223Ra-dichloride therapy in an elderly bone metastatic castration-resistant prostate cancer patient: a case report presentation and comparison with existing literature

Urolithins: Emerging natural compound targeting castration-resistant prostate cancer (CRPC)

Castration-resistant prostate cancer (CRPC) presents a significant challenge due to its resistance to conventional androgen deprivation therapies. Urolithins, bioactive metabolites derived from ellagitannins, have recently emerged as promising therapeutic agents for CRPC. Urolithins not only inhibit androgen receptor (AR) signaling, a crucial factor in the progression of CRPC, but also play a key role in regulating oxidative stress by their antioxidant properties, thereby inhibiting increased reactive oxygen species, a common feature of the aggressive nature of CRPC. Research has shown that urolithins induce apoptosis and diminish pro-survival signaling, leading to tumor inhibition. This review delves into the intricate mechanisms through which urolithins exert their therapeutic effects, focusing on both AR-dependent and AR-independent pathways. It also explores the exciting potential of combining urolithins with androgen ablation therapy, opening new avenues for CRPC treatment.

The Tight Relationship Between the Tumoral Microenvironment and Radium-223

Radium-223 (223Ra) was the first radioactive isotope approved for treating castration-resistant prostate cancer (CRPC) with symptomatic bone metastases without visceral metastatic disease. To better understand the action of 223Ra, its role in the tumor microenvironment represents a crucial aspect. A literature search was conducted using the PubMed/MEDLINE database and studies regarding the relationship between 223Ra and the tumoral microenvironment were considered. The tumoral microenvironment is a complex setting in which complex interactions between cells and molecules occur. Radium-223, as an alpha-emitter, induces double-stranded DNA breaks; to potentiate this effect, it could be used in patients with genetic instability but also in combination with therapies which inhibit DNA repair, modulate the immune response, or control tumor growth. In conclusion, a few studies have taken into consideration the tumoral microenvironment in association with 223Ra. However, its understanding is a priority to better comprehend how to effectively exploit 223Ra and its action mechanism.

Large Italian Multicenter Study on Prognostic Value of Baselines Variables in mCRPC Patients Treated with 223RaCl2: Ten Years of Clinical Experience

Background/Objectives: The prognostic value of baseline clinical parameters in predicting the survival prolonging effect of Radium-223-dichloride (223RaCl2) for metastatic castration resistant prostate cancer (mCRPC) patients has been the object of intensive research and remains an open issue. This national multicenter study aimed to corroborate the evidence of ten years of clinical experience with 223RaCl2 by collecting data from eight Italian Nuclear Medicine Units. Methods: Data from 581 consecutive mCRPC patients treated with 223RaCl2 were retrospectively analyzed. Several baseline variables relevant to the overall survival (OS) analysis were considered, including age, previous radical prostatectomy/radiotherapy, number of previous treatment lines, prior chemotherapy, Gleason score, presence of lymphoadenopaties, number of bone metastases, concomitant use of bisphosphonates/Denosumab, Eastern Cooperative Oncology Group Performance Status (ECOG-PS), as well as baseline values of hemoglobin (Hb), platelets, Total Alkaline Phosphatase (tALP), Lactate Dehydrogenase (LDH), and Prostate-Specific Antigen (PSA). Data were summarized using descriptive statistics, univariate analysis and multivariate analysis with the Cox model. Results: The median OS time was 14 months (95%CI 12-17 months). At univariate analysis age, the number of previous treatment lines, number of bone metastases, ECOG-PS, presence of lymphadenopathies at the time of enrollment, as well as baseline tALP, PSA, and Hb, were independently associated with OS. After multivariate analysis, the number of previous treatment lines (HR = 1.1670, CI = 1.0095-1.3491, p = 0.0368), the prior chemotherapy (HR = 0.6461, CI = 0.4372-0.9549, p = 0.0284), the presence of lymphadenopathies (HR = 1.5083, CI = 1.1210-2.0296, p = 0.0066), the number of bone metastases (HR = 0.6990, CI = 0.5416-0.9020, p = 0.0059), ECOG-PS (HR = 1.3551, CI = 1.1238-1.6339, p = 0.0015), and baseline values of tALP (HR = 1.0008, CI = 1.0003-1.0013, p = 0.0016) and PSA (HR = 1.0004, CI = 1.0002-1.0006, p = 0.0005) remained statistically significant. Conclusions: In the era of precision medicine and in the landscape of novel therapies for mCRPC, the prognostic stratification of patients undergoing 223RaCl2 has a fundamental role for clinical decision-making, ranging from treatment choice to optimal sequencing and potential associations. This large Italian multicenter study corroborated the prognostic value of several variables, emerging from ten years of clinical experience with 223RaCl2.

