Sheung-Fat Ko

Prospective Study of [18F]Fluorodeoxyglucose Positron Emission Tomography and Computed Tomography and Magnetic Resonance Imaging in Oral Cavity Squamous Cell Carcinoma With Palpably Negative Neck

PURPOSE To assess the clinical usefulness of [(18)F]fluorodeoxyglucose positron emission tomography ([18F]FDG PET) as well as computed tomography (CT) or magnetic resonance imaging (MRI) in oral squamous cell carcinoma (SCC) patients with palpably negative neck. PATIENTS AND METHODS In total, 134 oral SCC patients with palpably negative neck were prospectively evaluated with [18F]FDG PET, CT/MRI, and their visual correlation. Histopathologic analysis was used as the gold standard for assessment of these imaging techniques. RESULTS Thirty-five (26.1%) of our 134 patients were found to have neck metastases. On a level-by-level basis, the sensitivity of [18F]FDG PET for nodal metastases was two-fold higher than that of CT/MRI (41.2% v 21.6%, respectively; P = .021). Visual correlation of [(18)F]FDG PET and CT/MRI yielded slightly higher sensitivity and specificity than [18F]FDG PET alone (47.1% v 41.2%, P = .25; 98.0% v 96.8%, P = .125, respectively). On a patient-by-patient basis, the sensitivity of [18F]FDG PET for neck metastases was 51.4% and increased to 57.1% after visual correlation with CT/MRI. The probabilities of occult neck metastasis after using [(18)F]FDG PET were 6.7% in T1 tumors, 10.8% in T2 tumors, 13.3% in T3 tumors, and 25% in T4 tumors and decreased to 3.3% in T1 tumors and to 9.2% in T2 tumors after visual correlation with CT/MRI. CONCLUSION [(18)F]FDG PET was superior to CT/MRI for detecting palpably occult neck metastasis of oral SCC. Because [(18)F]FDG PET could reduce the probability of occult neck metastasis to less than 15% in T1 to T3 tumors, it should be indicated for evaluation of these subpopulations.

Nasopharyngeal carcinoma: MRI and CT assessment

Abstract Precise assessment of the extent of nasopharyngeal carcinoma (NPC) represents the basic step towards optimal treatment. We compared the capacity of CT and MRI in assessing the extent of NPC in 67 patients. MRI was superior to CT in demonstrating lesions in the retropharyngeal node, skull base, intracranial area, carotid space, longus colli muscle and levator palatini muscle. Of 25 cases in which retropharyngeal adenopathy was recognised only on MRI, seven had been reported as showing oropharyngeal involvement and 18 as primary extension to the carotid space on CT. MRI showed skull-base involvement in 40 patients compared with 27 on CT and intracranial involvement in 38 patients versus 24 on CT. There was not a single case in which skull base invasion was seen on CT but not on MRI. MRI enabled improved recognition of tumour infiltration of longus colli muscles (34 cases compared with 15 on CT). It allowed us to clarify 12 questionable sinonasal opacities on CT. Overall, T-staging was changed in 18 of 67 patients (26.9 %), including upstaging in 15 cases and downstaging in 3 cases, after comparing CT with MRI. The nodel status was changed from negative on CT to positive on MRI in 4 of 67 patients (6 %). We believe that MRI allows more accurate evaluation of the extent of NPC than CT and should be the primary mode of investigation.

Nodal metastases of nasopharyngeal carcinoma: patterns of disease on MRI and FDG PET

The patterns of nodal spread of nasopharyngeal carcinoma (NPC) have an important influence on treatment planning, but have not yet been fully addressed. We prospectively used MRI and FDG PET to document the patterns of nodal spread in NPC. One hundred and one patients with newly diagnosed NPC were studied with MRI and FDG PET. On MRI, nodes were considered as metastatic according to criteria regarding size, the presence of nodal necrosis, and extracapsular spread. FDG PET images were interpreted visually, and nodes were considered metastatic if they showed prominent FDG uptake against the background. Nodal metastases were found in 89 of our 101 patients. Analysis of the distributions of nodal metastases in these 89 patients showed that retropharyngeal nodes were less frequently involved than cervical nodes (82.0% vs 95.5%). The vast majority of cervical nodal metastases were to the internal jugular chain, including nodes at levels II, III, and IV, with decreasing incidences of 95.5%, 60.7%, and 34.8%, respectively. Level V nodal involvement was found in 27% of patients. Supraclavicular fossa nodal metastases were not uncommon and occurred in 22.5% of patients. Skip metastases in the lower-level nodes or supraclavicular fossa nodes occurred in 7.9% of patients. Mediastinal and abdominal metastatic adenopathy was present in 4.5% and 3.4% of patients, respectively, and was associated with advanced nodal metastasis in the supraclavicular fossa. Level VI (2.2%), level VII (1.1%), submandibular (2.2%), and parotid (3.4%) nodal metastases were uncommon and were always associated with advanced ipsilateral nodal metastases of the neck. We conclude that the combined use of FDG PET and MRI can comprehensively depict the pattern of nodal metastasis in NPC patients. Nodal metastases principally affected level II nodes, from which lymphatic spread extended down in an orderly manner to involve level III, level IV, and the supraclavicular fossa nodes, or extended posteriorly to involve level V nodes. The frequency of skip metastases was 7.9%. Distant spread to mediastinal or abdominal nodes was found in 3–5% of patients, usually in association with supraclavicular nodal metastases.

