Kaku igaku. The Japanese journal of nuclear medicine最新文献

Objective: To perform an exploratory analysis on the safety and effectiveness of radium-223 (Ra-223) by patient baseline age, using the results of a post-marketing surveillance study of Ra-223 in castration-resistant prostate cancer patients with bone metastasis in Japan.

Method: The safety analysis population of 296 patients was stratified into two groups based on age (<75 and ≥ 75 years-old [yo]), and their characteristics, drugrelated treatment-emergent adverse events (TEAEs), and clinical laboratory values were evaluated. Additionally, these endpoints were evaluated in patients aged ≥ 80 yo.

Results: There were 148 patients in each of the <75-yo and ≥ 75-yo age groups, and 69 patients in the ≥ 80-yo age group. The characteristics of patients in the <75-yo group were suggestive of more aggressive disease at diagnosis of prostate cancer and a greater proportion of patients had prior chemotherapy compared with patients in the ≥ 75-yo age group. The incidences of overall drugrelated TEAEs and drug-related hematological TEAEs were slightly higher in the <75-yo age group; however, there was little difference in the incidences of drug-related TEAEs leading to drug discontinuation (1.4-4.1%) between patient groups. Changes in total alkaline phosphatase and prostate-specific antigen values were similar in all groups.

Conclusions: Ra-223 therapy seemed tolerable regardless of age in real-world practice in Japan. Especially, there were no new safety concerns of Ra-223 in elderly patients.

Internal radiation therapy using lutetium-177(¹⁷⁷Lu)-DOTA-TATE injection will be applied in actual clinical practice soon. However, the NHI medical technical fee for the use of ¹⁷⁷Lu-DOTA-TATE injection has not yet been set. The Japanese Society of Nuclear Medicine surveyed health resource use in internal radiation therapy using ¹⁷⁷Lu via questionnaires sent to medical institutions that have used ¹⁷⁷Lu-DOTA-TATE injection. Results showed that the necessary cost per patient is 1,912,404 JPY, based on the Draft Proposal for Medical Examination Value (Ver. 7.2) of the Japanese Health Insurance Federation for Surgery. ¹⁷⁷Lu-DOTA-TATE injection is supposed to be administered 4 times to each patient at 8-week intervals, and the fee per treatment was calculated to be 478,101 JPY. The appropriate NHI medical technical fee is thus considered to be 47,810 points per patient per treatment, which can be claimed 4 times per patient. In addition, it costs 649,030 JPY per patient to take special measures to make the hospital room similar to the radiation therapy room. The cost other than the basic hospitalization fee per day was calculated to be 81,129 JPY. The appropriate additional points for NHI basic hospitalization fee is thus considered to be 8,113 points per patient per day.

Quality of the ⁶⁸Ga solution eluted from a ⁶⁸Ge/⁶⁸Ga generator (Galli Eo^®) was evaluated. Elution was performed 488 times from 21 to 484 days (ca. 15 months) after the calibration date. The eluted ⁶⁸Ga activity was 329 MBq to 1,148 MBq, which decreased with the decay of ⁶⁸Ge, but no significant change was observed in the elution yields (62.8±2.2%). The half-life of the eluted radioactivity was 67.8±0.1 min, the radionuclide purity of ⁶⁸Ga was ≥99.9%, the ⁶⁸Ge breakthrough was 0.000024 ±0.000004%, and the radiochemical purity of ⁶⁸Ga³⁺ was 99.7±0.2%. Fe and Zn were detected as metal impurities in the eluent, but both were ≤10 μg/GBq. The endotoxin concentration of the eluate was ≤5 EU/mL, and the eluent passed the sterility test. These results show that the generator can stably provide ⁶⁸Ga solution over a 15-month period.