Multicentre trial on the efficacy and toxicity of single-dose samarium-153-ethylene diamine tetramethylene phosphonate as a palliative treatment for painful skeletal metastases in China

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.

Bone Metastases

ABSTRACT

Bone metastases occur frequently in common malignancies such as breast and prostate cancer. They are responsible for considerable morbidity and skeletal-related events. Fortunately, there are now several systemic, focal, and targeted therapies that can improve quality and length of life, including radionuclide therapies. It is therefore important that bone metastases can be detected as early as possible and that treatment can be accurately and sensitively monitored. Several bone-specific and tumor-specific single-photon emission computed tomography and positron emission tomography molecular imaging agents are available, for detection and monitoring response to systemic therapeutics, as well as theranostic agents to confirm target expression and predict response to radionuclide therapies.

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.

177Lu-EDTMP for Metastatic Bone Pain Palliation: A Systematic Review and Meta-Analysis

Purpose: Painful metastatic bone involvement is common in advanced stages of many cancers. Between available radionuclides for bone pain palliation, no consensus has been reached on lutetium ethylenediaminetetramethylene phosphonate (¹⁷⁷Lu-EDTMP) administration in this milieu. The aim of this study is to evaluate the treatment efficacy, safety profile, and toxicities of ¹⁷⁷Lu-EDTMP in patients with metastatic bone involvement, according to the published literature. Methods: A comprehensive literature search of PubMed/MEDLINE, Scopus, and Google Scholar databases was carried out to retrieve pertinent articles published until January 2019, concerning the clinical efficacy and safety of ¹⁷⁷Lu-EDTMP for bone pain palliative purposes. Results: Eight studies (172 patients) were included. This analysis revealed statistically significant effect of ¹⁷⁷Lu-EDTMP therapy on the visual analog score (4.84% (95% CI: 3.88-5.81; p < 0.001), bone palliative pain response (84%, 95% CI: 75%-90%; p < 0.001), and Karnofsky performance status (21%, 95% CI: 18%-24%; p < 0.001) overall (as well as in the high-dose and low-dose subgroups). Complete palliative pain response to treatment was observed in 32% (95% CI: 16%-53%) of patients receiving ¹⁷⁷Lu-EDTMP. Anemia was found to be the most common hematologic toxicity imposed by this therapeutic approach (grade I/II anemia in 24% (95% CI: 14%-38%; p < 0.001) and grade III/IV anemia in 19% (95% CI: 12%-28%; p < 0.001)). Conclusions: ¹⁷⁷Lu-EDTMP seems to have comparable efficacy and safety profile as that of the frequently administered radiopharmaceuticals for bone palliation. Therefore, this agent can be a good option for bone pain palliative purposes, in case of limited access to other bone palliative radiopharmaceuticals.

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.

Spine and Non-spine Bone Metastases - Current Controversies and Future Direction

Bone is a common site of metastases in advanced cancers. The main symptom is pain, which increases morbidity and reduces quality of life. The treatment of bone metastases needs a multidisciplinary approach, with the main aim of relieving pain and improving quality of life. Apart from systemic anticancer therapy (hormonal therapy, chemotherapy or immunotherapy), there are several therapeutic options available to achieve palliation, including analgesics, surgery, local radiotherapy, bone-seeking radioisotopes and bone-modifying agents. Long-term use of non-steroidal analgesics and opiates is associated with significant side-effects, and tachyphylaxis. Radiotherapy is effective mainly in localised disease sites. Bone-targeting radionuclides are useful in patients with multiple metastatic lesions. Bone-modifying agents are beneficial in reducing skeletal-related events. This overview focuses on the role of surgery, including minimally invasive treatments, conventional radiotherapy in spinal and non-spinal bone metastases, bone-targeting radionuclides and bone-modifying agents in achieving palliation. We present the clinical data and their associated toxicity. Recent advances are also discussed.

Leveraging the power of non-radium radionuclide treatments in bone metastases

This review overviews the current status and clinical results of unsealed radionuclide therapies in skeletal metastasis. The other modes of treatment such as external bean radiotherapy and the newer receptor targeted radiopharmaceuticals tagged to alpha and beta particle emitting radionuclides have also been touched upon. With the advent of the latter in recent years, the intravenously administered radiopharmaceuticals that can be employed in the setting of skeletal metastases can be broadly categorized into (i) bone-seeking and (ii) receptor targeted specific tumor-seeking radiopharmaceuticals. The second category conceptualizes the "radionuclide based theranostics" and "precision oncology" and has the additional advantage of targeting both skeletal and non-skeletal disease and being the preferred therapy befitting the contemporary paradigm of clinical oncology.

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.

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.

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.

