Brain-Included 18F FDG PET/CT acquisition protocol: cancer-specified clinical impact of newly-diagnosed brain metastasis in extra-cerebral cancer patients

Background: Evolution of individualized radiosurgical therapeutic methods for brain metastasis as an ominous prognostic finding may encourage a more extensive application of neuroimaging in patients with extracerebral cancer. The aim of the present study was to investigate the added value of brain-included 18 F FDG PET/CT acquisition protocol based on primary cancer type and clinical indication

Materials and Methods: A retrospective review was performed on 3945 18 F FDG PET/CT reports of patients with extra-cerebral cancer underwent brain-included PET/CT study. Cerebral lesions suggestive of brain metastasis were subsequently verified by MRI, MRI+MRS, surgical pathology and a 1-year clinical formal follow up. The detection rate of new brain metastasis and related impact on disease status were then investigated in each cancer type based on clinical indication

Results: Of a total 3933 eligible patients, 44 [1.12%] were finally verified to have new cerebral metastasis. The most common primary sources were lung cancer [19/385, 4.93%], cancer of unknown primary [CUP] [5/168, 2.97%] and breast cancer [8/468, 1.71%]. The most common clinical indications were initial staging [17/44, 43.1%] and restaging [19/44, 36.4%]. Change in disease status occurred in 12 out of 44 patients [27.3%], more frequently occurred in lung cancer [n=4], in all indications and breast [n=3] cancers at restaging [n=7, 43.8%]

Conclusion: PET/CT acquisition protocol study may be best optimized based on the type of primary cancer and timing of evaluation. Brain-included field of view may be recommended for lung cancer regardless the clinical indication, cancer of unknown primary and breast cancer at restaging

Breast incidental lesions at 18 f FDG PET/CT: diagnostic performance of pet-derived metabolic parameters

Background: Breast incidental lesion at 18 F FDG PET/CT are occasionally encountered in cancer patients, which may represent a second primary malignancy. The aim of the present study was to investigate the diagnostic performance of PET metabolic parameters to characterize breast incidentaloma

Materials and Methods: All the images of patients with cancers other than breast with breast incidental lesion underwent PET/CT scan at Masih Daneshvari Hospital between May 2012 and May 2016 were retrieved and reviewed. SUVmax, SUVmean, MTV and TLG in addition to associated morphologic features on CT and demographics were recorded and correlated with final diagnosis defined by histophatologic confirmation or an at least 1-year clinical formal follow up

Results: Of a total 58 from 51 patients [51/5029, 1.01%], 10 [19.60%] were histopathologically verified as second primary breast cancers. There was a statistically significant difference in SUVmax, SUVmean, MTV and TLG between benign and malignant group [1.64 vs. 5.32 [p=0.009], 1.34 vs. 3.69 [p=0.027], 0.96 vs. 2.62 [p=0.035], 1.54 vs 8.89 [p=0.006]. Using cut off 2, 1.35, 1.16 and 1.75, sensitivity and specificity of SUVmax, SUVmean, MTV and TLG were calculated as 77% and 62%, 92% and 66.5%, 77% and 75% 77% and 67%, respectively

Conclusion: Despite a significantly higher value in malignant breast incidental lesion, PET-derivative metabolic parameters provided only modest sensitivity and specificity and hence may not be considered as the sole criteria for risk stratification in this clinical setting

Diagnostic performance of F-18 FDG PET/CT in patients with cancer of unknown primary: additional benefit over CT-based conventional work up

Background: In the era of well-developed site-specific treatment strategies in cancer, identification of occult primary is of paramount importance in CUP patients. Furthermore, exact determination of the extent of the disease may help in optimizing treatment planning. The aim of the present study was to investigate additional value of F-18 FDG PET/CT in patients with cancer of unknown primary [CUP] as an appropriate imaging tool in early phase of initial standard work up

Materials and Methods: Sixty-two newly diagnosed CUP patients with inconclusive diagnostic CT scan of chest, abdomen and pelvis referring for F-18 FDG PET/CT were enrolled in this study. Standard of reference was defined as histopathology, other diagnostic procedures and a 3-month formal clinical follow up. The results of PET/CT were categorized as suggestion for primary site and additional metastasis and classified as true positive, false positive, false negative and true negative. The impact of additional metastasis revealed by F-18 FDG PET/CT on treatment planning and the time contribution of F-18 FDG PET/CT in diagnostic pathway was investigated

Results: Sixty-two patients with mean age of 62 [30 men, 32 women], PET/CT correctly identified primary origin in 32% with false positive rate of 14.8%. No primary lesion was detected after negative PET/CT according to standard of reference. Sensitivity, Specificity and accuracy were 100%, 78% and 85%, respectively. Additional metastatic site was found in 56% with 22% impact on treatment planning. Time contribution for PET/CT was 10% of total diagnostic pathway

Conclusion: Providing higher detection rate of primary origin with excellent diagnostic performance, shortening the diagnostic pathway and improving treatment planning, F-18 FDG PET/CT may play a major role in diagnostic work up of CUP patients and may be recommended as an alternative imaging tool in early phase of investigation

McCune-albright syndrome: report of a case

A 29-year old female with bone pain and history of precocious puberty was referred for bone scintigraphy. On physical examination caf‚ au lait macular spots were noted on her neck, buttocks and left leg. Bone scan showed multiple areas of intense increased activity which was in favour of polyostotic fibrous dysplasia. Considering the presence of polyostotic fibrous dysplasia, precocious puberty and caf‚ au lait macular spots, MacCune-Albright syndrome was confirmed in this patient

Bone scan with incidental visualization of the entire colon

A 57-year-old male with history of prostatectomy, cyctectomy, cecal urinary diversion for invasive prostate cancer and with a recent rise in PSA level, was referred for bone scintigraphy to rule out osseous metastatic disease. An interesting finding was abnormal tracer accumulation throughout the large bowel, which was proved to be due to urinary diversion