Macrocyclic 1,2-Hydroxypyridinone-Based Chelators as Potential Ligands for Thorium-227 and Zirconium-89 Radiopharmaceuticals

Thorium-227 (227Th) is an α-emitting radionuclide that has shown preclinical and clinical promise for use in targeted α-therapy (TAT), a type of molecular radiopharmaceutical treatment that harnesses high energy α particles to eradicate cancerous lesions. Despite these initial successes, there still exists a need for bifunctional chelators that can stably bind thorium in vivo. Toward this goal, we have prepared two macrocyclic chelators bearing 1,2-hydroxypyridinone groups. Both chelators can be synthesized in less than six steps from readily available starting materials, which is an advantage over currently available platforms. The complex formation constants (log βmlh) of these ligands with Zr4+ and Th4+, measured by spectrophotometric titrations, are greater than 34 for both chelators, indicating the formation of exceedingly stable complexes. Radiolabeling studies were performed to show that these ligands can bind [227Th]Th4+ at concentrations as low as 10-6 M, and serum stability experiments demonstrate the high kinetic stability of the formed complexes under biological conditions. Identical experiments with zirconium-89 (89Zr), a positron-emitting radioisotope used for positron emission tomography (PET) imaging, demonstrate that these chelators can also effectively bind Zr4+ with high thermodynamic and kinetic stability. Collectively, the data reported herein highlight the suitability of these ligands for use in 89Zr/227Th paired radioimmunotheranostics.

The DASciS Software for BSI Calculation as a Valuable Prognostic Tool in mCRPC Treated with 223RaCl2: A Multicenter Italian Study

BACKGROUND/AIM

Radium-223 dichloride (²²³RaCl₂) represents a therapeutic option for metastatic castration-resistant prostate cancer (mCRPC) patients dealing with symptomatic bone metastases. The identification of baseline variables potentially affecting the life-prolonging role of ²²³RaCl₂ is still ongoing. Bone scan index (BSI) defines the total load of bone metastatic disease detected on a bone scan (BS) and is expressed as a percentage value of the whole bone mass. The aim of this multicenter study was to assess the impact of baseline BSI on overall survival (OS) in mCRPC patients treated with ²²³RaCl₂. For this purpose, the DASciS software developed by the Sapienza University of Rome for BSI calculation was shared between six Italian Nuclear Medicine Units.

METHODS

370 pre-treatment BS were analyzed through the DASciS software. Other clinical variables relevant to OS analysis were taken into account for the statistical analysis.

RESULTS

Of a total of 370 patients, 326 subjects had died at the time of our retrospective analysis. The median OS time from the first cycle of ²²³RaCl₂ to the date of death from any cause or last contact was 13 months (95%CI 12-14 months). The mean BSI value resulted in 2.98% ± 2.42. The center-adjusted univariate analysis showed that baseline BSI was significantly associated with OS as an independent risk factor (HR 1.137, 95%CI: 1.052-1.230, p = 0.001), meaning that patients with higher BSI values had worse OS. When adjusting for other measures on multivariate analysis, in addition to Gleason score and baseline values of Hb, tALP, and PSA, baseline BSI was confirmed to be a statistically significant parameter (HR 1.054, 95%CI: 1.040-1.068, p < 0.001).

CONCLUSIONS

Baseline BSI significantly predicts OS in mCRPC treated with ²²³RaCl₂. The DASciS software was revealed to be a valuable tool for BSI calculation, showing rapid processing time and requiring no more than a single demonstrative training for each participating center.

