Synthesis of 99mTc(CO)3-deoxyuridine derivatives as potential HSV1-tk gene expression imaging agents.

In this study, we synthesized (99m)Tc(CO)(3)-2'-aminomethylpyridyl-2'-deoxyuridine ((99m)Tc(CO)(3)-AMPDU) and (99m)Tc(CO)(3)-aminoethylpyridyl-2'-deoxyuridine ((99m)Tc(CO)(3)-AEPDU) as potential agents for imaging the expression of the non-invasive herpes simplex virus type-1 thymidine kinase. AMPDU and AEPDU were synthesized from uridine in five chemical steps and then labeled with [(99m)Tc(CO)(3)(H(2)O)(3)](+) (370MBq/0.5 mL) at 100 degrees C for 10 min. Under optimal conditions (0.5 and 1.0mg for AMPDU and AEPDU and heating for 10 min), the labeling efficiency was 95.3+/-2.8% for AMPDU and 94.2+/-5.1% for AEPDU. To validate the chemical structure of (99m)Tc(CO)(3)-labeled compounds, we also synthesized ReBr(CO)(3)-AMPDU and ReBr(CO)(3)-AEPDU by reacting [Et(4)N][ReBr(3)(CO)(3)] and AMPDU or AEPDU in methanol at 25 degrees C for 6h. (99m)Tc(CO)(3)-AMPDU and (99m)Tc(CO)(3)-AEPDU had the same retention time on HPLC analysis as ReBr(CO)(3)-AMPDU and ReBr(CO)(3)-AEPDU. (99m)Tc(CO)(3)-AMPDU and (99m)Tc(CO)(3)-AEPDU had high radiochemical stabilities of 98.1+/-1.5% and 98.0+/-1.7% for 6h, respectively.

Mediastinal single nodal relapse of a nasal NK/T cell lymphoma.

A nasal NK/T cell lymphoma is a very aggressive form of lymphoma. Patterns of relapse after treatment have not been systematically evaluated, and mediastinal nodal relapse at a primary site has never been documented. We describe here a 40-year old man who presented with a nasal obstruction caused by a protruding mass that was identified as a nasal NK/T cell lymphoma. The initial work-up, including chest and abdominopelvic computed tomography (CT) and positron emission tomography (PET), showed no regional or distant metastasis. A CT scan performed following three cycles of chemotherapy with cyclophosphamide, doxorubicin, vincristine, and prednisolone (CHOP) showed that the mass had nearly disappeared. Radiation therapy undertaken following chemotherapy was given to the primary site. However, PET performed following radiotherapy revealed a single mediastinal lymphadenopathy, with no evidence of residual tumor in the nasal cavity. A biopsy using video-assisted thoracoscopy (VATS) showed the presence of a recurrent NK/T cell lymphoma with an immunophenotype identical to that of the primary nasal lymphoma. An additional three cycles of CHOP chemotherapy were administered, and the patient remains alive, with no evidence of disease 30 months after the initial relapse. These findings indicate that early detection with PET and prompt surgical excision with the use of VATS can lead to successful treatment of a relapsed nasal NK/T cell lymphoma.