A comparative study of 188Re-HEDP, 186Re-HEDP, 153Sm-EDTMP and 89Sr in the treatment of painful skeletal metastases

Efficacy and Safety of 177Lu-DOTA-IBA in Tumor Bone Metastasis Treatment: A Prospective Clinical Trial

PURPOSE

The aim of this study was to evaluate the efficacy and safety of 177Lu-DOTA-IBA for pain palliation in participants with bone metastases and confirm its potential for treating bone metastasis.

PATIENTS AND METHODS

Overall, 69 participants with bone metastases were included. 68Ga-DOTA-IBA PET/CT was performed within 1 week before treatment. Vital signs, blood markers, electrocardiogram, Karnofsky Performance Status (KPS), and pain scores were evaluated within 7 days before treatment. Postadministration of 177Lu-DOTA-IBA, participants' vital signs and general conditions were monitored. Follow-up evaluations of KPS, pain scores, and blood biomarkers were performed within 8 weeks. 68Ga-DOTA-IBA PET/CT was repeated to evaluate imaging responses at 8 weeks. Imaging responses were defined as complete response, partial response, stable disease, and disease progression. Subsequent treatments were administered based on participants' agreement and clinical conditions.

RESULTS

Sixty-nine participants received at least 1 dose of 177Lu-DOTA-IBA treatment; 22 received 38 reinjected doses, totaling 107 treatments. The median injection dose of 177Lu-DOTA-IBA was 1110 MBq. The pain remission rates after first treatment, retreatment, and total treatment were 82.5%, 72.4%, and 79.3%, respectively. The improvement rates in KPS for first treatment, retreatment, and total treatment were 81.3%, 60.6%, and 74.2%, respectively. The total incidence of the pain flare reaction (temporary aggravation of pain intensity after treatment) was 16.8%. Comparative analysis of 68Ga-DOTA-IBA PET/CT showed a 27.1% rate of partial response imaging response. The total incidence of adverse hematological events was 15%.

CONCLUSIONS

177Lu-DOTA-IBA is a promising bone-seeking radiopharmaceutical with a considerable pain relief rate and safety. It also can benefit some participants with bone metastases in imaging response.

Adverse reactions to therapeutic radiopharmaceuticals

Radiopharmaceuticals are drugs used in treatment or diagnosis that contain a radioactive part, usually a pharmaceutical part in their structure. Adverse drug reactions are harmful and unexpected responses that occur when administered at normal doses. Although radiopharmaceuticals are regarded as safe medical products, adverse reactions should not be ignored. More serious adverse reactions such as myelosuppression, pleural effusion, and death may develop in therapeutic radiopharmaceuticals due to their use at higher doses than those used in diagnosis. Therefore, monitoring adverse reactions and reporting them to health authorities is important. This review aims to provide information about adverse reactions that may be related to radiopharmaceuticals used in treatment.

Bisphosphonates as Radiopharmaceuticals: Spotlight on the Development and Clinical Use of DOTAZOL in Diagnostics and Palliative Radionuclide Therapy

Bisphosphonates are therapeutic agents that have been used for almost five decades in the treatment of various bone diseases, such as osteoporosis, Paget disease and prevention of osseous complications in cancer patients. In nuclear medicine, simple bisphosphonates such as 99mTc-radiolabelled oxidronate and medronate remain first-line bone scintigraphic imaging agents for both oncology and non-oncology indications. In line with the growing interest in theranostic molecules, bifunctional bisphosphonates bearing a chelating moiety capable of complexing a variety of radiometals were designed. Among them, DOTA-conjugated zoledronate (DOTAZOL) emerged as an ideal derivative for both PET imaging (when radiolabeled with 68Ga) and management of bone metastases from various types of cancer (when radiolabeled with 177Lu). In this context, this report provides an overview of the main medicinal chemistry aspects concerning bisphosphonates, discussing their roles in molecular oncology imaging and targeted radionuclide therapy with a particular focus on bifunctional bisphosphonates. Particular attention is also paid to the development of DOTAZOL, with emphasis on the radiochemistry and quality control aspects of its preparation, before outlining the preclinical and clinical data obtained so far with this radiopharmaceutical candidate.

Dosimetry of bone seeking beta emitters for bone pain palliation metastases

Amongst cancer patients, bone pain due to skeletal metastases is a major cause of morbidity. A number of beta-emitting radiopharmaceuticals have been used to provide internal radiotherapy of bone metastases and provide palliative pain relief. In this article we describe the different physical characteristics of the various beta emitting radionuclides which have been used in this clinical setting and the potential impact of differences in dose-rate on radiobiological outcomes. A detailed review of the biodistribution of these treatments, based on both in-vivo clinical investigations and post mortem autoradiography assessments is provided. These treatments result in physiological delivery of radiation doses to the target disease as well as to critical healthy organs. Particular attention is paid to the radiation doses received by normal bone tissue, bone marrow as well as metastatic bone disease. The underlying models of radiation transport within bone and bone marrow are reviewed alongside the practical steps that must be taken to acquire and analyse the information require for clinical dosimetry assessments. The role of whole body measurements, blood and faecal assays as well as both planar and tomographic gamma camera imaging are considered. In addition we review the rationale for allocating measured bone uptake between trabecular and cortical bone tissue. The difference between bone volume and bone surface seeking radiopharmaceuticals are also discussed. This review also extends to the development of preclinical models of bone metastases which may inform future dosimetric calculations. Finally, we also present a comprehensive review of the dosimetry of the established treatments ⁸⁹Strontium-chloride; ³²Phosphorus; ¹⁸⁸Rhenium-hydroxyethylidine disphosphonate; ¹⁸⁶Rhenium-1,1-hydroxyethylidene disphosphonate (¹⁸⁶Re-HEDP); ¹⁵³Samarium-ethylenediaminetetramethylene phosphonate; as well as the emerging treatments ¹⁸⁸Rhenium-zoledronic acid; ¹⁸⁸Rhenium-ibedronat; ¹⁷⁷Lutetium-zoledronic acid; and ¹⁷⁷Lutetium ethylenediaminetetramethylene phosphonate. This review highlights not only the inter treatment differences in the radiation absorbed doses delivered to metastatic disease by different radiopharmaceuticals but also the intra treatment differences which result in a large range of observed doses between patients.

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.