Personalized Dosimetry in the Context of Radioiodine Therapy for Differentiated Thyroid Cancer

The most frequent thyroid cancer is Differentiated Thyroid Cancer (DTC) representing more than 95% of cases. A suitable choice for the treatment of DTC is the systemic administration of 131-sodium or potassium iodide. It is an effective tool used for the irradiation of thyroid remnants, microscopic DTC, other nonresectable or incompletely resectable DTC, or all the cited purposes. Dosimetry represents a valid tool that permits a tailored therapy to be obtained, sparing healthy tissue and so minimizing potential damages to at-risk organs. Absorbed dose represents a reliable indicator of biological response due to its correlation to tissue irradiation effects. The present paper aims to focus attention on iodine therapy for DTC treatment and has developed due to the urgent need for standardization in procedures, since no unique approaches are available. This review aims to summarize new proposals for a dosimetry-based therapy and so explore new alternatives that could provide the possibility to achieve more tailored therapies, minimizing the possible side effects of radioiodine therapy for Differentiated Thyroid Cancer.

Feasibility of a novel photoproduction of 225Ac and 227Th with natural thorium target

We propose an innovative way to produce both ²²⁵Ac and ²²⁷Th, two precious radioisotopes enabling promising targeted alpha therapy, in a natural thorium target bombarded with a 30–90 MeV electron beam. Bremsstrahlung photons in the target are analyzed by MCNP and in-situ photonuclear transmutation of ²³²Th is evaluated by using the TENDL nuclear data. In the photo-transmutation analysis, 13 nuclides including ²²⁹Th and ²³¹Pa are modelled. Special procedures with chemical separations are also proposed to produce pure ²²⁵Ac and ²²⁷Th in separate streams. In addition, performance of the new approach is compared with conventional methods in terms of the ²²⁵Ac and ²²⁷Th yields. After a Th target is bombarded with a 500 kW electron beam for a year, yearly ²²⁵Ac yield is ~ 8.47 GBq (semi-permanently) and yearly ²²⁷Th yield is ~ 48.9 GBq over 50 years, and their yields are at least doubled in a 2-year irradiation. This work will help increase global supply of the two precious isotopes and would invariably help advance TAT-related researches and developments.

Radium-223 Treatment in mCRPC Patient with Polycythemia Vera

There have been several studies on the clinical outcomes of Radium-223 treatment in patients with metastatic castration-resistant prostate cancer (mCRPC) who may have an increased risk of hematologic comorbidities. To the best of our knowledge, this is the first study to explore the potential bone marrow adverse effects (AEs) of Radium-223 administered with specific drugs used for hematologic conditions, such as polycythemia vera (PV). We report the case of a patient with mCRPC who was administered a combined treatment of Radium-223 and hydroxyurea for PV, aiming to support clinicians in predicting eventual AEs.

Potential prognostic value of miR-132 and miR-212 expression in mCRPC patients

To the Editor, we have been very pleased to read the interesting work proposed by Salemi et al. regarding the expression of specific fragments of microRNA (miRNA), particularly miR-132 and miR-212, as potential key regulators in prostate cancer (PCa). As outlined by the Authors, the altered expression of miRNAs in cancer pathogenesis represents a well-consolidated knowledge in the current literature. More specifically, both miR-212 and miR-132 regulate subsets of genes involved in tumor progression in several tumor cell types as PCa, proving a central role in tumorigenesis, cell adhesion, and angiogenesis. In addition, a strong association between miR-132 expression and high Gleason score PCa has been lately depicted [...].

A National Multicenter Study on overall survival in elderly metastatic castrate-resistant prostate cancer patients treated with Radium-223

BACKGROUND

Radium-223 prolongs overall survival (OS) and delays time to the first symptomatic skeletal events in patients with symptomatic metastatic castration-resistant prostate cancer (mCRPC). There is a lack of evidence on the safety and efficacy of Radium-223 treatment in the very elderly population.

AIMS

Aim of this multicentre study is to analyze mCRPC patients treated with Radium-223 in terms of OS and to assess whether there are differences between young and elderly, as well as to verify efficacy and safety in patients ≥ 75 years of age.

