be considered for determination of prophylactic CLND. METHODS A total of 551 patients diagnosed with clinically node-negative PTMC from 2005 to 2009 were included. All patients underwent total thyroidectomy (TT) and prophylactic CLND. Clinicopathologic risk factors of subclinical central LNM were analyzed. In addition, we investigated recurrences and postoperative complications after TT and CLND. RESULTS Among the 551 patients, 202 (37%) had subclinical central LNM. On univariate and multivariate analyses, male gender, tumor multifocality, and extrathyroidal extension were independently predictive of subclinical central LNM. During 3-year follow-up, there were no recurrences in the central cervical compartment. The frequency of permanent hypocalcemia and permanent vocal fold palsy were 1.1% and 1.3%, respectively. CONCLUSION Frequency of subclinical central LNM was high in PTMC. It was managed effectively with prophylactic CLND. In addition, prophylactic CLND did not cause significant permanent morbidities. We recommend that clinicopathologic features, such as male gender, tumor multifocality, and extrathyroidal extension, be considered for determination of prophylactic CLND in patients with PTMC.

Use of integrated 18F-FDG PET/CT to improve the accuracy of initial cervical nodal evaluation in patients with head and neck squamous cell carcinoma.

We investigated the accuracy of performing cervical nodal evaluation with using integrated 18F‐fluoro deoxyglucose positron emission tomography (PET)/CT for squamous cell carcinoma (SCC) of the head and neck as compared with using PET and contrast‐enhanced CT (CECT) alone.

Role of 18F-FDG PET/CT in Management of High-Grade Salivary Gland Malignancies

The role of 18F-FDG PET/CT for planning the treatment of high-grade salivary gland malignancies was investigated and was compared with that with using contrast-enhanced CT. Methods: The subjects chosen for the study had high-grade cancer of the salivary gland, as confirmed by surgical pathology. The diagnostic values from 37 CT and PET/CT scans of 33 subjects were compared. The ability to predict the extent of the disease was compared by performing a subsite-based analysis for the primary lesions and a level-by-level analysis for the neck node levels as well as for the final TNM staging. The surgical pathology (67.6%) and clinical follow-up examinations (32.4%) were used as the reference standards. Furthermore, the changes made in each subjects care, based on a PET/CT examination, were compared with the treatment received without using the PET/CT data. Results: Using a primary subsite-based analysis, the diagnostic accuracy for predicting the pathologic tumor extent was significantly higher for PET/CT (91.0%) compared with that using CT alone (70.1%, P < 0.001). For the neck nodes on a level-by-level analysis, the metastasis could be predicted more accurately on the basis of a PET/CT examination (97.6%) than with using only CT (86.0%, P = 0.01). PET/CT was also far superior to CT in terms of the TNM staging (83.7% vs. 62.1%, P = 0.03). For 43.2% of the subjects, changes in the clinical decision making were made as a result of the PET/CT scan data over what was previously determined by using the CT scans alone. Conclusion: PET/CT provides more accurate diagnostic information for the evaluation of high-grade salivary cancer than does CT and it has a major impact on making treatment decisions for patients with a high-grade salivary malignancy.

Tumor Volume Assessment by 18F-FDG PET/CT in Patients with Oral Cavity Cancer with Dental Artifacts on CT or MR Images

The purpose of this study was to investigate the clinical usefulness of PET/CT or CT-attenuated PET in the evaluation of patients with oral cavity cancer (OCC) in whom dental artifacts distorted the conventional CT or MR images of the oral cavity. Methods: A PET/CT scan, in addition to a CT or MRI scan, was performed in 69 patients with OCC who had dentures or dental implants. A total of 64 PET/CT, 64 CT, and 27 MR images were analyzed including images from scans performed on 40 patients with OCC without dental artifacts on the conventional images; these were used for comparison. The CT-attenuated PET scan for the detection of primary tumors was compared with the CT or MRI scan. We also evaluated the correlation between the PET/CT volume and the pathologic volume using a regression analysis. In addition, subgroup analysis was performed to determine what proportion of subjects benefited most from the PET/CT. Results: CT-attenuated PET detected more primary tumors than did CT in patients with OCC with dental artifacts (95.3% vs. 75.0%, respectively; P = 0.0016). PET/CT volume with a standardized uptake value (SUV) cutoff point of 3.5 predicted the pathologic volume more accurately than did the other cutoff points in patients with OCC with or without artifacts. After comparing pathologic volume and PET/CTSUV 3.5 volume, the following regression equation was developed: log (pathologic volume) = 0.6 × log (PET/CTSUV 3.5 volume) + 1.3 (R2 = 0.42, P < 0.0001). Subgroup analysis showed that the prediction of the pathologic volume from the PET/CT images was more reliable for tumors that were more than 2 cm in depth (R2 = 0.72). Conclusion: For patients with OCC with dental artifacts on the conventional imaging, PET/CT could provide useful clinical information about the primary tumors, particularly in cases with advanced tumors.