Targeted Palliative Radionuclide Therapy for Metastatic Bone Pain

Bone metastasis develops in multiple malignancies with a wide range of incidence. The presence of multiple bone metastases, leading to a multitude of complications and poorer prognosis. The corresponding refractory bone pain is still a challenging issue managed through multidisciplinary approaches to enhance the quality of life. Radiopharmaceuticals are mainly used in the latest courses of the disease. Bone-pain palliation with easy-to-administer radionuclides offers advantages, including simultaneous treatment of multiple metastatic foci, the repeatability and also the combination with other therapies. Several β¯- and α-emitters as well as pharmaceuticals, from the very first [⁸⁹Sr]strontium-dichloride to recently introduced [²²³Ra]radium-dichloride, are investigated to identify an optimum agent. In addition, the combination of bone-seeking radiopharmaceuticals with chemotherapy or radiotherapy has been employed to enhance the outcome. Radiopharmaceuticals demonstrate an acceptable response rate in pain relief. Nevertheless, survival benefits have been documented in only a limited number of studies. In this review, we provide an overview of bone-seeking radiopharmaceuticals used for bone-pain palliation, their effectiveness and toxicity, as well as the results of the combination with other therapies. Bone-pain palliation with radiopharmaceuticals has been employed for eight decades. However, there are still new aspects yet to be established.

ICRP Publication 140: Radiological Protection in Therapy with Radiopharmaceuticals

Radiopharmaceuticals are increasingly used for the treatment of various cancers with novel radionuclides, compounds, tracer molecules, and administration techniques. The goal of radiation therapy, including therapy with radiopharmaceuticals, is to optimise the relationship between tumour control probability and potential complications in normal organs and tissues. Essential to this optimisation is the ability to quantify the radiation doses delivered to both tumours and normal tissues. This publication provides an overview of therapeutic procedures and a framework for calculating radiation doses for various treatment approaches. In radiopharmaceutical therapy, the absorbed dose to an organ or tissue is governed by radiopharmaceutical uptake, retention in and clearance from the various organs and tissues of the body, together with radionuclide physical half-life. Biokinetic parameters are determined by direct measurements made using techniques that vary in complexity. For treatment planning, absorbed dose calculations are usually performed prior to therapy using a trace-labelled diagnostic administration, or retrospective dosimetry may be performed on the basis of the activity already administered following each therapeutic administration. Uncertainty analyses provide additional information about sources of bias and random variation and their magnitudes; these analyses show the reliability and quality of absorbed dose calculations. Effective dose can provide an approximate measure of lifetime risk of detriment attributable to the stochastic effects of radiation exposure, principally cancer, but effective dose does not predict future cancer incidence for an individual and does not apply to short-term deterministic effects associated with radiopharmaceutical therapy. Accident prevention in radiation therapy should be an integral part of the design of facilities, equipment, and administration procedures. Minimisation of staff exposures includes consideration of equipment design, proper shielding and handling of sources, and personal protective equipment and tools, as well as education and training to promote awareness and engagement in radiological protection. The decision to hold or release a patient after radiopharmaceutical therapy should account for potential radiation dose to members of the public and carers that may result from residual radioactivity in the patient. In these situations, specific radiological protection guidance should be provided to patients and carers.

Rhenium-188 Labeled Radiopharmaceuticals: Current Clinical Applications in Oncology and Promising Perspectives

Rhenium-188 (188Re) is a high energy beta-emitting radioisotope with a short 16.9 h physical half-life, which has been shown to be a very attractive candidate for use in therapeutic nuclear medicine. The high beta emission has an average energy of 784 keV and a maximum energy of 2.12 MeV, sufficient to penetrate and destroy targeted abnormal tissues. In addition, the low-abundant gamma emission of 155 keV (15%) is efficient for imaging and for dosimetric calculations. These key characteristics identify 188Re as an important therapeutic radioisotope for routine clinical use. Moreover, the highly reproducible on-demand availability of 188Re from the 188W/188Re generator system is an important feature and permits installation in hospital-based or central radiopharmacies for cost-effective availability of no-carrier-added (NCA) 188Re. Rhenium-188 and technetium-99 m exhibit similar chemical properties and represent a "theranostic pair." Thus, preparation and targeting of 188Re agents for therapy is similar to imaging agents prepared with 99mTc, the most commonly used diagnostic radionuclide. Over the last three decades, radiopharmaceuticals based on 188Re-labeled small molecules, including peptides, antibodies, Lipiodol and particulates have been reported. The successful application of these 188Re-labeled therapeutic radiopharmaceuticals has been reported in multiple early phase clinical trials for the management of various primary tumors, bone metastasis, rheumatoid arthritis, and endocoronary interventions. This article reviews the use of 188Re-radiopharmaceuticals which have been investigated in patients for cancer treatment, demonstrating that 188Re represents a cost effective alternative for routine clinical use in comparison to more expensive and/or less readily available therapeutic radioisotopes.

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.

Personalized Radiation Therapy in Cancer Pain Management

The majority of advanced cancer patients suffer from pain, which severely deteriorates their quality of life. Apart from analgesics, bisphosphonates, and invasive methods of analgesic treatment (e.g., intraspinal and epidural analgesics or neurolytic blockades), radiation therapy plays an important role in pain alleviation. It is delivered to a growing primary tumour, lymph nodes, or distant metastatic sites, producing pain of various intensity. Currently, different regiments of radiation therapy methods and techniques and various radiation dose fractionations are incorporated into the clinical practice. These include palliative radiation therapy, conventional external beam radiation therapy, as well as modern techniques of intensity modulated radiation therapy, volumetrically modulated arch therapy, stereotactic radiosurgery or stereotactic body radiation therapy, and brachytherapy or radionuclide treatment (e.g., radium-223, strontium-89 for multiple painful osseous metastases). The review describes the possibilities and effectiveness of individual patient-tailored conventional and innovative radiation therapy approaches aiming at pain relief in cancer patients.

