Dynamic Metabolic Changes during the First 3 Months after 90

Objective. To elucidate the time course of tumor metabolism during the first 3 months after 90Y-ibritumomab tiuxetan radioimmunotherapy (RIT) in patients with refractory malignant lymphoma. Materials and Methods. Seven patients with recurrent follicular lymphoma underwent FDG-PET imaging before and after 1-, 4-, and 12-week RIT with 90Y-ibritumomab tiuxetan. Tumor metabolic activity on FDG-PET scans was assessed as the maximum standard uptake value (SUVmax). Results. Decrease in metabolism was detected 1 week after RIT. In the most decreased lesion, SUVmax decreased to 20% of the baseline value during the first week. Most lesions continued to decrease for up to 4 weeks. Some lesions showed increased metabolism from 4 to 12 weeks, while the level of FDG accumulations at 12 weeks was still lower than the baseline. Conclusions. Tumor response to RIT could be observed as early as 1 week after the administration of RIT. After tumor activity decreases, the metabolism may increase at least between 4 and 12 weeks. It suggests that the metabolic changes should be carefully evaluated during this period

Clinical Study Dynamic Metabolic Changes during the First 3 Months after 90 Y-Ibritumomab Tiuxetan Radioimmunotherapy

Objective. To elucidate the time course of tumor metabolism during the first 3 months after 90 Y-ibritumomab tiuxetan radioimmunotherapy (RIT) in patients with refractory malignant lymphoma. Materials and Methods. Seven patients with recurrent follicular lymphoma underwent FDG-PET imaging before and after 1-, 4-, and 12-week RIT with 90 Y-ibritumomab tiuxetan. Tumor metabolic activity on FDG-PET scans was assessed as the maximum standard uptake value (SUVmax). Results. Decrease in metabolism was detected 1 week after RIT. In the most decreased lesion, SUVmax decreased to 20% of the baseline value during the first week. Most lesions continued to decrease for up to 4 weeks. Some lesions showed increased metabolism from 4 to 12 weeks, while the level of FDG accumulations at 12 weeks was still lower than the baseline. Conclusions. Tumor response to RIT could be observed as early as 1 week after the administration of RIT. After tumor activity decreases, the metabolism may increase at least between 4 and 12 weeks. It suggests that the metabolic changes should be carefully evaluated during this period

Cartilage quantification using contrast-enhanced MRI in the wrist of rheumatoid arthritis: cartilage loss is associated with bone marrow edema

Objective: To quantify wrist cartilage using contrast MRI and compare with the extent of adjacent synovitis and bone marrow edema (BME) in patients with rheumatoid arthritis (RA). Methods: 18 patients with RA underwent post-contrast fat-suppressed T-1 weighted coronal imaging. Cartilage area at the centre of the scaphoid-capitate and radius-scaphoid joints was measured by in-house developed software. We defined cartilage as the pixels with signal intensity between two thresholds (lower: 0.4, 0.5 and 0.6 times the muscle signal, upper: 0.9, 1.0, 1.1, 1.2 and 1.3 times the muscle signal). We investigated the association of cartilage loss with synovitis and BME score derived from RA MRI scoring system. Results: Cartilage area was correlated with BME score when thresholds were adequately set with lower threshold at 0.6 times the muscle signal and upper threshold at 1.2 times the muscle signal for both SC (r(s)=-0.469, p < 0.05) and RS (r(s)= -0.486,p < 0.05) joints, while it showed no significant correlation with synovitis score at any thresholds. Conclusion: Our software can accurately quantify cartilage in the wrist and BME associated with cartilage loss in patients with RA. Advances in knowledge: Our software can quantify cartilage using conventional MR images of the wrist. BME is associated with cartilage loss in RA patients

An Autopsied Case of Malignant Sarcomatoid Pleural Mesothelioma in Which Chest Pain Developed Several Months Earlier without Abnormality on Imaging

The patient experienced chest pain for about 7 months, but a diagnosis could not be made until after death. He was diagnosed with malignant sarcomatoid pleural mesothelioma on autopsy. In this case report, difficult aspects of the diagnosis are discussed. The 70-year-old Japanese man was a driver who transported ceramic-related products. Right chest pain developed in July 2013, but no abnormality was detected on a chest computed tomography (CT) performed in September 2013, and the pain was managed as right intercostal neuralgia. A chest CT performed in late October 2013 revealed a right pleural effusion, and the patient was referred to our hospital in early November 2013. Thoracentesis was performed, but the cytology was negative, and no diagnosis could be made. Close examination was postponed because the patient developed a subarachnoid hemorrhage. He underwent 18F-fluorodeoxyglucose positron emission tomography (18F-FDG PET) after discharge from the neurosurgery department, and extensive right pleural thickening and 18F-FDG accumulation in this region were observed. Based on these findings, malignant pleural mesothelioma was suspected, and a thoracoscopy was performed under local anesthesia in early December 2013, but no definite diagnosis could be made. The patient selected best supportive care and died about 7 months after the initial development of right chest pain. The disease was definitively diagnosed as malignant sarcomatoid pleural mesothelioma by a pathological autopsy. When chronic chest pain of unknown cause is observed and past exposure to asbestos is suspected, actions to prevent delay in diagnosis should be taken, including testing for suspicion of malignant pleural mesothelioma