METHODS

430 mCRPC patients of six Italian Centres were analyzed in this multicenter retrospective study. At baseline and after each cycle were collected clinical and diagnostic patients' parameters. The whole cohort was divided into two groups based on the age of the patients (< 75 years old and ≥ 75 years old).

RESULTS

47% of the patients were < 75 years old and 53% were ≥ 75 years old. The primary outcome, OS, does not show significant differences between the two subgroups if other basal parameters are considered. Considering clinical covariates in univariate models (p < 0.05) several clinical aspects have an impact on OS, except for age (p = 0.072). Age continues to have no significant impact on the OS (p = 0.274) even in multivariate models in the two groups. The toxic effects are similar in the two groups.

CONCLUSIONS

Radium-223 prolongs survival in both younger and older patients at the same baseline condition and is a good option in the symptomatic mCRPC setting compared to other agents.

Overall survival in mCPRC patients treated with Radium-223 in association with bone health agents: a national multicenter study

PURPOSE

Radium-223 has demonstrated efficacy in improving overall survival (OS) and in delaying symptomatic skeletal-related events (SREs). Bone Health Agents (BHA), i.e. RANK ligand inhibitor (Denosumab) and bisphosphonate such as zoledronic acid, are indicated to prevent SREs without a clear survival benefit. SREs on patient health have a high impact and it is, therefore, important to consider the role of new therapies with BHA to better understand the involvement of combination therapy. The primary aim of this multicentric study is to assess OS in mCRPC patients treated with Radium-223 in combination with BHA.

MATERIALS AND METHODS

430 consecutive patients treated with Radium-223 alone or in combination with BHA, affected by mCRPC, from January 2015 to July 2019 in six Italian Nuclear Medicine Units, were included. Furthermore, data were collected at baseline, after every Radium-223 administration, and during follow-up, at 3 and 6 months and 1 year after the 6th cycle. Clinical data have been evaluated before starting treatment with Radium-223 and at the end of treatment and/or at progression. Patients who received target bone therapy with BHA before Radium-223 treatment together with patients who did not receive this therapy at all (NO BHA GROUP), were compared to patients treated with concomitant Radium-223 and BHA (BHA GROUP).

RESULTS

In univariate models (p < .05) several clinical aspects have an impact on OS: concomitant BHA (p = .018), BMI (p .001), ECOG PS (p = .000), Baseline Hb (p = .000), Baseline PSA (p = .000), Baseline tALP (p = .000), Baseline LDH (p = .000), and Baseline neutrophils (p = .009). Baseline Hb, Baseline tALP, and Baseline LDH have been confirmed as statistically significant parameters in multivariate models. Indeed, concomitant BHA has not a significant impact on OS (p = .244) in multivariate models.

CONCLUSIONS

At univariate analysis, our data showed that NO BHA GROUP and BHA GROUP differ in OS by 7 months (95%CI: (1-16.4), p = .02). This is not confirmed at multivariate analysis where after adjusting for other baseline factors, BHA is not significant anymore. This is clearly explained as bias by indication: patients with the same levels of tALP, Hb, and LDH receiving or not receiving BHA are expected to have a similar survival. Our results support and confirm the role of Radium-223 therapy on OS and, furthermore, appear to confirm that BHA treatment has not a survival benefit.

Role of Nuclear Imaging in Cardiac Amyloidosis Management: Clinical Evidence and Review of Literature