Treatment of Bone Metastasis with Bone-Targeting Radiopharmaceuticals

Bone is a common metastatic site of cancer. Bone metastasis reduces life expectancy and results in serious symptoms and complications such as bone pain, pathological fractures, and spinal cord compression, decreasing quality of life by restricting sleep and mobility. Treatment for bone metastasis includes drugs (pure analgesics, hormones, cytotoxic chemotherapy, and bisphosphonates, among others), external radiation therapy, surgery, and radionuclide therapy using bone-targeting radiopharmaceuticals. Particulate radiation with α- or β-rays is used as a bone-targeting radiopharmaceutical in radionuclide therapy. β-Emitters have lower energy and a longer range than α-emitters and have less tumoricidal activity and deliver more radiation to adjacent normal tissue. Therefore, the main therapeutic effect of bone-targeting β-emitters such as 89Sr-dichloride is bone pain palliation rather than enhanced survival. In contrast, α-emitters such as 223Ra-dichloride have high energy and a short range, resulting in greater tumoricidal activity and less radiation damage to adjacent normal tissue. Treatment with bone-targeting α-emitters can improve survival and decrease bone pain. This review focuses on the principles and clinical utility of several clinically available bone-targeting radiopharmaceuticals in metastatic bone disease.

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

Sentinel Node Mapping for Malignant Melanoma

Sixty-seven patients with malignant melanomas were seen in our institute since 1998. We looked for a sentinel node in 26 (38%) patients with lesions thicker than 1 mm, employing a double technique: staining with methylene blue and gamma probe mapping after injection of 99mTc. Forty-six nodes were retrieved, 25% of them containing tumor cells. This approach enabled us to choose between a wait-and-see policy and radical surgery.

Efficacy and safety of 153Sm-EDTMP as treatment of painful bone metastasis: a large single-center study

PURPOSE

The purpose of this study is to assess the efficacy of ¹⁵³Sm-EDTMP (Quadramet®) in a clinical setting.

METHODS

We have conducted a retrospective study of all consecutive patients (pts) treated with ¹⁵³Sm-EDTMP for painful bone metastases. At each visit (before and after treatment), four parameters were collected: (i) pain assessment according to the 10-step visual analogue scale (VAS), (ii) sleep disturbance related to pain, (iii) dose of analgesic medication, and (iv) answer to the following closed question "Do you think you obtained a benefit from treatment?" Success of treatment was defined by the combination of these four parameters.

RESULTS

Three hundred seventy consecutive ¹⁵³Sm-EDTMP treatments for painful bone metastases were given. Patients had the following primary tumors: breast carcinoma (153), prostate carcinoma (155), lung carcinoma (27), or other cancers (35). Fifty-eight percent of the patients had received previous external osseous radiotherapy. Ninety-seven percent of the patients were treated with concomitant analgesics and 61% were treated with diphosphonates. A clinical benefit was described in 55.0% of cases at D30. Treatment was more effective in cases of breast and prostate cancers compared with other types of primary cancers. Patients described a benefit at D30 in 62, 58, 6, and 38% of cases of breast, prostate, lung, and other cancers. The subjective efficacy was accompanied by a decrease in analgesic intake in 35.0% of cases.

CONCLUSION

¹⁵³Sm-EDTMP therapy is an effective supportive treatment in patients who suffer from bone metastases, especially in patients with breast or prostate cancer.

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.

Effect of Bisphosphonates, Denosumab, and Radioisotopes on Bone Pain and Quality of Life in Patients with Non-Small Cell Lung Cancer and Bone Metastases: A Systematic Review

Bone metastases are common in patients with non-small cell lung cancer (NSCLC), often causing pain and a decrease in quality of life (QoL). The effect of bone-targeted agents is evaluated by reduction in skeletal-related events in which neither pain nor QoL are included. Radioisotopes can be administered for more diffuse bone pain that is not eligible for palliative radiotherapy. The evidence that bone-targeted agents relieve pain or improve QoL is not solid. We performed a systematic review of the effect of bone-targeted agents on pain and QoL in patients with NSCLC. Our systematic literature search included original articles or abstracts reporting on bisphosphonates, denosumab, or radioisotopes or combinations thereof in patients with bone metastases (≥5 patients with NSCLC), with pain, QoL, or both serving as the primary or secondary end point. Of the twenty-five eligible studies, 13 examined bisphosphonates (one also examined denosumab) and 12 dealt with radioisotopes. None of the randomized studies on bisphosphonates or denosumab evaluated pain and QoL as the primary end point. In the single-arm studies of bisphosphonates a decrease in pain or analgesic consumption was found for 38% to 77% of patients. QoL was included in five of 13 studies, but improvement was found in only two. No high-level evidence that bisphosphonates or denosumab reduce pain or improve QoL was found. Although the data are limited, radioisotopes seem to reduce pain with a rapid onset of action and duration of response of 1 to 3 months. The evidence that bisphosphonates or denosumab reduce or prevent pain in patients with NSCLC and bone metastases or that they have an influence on QoL is very weak. Radioisotopes can be used to reduce diffuse pain, although there is no high-level evidence supporting such use.

Clinical Efficacy and Safety Comparison of 177Lu-EDTMP with 153Sm-EDTMP on an Equidose Basis in Patients with Painful Skeletal Metastases

This prospective study compared 177Lu-ethylene diamine tetramethylene phosphonate (EDTMP) with 153Sm-EDTMP for painful skeletal metastases.

METHODS

Half of the 32 patients were treated with 177Lu-EDTMP and half with 153Sm-EDTMP, at 37 MBq/kg of body weight. Analgesic, pain, and quality-of-life scores (EORTC, Karnofsky, ECOG) and bone proliferation marker were used to examine efficacy. Hematologic toxicity was evaluated using NCI-CTCAE and compared between groups at baseline and each month till 3 mo after therapy. Pain relief was categorized as complete, partial, minimal, or none.