Staging of untreated nasopharyngeal carcinoma with PET/CT: comparison with conventional imaging work-up

PurposeWe prospectively compared PET/CT and conventional imaging for initial staging of nasopharyngeal carcinoma (NPC).MethodsA total of 111 patients with histologically proven NPC were investigated with PET/CT and conventional imaging (head-and-neck MRI, chest X-ray, abdominal ultrasound, and bone scan) before treatment. The respective findings were reviewed independently and then compared with each other.ResultsWith regard to T staging, PET/CT showed a discrepancy with head-and-neck MRI in 36 (32.4%) of the study subjects. With regard to N staging, PET/CT showed a discrepancy with head-and-neck MRI in 15 (13.5%) patients. Among the discordant cases, MRI was superior in demonstrating tumor involvement in the parapharyngeal space, skull base, intracranial area, sphenoid sinus, and retropharyngeal nodes while PET/CT was superior in demonstrating neck nodal metastasis. PET/CT disclosed 13 of 16 patients with distant malignancy compared with four patients disclosed by conventional imaging work-up. The false-positive rate of PET/CT was 18.8%. PET/CT correctly modified M staging in eight patients (7.2%) and disclosed a second primary lung malignancy in one patient (0.9%).ConclusionIn NPC patients, MRI appears to be superior to PET/CT for the assessment of locoregional invasion and retropharyngeal nodal metastasis. PET/CT is more accurate than MRI for determining cervical nodal metastasis and should be the better reference for the neck status. PET/CT has an acceptable diagnostic yield and a low false-positive rate for the detection of distant malignancy and can replace conventional work-up to this aim. PET/CT and head-and-neck MRI are suggested for the initial staging of NPC patients.

Intensity-modulated or conformal radiotherapy improves the quality of life of patients with nasopharyngeal carcinoma: comparisons of four radiotherapy techniques.

It was reported previously that the dosimetric superiority of conformal radiotherapy (RT), either 3‐dimensional conformal RT (3D‐CRT) or intensity‐modulated RT (IMRT), over conventional 2D‐RT translated into clinical benefits for patients with nasopharyngeal carcinoma (NPC). In this study, the authors compared quality‐of‐life (QOL) outcomes of NPC survivors who received treatment with 1 of 4 different RT techniques at a single institute during different periods.

CT findings at lupus mesenteric vasculitis

Purpose: To describe the spectrum of early CT findings of lupus mesenteric vasculitis (LMV) and to assess the utility of CT in the management of this uncommon entity. Methods: Abdominal CT was performed within 1–4 days (average 2.2 days) of the onset of severe abdominal pain and tenderness in 15 women with systemic lupus erythematosus. Prompt high-dose i.v. corticosteroid was administered in 11 patients after the CT diagnosis of LMV was made. CT was performed after abdominal symptoms subsided. Results: Eleven cases revealed CT features suggestive of LMV including conspicuous prominence of mesenteric vessels with palisade pattern or comb-like appearance (CT comb sign) supplying focal or diffuse dilated bowel loops (n=11), ascites with slightly increased peritoneal enhancement (n=11), small bowel wall thickening (n=10) with double halo or target sign (n=8). Follow-up CT before high-dose steroid therapy revealed complete or marked resolution of the abnormal CT findings. Conclusion: CT is helpful for confirming the diagnosis of LMV, especially the comb sign which may be an early sign. Bowel ischemia due to LMV is less ominous than previously expected, and the abnormal CT findings were reversible when early diagnosis and prompt i.v. steroid therapy could be achieved.

Autologous Transplantation of Adipose-Derived Mesenchymal Stem Cells Markedly Reduced Acute Ischemia-Reperfusion Lung Injury in a Rodent Model

BackgroundThis study tested the hypothesis that autologous transplantation of adipose-derived mesenchymal stem cells (ADMSCs) can effectively attenuate acute pulmonary ischemia-reperfusion (IR) injury.MethodsAdult male Sprague-Dawley (SD) rats (n = 24) were equally randomized into group 1 (sham control), group 2 (IR plus culture medium only), and group 3 (IR plus intravenous transplantation of 1.5 × 106 autologous ADMSCs at 1h, 6h, and 24h following IR injury). The duration of ischemia was 30 minutes, followed by 72 hours of reperfusion prior to sacrificing the animals. Blood samples were collected and lungs were harvested for analysis.ResultsBlood gas analysis showed that oxygen saturation (%) was remarkably lower, whereas right ventricular systolic pressure was notably higher in group 2 than in group 3 (all p < 0.03). Histological scoring of lung parenchymal damage was notably higher in group 2 than in group 3 (all p < 0.001). Real time-PCR demonstrated remarkably higher expressions of oxidative stress, as well as inflammatory and apoptotic biomarkers in group 2 compared with group 3 (all p < 0.005). Western blot showed that vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, oxidative stress, tumor necrosis factor-α and nuclear factor-κB were remarkably higher, whereas NAD(P)H quinone oxidoreductase 1 and heme oxygenase-1 activities were lower in group 2 compared to those in group 3 (all p < 0.004). Immunofluorescent staining demonstrated notably higher number of CD68+ cells, but significantly fewer CD31+ and vWF+ cells in group 2 than in group 3.ConclusionADMSC therapy minimized lung damage after IR injury in a rodent model through suppressing oxidative stress and inflammatory reaction.