Cardiac amyloidosis (CA) is an infiltrative disease characterized by the extracellular deposition of fibrils, amyloid, in the heart. The vast majority of patients with CA has one of two types between transthyretin amyloid (ATTR) and immunoglobulin light chain associated amyloid (AL), that have different prognosis and therapeutic options. CA is often underdiagnosed. The histological analysis of endomyocardial tissue is the gold standard for the diagnosis, although it has its limitations due to its invasive nature. Nuclear medicine now plays a key role in the early and accurate diagnosis of this disease, and in the ability to distinguish between the two forms. Recent several studies support the potential advantage of bone-seeking radionuclides as a screening technique for the most common types of amyloidosis, in particular ATTR form. This review presents noninvasive modalities to diagnose CA and focuses on the radionuclide imaging techniques (bone-seeking agents scintigraphy, cardiac sympathetic innervation and positron emission tomography studies) available to visualize myocardial amyloid involvement. Furthermore, we report the case of an 83-year old male with a history of prostate cancer, carcinoma of the cecum and kidney cancer, submitted to bone scan to detect bone metastasis, that revealed a myocardial uptake of 99mTC-HMPD suggestive of ATTR CA. An accurate and early diagnosis of CA able to distinguish beyween AL and ATTR CA combined to the improving therapies could improve the survival of patients with this disease.

Radium-223 in mCPRC patients: a large real-life Italian multicenter study

BACKGROUND

Radium-223 is a targeted alpha-particles therapy approved for the treatment of mCRPC patients with symptomatic bone metastases. To our knowledge we account for the largest cohort of mCRPC patients subjected to Radium-223 treatment in our country. We aim to describe in a real-life setting the largest cohort of mCRPC patients treated with Radium-223 ever taken into consideration.

METHODS

Four hundred and thirty consecutive mCRPC patients were enrolled. Clinical data have been collected at baseline and at the end of the Radium-223 treatment. Furthermore, the overall survival(OS) of our population has been provided.

RESULTS

One hundred fifty-seven patients (36.5%) were still alive at the time of data analysis. A mean number of 4.95±1.6 cycles of Radium-223 was reached by our cohort. 265 patients (61.6%) completed the whole six cycles regimen. The mean follow-up period from the first cycle of Radium-223 to the date of the analysis was 12.7 months. The analysis of patients Annual Incidence Rate (AIR) in relation to the number of Radium-223 cycles received depicting a clear advantage for those patients who completed the whole six administrations planned, with an AIR (AIR=0.32) of much lesser value compared to those that have performed five cycles (AIR =0.98). 165 patients (38.4%) dropped out of treatment for death or disease progression.

CONCLUSIONS

This study offers a cross-section of the clinical performance of Radium-223 treatment in a real-world context, confirming on a large scale the effectiveness of Radium-223 in improving the OS and quality of life, along with the preservation of an excellent safety profile.

New insight and future perspective of mesothelin-targeted agents in nuclear medicine

Purpose

The aim of this review is to summarize the main applications of mesothelin-targeting agents in the diagnosis of different types of cancers with a brief mention of nuclear magnetic resonance.

Methods

The articles taken into account were selected from PubMed, Scopus, and Web of Sciences, including research articles and abstracts that deal with radioimmunotherapy and new tracers for nuclear medicine and radiodiagnosis. Articles that are not in English have been excluded.

Results

Mesothelin-targeting agents were the subject of the selected articles in which tracers as 64Cu-DOTA-11-25mAb anti MSLN, 111In-MORAb-009-CHX-A″, 89Zr-MMOT0530A, 111In-amatuximab, 99mTc-A1, 89Zr-AMA, 89Zr-amatuximab, 64Cu-amatuximab, 89Zr-labeled MMOT0530A and 89Zr-B3 found application in detection of malignancies that overexpressed mesothelin. Only one article approached magnetic resonance imaging (MRI) diagnosis using superparamagnetic iron oxide nanoparticles linked to anti-mesothelin antibodies. The tracers proved to be highly sensitive in detecting mesothelin positive cells. 89Zr-labeled MMOT0530A could also be used to predict the suitability of patients to radioimmunotherapy.

Conclusions

Radiolabeled anti-mesothelin antibodies could be crucial as a treatment tool and for predicting the eligibility and the response of the patient to radioimmunotherapy through the study of the expression grade of mesothelin. They can be a relevant tool for pancreatic adenocarcinoma, lung cancer, human epidermoid carcinoma, ovarian cancer, malignant mesothelioma in which mesothelin is widely expressed.