RESULTS

Pain relief with 177Lu-EDTMP was 80%: 50% complete, 41.67% partial, and 8.33% minimal. Pain relief with 153Sm-EDTMP was 75%: 33.33% complete, 58.33% partial, and 8.33% minimal. The difference was not significant (P=1.000). Quality of life at 3 mo after therapy improved significantly in both groups as per ECOG score (P=0.014 and 0.005 for 177Lu-EDTMP and 153Sm-EDTMP, respectively), Karnofsky index (P=0.007 and 0.023 for 177Lu-EDTMP and 153Sm-EDTMP, respectively), and EORTC score (P=0.004 and <0.001 for 177Lu-EDTMP and 153Sm-EDTMP, respectively). Bone proliferation marker in responders of both groups dropped significantly (P=0.008 for 177Lu-EDTMP and P=0.019 for 153Sm-EDTMP), parallel to clinical response. For 177Lu-EDTMP, anemia, leukopenia, and thrombocytopenia were nonserious (grade I/II) in 46.67%, 46.67%, and 20%, respectively, and serious (grade III/IV) in 20%, 6.67%, and 0%, respectively. For 153Sm-EDTMP, anemia, leukopenia, and thrombocytopenia were nonserious (grade I/II) in 62.5%, 31.25%, and 18.75%, respectively, and serious (grade III/IV) in 18.75%, 0%, and 6.25%, respectively. One patient treated with 153Sm-EDTMP had grade IV thrombocytopenia but required no blood transfusion. Differences between groups were not significant for either nonserious or serious toxicity. For 177Lu-EDTMP, 3 of 12 responders experienced the flare phenomenon on the third day after therapy and one on the fifth day, showing no response to therapy. For 153Sm-EDTMP, 2 of 12 responders experienced the flare phenomenon, both on the third day after therapy.

CONCLUSION

177Lu-EDTMP has pain response efficacy similar to that of 153Sm-EDTMP and is a feasible and safe alternative, especially in centers with no nearby access to 153Sm-EDTMP.

The role of radiation therapy in the treatment of metastatic castrate-resistant prostate cancer

In the setting of castrate-resistant prostate cancer, patients present with a variety of symptoms, including bone metastases, spinal cord compression and advanced pelvic disease. Fortunately, a variety of radiotherapeutic options exist for palliation. This article focuses on these options, including both external beam radiotherapy and radiopharmaceuticals.

Bone-targeted agents in the treatment of lung cancer

Over a third of patients with lung cancer will develop bone metastases during the course of their disease, resulting in symptoms of pain and immobility, and skeletal-related events (SREs) such as fracture, hypercalcaemia, surgery or radiotherapy to bones, and malignant spinal cord compression. These reduce quality of life and increase mortality. Preclinical research has identified the interactions between tumour cells and bone that are key to tumour cell survival and associated osteolysis. These data have led to the development of drugs to prevent osteoclast-mediated bone breakdown, such as zoledronic acid and denosumab, which are now licensed for use in patients with bone metastases from solid tumours. Both zoledronic acid and denosumab reduce the risk of SREs and increase time to first SRE, with minimal side effects. In addition, denosumab improved survival in patients with lung cancer compared with zoledronic acid. Ongoing trials are testing whether these drugs can prevent the development of bone metastases from lung cancer. New bone-targeted agents showing promise in breast and prostate cancer include radium-223, cabozantinib and Src inhibitors. These agents require further evaluation in patients with lung cancer.

How are palliative care cancer populations characterized in randomized controlled trials? A literature review

CONTEXT

The difficulties in defining a palliative care patient accentuate the need to provide stringent descriptions of the patient population in palliative care research.

OBJECTIVES

To conduct a systematic literature review with the aim of identifying which key variables have been used to describe adult palliative care cancer populations in randomized controlled trials (RCTs).

METHODS

The data sources used were MEDLINE (1950 to January 25, 2010) and Embase (1980 to January 25, 2010), limited to RCTs in adult cancer patients with incurable disease. Forty-three variables were systematically extracted from the eligible articles.

RESULTS

The review includes 336 articles reporting RCTs in palliative care cancer patients. Age (98%), gender (90%), cancer diagnosis (89%), performance status (45%), and survival (45%) were the most frequently reported variables. A large number of other variables were much less frequently reported.

CONCLUSION

A substantial variation exists in how palliative care cancer populations are described in RCTs. Few variables are consistently registered and reported. There is a clear need to standardize the reporting. The results from this work will serve as the basis for an international Delphi process with the aim of reaching consensus on a minimum set of descriptors to characterize a palliative care cancer population.

Samarium-153-ethylene diamine tetramethylene phosphonate, a beta-emitting bone-targeted radiopharmaceutical, useful for patients with osteoblastic bone metastases

Bone metastases are prevalent among cancer patients and frequently cause significant morbidity. Oncology providers must mitigate complications associated with bone metastases while limiting therapy-related adverse effects and their impact on quality of life. Multiple treatment modalities, including chemotherapy, surgery, external beam radiation therapy, and radioisotopes, among others, have been recommended and utilized for palliative treatment of bone metastases. Radioisotopes such as samarium-153 are commonly used in the setting of multifocal bone metastases due to their systemic distribution, affinity for osteoblastic lesions, acceptable toxicity profile, and convenience of administration. This review focuses on samarium-153, first defining its radiobiologic and pharmacokinetic properties before describing many clinical trials that support its use as a safe and effective tool in the palliation of patients with bone metastases.

