A Rare Case of Renal Malakoplakia Incidentally Detected on 18F-FDG PET/CT in a Patient With Concomitant Breast Cancer and Lymphoma.

ABSTRACT: Malakoplakia is a rare inflammatory disease that most frequently affects the urinary tract. We present the case of a patient who had been receiving treatment for breast cancer, who later on went on to develop diffuse large B-cell lymphoma for which she was started on RCHOP therapy. It was during her treatment that she underwent a whole-body 18F-FDG PET/CT for response evaluation and was incidentally diagnosed to have bilateral renal malakoplakia, which resolved after a prolonged course of antibiotic therapy.

Palliative chemotherapy with or without cetuximab in recurrent or metastatic squamous cell carcinoma of the head and neck: Indian tertiary care retrospective analysis.

BACKGROUND: We report our experience with Indian patients who received palliative chemotherapy with/without cetuximab for recurrent/metastatic squamous cell carcinoma of the head and neck (R/M SCCHN). METHODS: Data from 229 R/M SCCHN patients treated with cetuximab and chemotherapy (n = 140) or chemotherapy alone (n = 89) were retrospectively analyzed for response rate (RR), progression-free survival (PFS), overall survival (OS), and safety. RESULTS: Patients receiving cetuximab with chemotherapy demonstrated significant increase in RR (77.1% vs 44.9%, P = .0001), PFS (8.1 vs 6.1 months, P = .039), and OS (11.8 vs 8.0 months, P = .002) compared with patients receiving chemotherapy alone. Continuing cetuximab and changing chemotherapy combination (second line and beyond) in fit patients doubled OS (13.5 vs 6.1 months, P = .001). Adverse effects, except skin reactions (more in the cetuximab with chemotherapy group; P = .001), were similar in both groups. CONCLUSION: Adding cetuximab to chemotherapy improved ORR, PFS, and OS in Indian R/M SCCHN patients, and cetuximab was well tolerated.

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.

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.