Validation of the 3-variable prognostic score (3-PS) in mCRPC patients treated with 223Radium-dichloride: a national multicenter study

Objective

Radium-223 (²²³Ra) has been approved for treatment in patients with metastatic castration-resistant prostatic cancer (mCRPC) and bone metastasis. This α-emitting radionuclide has a beneficial effect on pain and is also capable to increase overall survival (OS). Several studies evaluated the prognostic value of different biomarkers at baseline, such as serum values, imaging parameters or pain. To date, however, clinicians lack a validated and simple system to assess which patients will most likely benefit from ²²³Ra treatment. The 3-variable prognostic score (3-PS), proposed in a single-center study in 2017 classifies patients in five prognostic groups with a specific OS. This study aims to validate the 3-PS in a larger multicenter population.

Methods

Four hundred and thirty mCRPC patients treated with ²²³Ra from six different centers were analyzed. The 3-PS score consists of the collection of baseline hemoglobin, prostatic specific antigen and Eastern cooperative oncology group performance status and was initially applied to the whole population (total group). The score was then validated on the 338 patient’s subgroup (clean group) obtained by subtracting the 92 patients enrolled for the original study of the 3-PS score. This purified group served as further validation evidence.

Results

Statistical analysis showed that the 3-PS score was valid on the total group as well as in the clean group as the AUC estimated (0.74) falls within the CI of the AUC calculated on the validation sample (95% CI 0.66–0.82).

Conclusion

This study confirms the validity of the 3-PS score for mCRPC patients. This score is simple, noninvasive and affordable and can be easily used to select patients that will most probably complete ²²³Ra treatment. In addition, this tool provides an exact estimate of life expectancy in terms of OS.

Targeted Alpha Therapy with Thorium-227

Targeted alpha therapy (TAT) can deliver high localized burden of radiation selectively to cancer cells as well as the tumor microenvironment, while minimizing toxicity to normal surrounding cell. Radium-223 (²²³Ra), the first-in-class α-emitter approved for bone metastatic castration-resistant prostate cancer has shown the ability to prolong patient survival. Targeted Thorium-227 (²²⁷Th) conjugates represent a new class of therapeutic radiopharmaceuticals for TAT. They are comprised of the α-emitter ²²⁷Th complexed to a chelator conjugated to a tumor-targeting monoclonal antibody. In this review, the authors will focus out interest on this therapeutic agent. In recent studies ²²⁷Th-labeled radioimmunoconjugates showed a relevant stability both in serum and vivo conditions with a significant antigen-dependent inhibition of cell growth. Unlike ²²³Ra, the parent radionuclide ²²⁷Th can form highly stable chelator complexes and is therefore amenable to targeted radioimmunotherapy. The authors discuss the future potential role of ²²⁷Th TAT in the treatment of several solid as well as hematologic malignancies.

Scintigraphic load of bone disease evaluated by DASciS software as a survival predictor in metastatic castration-resistant prostate cancer patients candidates to 223RaCl treatment

Background

Aim of our study was to assess the load of bone disease at starting and during Ra-223 treatment as an overall survival (OS) predictor in metastatic castration-resistant prostate cancer (mCRPC) patients. Bone scan index (BSI) is defined as the percentage of total amount of bone metastasis on whole-body scintigraphic images. We present a specific software (DASciS) developed by an engineering team of “Sapienza” University of Rome for BSI calculation.

Patients and methods

127 mCRPC patients bone scan images were processed with DASciS software, and BSI was tested as OS predictor.

Results

546 bone scans were analyzed revealing that the extension of disease is a predictor of OS (0–3% = 28 months of median survival (MoMS]; 3%–5% = 11 MoMS, > 5% = 5 MoMS). BSI has been analyzed as a single parameter for OS, determining an 88% AUC. Moreover, the composition between the BSI and the 3-PS (3-variable prognostic score) determines a remarkable improvement of the AUC (91%), defining these two parameters as the best OS predictors.

Conclusions

This study suggests that OS is inversely correlated with the load of bone disease in mCRPC Ra-223-treated subjects. DASciS software appears a promising tool in identifying mCRPC patients that more likely take advantage from Ra-223 treatment. BSI is proposed as a predictive variable for OS and included to a multidimensional clinical evaluation permits to approach the patients’ enrollment in a rational way, allowing to enhance the treatment effectiveness together with cost optimization.