Radionuclide Therapy of Metastatic Prostate Cancer

The current mainstay of treatment in metastatic prostate cancer is based on hormonal manipulations. Standard androgen deprivation therapy and novel androgen axis drugs are commonly well tolerable and can stabilize metastatic hormone-sensitive prostate cancers for years. However, metastatic castration-resistant prostate cancer is still challenging to treat. Except taxanes, prostate cancer presents intrinsic resistance against conventional chemotherapies. The typically elderly patient population excludes more aggressive treatment regimens. First clinical trials evaluating immunotherapy or tyrosine-kinase-inhibitors against prostate cancer failed. In contrast, prostate cancer can be radiosensitive and external beam radiotherapy is effective in localized prostate cancer, thus providing a good rationale for the use of systemic radiopharmaceuticals in the metastatic setting. Beta-particle emitting "bone-seekers" have a long history and are effective as analgesics but do not improve survival because they are limited by red-marrow dose. Alpha emitting ²²³Radium can be used in a dose that prolongs survival but is restricted to bone-confined patients. Currently radiolabeled high-affinity ligands to the prostate-specific membrane antigen are in clinical evaluation. While radioimmunotherapy approaches were limited by the long circulation time and slow tumor-accumulation of antibodies, low molecular weight PSMA-specific ligands offer an approx. ten-fold improved tumor to red-marrow ratio in comparison to the unspecific bone-seekers. Early clinical studies demonstrate that regarding surrogate markers, such as >50% PSA reduction (60%) and radiologic response (80%), PSMA-therapy exceeds the antitumor activity of all approved or other recently tested compounds; for example, PSA-response was only observed in approx. a total of 10% of patients treated with ipilimumab, sunitinib, cabozantinib, or xofigo, respectively and in approx. 30, 40, 50% of patients treated with abiraterone, cabazitaxel, or enzalutamide. Also progression free and overall survivals of these single-arm studies appear promising when compared to historical controls. Consecutively, the first PSMA-RLT recently advanced into phase-3 (¹⁷⁷Lu-PSMA-617; VISION-trial). Future developments aim to avoid off-target radiation by ligand-optimization and to outperform the antitumor activity of beta-emitter PSMA-RLT by labeling with highly focused, high energy transferring alpha-nuclides; however the latter potentially also increasing the risk of side-effects and additional early phase studies are needed to improve treatment protocols. Academically clinical research is developing prognostic tools to improve treatment benefit by selecting the most appropriate patients in advance.

Targeted Radionuclide Therapy of Painful Bone Metastases: Past Developments, Current Status, Recent Advances and Future Directions

Bone pain arising from secondary skeletal malignancy constitutes one of the most common types of chronic pain among patients with cancer which can lead to rapid deterioration of the quality of life. Radionuclide therapy using bone-seeking radiopharmaceuticals based on the concept of localization of the agent at bone metastases sites to deliver focal cytotoxic levels of radiation emerged as an effective treatment modality for the palliation of symptomatic bone metastases. Bone-seeking radiopharmaceuticals not only provide palliative benefit but also improve clinical outcomes in terms of overall and progression-free survival. There is a steadily expanding list of therapeutic radionuclides which are used or can potentially be used in either ionic form or in combination with carrier molecules for the management of bone metastases. This article offers a narrative review of the armamentarium of bone-targeting radiopharmaceuticals based on currently approved investigational and potentially useful radionuclides and examines their efficacy for the treatment of painful skeletal metastases. In addition, the article also highlights the processes, opportunities, and challenges involved in the development of bone-seeking radiopharmaceuticals. Radium-223 is the first agent in this class to show an overall survival advantage in Castration-Resistant Prostate Cancer (CRPC) patients with bone metastases. This review summarizes recent advances, current clinical practice using radiopharmaceuticals for bone pain palliation, and the expected future prospects in this field.

Bone Metastasis Pain, from the Bench to the Bedside

Bone is the most frequent site of metastasis of the most common cancers in men and women. Bone metastasis incidence has been steadily increasing over the years, mainly because of higher life expectancy in oncologic patients. Although bone metastases are sometimes asymptomatic, their consequences are most often devastating, impairing both life quality and expectancy, due to the occurrence of the skeletal-related events, including bone fractures, hypercalcemia and spinal cord compression. Up to 75% of patients endure crippling cancer-induced bone pain (CIBP), against which we have very few weapons. This review's purpose is to discuss the molecular and cellular mechanisms that lead to CIBP, including how cancer cells convert the bone "virtuous cycle" into a cancer-fuelling "vicious cycle", and how this leads to the release of molecular mediators of pain, including protons, neurotrophins, interleukins, chemokines and ATP. Preclinical tests and assays to evaluate CIBP, including the incapacitance tester (in vivo), and neuron/glial activation in the dorsal root ganglia/spinal cord (ex vivo) will also be presented. Furthermore, current therapeutic options for CIBP are quite limited and nonspecific and they will also be discussed, along with up-and-coming options that may render CIBP easier to treat and let patients forget they are patients.

Rhenium-188 Hydroxyethane 1,1-Diphosphonic Acid (HEDP) for Bone Pain Palliation Using BARC-HEDP Kits versus Pars-HEDP Kits: A Comparison on Preparation and Performance Aspects at Hospital Radiopharmacy

Purpose of the Study:

Rhenium-188 hydroxyethane 1,1-diphosphonic acid (HEDP) is a clinically established radiopharmaceutical for palliation of bone pain due to osseous metastases. Recently, the Bhabha Atomic Research Centre (BARC) had developed a freeze-dried kit for the preparation of rhenium-188 HEDP. The present study compares the radiochemistry aspects of indigenous BARC-HEDP kits with commercially available HEDP kits from Pars Isotope Company, Iran.

Materials and Methods:

Freeze-dried HEDP kits were obtained from Radiopharmaceuticals Division, BARC, and Pars Isotope Company, Iran. Following recommended procedures, rhenium-188 HEDP was prepared using freeze-dried kits from both sources using freshly eluted rhenium-188 sodium perrhenate obtained from a commercial tungsten-188/rhenium-188 generator.

Results:

Both kits could be used for the preparation of rhenium-188 HEDP in >95% radiochemical purity (RCP). Rhenium-188 HEDP prepared from both kits showed comparable in vitro stability as well as pharmacokinetic properties. The normal bone-to-soft tissue ratio observed for rhenium-188 HEDP prepared using BARC-HEDP kit and Pars-HEDP kit was 1.993 and 1.416, respectively.

Conclusions:

Both HEDP kits provided a user-friendly solution for the preparation of rhenium-188 HEDP. While Pars-HEDP-kit permits the addition of only 2 mL of rhenium-188 perrhenate solution per kit vial, BARC-HEDP-kit allows up to 5 mL. This feature permits the preparation of patient dose of rhenium-188 HEDP even with older generators providing rhenium-188 perrhenate having a low radioactive concentration (activity/mL). In addition, availability of an indigenous product is always preferable over imported options.

Pain Management in Metastatic Bone Disease: A Literature Review

Cancer means an uncontrolled division of abnormal cells in the body. It is a leading cause of death today. Not only the disease itself but its complications are also adding to the increase in mortality rate. One of the major complications is the pain due to metastasis of cancer. Pain is a complex symptom which has physical, psychological, and emotional impacts that influence the daily activities as well as social life. Pain acts as an alarm sign, telling the body that something is wrong. Pain can manifest in a multitude fashion. Management of bone pain due to metastasis involves different modes with some specific treatments according to the type of primary cancer. Over the years various treatment modalities have been tried and tested to improve the pain management including the use of non-steroidal anti-inflammatory drugs (NSAIDs), opioids, bisphosphonates, tricyclic antidepressants, corticosteroids, growth factors and signaling molecules, ET-1 receptor antagonists, radiotherapy as well as surgical management. The topic of discussion will cover each one of these in detail.

