Assessment of objective responses using volumetric evaluation in advanced thymic malignancies and metastatic non-small cell lung cancer.

INTRODUCTION: Measurement of tumor response by standard response criteria is challenging in thymic malignancies, especially when the pleura is involved, as it often is in stage IV disease. In this study, we aimed to determine the effectiveness of volumetric response evaluation criteria in solid tumors (volumetrics) for evaluating response in patients with thymic malignancies treated on a phase II study of belinostat. METHODS: We evaluated the tumor responses of 25 patients with thymic cancer using computed tomography-based RECIST, World Health Organization (WHO), modified RECIST, and volumetrics. As a control, we assessed 37 patients with non-small cell lung cancer (NSCLC) with RECIST and volumetrics. RESULTS: Agreement analyses in 23 patients with thymic cancer at the time of RECIST-determined progressive disease (PD) compared volumetrics with RECIST, modified RECIST, and WHO criteria. Use of volumetrics was associated with 22% discordance compared with RECIST, 15% versus modified RECIST, and 22% versus WHO criteria. Volumetrics revealed PD 72 days earlier than RECIST (p = 0.016). In another cohort of 35 patients with NSCLC, there was 9% discordance between volumetrics and RECIST at the time of PD. Volumetrics demonstrated PD 32 days earlier than RECIST in NSCLC (p = 0.0078). CONCLUSIONS: Our study suggests that volumetrics might improve detection of PD. Prospective evaluation of this technique in a larger series of patients with thymic malignancies will be required.

O-(2-[18F]fluoroethyl)-L-tyrosine (18F-FET) uptake in mouse thymoma cells, and its biodistribution in mice and human volunteers.

PURPOSE: To evaluate O-(2-[18F]fluoroethyl)-l-tyrosine (18F-FET) uptake in mouse malignant thymoma (EL4), and its biodistribution in mice and humans. MATERIAL AND METHODS: First, 18F-FET uptake in EL4 cells was examined in an in vitro study. Second, the kinetics of 18F-FET uptake and its biodistribution were examined in mice after subcutaneous injection of EL4 cells and complete Freund's adjuvant. Finally, the kinetics of 18F-FET uptake and its biodistribution in healthy human volunteers were examined. RESULTS: In an in vitro study, 18F-FET was extensively incorporated in EL4 cells. In an animal study, 18F-FET accumulation in normal organs peaked within 30 min postinjection. The mean ratios of 18F-FET uptake in tumors and in inflammatory lesions to that in muscle tissue at 60 min postadministration were 2.18 (range 2.00-2.29) and 1.04 (range 0.95-1.14), respectively. In a human study, static images were taken 60 min after 18F-FET administration. Mean standardized uptake values (SUVs) of the liver (1.52, range 1.38-1.71) and kidneys (1.90, range 1.74-2.24) were nearly equal or slightly higher than that of muscle tissue (1.19, range 0.99-1.33). CONCLUSION: This study demonstrates that 18F-FET accumulation in thymoma is significantly higher than in normal organs. 18F-FET could be a useful tracer for tumor imaging.

Surgical resection combined with intrathoracic hyperthermic perfusion for thymic carcinoma with an intrathoracic disseminated lesion: a case report.

Thymic undifferentiated carcinoma has a poor prognosis. We encountered a patient with thymic carcinoma associated with an intrathoracic disseminated lesion, who underwent surgery combined with intrathoracic hyperthermic perfusion after systemic chemotherapy and showed good results. The 45-year-old man was diagnosed as having a thymoma with an intrathoracic disseminated lesion. After he underwent three courses of systemic chemotherapy, he was admitted to our hospital. An anterior mediastinal tumor and an intrathoracic disseminated lesion remained, and were treated by surgical resection combined with intrathoracic hyperthermic perfusion. The tumors were histopathologically diagnosed as thymic undifferentiated carcinomas with pleural dissemination. At present, approximately 16 months after surgery, the patient is alive without recurrence.

Scintiscanning demonstration of thymoma: comparative study on scintiscans using 201Tl, 67Ga and 75Se.

Thymus scintigraphy was performed using 201Tl-chloride, 67Ga-citrate and 75Se-selenomethionine on 30 thymoma patients with or without myasthenia gravis. Mass negativity was observed in 6 out of 17 (35.3 per cent) and 3 out of 13 cases (23.1 per cent), respectively. A rate of 70 per cent (21 cases out of 30) of mass positivity was observed by thymus scan using 201Tl. With regard to the relation between thymus scan and cell type, 201Tl-scan exhibited a high rate of mass positivity, regardless of the cell type while the 75Se-scan showed a trend toward mass positivity in epithelial cell predominant cases. With 201Tl, mass positivity was observed when the CPM/g ratio for tumors and blood exceeded 3.0. This trend can serve as an index for the suitability of supplementary chemo- and radiotherapies, as well as for prognosis in cases of relapse, and in those for whom excision was not complete.

Selective uptake of 75Se-selenomethionine by thymoma with pre red cell aplasia.

Red cell aplasia and an enlarging anterior mediastinal mass developed in a patient being followed for thyroid carcinoma. Differential diagnosis included thymoma and metastatic thyroid carcinoma. Preoperative scanning demonstrated significant uptake of 75Se-selenomethionine whereas 67Ga-galiium citrate failed to visualize the mass. Subsequent thoracotomy revealed a lymphocytic thymoma which was resected, resulting in reversal of the red cell aplasia. The use of 75Se-selenomethionine scanning maybe a useful adjunct in the preoperative evaluation of suspected thymomas.