Significance of perineural invasion in locally advanced bucco alveolar complex carcinomas treated with surgery and postoperative radiation ± concurrent chemotherapy.

BACKGROUND: The purpose of this study was to evaluate prognostic factors, locoregional control, and survival in locally advanced bucco-alveolar complex cancers. METHODS: A retrospective review of 83 patients treated between January 2009 and December 2012 with bucco-alveolar complex cancers was conducted. All patients had surgery and adjuvant radiotherapy with intensity-modulated radiotherapy (IMRT) with/without concurrent chemotherapy. Survival analysis was performed using Kaplan-Meier and multivariable Cox regression model. RESULTS: On univariate and multivariate analysis, perineural invasion (PNI) was found to be an independent adverse risk factor. Patients with PNI-positive disease had significantly worse 2-year disease-free survival (DFS), locoregional failure free survival, and overall survival (OS) as compared to patients with PNI-negative disease (P < 0. 001, 0.001 and < 0. 001) respectively. CONCLUSION: Compared with patients with PNI-negative disease, patients with PNI-positive disease had much worse outcome despite aggressive adjuvant treatment. It warrants escalation of therapy and modification in radiation portals to cover neural pathways in patients with PNI-positive disease.

Comparison of F-18 FDG and C-11 methionine PET/CT for the evaluation of recurrent primary brain tumors.

PURPOSE OF STUDY: With the availability of multiple positron emission tomography (PET) tracers for neurooncology, there is a need to define the appropriate tracer in a given clinical setting, and it is in this regard that we undertook this study to directly compare F-18 flurodeoxyglucose (FDG) PET and C-11 methionine (MET) PET for the evaluation of recurrence in primary brain tumors. PATIENTS AND METHODS: Thirty-seven patients with a history of treated primary brain tumors referred for evaluation of recurrent disease were initially included in the study. Two patients had to be excluded because of insufficient follow-up. There were 23 males and 12 females, mean age: 33.7 ± 16.4 years; range: 5 to 65 years. All patients underwent the MET and FDG study on the same day. Visual image interpretation was performed independently by 2 PET physicians for each tracer using the plain PET and fused PET/CT images; the FDG images were evaluated first. Images were analyzed semiquantitatively using tumor to normal contralateral cortex ratios (T/N). Each patient was followed up for a minimum of 18 months. Imaging results were compared with histopathology on tumor excision or biopsy in 14 patients and with clinical follow-up and MRI/MRS at the end of 18 months in 21 patients. RESULTS: The final diagnosis was tumor recurrence in 24 patients and no recurrence/stable disease in 11 patients. On FDG, findings in 15/35 (42%) were suggestive of recurrent tumors. On MET, findings in 24/34 (70.5%) cases were suggestive of recurrent tumors. Spatially separated secondary lesions including intraventricular deposits were clearly delineated in 5 cases, 3 were glioblastoma multiforme (GBM) and 2 were anaplastic astrocytomas. One of the secondary lesions was missed on FDG PET. Using a cutoff for T/N ratio on FDG of >0.75 to differentiate recurrence from no recurrence, sensitivity of FDG was 81.2% (confidence interval [CI] = 54.4%-96%), whereas specificity was 88.9% (CI = 51.8%-99.7%). Area under the curve was 0.819 (CI = 0.615-0.943), P = 0.0003. Using a cutoff for T/N ratio of >1.9 to differentiate recurrence from no recurrence, sensitivity of MET was 94.7% (CI = 74.0%-99.9%), whereas specificity was 88.89% (CI = 51.8%-99.7%). Area under the curve was 0.942 (CI = 0.785-0.995), P < 0.0001. Interobserver agreement, κ coefficient, for MET was 0.93, suggesting good interobserver agreement, whereas for FDG, it was fair (0.23). CONCLUSIONS: MET should be the radiotracer of choice in the evaluation of recurrence of primary brain tumors because the sensitivity for detection and delineation of the possible recurrent tumor, as well as secondary deposits, is higher with MET. MET-PET is an easier technique to interpret, irrespective of the glioma grade, with less interobserver variability and straightforward localization of tumorous accumulation.

Usefulness of automated cell counter in detection of malaria in a cancer set up--our experience.