Radionuclide Therapy for Bone Metastases: Utility of Scintigraphy and PET Imaging for Treatment Planning

The skeleton is a common site for cancer metastases. Bone metastases are a major cause of morbidity and mortality and associated with pain, pathologic fractures, spinal cord compression, and decreased survival. Various radionuclides have been used for pain therapy. Recently, an α-emitter has been shown to improve overall survival of patients with bone metastases from castration-resistant prostate cancer and was approved as a therapeutic agent. The aim of this article is to provide an overview regarding state of the art radionuclide therapy options for bone metastases, with focus on the role of PET imaging in therapy planning.

188Re-HEDP therapy in the therapy of painful bone metastases

For bone-targeted radionuclide therapy (BTRT), different commercial radiopharmaceuticals are available such as strontium-89, 186Rhenium-hydroxyethylidene diphosphonate (186Re-HEDP), Samarium-153-ethylenediamine tetramethylene phosphonic acid, and radium-223. Unfortunately, the commercial available radiopharmaceuticals are very expensive (from 1,200 to 36,000€ per patient in Europe). The 188W/188Re generator is an ideal source for the long-term (4-6 months) continuous availability of 188Re suitable for the preparation of radiopharmaceuticals for different radionuclide therapies. Labeling at HEDP, it can use cost-effective for BTRT, if enough patients are available for therapy. And so, 188Re-HEDP is the ideal candidate in developing countries which high population to replace the other agents. Two German groups documented a response rate of 80% without any severe side effects and similar bone marrow toxicity compared to the other compounds for 188Re-HEDP. Using 188Re-HEDP in repeated treatments, a prolonged overall survival of repeated to single application was observed (from 4.5 months for single to 15.7 months using ≥≥3 applications).

EANM guidelines for radionuclide therapy of bone metastases with beta-emitting radionuclides

The skeleton is the most common metastatic site in patients with advanced cancer. Pain is a major healthcare problem in patients with bone metastases. Bone-seeking radionuclides that selectively accumulate in the bone are used to treat cancer-induced bone pain and to prolong survival in selected groups of cancer patients. The goals of these guidelines are to assist nuclear medicine practitioners in: (a) evaluating patients who might be candidates for radionuclide treatment of bone metastases using beta-emitting radionuclides such as strontium-89 (89Sr), samarium-153 (153Sm) lexidronam (153Sm-EDTMP), and phosphorus-32 (32P) sodium phosphate; (b) performing the treatments; and

Clinical utility of 188Rhenium-hydroxyethylidene-1,1-diphosphonate as a bone pain palliative in multiple malignancies

¹⁸⁸Rhenium-hydroxyethylidene-1,1-diphosphonate (¹⁸⁸Re-HEDP) is a clinically established radiopharmaceutical for bone pain palliation of patients with metastatic bone cancer. Herein, the effectiveness of ¹⁸⁸Re-HEDP for the palliation of painful bone metastases was investigated in an uncontrolled initial trial in 48 patients with different types of advanced cancers. A group of 48 patients with painful bone metastases of lung, prostate, breast, renal, and bladder cancer was treated with 2.96–4.44 GBq of ¹⁸⁸Re-HEDP. The overall response rate in this group of patients was 89.5%, and their mean visual analog scale score showed a reduction from 9.1 to 5.3 (P < 0.003) after 1 week posttherapy. The patients did not report serious adverse effects either during intravenous administration or within 24 h postadministration of ¹⁸⁸Re-HEDP. Flare reaction was observed in 54.2% of patients between day 1 and day 3. There was no correlation between flare reaction and response to therapy (P < 0.05). Although bone marrow suppression was observed in patients receiving higher doses of ¹⁸⁸Re-HEDP, it did not result in any significant clinical problems. The present study confirmed the clinical utility and cost-effectiveness of ¹⁸⁸Re-HEDP for palliation of painful bone metastases from various types of cancer in developing countries.

Feasibility study for production and quality control of Yb-175 as a byproduct of no carrier added Lu-177 preparation for radiolabeling of DOTMP

Skeletal uptake of β^- emitters of DOTMP complexes is used for the bone pain palliation. In this study, two moderate energy β^- emitters, ¹⁷⁷Lu (T_1/2 = 6.7 days, E_βmax = 497 keV) and ¹⁷⁵Yb (T_1/2 = 4.2 days, E_βmax = 480 keV), are considered as potential agents for the development of the bone-seeking radiopharmaceuticals. Since the specific activity of the radiolabelled carrier molecules should be high, the non-carrier-added (NCA) radionuclides have an effective role in nuclear medicine. Many researchers have presented the synthesis of NCA ¹⁷⁷Lu. Among these separation techniques, extraction chromatography has been considered more capable than other methods. In this study, a new approach, in addition to production of NCA ¹⁷⁷Lu by EXC procedure is using pure ¹⁷⁵Yb that was usually considered as a waste material in this method but because of high radionuclidic purity of ¹⁷⁵Yb produced by this method we used it for radiolabeling as well as NCA ¹⁷⁷Lu. To obtain optimum conditions, some effective factors on separation of Lu/Yb by EXC were investigated. The NCA ¹⁷⁷Lu and pure ¹⁷⁵Yb were produced with radionuclidic purity of 99.99 and 99.97% respectively by irradiation of enriched ¹⁷⁶Yb target in thermal neutron flux of 5 × 10¹³ n/cm² s for 14 days. ¹⁷⁷Lu-DOTMP and ¹⁷⁵Yb-DOTMP were obtained with high radiochemical purities (> 95%) under optimized reaction conditions. Two radiolabeled complexes exhibited excellent stability at room temperature. Biodistribution studies in rats showed favorable selective skeletal uptake with rapid clearance from blood along with insignificant accumulation of activity in other non-target organs for two radiolabelled complexes.

Theranostics in nuclear medicine practice

The importance of personalized medicine has been growing, mainly due to a more urgent need to avoid unnecessary and expensive treatments. In nuclear medicine, the theranostic approach is an established tool for specific molecular targeting, both for diagnostics and therapy. The visualization of potential targets can help predict if a patient will benefit from a particular treatment. Thanks to the quick development of radiopharmaceuticals and diagnostic techniques, the use of theranostic agents has been continually increasing. In this article, important milestones of nuclear therapies and diagnostics in the context of theranostics are highlighted. It begins with a well-known radioiodine therapy in patients with thyroid cancer and then progresses through various approaches for the treatment of advanced cancer with targeted therapies. The aim of this review was to provide a summary of background knowledge and current applications, and to identify the advantages of targeted therapies and imaging in nuclear medicine practices.