Beyond Palliation: Therapeutic Applications of 153Samarium-EDTMP

Primary and metastatic malignant bone lesions result in significant pain and disability in oncology patients. Targeted bone-seeking radioisotopes including ¹⁵³Samarium ethylene-diamine-tetramethylene-phosphonic acid (¹⁵³Sm-EDTMP) have been shown to effectively palliate bone pain, often when external beam radiotherapy (EBRT) is not feasible. However, recent evidence also suggests ¹⁵³Sm-EDTMP has cytotoxic activity either alone or in combination with chemotherapy or EBRT. ¹⁵³Sm-EDTMP may be useful as anti-neoplastic therapy apart from pain palliation in a variety of malignancies. For prostate cancer patients, several phase I and II clinical trials have shown that combined ¹⁵³Sm-EDTMP and docetaxel-based chemotherapy can result in >50% decrease in prostate-specific antigen with manageable myelosuppression. In hematologic malignancies, ¹⁵³Sm-EDTMP produced clinical responses when combined with bortezomib in multiple myeloma. ¹⁵³Sm-EDTMP also can be used with myeloablative chemotherapy for marrow conditioning prior to stem cell transplant. In osteosarcoma, ¹⁵³Sm-EDTMP infusion delivers radiation to multiple unresectable lesions simultaneously and provides local cytotoxicity without soft tissue damage that can be combined with chemotherapy or radiation. Prior to routine incorporation of ¹⁵³Sm-EDTMP into therapeutic regimens, we must learn how to ensure optimal delivery to tumors, determine which patients are likely to benefit, improve our ability to assess clinical response in bone lesions and further evaluate the efficacy ¹⁵³Sm-EDTMP in combination with chemotherapy, radiation and novel targeted agents.

Radiopharmaceuticals for bone metastasis therapy and beyond: a voyage from the past to the present and a look to the future

Bone cancer can be divided into primary and secondary (metastatic) bone cancer. Osteosarcoma is the most common type of primary bone cancer, but still is a rare cancer. The development of bone metastases is a common event for the cancer patient and the main cause of treatment failure and death, being chronic pain syndrome the most important complication. There are currently several therapeutic modalities for the treatment of metastatic bone disease, including radiation therapy. Treatment with radionuclides (β- and α-particle emitters and Auger electron cascades) is a safe and effective tool of medicine. There is a great deal of interest in diphosphonic acids in nuclear medicine as ligands for radiometals in bone-seeking diagnostic and therapeutic agents. Several radiopharmaceuticals have been designed with the phosphonates as ligands. A recent approach to develop an effective radiopharmaceutical for therapy of bone cancer was the design of a water-soluble polymer that would exploit the disrupted vasculature in tumors according to the enhanced permeability and retention effect. To enhance the effect of radionuclide therapy on the cancer cells, new strategies have recently been investigated, such as the combined radionuclide and chemotherapy, high-dose radionuclide therapy, and repeated radionuclide therapy.

The Role of Bone-Seeking Radionuclides in the Palliative Treatment of Patients with Painful Osteoblastic Skeletal Metastases

Background

Pain from skeletal metastases represents a major burden of advanced disease from solid tumors. Analgesic medications, bisphosphonates, hormonal agents, cytotoxic chemotherapy, and external beam radiotherapy are all effective treatments. However, patients often suffer from diffuse painful metastases and respond poorly to these standard therapies. Bone-seeking radionuclides can specifically target osteoblastic lesions to offer palliation of pain.

Methods

This article offers a narrative review of bone-seeking radionuclides, examines the evidence of safety and efficacy for the treatment of painful skeletal metastases, and presents guidelines for their appropriate use in this patient population.

Results

Seven bone-seeking radionuclides have shown evidence of both safety and efficacy in reducing pain from diffuse skeletal metastases. 153Sm-EDTMP and 89Sr are most commonly used in the United States and have been safely utilized for both repeat dosing as well as concurrent dosing with cytotoxic chemotherapy.

Conclusions

Targeted bone-seeking radionuclides are underutilized in the treatment of painful diffuse osteoblastic metastases. Several new agents are in active clinical investigation, and the pending approval of the first alpha-emitting radionuclide (223Ra) may offer a new class of agents that provide greater efficacy and less toxicity than those currently available for routine clinical use.

Palliation and survival after repeated (188)Re-HEDP therapy of hormone-refractory bone metastases of prostate cancer: a retrospective analysis

This retrospective study compared the effects of single and multiple administrations of (186)Re-hydroxyethylidenediphosphonate ((186)Re-HEDP) on palliation and survival of prostate cancer patients presenting with more than 5 skeletal metastases.

METHODS

A total of 60 patients were divided into 3 groups. Group A (n = 19) consisted of patients who had received a single injection; group B (n = 19), patients who had 2 injections; and group C (n = 22), patients who had 3 or more successive injections. The (188)Re-HEDP was prepared using non-carrier-added (188)Re obtained from an in-house (188)W/(188)Re generator after dilution with carrier perrhenate. Patients' data available from the referring physicians-including prostate-specific antigen levels-were entered into a Windows-based matrix and analyzed using a statistical program. The Gleason scores were similar for all 3 groups.