Primary Radical Prostatectomy or Ablative Radiotherapy as Protective Factors for Patients With mCRPC Treated With Radium-223 Dichloride: An Italian Multicenter Study

BACKGROUND

We investigated, in a real-life setting, the prognostic relevance of previous primary treatment (radical prostatectomy [RP] or external beam radiotherapy [EBRT]) on overall survival for patients with metastatic castration-resistant prostate cancer (mCRPC) treated with radium-223 (²²³Ra).

MATERIALS AND METHODS

In the present multicenter retrospective study, we enrolled 275 consecutive patients. The demographic and clinical data and mCRPC characteristics were recorded and evaluated at baseline and at the end of treatment or progression. ²²³Ra was administered according to the current label authorization until disease progression or unacceptable toxicity. We divided the whole cohort into 2 groups: those who had undergone primary radical prostatectomy or ablative radiotherapy (RP/EBRT) and those who had not received previous primary treatment (NO).

RESULTS

Of the 275 patients, 128 (46.5%) were alive and undergoing monitoring at the last follow-up examination, 103 (37.4%) had stopped treatment because of disease progression or the onset of comorbidities, and 147 (53.5%) had died during the study period. Of the 275 patients, 132 were in the RP/EBRT group (48%), of whom 93 had undergone RP and 76 had undergone ablative EBRT, and 143 patients were in the NO group (52%). The data showed a clear advantage for the patients in the RP/EBRT group compared with those in the NO group, with an estimated median survival of 18 versus 11 months, respectively (P < .001). The results from the multivariate analysis corroborated this trend, with a hazard ratio of 0.7 (P = .0443), confirming the better outcome for the RP/EBRT group.

CONCLUSIONS

Previous radical treatment provides a protective role for patients with mCRPC undergoing ²²³Ra treatment.

Analysis of Unusual Adverse Effects After Radium-223 Dichloride Administration

BACKGROUND

To our knowledge, no previous study or literature review has been performed about the effects of the extravasation of therapeutic radiopharmaceutical agents and its potential consequences, especially regarding alpha-particle emitting radiopharmaceuticals.

METHODS

Even if Radium-223 dichloride is known to be a relatively safe drug to manage, despite the correctness of the procedures applied , unexpected delayed adverse effects can occur. In our vast experience, we rarely observed lymphedema, even after some time, at the site of administration.

RESULTS

Management of lymphedema caused by radiopharmaceuticals administration has been addressed through clinical examples. The sudden intervention allowed a fast remission of the signs and symptoms complained by patients treated with Radium-223 dichloride.

CONCLUSION

The management of adverse effects after radiopharmaceuticals administration as in case of lymphedema onset, is extremely simple. These data confirm the safety of Radium-223 treatment.

Reversibility of castration resistance status after Radium-223 dichloride treatment: clinical evidence and review of the literature

In the history of prostate cancer, some of the patients progressed to castration-resistant prostate cancer (CRPC) stage and, although new drugs and treatment protocols have been introduced, CRPC presents poor prognosis. This review is focused on biological mechanisms, underlying CRPC described in scientific literature in order to explain the reversion of resistance to castration. We present the case of a 73-year-old man, affected by bone metastatic CRPC, early treated with Radium-223 with a complete response. After 15 months from Radium-223 treatment, prostate-specific antigen increased with radiological progression. Androgen deprivation therapy was again performed and was effective, despite previous CRPC condition and no known mechanisms that may explain the reversion of this condition. Therefore, to our knowledge, he is the unique described case of the reversion of resistance to castration. Nevertheless, promising aspects may be lack of intrametastatic production of androgen or the suppression of bypass androgen receptor signaling pathways. Furthermore, the cytotoxic action of Radium-223 on cancer stem cell (CSC), due to surrounding clones with high-bone turnover, or the immune response that underlying the abscopal effect, may also modulate the reversion of CRPC after Radium-223. If confirmed by multicenter trials, the reversion of CRPC may impact on the management of prostate cancer.