Imaging and dosimetry for radium-223: the potential for personalized treatment

Radium-223 (223Ra) offers a new option for the treatment of bone metastases from prostate cancer. As cancer treatment progresses towards personalization, the potential for an individualized approach is exemplified in treatments with radiotherapeutics due to the unique ability to image in vivo the uptake and retention of the therapeutic agent. This is unmatched in any other field of medicine. Currently, 223Ra is administered according to standard fixed administrations, modified according to patient weight. Although gamma emissions comprise only 1% of the total emitted energy, there are increasing reports that quantitative imaging is feasible and can facilitate patient-specific dosimetry. The aim of this article is to review the application of imaging and dosimetry for 223Ra and to consider the potential for treatment optimization accordingly, in order to ensure clinical and cost effectiveness of this promising agent.

WITHDRAWN: Radioisotopes for metastatic bone pain

BACKGROUND

This is an update of the review published in Issue 4, 2003. Bone metastasis cause severe pain as well as pathological fractures, hypercalcaemia and spinal cord compression. Treatment strategies currently available to relieve pain from bone metastases include analgesia, radiotherapy, surgery, chemotherapy, hormone therapy, radioisotopes and bisphosphonates.

OBJECTIVES

To determine efficacy and safety of radioisotopes in patients with bone metastases to improve metastatic pain, decrease number of complications due to bone metastases and improve patient survival.

SEARCH METHODS

We sought randomised controlled trials (RCTs) in MEDLINE, EMBASE, CENTRAL, and the PaPaS Trials Register up to October 2010.

SELECTION CRITERIA

Studies selected had metastatic bone pain as a major outcome after treatment with a radioisotope, compared with placebo or another radioisotope.

DATA COLLECTION AND ANALYSIS

We assessed the risk of bias of included studies by their sequence generation, allocation concealment, blinding of study participants, researchers and outcome assessors, and incomplete outcome data. Two review authors extracted data. We performed statistical analysis as an "available case" analysis, and calculated global estimates of effect using a random-effects model. We also performed an intention-to-treat (ITT) sensitivity analysis.

MAIN RESULTS

This update includes 15 studies (1146 analyzed participants): four (325 participants) already included and 11 new (821 participants). Only three studies had a low risk of bias. We observed a small benefit of radioisotopes for complete relief (risk ratio (RR) 2.10, 95% CI 1.32 to 3.35; Number needed to treat to benefit (NNT) = 5) and complete/partial relief (RR 1.72, 95% CI 1.13 to 2.63; NNT = 4) in the short and medium term (eight studies, 499 participants). There is no conclusive evidence to demonstrate that radioisotopes modify the use of analgesia with respect to placebo. Leucocytopenia and thrombocytopenia are secondary effects significantly associated with the administration of radioisotopes (RR 5.03; 95% CI 1.35 to 18.70; Number needed to treat to harm (NNH) = 13). Pain flares were not higher in the radioisotopes group (RR 0.74; 95% CI 0.27 to 2.06). There are scarce data of moderate quality when comparing Strontium-89 (89Sr) with Samarium-153 (153Sm), Rhenium-186 (186Re) and Phosphorus-32 (32P). We observed no significant differences between treatments. Similarly, we observed no differences when we compared different doses of 153Sm (0.5 versus 1.0 mCi).

AUTHORS' CONCLUSIONS

This update adds new evidence on efficacy of radioisotopes versus placebo, 89Sr compared with other radioisotopes, and dose-comparisons of 153Sm and 188Re. There is some evidence indicating that radioisotopes may provide complete reduction in pain over one to six months with no increase in analgesic use, but severe adverse effects (leucocytopenia and thrombocytopenia) are frequent.

Preparation and evaluation of rhenium-188-pamidronate as a palliative treatment in bone metastasis

OBJECTIVE

Rhenium-188-hydroxyethylidene diphosphonate (¹⁸⁸Re-HEDP) as a first generation bisphosphonate has been widely used for bone seeking radiopharmaceutical in cases of metastatic bone disease. No study has been yet reported on preparing a complex of ¹⁸⁸Re with pamidronate (3-aminohydroxypropylidene-1,1-bisphosphonic acid) (PMA) as a second generation bisphosphonate. Based on this fact, it was hypothesized that a bone-seeking ¹⁸⁸Re-PMA radiopharmaceutical could be developed as an agent for palliative radiotherapy of bone pain due to skeletal metastases.

METHODS

Pamidronate was labeled with ¹⁸⁸ReO₄^- eluted from the alumina based ¹⁸⁸W/¹⁸⁸Re generator. Labeling was optimized, and radiochemical analysis was performed by thin layer chromatography (TLC) and high performance liquid chromatography (HPLC). Biodistribution of this radioconjugate was evaluated and verified further in mice.

RESULTS

¹⁸⁸Re-PMA was prepared successfully in a high labeling yield (˃95%) corresponding to a specific activity of 124MBq/μmol and good in vitro stability, but it is likely to consist of multiple species. In biodistribution studies selective uptake and retention of activity in the skeletal system (0.81±0.25% ID/g and 0.57±0.16 at 4 and 48h in bone post injection respectively) followed by clearance in the soft tissues were observed.

CONCLUSION

These results show that due to its biological capabilities it would be advantageous to use ¹⁸⁸Re-PMA for bone pain palliation therapy.

Production and quality control 177Lu (NCA)-DOTMP as a potential agent for bone pain palliation

Skeletal uptake of radiolabeled-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetramethylene phosphoric acid (e.g., 177Lu-DOTMP) complex, is used for bone pain palliation. The moderate energy of β-emitting 177Lu (T½ = 6.7 d, Eβmax = 497keV) has been considered as a potential radionuclide for development of the bone-seeking radiopharmaceutical. Since the specific activity of the radiolabeled carrier molecules should be high, the "no-carrier-added radionuclides" have sig-nificant roles in nuclear medicine. Many researchers illustrated no-carrier-added 177Lu production; among these separation techniques such as ion exchange chromatography, reversed phase ion-pair, and electrochemical method, extraction chromatography has been considered more capable than other methods. In order to optimize the conditions, some effective factors on separation of Lu/Yb were investigated by EXC. The NCA 177Lu, produced by this method, was mixed with 300 μl of DOTMP solution (20 mg in 1 mL of 0.5 M NaHCO3, pH = 8) and incu-bated under stirring at room temperature for 45 min. Radiochemical purity of the 177Lu-DOTMP complex was determined using radio-thin-layer chromatography (RTLC) method. The complex was injected to wild-type rats and biodistribution was then studied for seven days. The NCA 177Lu was produced with specific activ-ity of 48 Ci/mg and with a radinuclidic purity of 99.99% through irradiation of enriched 176Yb target (1 mg) in a thermal neutron flux of 4 × 1013 n.cm-2.s-1 for 14 days. 177Lu-DOTMP was obtained with high radiochemical purities (> 98%) under optimized reaction conditions. The radiolabeled complex exhibited excellent stability at room temperature. Biodistribution of the radiolabeled complex studies in rats showed favorable selective skeletal uptake with rapid clearance from blood along with insignificant accumulation within the other nontargeted organs.