RESULTS

Mean survival from the start of treatment was 4.50 ± 0.81 mo (95% confidence interval [CI], 2.92-6.08) for group A, 9.98 ± 2.21 mo (95% CI, 5.65-14.31) for group B, and 15.66 ± 3.23 (95% CI, 9.33-22.0) for group C. Although the 3 groups did not differ in Gleason score, the number of lost life-years was significantly lower in group C than in groups A and B. Pain palliation was achieved in 89.5% of group A, 94.7% of group B, and 90.9% of group C.

CONCLUSION

Posttreatment overall survival could be improved from 4.50 to 15.66 mo by multiple-injection bone-targeted therapy with (188)Re-HEDP, when compared with a single injection. Significant pain palliation was common and independent of administration frequency.

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 STRATEGY

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 ((89)Sr) with Samarium-153 ((153)Sm), Rhenium-186 ((186)Re) and Phosphorus-32 ((32)P). We observed no significant differences between treatments. Similarly, we observed no differences when we compared different doses of (153)Sm (0.5 versus 1.0 mCi).

AUTHORS' CONCLUSIONS

This update adds new evidence on efficacy of radioisotopes versus placebo, (89)Sr compared with other radioisotopes, and dose-comparisons of (153)Sm and (188)Re. 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.

In vitro evaluation of samarium (III) oxide as a bone substituting material

The biocompatibility of natural samarium (III) oxide, which has previously been used for treatment in bone-related diseases was determined as a first step in its evaluation as a bone implant material. Assessment for 28 days using osteoblast-like cells revealed no indications of cytotoxicity. The cells adhered and proliferated on the surface. Furthermore, the differentiation and mineralization were observed, indicating a normal biological response of the cells on the samarium (III) oxide surface. The in vitro, short term biocompatibility assessment of this oxide has indicated its biosafety with no damaging toxic effects on the cells and biofunctionality; with an appropriate cell response for a bone-contacting material. Hence, samarium (III) oxide deserves recognition in the field of biomaterials for its excellent in vitro performance and demonstrates that the class of potential bioceramics may be larger than previously thought. (c) 2010 Wiley Periodicals, Inc. J Biomed Mater Res, 2010.

188Re(CO)3-dipicolylamine-alendronate: a new bisphosphonate conjugate for the radiotherapy of bone metastases

The palliation of pain due to bone metastases using targeted compounds containing beta-emitters such as rhenium-188 ((188)Re) is an accepted and effective form of treatment. Here, we describe the efficient synthesis and preclinical evaluation of (188)Re(CO)(3)-dipicolylamine(DPA)-alendronate, a novel bifunctional bisphosphonate for the palliative treatment of bone metastases. (188)Re(CO)(3)-DPA-alendronate can be easily synthesized with high specific activities and yields (18.8 GBq/mg, radiochemical yield > or =96%) in two steps using kit-based methodology, and in contrast with the clinically approved bisphosphonate (186/188)Re-HEDP, it forms inert, single species that have been well-characterized. In vivo imaging and biodistribution studies demonstrate that (188)Re(CO)(3)-DPA-alendronate is superior to (188)Re-HEDP in targeting and accumulating in areas of high metabolic bone activity while having low soft-tissue uptake. In addition to these studies, a simple and convenient new method for purifying its precursor, fac-[(188)Re(CO)(3)(H(2)O)(3)](+), is described.

Systemic metabolic radiopharmaceutical therapy in the treatment of metastatic bone pain

Bone pain due to skeletal metastases constitutes the most common type of chronic pain among patients with cancer. It significantly decreases the patient's quality of life and is associated with comorbidities, such as hypercalcemia, pathologic fractures and spinal cord compression. Approximately 65% of patients with prostate or breast cancer and 35% of those with advanced lung, thyroid, and kidney cancers will have symptomatic skeletal metastases. The management of bone pain is extremely difficult and involves a multidisciplinary approach, which usually includes analgesics, hormone therapies, bisphosphonates, external beam radiation, and systemic radiopharmaceuticals. In patients with extensive osseous metastases, systemic radiopharmaceuticals should be the preferred adjunctive therapy for pain palliation. In this article, we review the current approved radiopharmaceutical armamentarium for bone pain palliation, focusing on indications, patient selection, efficacy, and different biochemical characteristics and toxicity of strontium-89 chloride, samarium-153 lexidronam, and rhenium-186 etidronate. A brief discussion on the available data on rhenium-188 is presented focusing on its major advantages and disadvantages. We also perform a concise appraisal of the other available treatment options, including pharmacologic and hormonal treatment modalities, external beam radiation, and bisphosphonates. Finally, the available data on combination therapy of radiopharmaceuticals with bisphosphonates or chemotherapy are discussed.

