Bone radionuclide therapy and increased survival with radium-223 is the way to go for nuclear medicine: the offer that oncologists cannot refuse

Whole-body MRI Versus [18F]FDG PET/CT in Diagnosing and Monitoring Plasmacytomas: A Comparative Study

BACKGROUND/OBJECTIVES

Current guidelines recommend [18F]FDG PET/CT as the preferred imaging modality for suspected extramedullary bone plasmacytomas, while whole-body magnetic resonance imaging (WB-MRI) is indicated for solitary bone plasmacytomas. Despite these recommendations, the available evidence comparing the diagnostic efficacy of both techniques remains limited. The aim of this study was to compare the diagnostic efficacy of WB-MRI and [18F]FDG PET/CT in the initial evaluation of plasmacytomas.

METHODS

We performed a multicenter, observational, and retrospective analysis of patients diagnosed with plasmacytoma who underwent WB-MRI and/or [18F]FDG PET/CT as part of their diagnostic workup. Lesions identified were categorized by anatomic location, and concordance between WB-MRI and [18F]FDG PET/CT findings was assessed. The McNemar test and Pearson χ2 test were used to compare detection rates between WB-MRI and [18F]FDG PET/CT.

RESULTS

The study included 73 patients (33 men) recruited between 2012 and 2023, age range 30-94 years (mean 63.4 ± 12.2 y). Of these, 56 patients underwent both diagnostic tests. Diagnoses revealed solitary plasmacytoma in 16 patients, concurrent multiple myeloma (MM) and plasmacytoma in 18 patients, and plasmacytoma in 22 patients with a prior MM history. Out of the 56 plasmacytomas, 40 were osseous and 16 were extramedullary. WB-MRI detected 98.2% of plasmacytomas compared with 83.9% for [18F]FDG PET/CT, with a statistically significant difference of OR 9 (95% CI: 1.2-394.5), P=0.021. Concordance was very high for osseous plasmacytomas but moderate for extramedullary plasmacytomas.

CONCLUSIONS

These findings suggest WB-MRI is an alternative to [18F]FDG PET/CT for detecting plasmacytomas. A comprehensive clinical and radiologic assessment is essential for the optimal evaluation of patients with plasmacytoma.

[177Lu]Lu-EDTMP -a bone pain palliating agent: pharmacokinetics, biodistribution, safety profile and clinical evaluation in osseous metastatic patients

BACKGROUND

[177Lu]Lu-EDTMP has emerged as a promising radiopharmaceutical for the palliation of pain caused by osseous metastases. This phase I/II study comprehensively evaluate the pharmacokinetics, biodistribution, clinical efficacy, and safety profile of [177Lu]Lu-EDTMP, in patients with skeletal metastases from breast and prostate cancer.

METHODS

A total of 27 patients with skeletal metastases were included in the study. Pharmacokinetics and biodistribution were analyzed in 17 patients through whole-body gamma camera imaging and quantification at multiple time points. Clinical efficacy and safety were evaluated in 18 patients receiving either low (1.3 GBq) or high (2.6 GBq) administered activity. Pain palliation was assessed using visual analog scale scores, analgesic usage (frequency and type), mobility scores, and Karnofsky performance status. The safety profile was determined through hematological and biochemical monitoring over 12 weeks.

RESULTS

[177Lu]Lu-EDTMP demonstrated rapid blood clearance, with negligible residual activity at 24 h. Urinary excretion accounted for over 30% of administered activity at 24 h. Bone uptake increased progressively to over 70%. Scintigraphy revealed selective uptake in metastases, improving lesion-to-bone and lesion-to-soft tissue ratios. Both low (1.3 GBq) and high (2.6 GBq) activity groups showed significant pain relief, with faster, longer-lasting effects in the high-dose group, reducing opioid/NSAID use. No Grade III/IV myelotoxicity or major renal/hepatic events occurred.

CONCLUSION

[177Lu]Lu-EDTMP is a safe and effective bone pain palliation agent, with favorable pharmacokinetics, targeted skeletal uptake, and minimal toxicity. These findings support its potential use as an alternative radiopharmaceutical for pain palliation in patients with skeletal metastases.

CLINICAL TRIAL NUMBER

Not applicable.

Fibroblast Activation Protein Inhibitor (FAPI) PET Imaging in Sarcomas: A New Frontier in Nuclear Medicine

The field of nuclear medicine has witnessed significant advancements in recent years, particularly in the area of PET imaging. One such development is the use of Fibroblast Activation Protein Inhibitors (FAPI) as a novel radiotracer. FAPI PET imaging has shown promising results in various malignancies, including sarcomas, which are a diverse group of cancers originating from mesenchymal cells. This paper aims to explore the potential of FAPI PET imaging in the diagnosis, staging, and treatment monitoring of sarcomas. Several studies have demonstrated the potential of FAPI PET in sarcomas. Furthermore, FAPI PET imaging has shown potential in assessing treatment response, with changes in FAPI uptake correlating with treatment outcomes. However, there are challenges to be addressed. The heterogeneity of sarcomas, both inter- and intra-tumoral, may affect the uniformity of Fibroblast Activation Protein (FAP) expression and thus the effectiveness of FAPI PET imaging. Additionally, the optimal timing and dosage of FAPI for PET imaging in sarcomas need further investigation. In conclusion, the introduction of FAPI PET imaging represents a significant advancement in the field of nuclear medicine and oncology. The ability to target FAP, a protein overexpressed in the majority of sarcomas, offers new possibilities for the diagnosis and treatment of these complex and diverse tumors. Its potential applications in diagnosis, staging, and theranostics are vast, and on-going research continues to explore and address its limitations. As we continue to deepen our understanding of this novel imaging technique, it is hoped that FAPI PET imaging will play an increasingly important role in the fight against cancer. However, as with any new technology, further research is needed to fully understand the potential and limitations of FAPI PET imaging in the clinical setting.

