ABSTRACT
BACKGROUND: In 18F-fluorodeoxyglucose PET/CT, respiratory motion induces bias in image interpretations (i.e. organ misregistration or lesion omission/underestimation). OBJECTIVE: The present study applied our custom gating method (referred to as 'CT-based gated PET' and that has already been validated by our research group) to PET imaging of the liver and compared its per lesion sensitivity with that of standard clinical (i.e. ungated) PET. METHODS: A total of 13 patients scheduled for liver surgery were referred to our department for PET/CT imaging. Each patient underwent both ungated and CT-based gated PET imaging protocols. Two independent, blinded observers interpreted the two sets of PET images and reached a consensus when necessary. Image interpretations were combined with histological analysis and/or intraoperative ultrasound examination to compute each method's per lesion sensitivity and true positive fraction. Analyses were also performed by considering lesions according to their size (longest axis over 10 mm or over 15 mm). RESULTS: Forty-eight lesions were confirmed by pathology reports. When considering all the uptakes, the ungated and the CT-based gated PET methods had sensitivities of 54.2 and 64.6% (P=0.025) and true positive fractions of 83.9 and 86.1%, respectively. When considering uptakes greater than 10 mm in size, ungated and CT-based gated PET had sensitivities of 74.3 and 88.6% (P=0.025), respectively. For lesions greater than 15 mm in size, the corresponding sensitivities were 85.2 and 100% (P=0.046). CONCLUSION: CT-based gated PET yielded a higher lesion-based sensitivity than routine, ungated PET did. Hence, this method improves the detection of intrahepatic colorectal metastases--especially for lesions that are close in size to the detection limit of the PET gantry.
Subject(s)
Liver Neoplasms/diagnostic imaging , Multimodal Imaging/methods , Positron-Emission Tomography , Respiratory-Gated Imaging Techniques/methods , Tomography, X-Ray Computed , Adult , Aged , Aged, 80 and over , Colorectal Neoplasms/pathology , Female , Fluorodeoxyglucose F18 , Humans , Liver Neoplasms/secondary , Male , Middle Aged , Prospective Studies , Radiopharmaceuticals , Reproducibility of Results , Sensitivity and SpecificityABSTRACT
Melorheostosis is a rare benign bone pathology which can be responsible for incapacitating pain and bone deformations. Its imaging abnormalities are often typical. We describe here the case of a patient with melorheostosis involving the lower limbs, associated with a peripheral form of inflammatory spondyloarthropathy, who underwent 18FNa positron emission tomography coupled to a computed tomography scan. Our objective is to present this new image, to show the value of this new modality and emphasize its advantages compared to the 99mTechnetium bone scan.
ABSTRACT
OBJECTIVES: To report our experience with concurrent chemoradiotherapy for clinical Stage T2 bladder cancer. METHODS: From 1996 to 2002, 43 patients were treated with concurrent chemotherapy and radiotherapy for clinical Stage T2 bladder cancer. After complete bladder transurethral resection, all patients underwent chemotherapy, consisting of one daily infusion of cisplatin at a dose of 15 mg/m2 and 5-fluorouracil at a dose of 400 mg/m(2) on days 1 to 3 (first cycle) and days 15 to 17 (second cycle). Pelvic irradiation was administered at a dose of 24 Gy, using two daily fractions of 3 Gy on days 1, 3, 15, and 17. Random biopsies were performed 6 weeks after the end of the first two cycles. Patients with persistent invasive tumor underwent cystectomy; others received two additional cycles of concurrent chemoradiotherapy. RESULTS: The mean follow-up was 36.3 months (range 3 to 72). Nine patients underwent early cystectomy for nonresponse, and 2 patients underwent delayed cystectomy. The overall rate of cystectomy was 25.6%. The rate of specific survival at 3 and 5 years was 75% and 60%, respectively. The overall rate of recurrence-free survival at 3 and 5 years was 63% and 33%, respectively. Two factors correlated with patient survival: the presence of carcinoma in situ at first resection (P = 0.01) and the response after the first two cycles (half dose; P = 0.004). CONCLUSIONS: In our experience, concurrent chemoradiotherapy is less effective than primary cystectomy for clinical Stage T2 bladder cancer. This treatment may be unwarranted in patients with concomitant carcinoma in situ at the first resection.