Evaluation of a method for activity estimation in Sm-153 EDTMP imaging

Absolute activity evaluation is fundamental for internal radionuclide dosimetry when patient-specific therapy optimization is wanted. Often, quantification is attempted with 3D SPECT image based (IB) methods, but the true concentration values can be underestimated due to the partial volume effect (PVE). This is especially true when small diffuse lesions are present. In this paper, we describe a 3D region of interest (ROI) based quantification method (LS-ROI), which estimates the ROI concentration values directly from the projection data acquired in the tomographic scan once ROIs have been segmented on a CT and/or a SPECT image. The method, which has inherent PVE correction capabilities, was applied both on simulated and on real phantom data. Simulations reflected the case of a patient with bone metastases treated with 153Sm-EDTMP: Both the activity in the metastases and the total retention in the skeleton were evaluated. Thirty noisy data sets were produced in order to evaluate the accuracy and precision of the method. The effect of region segmentation errors on estimated concentrations was thoroughly investigated. Real data were acquired on a NEMA phantom, where a cylindrical central region (283 cm3) simulated the bone and two spheres (10.3 and 25.5 cm3) simulated the metastases. The results obtained with the LS-ROI method were compared with those of a conventional 3D IB method and those of a quantitative conjugate view approach derived from LS-ROI and applied to the anterior and posterior views acquired in the tomographic scan (LS-ROI anterior-posterior: LS-ROI-AP). Simulations showed that when the geometry of regions is known, the LS-ROI method recovered the simulated concentration values within 20%, while the IB method underestimated the concentration in high activity small lesions by as much as 49%. Segmentation errors, up to 44% of the true region volume, produced a higher variation in LS-ROI estimates than in IB ones; however, the overall bias of the LS-ROI estimates (< or = 25%) remained lower than that of IB estimates. In the case of the evaluation of the total retention in the skeleton, the LS-ROI method recovered the simulated value within 2%, while IB underestimated it up to 13%. In all the cases, the LS-ROI-AP method showed an accuracy comparable with that of the LS-ROI one, and a worse precision just because of the lower number of counts used in the analysis. However, a worsening of LS-ROI-AP performances was demonstrated in the case of strong overlap of regions: In this case, a bias of up to 40% was observed. The results obtained on real phantom data confirmed the simulation results: The IB method underestimated activity up to 47% in the smallest sphere, while the bias was reduced to 13% with LS-ROI and LS-ROI-AP estimates. The good quantification capabilities of the LS-ROI method can be useful for absolute activity quantification in the case of small active diffused lesions and constitute the basis for the development of an accurate patient-specific planning strategy in internal radionuclide treatments, provided there is a reliable segmentation of lesions.

153Sm: its use in multiple myeloma and report of a clinical experience

BACKGROUND

In the past years the bone seeking radiopharmaceutical samarium lexidronam ((153)Sm-EDTMP) has been increasingly used alone or in conjunction with chemotherapy and/or bisphosphonates for the treatment of painful bone metastasis.

OBJECTIVE

Its use has been explored in different solid tumours. In this report we explore its interesting characteristics and describe our experience in multiple myeloma (MM).

METHODS

(153)Sm-EDTMP has an affinity for bone and concentrates in areas of bone turnover. It decays as a therapeutic beta-emission and at the same time as gamma-photon that can be used for tracking its concentration with bone scan imaging. Ten patients with symptomatic MM were treated to achieve pain control.

RESULTS

Encouraging results were obtained in MM patients. The use of this radioisotope could be largely improved.

Combined use of zoledronic acid and 153Sm-EDTMP in hormone-refractory prostate cancer patients with bone metastases

Purpose

¹⁵³Sm-ethylenediaminetetramethylenephosphonic acid (EDTMP; Quadramet®) is indicated for the treatment of painful bone metastases, whereas zoledronic acid (Zometa®) is indicated for the prevention of skeletal complications. Because of the different therapeutic effects, combining the treatments may be beneficial. Both, however, accumulate in areas with increased osteoblastic activity. Possible drug interactions were investigated.

Methods

Patients with hormone-refractory prostate cancer were treated with 18.5 MBq/kg ¹⁵³Sm-EDTMP in weeks 1 and 3 and with 37 MBq/kg in week 15. Treatment with 4 mg zoledronic acid began in week 3 and continued every 4 weeks through week 23. In weeks 3 and 15, zoledronic acid was administered 2 days before ¹⁵³Sm-EDTMP treatment. Urine was collected 48 h after injection of ¹⁵³Sm-EDTMP, and whole-body images were obtained 6, 24 and 48 h post-injection. The effect of zoledronic acid on total bone uptake of ¹⁵³Sm-EDTMP was measured indirectly by the cumulative activity excreted in the urine in weeks 1, 3 and 15. Biodistribution, safety, tolerability and effect on prostate-specific antigen level were also studied.

Results

The urinary excretion in week 3 divided by the urinary excretion in week 1 (baseline) times 100% was mean 98.4 ± 11.6% (median 96.2%). From week 1 to 15, after four zoledronic acid treatments, the mean ratio was 101.9 ± 10.7% (median 101.8%). Bioequivalence could be concluded by using a two-sample t test for both per-protocol (n = 13) and full-analysis sets (n = 18). Toxicity was comparable to of monotherapy with ¹⁵³Sm-EDTMP.

Conclusion

Zoledronic acid treatment does not influence ¹⁵³Sm-EDTMP skeletal uptake. Combined treatment is feasible and safe.