Laser isotope separation of 223Ra

A three-step photoionization has been theoretically studied for the laser isotope separation of ²²³Ra through the following photoionization scheme. [Formula: see text] The effect of bandwidth, peak power density of the excitation and ionization lasers, Doppler broadening of the atomic ensemble, number density of the atoms, and charge exchange collisions on the laser isotope separation process has been studied. The optimum system parameters for the separation of ²²³Ra through this photoionization scheme have been derived. The effect of unknown parameters on the degree of enrichment has also been discussed. It has been theoretically shown that it is possible to produce ²²³Ra isotope with 98.5% radio-isotopic purity at a rate of 0.74 μg/h corresponding to the production rate of 435 patient doses per hour. This is the first ever study on the laser isotope separation of Radium isotopes.

Extended X-ray absorption fine structure spectroscopy measurements and ab initio molecular dynamics simulations reveal the hydration structure of the radium(II) ion

Radium is refocused from the viewpoint of an environmental pollutant and cancer therapy using alpha particles, where it mainly exists as a hydrated ion. We investigated the radium hydration structure and the dynamics of water molecules by extended X-ray absorption fine structure (EXAFS) spectroscopy and ab initio molecular dynamics (AIMD) simulation. The EXAFS experiment showed that the coordination number and average distance between radium ion and the oxygen atoms in the first hydration shell are 9.2 ± 1.9 and 2.87 ± 0.06 Å, respectively. They are consistent with those obtained from the AIMD simulations, 8.4 and 2.88 Å. The AIMD simulations also revealed that the water molecules in the first hydration shell of radium are less structured and more mobile than those of barium, which is an analogous element of radium. Our results indicate that radium can be more labile than barium in terms of interactions with water.

Progress in Targeted Alpha-Particle-Emitting Radiopharmaceuticals as Treatments for Prostate Cancer Patients with Bone Metastases

Bone metastasis remains a major cause of death in cancer patients, and current therapies for bone metastatic disease are mainly palliative. Bone metastases arise after cancer cells have colonized the bone and co-opted the normal bone remodeling process. In addition to bone-targeted therapies (e.g., bisphosphonate and denosumab), hormone therapy, chemotherapy, external beam radiation therapy, and surgical intervention, attempts have been made to use systemic radiotherapy as a means of delivering cytocidal radiation to every bone metastatic lesion. Initially, several bone-seeking beta-minus-particle-emitting radiopharmaceuticals were incorporated into the treatment for bone metastases, but they failed to extend the overall survival in patients. However, recent clinical trials indicate that radium-223 dichloride (223RaCl2), an alpha-particle-emitting radiopharmaceutical, improves the overall survival of prostate cancer patients with bone metastases. This success has renewed interest in targeted alpha-particle therapy development for visceral and bone metastasis. This review will discuss (i) the biology of bone metastasis, especially focusing on the vicious cycle of bone metastasis, (ii) how bone remodeling has been exploited to administer systemic radiotherapies, and (iii) targeted radiotherapy development and progress in the development of targeted alpha-particle therapy for the treatment of prostate cancer bone metastasis.

ECCO Essential Requirements for Quality Cancer Care: Prostate cancer

BACKGROUND

ECCO Essential Requirements for Quality Cancer Care (ERQCC) are written by experts representing all disciplines involved in cancer care in Europe. They give oncology teams, patients, policymakers and managers an overview of essential care throughout the patient journey.

PROSTATE CANCER

Prostate cancer is the second most common male cancer and has a wide variation in outcomes in Europe. It has complex diagnosis and treatment challenges, and is a major healthcare burden. Care must only be a carried out in prostate/urology cancer units or centres that have a core multidisciplinary team (MDT) and an extended team of health professionals. Such units are far from universal in European countries. To meet European aspirations for comprehensive cancer control, healthcare organisations must consider the requirements in this paper, paying particular attention to multidisciplinarity and patient-centred pathways from diagnosis, to treatment, to survivorship.

177Lu/153Sm-Ethylenediamine Tetramethylene Phosphonic Acid Cocktail: A Novel Palliative Treatment for Patients with Bone Metastases

Background: Production of effective, low-cost, and efficient radiopharmaceuticals is an important task and requires further research and clinical studies. In this clinical trial, safety and efficacy of ¹⁷⁷Lu/¹⁵³Sm-ethylenediamine tetramethylene phosphonic acid (EDTMP) cocktail has been evaluated for pain relief of bone metastases. Materials and Methods: Twenty-five patients with the mean age of 55.5 ± 15.8 years participated in this study. Patients received a total dose of 37 MBq/kg. Pain and performance assessments were followed using a Brief Pain Inventory form. Complete blood count and renal and liver function tests were also performed up to 12 weeks postadministration. Results: Eighteen patients (72%) demonstrated complete pain relief (relief = 100%) and approximately all patients (96%) experienced significant improvement in their quality of life. No grade IV hematological toxicity was observed during the 12-week follow-up period, and grade III toxicity was seen in 1 patient only. In addition, no abnormalities were seen in renal and liver function during the follow-up period. Conclusions: There were no considerable complications after administration of ¹⁷⁷Lu/¹⁵³Sm EDTMP; this cocktail seems to be a safe and effective treatment for bone pain palliation in patients with skeletal metastases and improves the quality of life.