Questionnaire evaluation of sequelae over 5 years after parotidectomy for benign diseases

The aim of this study was to evaluate long-term (more than 5 years) quality of life issues after parotidectomy for the treatment of benign disease. A questionnaire survey was performed after institutional review board approval, on patients who had undergone any type of parotidectomy for benign salivary diseases. Fifty-three patients were surveyed at more than 5 years (the long term group) and 39 patients at 1-2 years after surgery (the control group). The questionnaire included the items on self perception of known sequelae. Descriptive and comparative analyses were performed to determine major sources of discomfort and changes in sequelae over time. Possible factors that contribute to sequelae were also analysed for significance. Freys syndrome was identified as the most serious self-perceived sequela, and resulting discomfort worsened with time (P=0.01). Scores for other sequelae were similar in the two study groups. Subjective perception of Freys syndrome was significantly different (P<0.001) according to the extent of surgery, and it was most serious in total parotidectomy cases, even from 1 year postoperatively. Of the sequelae of parotidectomy for benign diseases, Freys syndrome was of greatest concern to patients, even at more than 5 years postoperatively. Therefore, additional measures which prevent or ameliorate Freys syndrome are likely to improve long-term quality of life after parotidectomy.

Preoperative BRAF Mutation Has Different Predictive Values for Lymph Node Metastasis according to Tumor Size

Objective. To investigate whether BRAF mutation of papillary thyroid carcinoma (PTC) has different predictive values for regional lymph node (LN) metastasis according to tumor size. Study Design. Prospective cohort study. Setting. A tertiary hospital. Subjects and Methods. From January 2009 to August 2009, the authors prospectively enrolled 102 consecutive patients with unifocal PTC based on the findings of ultrasonography-guided fine-needle aspiration biopsy (FNAB). BRAF mutation was tested on preoperative FNAB specimens. Total thyroidectomy and bilateral central neck dissection (± lateral neck dissection) was performed for all patients. Among 102 patients, 71 who were confirmed to have unifocal PTC by the surgical pathology were finally selected. The 71 patients were classified into 3 groups according to their tumor size: group I, ≤0.5 cm; group II, >0.5 cm and ≤1 cm; and group III, >1 cm. LN metastasis was evaluated in the surgical specimen as a dependent variable. The authors investigated whether BRAF mutation is predictive of LN metastasis in each group. Results. Overall, BRAF mutation was a significant predictor of LN metastasis (P = .045). When patients were classified into 3 groups, frequency of LN metastasis increased with tumor size: 4.8%, 50.0%, and 66.7% (P < .001). However, the frequency of BRAF mutation was not different among 3 groups: 61.9%, 56.3%, and 72.2% (P = .536). BRAF mutation was predictive of LN metastasis only in group II (P = .026). Conclusion. BRAF mutation of PTC may have differential predictive values for LN metastasis, according to tumor size.

Pulmonary recovery after rigid bronchoscopic retrieval of airway foreign body.

Objective: The aim of this study was to determine how long postoperative pulmonary care is needed in patients after rigid bronchoscopic retrieval of foreign body from the airway and to identify the factors affecting pulmonary recovery.

Correlation between lymphatic vessel density and regional metastasis in squamous cell carcinoma of the tongue.

The aim of this study was to investigate the correlation between lymphatic vessel density in squamous cell carcinoma of the tongue and regional metastasis.

Intraoral sonography–assisted resection of T1-2 tongue cancer for adequate deep resection

Objective To investigate the clinical usefulness of intraoral sonography-assisted resection for securing adequate deep resection margins in T1–2 tongue cancers. Study Design Prospective clinical trial. Materials and Methods Twenty consecutive patients with clinical T1–2 tongue cancers were enrolled and their lesions were removed by intraoral sonography-assisted resection. We then retrospectively collected data from 20 T stage-matched patients without intraoral sonography-assisted resection as the control group. All resections were performed with a goal of 15 mm margin. The mucosal and deep safety margins were compared between the two groups. Results Intraoral sonography could predict the paraffin-embedded tumor thickness with an error of 3.16 ± 2.24 mm. The deep safety margins were more adequate for intraoral sonography–assisted resection (9.8 ± 5.2 mm) than for conventional resection (4.0 ± 2.03 mm) (P < 0.001), while the mucosal safety margins were not different Conclusion Intraoral sonography-assisted resection provides a more adequate deep resection margin for early T-stage tongue cancers.