Analysis of multiple factors related to hematologic toxicity following 153Sm-EDTMP therapy

PURPOSE

The aim of this study was to investigate the clinical factors related to hematologic toxicity caused by treatment with samarium-153 ethylenediaminetetramethylene phosphonic acid (153Sm-EDTMP).

MATERIALS AND METHODS

A total of 206 secondary bone neoplasm patients treated with 153Sm-EDTMP were analyzed retrospectively. Logistic regression (SPSS 10.0 for Windows; Chicago, IL) and correlation analysis were used to evaluate the factors concerned.

RESULTS

Age, number of bone metastatic lesions, chemotherapy before treatment with 153Sm-EDTMP, concurrence of radiotherapy, and times of repeated treatments with 153Sm-EDTMP were determined by single factor analysis to be related to hematologic toxicity. Chemotherapy before treatment with 153Sm-EDTMP, concurrence of radiotherapy, drug use to maintain normal white blood cell counts, and times of repeated treatments with 153Sm-EDTMP were determined by multiple factor analysis to be related to hematologic toxicity.

CONCLUSIONS

Chemotherapy before treatment with 153Sm-EDTMP, concurrence of radiotherapy, drug use to maintain normal white blood cell counts, and times of repeated treatments with 153Sm-EDTMP are the main clinical factors related to hematologic toxicity caused by 153Sm-EDTMP therapy. In patients with such factors, more attention might be paid to the change of blood cell counts after 153Sm-EDTMP therapy.

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

AIM

The surface bone-seeking radiopharmaceuticals 188Re-HEDP, 186Re-HEDP and 153Sm-EDTMP, and the volume seeker 89Sr were investigated to determine the efficacy and toxicity in pain palliation of bone metastases.

METHOD

The effect of treatment with 188Re-HEDP, 186Re-HEDP, 153Sm-EDTMP and 89Sr on pain symptoms, quality of life, and bone marrow function were studied. In total, 79 patients (18 with breast cancer and 61 with prostate cancer) were treated (31 patients with 188Re-HEDP, 15 patients each with 186Re-HEDP and 153Sm-EDTMP, and 18 patients with 89Sr). All patients were interviewed using standardized sets of questions before and after therapy weekly for 12 weeks. Blood counts were taken weekly for 6 weeks and after 12 weeks.

RESULTS

In total, 73% of patients reported pain relief (77% after 188Re-HEDP, 67% after 186Re-HEDP 73% after 153Sm-EDTMP, and 72% after 89Sr). Fifteen percent of patients could discontinue their analgesics and were pain-free. Pain showed a decrease from 3.6+/-1.7 to a maximum of 2.2+/-1.8 at visual analogue scale in 10 steps (P<0.01). Patients described an improvement on the Karnofsky performance scale from 70+/-10% to 78+/-14% 12 weeks after treatment (P=0.15). There were eight patients with a thrombocytopenia grade I, two patients with grade II and one with grade III. The maximum nadir of platelet and leukocyte counts were observed between the 2nd to 5th week after treatment and was reversible within 12 weeks. There were no significant differences in pain palliation, Karnofsky performance status (KPS) and bone marrow toxicity between the different radionuclides (P=0.087-0.449).

CONCLUSION

All radiopharmaceuticals were effective in pain palliation, without induction of severe side effects or significant differences in therapeutic efficacy or toxicity.

[An economic analysis of the management of bone metastases in lung cancer]

BACKGROUND

Bone metastases are common in lung cancer and are leading to increasing consumption of health care resources. The therapeutic choice for the clinician is extensive, from biphosphonates to percutaneous vertebroplasty. In the absence of official guidelines the management varies from centre to centre. There are very few economic analyses of these patients.

METHODS

Study 06-01 of the French Lung Oncology Group is a medico-economic analysis of the management of bone metastases in lung cancer. It is a national, multicentre, observational, epidemiological study. The primary objective is to assess the epidemiology, the management strategies and the costs of bone metastases in lung cancer. The secondary objective is to develop a medico-economic model of the management based on a Markov model in order to evaluate the effectiveness of different therapeutic strategies.

EXPECTED RESULTS

The aim of this study is a better understanding of theses patients at a time when few observational studies have been undertaken.

Safety and efficacy of repeat administration of samarium Sm-153 lexidronam to patients with metastatic bone pain

BACKGROUND

Samarium Sm 153 lexidronam (Sm-153) is an effective and well-tolerated treatment for painful bone metastases. The purpose of the analysis was to assess the safety and efficacy of repeated doses of Sm-153 in patients with metastatic bone pain.

METHODS

Data were collected prospectively for 202 patients administered 1.0 mCi/kg of Sm-153. Particular emphasis was placed on analysis of data from 55 patients receiving > or = 2 doses. Pain scores, adverse events, and hematologic parameters were assessed after each dose.

RESULTS

Mild, transient suppression of platelets and white blood cell counts was the most common adverse event after treatment. Nadirs were approximately half of baseline at 4 weeks after dosing with recovery by Week 8 in 90% of patients. Temporary grade 3 thrombocytopenia occurred in 11%, 12%, and 17% of patients after the first, second, and third drug administration, respectively. Grade 3 leukopenia occurred in less than 7% of patients independent of the number of administrations. Significant decreases in pain scores (P < .001) were observed at Week 4 after each of the first 3 doses and maintained at Week 8 after the first 2 doses (P < .003) but not the third. Decreases in pain scores were observed in 70%, 63%, and 80% of patients, respectively, at Week 4 after the first 3 administrations.