BACKGROUND: Malaria diagnosis presents a challenge to all laboratories. In malaria-endemic areas, there is a need for rapid, sensitive and cost-effective method to effectively screen all samples, especially when the workload is very high. Various hematology analyzers have been investigated for detection of malaria in the past. Here, we present our experience of malaria detection in a cancer hospital where a large number of complete blood count requests are received either before or during chemotherapy. Fever, being a very common symptom in cancer patients, causes a suspicion of malaria. AIM: This study was conducted to assess the usefulness of hematology cell counter, viz. WBC-DIFF and WBC/BASO scatter plots and the flaggings generated in malaria-positive cases. The occurrence of pseudoeosinophilia as reported by previous studies was also assessed. The parasitic index was determined and its correlation with the abnormalities found on the Hematology analyzer was also studied. MATERIALS AND METHODS: Blood samples were collected from 80 out-patient department and inpatients with various solid as well as hematological malignancies, who presented with acute febrile illness during September 2010 and January 2012, and for whom complete blood cell analysis and peripheral smear for malaria parasite had been requested. RESULTS: Of the 80 patients who presented with fever and suspicion of malaria, 29 patients were positive for malaria and 10 cases were diagnosed incidentally by the findings on the cell counter and were confirmed by Giemsa-stained blood smears. The sensitivity and specificity of the abnormalities detected in the WBC-Diff channel in detecting malaria is 82% and 100% respectively. Using WBC-BASO channel abnormality for initial diagnosis the sensitivity and specificity is 50% and 92.5% respectively. The sensitivity and specificity with respect to pseudoeosinophilia is 18% and 100% respectively. The most common WBC and PLT flags were leukopenia, atypical lymphocytes, lymphopenia, WBC abnormal scattergram, platelet clumps, thrombocytopenia, platelet abnormal distribution flag. CONCLUSION: The instrument provides significantly valuable diagnostic parameters in detecting acute Plasmodium vivax malaria; however, it is not very useful for acute falciparum malaria infection. It is suggested that the laboratories using the hematology analyzers should be aware of such specific parameters, even in the absence of a clinical request.

Comparision of F-18 FDG and C-11 Methionine PET/CT for demonstration of subependymal deposit in a treated case of glioblastoma multiforme.

A 10-year-boy post-operative, post-radiotherapy case of left temporal glioblastoma multiforme (GBM) was referred for F-18 Flurodeoxyglucose (FDG) Positron emission tomography/Computed Tomography (PET/CT) to rule out residual/recurrent disease 6 months following completion of therapy. The FDG scan 3 months following therapy had not shown evidence of viable residual or metastatic disease. The present scan showed a tiny focus of abnormal FDG accumulation in the region of the trigone of the left lateral ventricle which was best appreciated on the plain PET image. A correlative C-11 methionine study showed a well defined focus of abnormal tracer accumulation in the region of the left trigone. CECT and MRI done subsequently proved it to be a subependymal deposit. This case therefore demonstrates the possibility of subependymal deposits in GBM and the need for this possibility to be entertained during interpretation of the FDG study. It also highlights the advantage of labelled amino acids like C-11 methionine for clearly delineating subependymal deposits apart from the advantage for unequivocal interpretation of the PET study in recurrent brain tumors.

Spectrum of brain abnormalities detected on whole body F-18 FDG PET/CT in patients undergoing evaluation for non-CNS malignancies.

We present the pattern of metabolic brain abnormalities detected in patients undergoing whole body (WB) F-18 flurodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) examination for non-central nervous system (CNS) malignancies. Knowledge of the PET/CT appearance of various intracranial metabolic abnormalities enables correct interpretation of PET scans in oncological patients where differentiation of metastasis from benign intracranial pathologies is important and improves specificity of the PET study. A complete clinical history and correlation with CT and MRI greatly helps in arriving at a correct imaging diagnosis.

Sagittal sinus tumor thrombosis in a case of NHL demonstrated on F-18 FDG PET/CT.

We report a case of a 60-year-old woman, diagnosed as a case of non Hodgkins lymphoma (NHL), referred for F-18 fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) following 6 cycles of chemotherapy to evaluate response to therapy. The scan revealed a curvilinear pattern of FDG accumulation in the midline extending anteroposteriorly, just adjacent to the inner table of the skull on the fused PET/CT images with no corresponding abnormality on the low-dose CT. Because this site anatomically corresponded to that of the sagittal sinus, an MRI and magnetic resonance venography was advised which confirmed the presence of sagittal sinus tumor deposits. This case highlights the pattern of sagittal sinus tumor thrombosis on FDG PET/CT and the possibility of its occurrence in NHL.