Distant metastases and synchronous second primary tumors in patients with newly diagnosed oropharyngeal and hypopharyngeal carcinomas: evaluation of (18)F-FDG PET and extended-field multi-detector row CT.

IntroductionPatients with oropharyngeal or hypopharyngeal squamous cell carcinoma (SCC) have a high risk of having distant metastases or second primary tumors. We prospectively evaluate the clinical usefulness of 18F-fluoro-2-deoxyglucose positron emission tomography (18F-FDG PET), extended-field multi-detector computed tomography (MDCT), and their side-by-side visual correlation for the detection of distant malignancies in these two tumors at presentation.Materials and methodsA total of 160 patients with SCC of the oropharynx (n = 74) or hypopharynx (n = 86) underwent 18F-FDG PET and extended-field MDCT to detect distant metastases or second primary tumors. Suspected lesions were investigated by means of biopsy, clinical, or imaging follow-up.ResultsTwenty-six (16.3%) of our 160 patients were found to have distant malignancy. Diagnostic yields of 18F-FDG PET and MDCT were 12.5% and 8.1%, respectively. The sensitivity of 18F-FDG PET for detection of distant malignancies was 1.5-fold higher than that of MDCT (76.9% vs. 50.0%, P = 0.039), while its specificity was slightly lower (94.0% vs. 97.8%, P = 0.125). Side-by-side visual correlation of MDCT and 18F-FDG PET improved the sensitivity and specificity up to 80.8% and 98.5%, respectively, leading to alteration of treatment in 13.1% of patients. A significant difference in survival rates between its positive and negative results was observed.Conclusion18F-FDG PET and extended-field MDCT had acceptable diagnostic yields for detection of distant malignancies in untreated oropharyngeal and hypopharyngeal SCC. 18F-FDG PET was 1.5-fold more sensitive than MDCT, but had more false-positive findings. Their visual correlation improved the diagnostic accuracy, treatment planning, and prognosis prediction.

Small bowel obstruction due to phytobezoar: CT diagnosis

Abstract. We report two cases of small bowel obstruction (SBO) due to phytobezoar impaction. In both cases, computed tomography (CT) demonstrated a well-defined, ovoid intraluminal mass with mottled gas pattern within the dilated small bowel at the site of obstruction and an abruptly collapsed lumen beyond the lesion. Recognition of these CT findings allows specific preoperative diagnosis of SBO owing to this uncommon lesion.

Small Bowel Intussusception in Symptomatic Pediatric Patients: Experiences with 19 Surgically Proven Cases

Nineteen cases of surgically proven symptomatic pediatric small bowel intussusceptions (SBI) were retrospectively reviewed. Clinical presentations included vomiting (89.5%), abdominal pain and/or irritable crying (89.5%), fever (52.6%), bloody stools (26.3%), palpable abdominal masses (15.8%), hematemesis (10.5%), jaundice (5.3%), and seizures (5.3%). The duration between symptom onset and hospitalization ranged between 20 and 336 hours (average 75.8 hours). Two patients with suspected appendicitis and small bowel obstruction were operated on promptly. Sonograms revealed target lesions (average diameter 2.9 cm) suggestive of intussusception in 13 out of 17 patients, with 10 lesions located in the paraumbilical or left abdominal regions. Barium enemas in 12 of these 13 patients demonstrated no colonic lesions. Diagnosis and surgery were delayed in 16 patients (average delay = 32 hours). The remaining 1 patient with positive sonographic findings underwent early surgery after computed tomographic (CT) confirmation of SBI. Surgery revealed ileoileal intussusceptions in 11 patients, jejunojejunal in 4, jejunoileal in 3, and duodenojejunal in 1. Eight patients had lead points. Bowel complications (ischemia, necrosis, or perforation) occurred in 8 patients. The duration between symptom onset and surgery in patients with bowel complications was significantly longer than for patients without complications (p = 0.0026). In conclusion, delayed diagnosis and surgical treatment in symptomatic pediatric patients with SBI were common, leading to a high rate (42%) of bowel complications. Sonographic demonstration of a 2–3 cm target lesion, especially if paraumbilical or left abdominal, is suggestive of SBI and may obviate the need for a barium enema; however, CT is helpful for confirming SBI. In symptomatic SBI, once diagnosed, early surgical referral is strongly recommended.