CONCLUSIONS

Repeated dosing of 1.0 mCi/kg of Sm-153 was both safe and effective and is a reasonable treatment option in patients whose bone pain responds and then recurs after an initial dose provided that adequate hematologic function is present at the time of drug administration.

Clinical Role of Sm-153 EDTMP in the Treatment of Painful Bone Metastatic Disease

PURPOSE

Sm-153 EDTMP is an effective treatment of painful bone metastases from different neoplasms. However, there are few studies describing clinical experience with this therapeutic modality. The aim of this clinical study was to evaluate the efficacy of Sm-153 EDTMP in a group of patients with skeletal metastases and poor pain control with conventional therapies.

MATERIALS AND METHODS

Sixty-four patients with painful bone metastases treated with Sm-153 EDTMP were retrospectively evaluated. Nine patients were treated twice. The most common primaries were breast in 28 cases (44%) and prostate in 27 (41%). Treatment efficacy was assessed by a visual analog scale, analgesic consumption, and performance status before and after treatment. Response was graded as complete, moderate, or minor. Toxicity evaluation included analytic parameters (blood counts, renal function) and clinical follow up.

RESULTS

Efficacy and toxicity were evaluated separately for each dose (total doses: 73), and complete follow up was only possible in 62 of 73 administrations. The response rate was 85% (21% complete, 40% moderate, and 24% minor). Onset of improvement took place a median of 7 days after Sm-153 EDTMP administration, and pain relief persisted for a mean of 3 months. No relevant toxicity was found in the early phase. Myelotoxicity appeared in 29% of the administrations and was mild in most cases (there was one case of grade 4 leukopenia).

CONCLUSIONS

Sm-153 EDTMP is a good therapeutic option for patients with painful bone metastases. It is an effective treatment of pain relief without major secondary effects.

[Treatment of bone metastatic pain with Sm153-EDTMP. Evaluation of the analgesic response and the existence of differences according to the primary tumor and the metastatic pattern]

AIMS

To evaluate the response to Sm153-EDTMP treatment in patients with metastatic bone pain and the existence of differences in the response according to the scintigraphic pattern (99mTc-MDP) and the primary tumor.

MATERIAL AND METHODS

We have evaluated the response to Sm153-EDTMP treatment in 32 patients (17 male and 15 female) who received 38 doses (1 mCi/kg). The primary tumor was prostate cancer in 15 patients, breast in 13, lung in 2, intestinal carcinoid in one and unknown in one. Two types of response were considered: a) effective and b) non-effective. Patients were classified into 3 groups according to the metastatic pattern: 1) Superscan (SS), 2) Generalized metastases (GM) and 3) Regional metastases (RM).

RESULTS

There was effective response in 24 doses (63.15%) and non-effective in 14 (36.84%). The mean duration of the response was 12.08 weeks. Patients with GM pattern showed 16 effective responses (76.19%) and 5 non-effective (23.8%). In SS pattern there were 6 effective responses (60%) and 4 non-effective (40%) and 2 effective (28.57%) and 5 non-effective (71.53%) in RM pattern. These differences did not reach statistical significance (p > 0.05). We did not find differences in the response between prostate cancer (12 effective and 6 non-effective) and breast cancer (10 effective and 6 non-effective) (p = 0.79968).

CONCLUSIONS

Sm153-EDTMP treatment is efficacious in patients with metastatic bone pain with effective response in 63.15% of the treatments. The response percentage was lower in patients with RM pattern but the differences did not reach statistical significance. There were no differences in the response between prostate and breast cancer patients.

Recent Developments in Nuclear Medicine in the Management of Bone Metastases

OBJECTIVE

To review recent developments and to examine the role of nuclear medicine-based radionuclide therapy in the management of bone metastases.

METHODS

Recent developments in the use of radionuclides were broadly reviewed in the context of treatment paradigms, radionuclide toxicity, cost, and overall outcomes, and an impression of the use of radionuclides in metastatic bone disease was derived.

RESULTS

Through a number of studies, radionuclide therapy has been shown to be an efficacious and cost-effective means of alleviating bone pain in metastatic disease. Moreover, its early use in pain therapy may limit cancer progression by inhibiting oligometastases. Thus, radionuclides can significantly decrease patient morbidity, increase patient survival, and perhaps attenuate the aggressiveness of cancer. Nonetheless, in comparison with analgesics, external beam radiotherapy, or surgery, it still appears to have lower priority among medical oncologists.

CONCLUSION

Bone pain palliation is critical for cancer patients afflicted with bone metastases, but radionuclides remain underutilized in such treatments. The authors propose that physician education regarding radionuclide therapy be improved and additional investigations to evaluate newer radionuclides and treatment paradigms (eg, higher activities, repetitive or cyclic administration, chemosensitization, or chemosupplementation) be strongly encouraged. A comprehensive and an interdisciplinary clinical approach toward increasing the use of radionuclides in alleviating metastatic bone pain is proposed. Data from clinical collaborations will help optimize radiopharmaceutical therapy for pain palliation, increase its awareness among oncologists, and contribute effectively to patient palliation and quality-of-life improvements.