Flare Phenomenon After 177 Lu-DOTA-IBA Therapy in Bone Metastases of Lung Cancer.

ABSTRACT: The flare phenomenon is a transient increase in the number or intensity of lesions on bone scans after treatment, signifying curative effect. DOTA-ibandronic acid (DOTA-IBA) is a new prodrug that targets bone metastases and can be labeled with 177 Lu. Here, we report the case of a 58-year-old woman with bone metastasis, in whom the flare phenomenon was observed after 4 cycles of 177 Lu-DOTA-IBA treatment. No adverse effects were observed during the treatment and follow-up periods.

Favorable Response of 225 Ac-PSMA in the Treatment of Castration-Resistant Prostate Cancer With High Bone Metastasis Burden.

ABSTRACT: 225 Ac-PSMA treatment demonstrated low hematologic toxicity for prostate cancer with diffuse red marrow infiltration. A 70-year-old man with diffuse bone metastases of castration-resistant prostate cancer received 225 Ac-PSMA radiation therapy. After 1 treatment cycle, the patient's skeletal lesions demonstrated a significant response and a significant decrease in PSA. 225 Ac-PSMA may be a promising therapeutic option for metastatic castration-resistant prostate cancer patients with high bone metastatic burden.

Biodistribution and dosimetry of 177Lu-DOTA-IBA for therapy of bone metastases.

BACKGROUND: We designed and synthesized a novel bisphosphonate radiopharmaceutical (68 Ga- or 177Lu-labeled DOTA-ibandronate [68 Ga/177Lu-DOTA-IBA]) for the targeted diagnosis and treatment of bone metastases. The biodistribution and internal dosimetry of a single therapeutic dose of 177Lu-DOTA-IBA were evaluated using a series of single-photon emission computerized tomography (SPECT) images and blood samples. Five patients with multiple bone metastases were included in this prospective study. After receiving 1110 MBq 177Lu-DOTA-IBA, patients underwent whole-body planar, SPECT/CT imaging and venous blood sampling over 7 days. Dosimetric evaluation was performed for the main organs and tumor lesions. Safety was assessed using blood biomarkers. RESULTS: 177Lu-DOTA-IBA showed fast uptake, high retention in bone lesions, and rapid clearance from the bloodstream in all patients. In this cohort, the average absorbed doses (ADs) in the bone tumor lesions, kidneys, liver, spleen, red marrow, bladder-wall, and osteogenic cells were 5.740, 0.114, 0.095, 0.121, 0.095, and 0.333 Gy/GBq, respectively. Although no patient reached the predetermined dose thresholds, the red marrow will be the dose-limiting organ. There were no adverse reactions recorded after the administration of 1110 MBq 177Lu-DOTA-IBA. CONCLUSION: Dosimetric results show that the ADs for critical organs and total body are within the safety limit and with high bone retention. It is a promising radiopharmaceutical alternative for the targeted treatment of bone metastases, controlling its progression, and improving the survival and quality of life of patients with advanced bone metastasis.

177 Lu-PSMA-617 Therapy in a Case of Metastatic Castration-Resistant Prostate Cancer.

ABSTRACT: We report a 65-year-old man with metastatic castration-resistant prostate cancer who was treated with 2 cycles of 177 Lu-PSMA-617 therapy. PET/CT imaging of 68 Ga-PSMA-11 revealed a complete metabolic response (PERCIST1.0) after therapy. The prostate-specific antigen concentration drastically decreased (97.7% down).

177Lu-DOTA-IBA Therapy in Prostate Cancer With Bone Metastases.

ABSTRACT: Bone is the most common metastatic site in patients with prostate cancer. 177Lu-DOTA-ibandronic acid (177Lu-DOTA-IBA) is a new therapeutic radiopharmaceutical targeting bone metastasis. We report a case of refractory bone pain due to bone metastasis, who demonstrated an excellent therapy response after 3 cycles of 177Lu-DOTA-IBA therapy. In addition, the patient did not have any observable adverse reactions. 177Lu-DOTA-IBA may be a promising radiopharmaceutical for the treatment of bone metastasis.