Treatment of painful bone metastases in prostate and breast cancer patients with the therapeutic radiopharmaceutical rhenium-188-HEDP. Clinical benefit in a real-world study

AIM

Rhenium-188-HEDP ((188)Re-HEDP) is an effective radiopharmaceutical for the palliative treatment of osteoblastic bone metastases. However, only limited data on its routine use are available and its effect on quality of life (QoL) has not been studied. Therefore, we evaluated the clinical benefit of (188)Re-HEDP in routine clinical care.

PATIENTS AND METHODS

Prostate or breast cancer patients with painful bone metastases receiving (188)Re-HEDP as a routine clinical procedure were eligible for evaluation. Clinical benefit was assessed in terms of efficacy and toxicity. Pain palliation and QoL were monitored using the visual analogue scale (VAS), corrected for opioid intake, and the EORTC QLQ-C30 Global health status/QoL-scale. Thrombocyte and leukocyte nadirs were used to assess haematological toxicity.

RESULTS

45 and 47 patients were evaluable for pain palliation and QoL, respectively. After a single injection of (188)Re-HEDP, the overall pain response rate was 69% and mean VAS-scores decreased relevantly and significantly (p < 0.05). Repeated treatment resulted in similar pain response. The overall QoL response rate was 68% and mean Global health status/QoL-scores increased relevantly and significantly. Haematological side effects were mild and transient.

CONCLUSION

The clinically relevant response on pain and quality of life and the limited adverse events prove clinical benefit of treatment with (188)Re-HEDP and support its use in routine clinical care. Its effectiveness appears comparable to that of external beam radiotherapy.

Treatment efficacy of (153)Sm-EDTMP for painful bone metastasis

Introduction:

Involvement of the skeleton can cause an excruciating pain in two-thirds of terminal patients with a history of malignancy. Due to several limitations of other therapies, such as analgesics, bisphosphonates, chemotherapy, hormonal therapy and external beam radiotherapy; bone-seeking radiopharmaceuticals have an important role in palliation of pain from bone metastases. Although these kinds of therapies have many advantages including the ability to treat multiple sites of tumoral involvement simultaneously, no significant confliction with other treatments, ease of administration and the potential to be used repetitively; in Iran using of this modality is not widely practiced. In this study we evaluated the clinical usefulness of Sm-153 lexidronamfor pain management of bone metastases.

Methods:

28 patients (14 males and 14 females) aged 38-77 years with a history of painful bone metastases caused by different cancers, not responding to conventional treatments were included in the study. All patients had a recent whole body bone scan indicating multiple bone metastases. 1 mCi/Kg Sm-153 lexidronam was injected intravenously to the patients. Whole body scintigraphy was done 3 or 18 hours post injection. Pain relief and quality of life have been evaluated by analog pain scale and Karnofsky index every week, respectively. Also, all patients were evaluated for hematological toxicity every two weeks. Active follow ups were performed.

Results:

43% of patients showed the presence of the flare phenomenon during the first three days after Sm injection with a mean duration of 2.2 days. The pain relief began between 2 and 16 days post injection and the duration of pain palliation was in the range of 4 to 32 weeks (mean±SD=15.22±7.8). 64.3% of patients showed complete relief of pain and 21.4% achieved partial response to therapy. (Over all response to therapy was 85.7%). The lowest amount of peripheral blood cells was detected in the fourth week for RBCs and in the 6th week for WBCs and PLTs. No one experienced hematological toxicity induced problems.

Conclusion:

Sm-153 lexidronam is an effective treatment for painful bone metastases. The complication rate is low and the quality of life of the patients after treatment would be significantly improved.

Comparative efficacy, tolerability, and survival outcomes of various radiopharmaceuticals in castration-resistant prostate cancer with bone metastasis: a meta-analysis of randomized controlled trials

Background

A meta-analysis was conducted to assess the impact of radiopharmaceuticals (RPs) in castration-resistant prostate cancer (CRPC) on pain control, symptomatic skeletal events (SSEs), toxicity profile, quality of life (QoL), and overall survival (OS).

Materials and methods

The PubMed/MEDLINE, CANCERLIT, EMBASE, Cochrane Library database, and other search engines were searched to identify randomized controlled trials (RCTs) comparing RPs with control (placebo or radiation therapy) in metastatic CRPC. Data were extracted and assessed for the risk of bias (Cochrane’s risk of bias tool). Pooled data were expressed as odds ratio (OR), with 95% confidence intervals (CIs; Mantel–Haenszel fixed-effects model).

Results

Eight RCTs with a total patient population of 1,877 patients were identified. The use of RP was associated with significant reduction in pain intensity and SSE (OR: 0.63, 95% CI: 0.51–0.78, I²=27%, P,0.0001), improved QoL (OR: 0.71, 95% CI: 0.55–0.91, I²=65%, three trials, 1,178 patients, P=0.006), and a minimal improved OS (OR: 0.84, 95% CI: 0.64–1.04, I²=47%, seven trials, 1,845 patients, P=0.11). A subgroup analysis suggested an improved OS with radium-223 (OR: 0.68, 95% CI: 0.51–0.90, one trial, 921 patients) and strontium-89 (OR: 0.21, 95% CI: 0.05–0.91, one trial, 49 patients). Strontium-89 (five trials) was associated with increased rates of grade 3 and 4 thrombocytopenia (OR: 4.26, 95% CI: 2.22–8.18, P=0.01), leucopenia (OR: 7.98, 95% CI: 1.82–34.95, P=0.02), pain flare (OR: 6.82, 95% CI: 3.42–13.55, P=0.04), and emesis (OR: 3.61, 95% CI: 1.76–7.40, P=0.02).

Conclusion

The use of RPs was associated with significant reduction in SSEs and improved QoL, while the radium-223-related OS benefit warrants further large, RCTs in docetaxel naive metastatic CRPC patients.

Dosimetry of bone metastases in targeted radionuclide therapy with alpha-emitting (223)Ra-dichloride

PURPOSE

Ra-dichloride is an alpha-emitting radiopharmaceutical used in the treatment of bone metastases from castration-resistant prostate cancer. Image-based dosimetric studies remain challenging because the emitted photons are few. The aim of this study was to implement a methodology for in-vivo quantitative planar imaging, and to assess the absorbed dose to lesions using the MIRD approach.

METHODS

The study included nine Caucasian patients with 24 lesions (6 humeral head lesions, 4 iliac wing lesions, 2 scapular lesions, 5 trochanter lesions, 3 vertebral lesions, 3 glenoid lesions, 1 coxofemoral lesion). The treatment consisted of six injections (one every 4 weeks) of 50 kBq per kg body weight. Gamma-camera calibrations for (223)Ra included measurements of sensitivity and transmission curves. Patients were statically imaged for 30 min, using an MEGP collimator, double-peak acquisition, and filtering to improve the image quality. Lesions were delineated on (99m)Tc-MDP whole-body images, and the ROIs superimposed on the (223)Ra images after image coregistration. The activity was quantified with background, attenuation, and scatter correction. Absorbed doses were assessed deriving the S values from the S factors for soft-tissue spheres of OLINDA/EXM, evaluating the lesion volumes by delineation on the CT images.

RESULTS

In 12 lesions with a wash-in phase the biokinetics were assumed to be biexponential, and to be monoexponential in the remainder. The optimal timing for serial acquisitions was between 1 and 5 h, between 18 and 24 h, between 48 and 60 h, and between 7 and 15 days. The error in cumulated activity neglecting the wash-in phase was between 2 % and 12 %. The mean effective half-life (T 1/2eff) of (223)Ra was 8.2 days (range 5.5-11.4 days). The absorbed dose (D) after the first injection was 0.7 Gy (range 0.2-1.9 Gy. Considering the relative biological effectiveness (RBE) of alpha particles (RBE = 5), D RBE = 899 mGy/MBq (range 340-2,450 mGy/MBq). The percent uptake of (99m)Tc and (223)Ra (activity extrapolated to t = 0) were significantly correlated.

CONCLUSION

The feasibility of in vivo quantitative imaging in (223)Ra therapy was confirmed. The lesion uptake of (223)Ra-dichloride was significantly correlated with that of (99m)Tc-MDP. The D RBE to lesions per unit administered activity was much higher than that of other bone-seeking radiopharmaceuticals, but considering a standard administration of 21 MBq (six injections of 50 kBq/kg to a 70-kg patient), the mean cumulative value of D RBE was about 19 Gy, and was therefore in the range of those of other radiopharmaceuticals. The macrodosimetry of bone metastases in treatments with (223)Ra-dichloride is feasible, but more work is needed to demonstrate its helpfulness in predicting clinical outcomes.

Synthesis, structures, luminescent and molecular recognition properties of three new alkaline earth metal carboxyphosphonates with a 3D supramolecular structure

Three new alkaline earth metal carboxyphosphonates with a 3D supramolecular structure, namely, Ca[(H₃L)(H₂O)] (1), Sr[(H₃L)(H₂O)₂] (2) and Ba₂[(H₃L)₂(H₂O)₄] (3) have been hydrothermally synthesized. The luminescent and molecular recognition properties of compounds 1–3 were investigated.

Burden of skeletal-related events in prostate cancer: unmet need in pain improvement

PURPOSE

Up to 75% of patients with prostate cancer experience metastatic bone disease, which leads to an increased risk for skeletal-related events (SREs) including pathological bone fracture, spinal cord compression, and hypercalcemia of malignancy. Our objective was to systematically review the literature on the impact of SREs on quality of life (QOL), morbidity, and survival with a primary focus on the impact of SREs on pain in prostate cancer patients.

METHODS

We searched PubMed, limiting to peer-reviewed English-language human studies published in 2000-2010. The search was based on the US Food and Drug Administration and European Medicines Agency definition of an SRE, which includes pathologic fracture, spinal cord compression (SCC), hypercalcemia of malignancy, and radiotherapy or surgery to bone resulting from severe bone pain.

RESULTS

A total of 209 articles were screened, of which 173 were excluded, and 36 were included in this review. Patients with SREs had more pain and worse survival compared with no SREs. Pathologic bone fractures worsened QOL and were associated with shorter survival. Radiation therapy of SCC alleviated pain and improved morbidity. SCC was associated with decreases in patient survival. Radiation therapy and surgery to bone improved pain.

CONCLUSIONS

Specific SREs are associated with worse outcomes, including increased pain, poorer QOL, morbidity, and survival. Treatment of SREs is associated with improved pain, although there remains a need for more effective treatment of SREs in prostate cancer patients.

(177)Lu-EDTMP for palliation of pain from bone metastases in patients with prostate and breast cancer: a phase II study

PURPOSE

The purpose of this study was to evaluate the efficacy and safety of (177)Lu-EDTMP for pain palliation in patients with bone metastases from castration-resistant prostate and breast cancer. The secondary objective was to compare low-dose and high-dose (177)Lu-EDTMP in bone pain palliation.

METHODS

Included in the study were 44 patients with documented breast carcinoma (12 patients; age 47 ± 13 years) or castration-resistant prostate carcinoma (32 patients; age 66 ± 9 years) and skeletal metastases. Patients were randomized into two equal groups treated with (177)Lu-EDTMP intravenously at a dose of 1,295 MBq (group A) or 2,590 MBq (group B). Pain palliation was evaluated using a visual analogue score (VAS), analgesic score (AS) and Karnofsky performance score (KPS) up to 16 weeks. Toxicity was assessed in terms of haematological and renal parameters.

RESULTS

The overall response rate (in all 44 patients) was 86 %. Complete, partial and minimal responses were seen in 6 patients (13 %), 21 patients (48 %) and 11 patients (25 %), respectively. A favourable response was seen in 27 patients (84 %) with prostate cancer and in 11 patients (92 %) with breast cancer. There was a progressive decrease in the VAS from baseline up to 4 weeks (p < 0.05). Also, AS decreased significantly from 1.8 ± 0.7 to 1.2 ± 0.9 (p < 0.0001). There was an improvement in quality of life of the patients as reflected by an increase in mean KPS from 56 ± 5 to 75 ± 7 (p < 0.0001). The overall response rate in group A was 77 % compared to 95 % in group B (p = 0.188). There was a significant decrease in VAS and AS accompanied by an increase in KPS in both groups. Nonserious haematological toxicity (grade I/II) was observed in 15 patients (34 %) and serious toxicity (grade III/IV) occurred in 10 patients (23 %). There was no statistically significant difference in haematological toxicity between the groups.

CONCLUSION

(177)Lu-EDTMP was found to be a safe and effective radiopharmaceutical for bone pain palliation in patients with metastatic prostate and breast carcinoma. There were no differences in efficacy or toxicity between patients receiving low-dose and high-dose (177)Lu-EDTMP.

The Na+/I- symporter (NIS): mechanism and medical impact

The Na(+)/I(-) symporter (NIS) is the plasma membrane glycoprotein that mediates active I(-) transport in the thyroid and other tissues, such as salivary glands, stomach, lactating breast, and small intestine. In the thyroid, NIS-mediated I(-) uptake plays a key role as the first step in the biosynthesis of the thyroid hormones, of which iodine is an essential constituent. These hormones are crucial for the development of the central nervous system and the lungs in the fetus and the newborn and for intermediary metabolism at all ages. Since the cloning of NIS in 1996, NIS research has become a major field of inquiry, with considerable impact on many basic and translational areas. In this article, we review the most recent findings on NIS, I(-) homeostasis, and related topics and place them in historical context. Among many other issues, we discuss the current outlook on iodide deficiency disorders, the present stage of understanding of the structure/function properties of NIS, information gleaned from the characterization of I(-) transport deficiency-causing NIS mutations, insights derived from the newly reported crystal structures of prokaryotic transporters and 3-dimensional homology modeling, and the novel discovery that NIS transports different substrates with different stoichiometries. A review of NIS regulatory mechanisms is provided, including a newly discovered one involving a K(+) channel that is required for NIS function in the thyroid. We also cover current and potential clinical applications of NIS, such as its central role in the treatment of thyroid cancer, its promising use as a reporter gene in imaging and diagnostic procedures, and the latest studies on NIS gene transfer aimed at extending radioiodide treatment to extrathyroidal cancers, including those involving specially engineered NIS molecules.

Pain palliative therapy in women with breast cancer osseous metastatic disease and the role of specific serum cytokines as prognostic factors

PURPOSE

To evaluate the efficacy of radionuclide palliative therapy (RPT) in women suffering from painful metastatic bone disease (MBD) due to breast cancer (BrCa), and to investigate the possible relationship between the RPT efficacy and cytokines levels.

METHODS

Sixty-three BrCa women patients with MBD enrolled in a prospective, nonrandomized study. Thirty were treated with Rhenium-186-hydroxyethylidenediphosphonic acid ((186)Re-HEDP), 21 with Strontium-89-Chloride ((89)Sr-Cl2), and 12 with Samarium-153-thylenediaminetetramethylenephosphonic acid ((153)Sm-EDTMP). Blood samples were collected pre- and post-therapy to assess the interleukin (IL)-2, IL-6 and tumor necrosis factor (TNF)-a titers. The palliative effect of the treatment was evaluated using a modified Wisconsin test.

RESULTS

All three radiopharmaceuticals were equally effective in pain relief. Pain palliation was complete in 52% of patients, partial in 31%, and absent in 16%. Responders to therapy had higher IL-2 and lower IL-6/TNF-a concentrations, compared with nonresponders, even though statistically significant difference in cytokines levels between responders and nonresponders before treatment was noted only for IL-6.

CONCLUSION

All used radiopharmaceuticals had the same therapeutic effect. Pretherapy low titers of IL-6 levels seems to have a favorable prognostic value for the therapeutic outcome, while IL-2 and TNF-a alterations pre- and post-therapy can only serve as markers of a better RPT response.

Pathobiology and management of prostate cancer-induced bone pain: recent insights and future treatments

Prostate cancer (PCa) has a high propensity for metastasis to bone. Despite the availability of multiple treatment options for relief of PCa-induced bone pain (PCIBP), satisfactory relief of intractable pain in patients with advanced bony metastases is challenging for the clinicians because currently available analgesic drugs are often limited by poor efficacy and/or dose-limiting side effects. Rodent models developed in the past decade show that the pathobiology of PCIBP comprises elements of inflammatory, neuropathic and ischemic pain arising from ectopic sprouting and sensitization of sensory nerve fibres within PCa-invaded bones. In addition, at the cellular level, PCIBP is underpinned by dynamic cross talk between metastatic PCa cells, cellular components of the bone matrix, factors associated with the bone microenvironment as well as peripheral components of the somatosensory system. These insights are aligned with the clinical management of PCIBP involving use of a multimodal treatment approach comprising analgesic agents (opioids, NSAIDs), radiotherapy, radioisotopes, cancer chemotherapy agents and bisphosphonates. However, a major drawback of most rodent models of PCIBP is their short-term applicability due to ethical concerns. Thus, it has been difficult to gain insight into the mal(adaptive) neuroplastic changes occurring at multiple levels of the somatosensory system that likely contribute to intractable pain at the advanced stages of metastatic disease. Specifically, the functional responsiveness of noxious circuitry as well as the neurochemical signature of a broad array of pro-hyperalgesic mediators in the dorsal root ganglia and spinal cord of rodent models of PCIBP is relatively poorly characterized. Hence, recent work from our laboratory to develop a protocol for an optimized rat model of PCIBP will enable these knowledge gaps to be addressed as well as identification of novel targets for drug discovery programs aimed at producing new analgesics for the improved relief of intractable PCIBP.

An alternate approach to the production of radioisotopes for nuclear medicine applications

There is a growing need for the production of radioisotopes for both diagnostic and therapeutic medical applications. Radioisotopes that are produced using the (n,γ) or (γ,n) reactions, however, typically result in samples with low specific activity (radioactivity∕gram) due to the high abundance of target material of the same element. One method to effectively remove the isotopic impurity is electro-magnetic mass separation. An Ion Source Test Facility has been constructed at TRIUMF to develop high-intensity, high-efficiency, reliable ion sources for purification of radioactive isotopes, particularly those used in nuclear medicine. In progress studies are presented.

Inorganic chemistry in nuclear imaging and radiotherapy: current and future directions

Radiometals play an important role in diagnostic and therapeutic radiopharmaceuticals. This field of radiochemistry is multidisciplinary, involving radiometal production, separation of the radiometal from its target, chelate design for complexing the radiometal in a biologically stable environment, specific targeting of the radiometal to its in vivo site, and nuclear imaging and/or radiotherapy applications of the resultant radiopharmaceutical. The critical importance of inorganic chemistry in the design and application of radiometal-containing imaging and therapy agents is described from a historical perspective to future directions.

Radionuclide therapy beyond radioiodine

For decades, Iodine-131 has been used for the treatment of patients with thyroid cancer. In recent years, increasingly, other radiopharmaceuticals are in clinical use in the treatment of various malignant diseases. Although in principle these therapies-as in all applications of radionuclides-special radiation protection measures are required, a separate nuclear medicine therapy department is not necessary in many cases due to the lower or lack of gamma radiation. In the following article, four different radionuclide therapies are more closely presented which are emerging in the last years. One of them is the "Peptide Receptor Radionuclide Therapy," the so-called PRRT in which radiolabeled somatostatin (SST)-receptor(R) ligands are used in patients with neuroendocrine tumors. On the basis of radiolabeled antibodies against CD20-positive cells, the so-called radioimmunotherapy is used in the treatment of certain forms of malignant lymphoma. In primary or secondary liver tumors, the (90)Y-labeled particles can be administered. Last but not the least, the palliative approach of bone-seeking radiopharmaceuticals is noted in patients with painful bone metastases.