Combined therapy of Sr-89 and zoledronic acid in patients with painful bone metastases

Strontium-89 plus zoledronic acid versus zoledronic acid for patients with painful bone metastatic breast cancer

INTRODUCTION

β-ray strontium-89 (Sr-89) intra-irradiation therapy has been approved and clinically used to reduce bone metastasis pain not alleviated by bone-modifying agents, external radiation, and analgesic agents. We examined the efficacy of zoledronic acid (ZOL) and Sr-89 combination therapy compared with ZOL alone in breast cancer patients with bone metastases.

MATERIALS AND METHODS

A randomized controlled trial was conducted on breast cancer patients with bone metastasis to compare the efficacy between ZOL monotherapy and ZOL plus Sr-89 combination therapy. The primary endpoints were changes in urinary NTX levels at 13 weeks and brief pain inventory scores. The secondary endpoints were analgesic drug usages, response rates, changes in bone metabolism markers, quality of life, and adverse event rates.

RESULTS

Thirty of the planned 60 cases were randomly assigned to ZOL alone or ZOL + Sr-89. There were no significant differences in the changes in urinary NTX levels between the 2 groups (P = 0.365). There was no consistent difference in the pain score changes between the 2 groups. Sr-89 addition to ZOL slightly reduced the white blood cell and platelet counts. However, all adverse events were Grade 1. Safety and analgesic drug dose reduction were more evident in ZOL + Sr-89.

CONCLUSION

This trial showed the lack of benefits from Sr-89 addition to ZOL for breast cancer patients with painful bone metastases. However, safety and analgesic drug dose reduction were more evident in ZOL + Sr-89, indicating its potential for pain control. Sr-89 therapy is safe, thus more effective radiopharmaceuticals are anticipated.

Combined bone scintigraphy and fluorocholine PET/computed tomography predicts response to radium-223 therapy in patients with prostate cancer

Aim

To assess the value of bone scintigraphy and ¹⁸F-fluorocholine PET/computed tomography (CT) in predicting outcome in patients with prostate cancer and bone metastases treated with ²²³radium.

Materials & methods

Retrospective analysis of 48 patients that underwent ²²³radium therapy. End points were pain relief and overall survival.

Results

After therapy, pain relief was observed in 27 patients. Patients without pain relief had more bone lesions at PET/CT than at bone scintigraphy (pretherapy imaging mismatch). In 39 patients who completed treatment protocol, post-therapy alkaline phosphatase and pretherapy imaging mismatch were independent predictors of poor overall survival.

Conclusion

Patients with more lesions at ¹⁸F-fluorocholine PET/CT than at bone scintigraphy had a poor prognosis. The combined imaging approach could be useful to predict outcome after ²²³radium therapy.

Systemic Radiotherapy of Bone Metastases With Radionuclides

Treatments of bone metastases using radionuclides are now well established in oncology. It is also a field that continues to develop. This article reviews the evidence base that led to the approval of strontium-89 and samarium-153 ethylenediaminetetramethylene phophanate (EDTMP) for the palliation of pain from bone metastases, as well as the evidence for the use of radium-223 in metastatic castrate-resistant prostate cancer. Efforts to optimise treatments and improve response rates, either by safely increasing the radiation dose to bone metastases or by combining treatment with non-radiation-based therapies, are discussed. In addition, the development of both alpha- and beta-particle-emitting radiopharmaceuticals designed to target prostate-specific membrane antigen are reviewed.

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.

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.

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

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.

Diagnosis and treatment of bone metastasis: comprehensive guideline of the Japanese Society of Medical Oncology, Japanese Orthopedic Association, Japanese Urological Association, and Japanese Society for Radiation Oncology

Diagnosis and treatment of bone metastasis requires various types of measures, specialists and caregivers. To provide better diagnosis and treatment, a multidisciplinary team approach is required. The members of this multidisciplinary team include doctors of primary cancers, radiologists, pathologists, orthopaedists, radiotherapists, clinical oncologists, palliative caregivers, rehabilitation doctors, dentists, nurses, pharmacists, physical therapists, occupational therapists, medical social workers, etc. Medical evidence was extracted from published articles describing meta-analyses or randomised controlled trials concerning patients with bone metastases mainly from 2003 to 2013, and a guideline was developed according to the Medical Information Network Distribution Service Handbook for Clinical Practice Guideline Development 2014. Multidisciplinary team meetings are helpful in diagnosis and treatment. Clinical benefits such as physical or psychological palliation obtained using the multidisciplinary team approaches are apparent. We established a guideline describing each specialty field, to improve understanding of the different fields among the specialists, who can further provide appropriate treatment, and to improve patients’ outcomes.

A patient with esophageal cancer with bone metastasis who achieved pain relief with repetitive administration of strontium-89 chloride

A 75-year-old woman was diagnosed with esophageal cancer with difficulty in swallowing. She had a past history of rheumatoid arthritis, scleroderma, interstitial pneumonia, angina pectoris (with coronary artery bypass surgery) and arrhythmia (with pacemaker implantation). She refused surgery, and chemotherapy and radiotherapy were not performed because of the high risk accompanied with multiple comorbidities. She received proton therapy at another hospital and the primary lesion shrank. Bone metastasis in the thoracic vertebrae was diagnosed 10 months after diagnosis of esophageal cancer. Non-steroidal anti-inflammatory drugs and zoledronic acid were administered for back pain. Oxycodone was also administered but discontinued due to nausea. After strontium-89 ((89)Sr) chloride administration, her back pain was relieved. (89)Sr was administered five times every 3 months, and the pain did not worsen until her death due to pneumonia 2 years after diagnosis of esophageal cancer. (89)Sr was effective for pain from bone metastasis of esophageal cancer, and its repeated administration was safe.

Palliative treatment of bone metastases with samarium-153 EDTMP at onset of pain

We evaluated the pain response and daily discomfort in patients suffering from a borderline degree of bone pain due to breast or lung cancer bone metastases, who had undergone early palliative radionuclide treatment. The results were compared with those from patients who had received standard analgesic therapy. Twenty-one patients (65.7 ± 3 years; 17 women) with metastatic bone cancer underwent samarium-153 (Sm-153) ethylene diamine tetramethylene phosphonate (EDTMP) administration (group A) and 18 patients (64.3 ± 8 years; 16 women)continued to receive standard analgesics (group B; control group). The patients kept a daily pain diary assessing both their discomfort and the pain at specific sites by means of a visual analog scale, rating from 0 (no discomfort–no pain)to 10 (worst discomfort–pain). These diaries were reviewed weekly for 2 months and three physicians rated the pain response on a scale from -2 (considerable deterioration) to +2 (considerable improvement). Baseline characteristics were similar in both groups. The reduction of total discomfort and of bone pain in group A was significantly greater compared to group B (p < 0.0001). A significant improvement of clinical conditions was observed in group A, where the physician rate changed from -1 to 1, compared to group B in which the rate changed from -1 to 0. Sm-153 EDTMP therapy can be considered for patients with bone pain from breast and lung cancer in advance, i.e.,before the establishment of severe pain syndrome.

Optimal timing of bisphosphonate administration in combination with samarium-153 oxabifore in the treatment of painful metastatic bone disease

While bisphosphonates are indicated for prevention of skeletal-related events, radionuclide therapy is widely used for treatment of painful bone metastases. Combined radionuclide therapy with bisphosphonates has demonstrated improved effectiveness in achieving bone pain palliation in comparison to mono therapy with radionuclides or bisphosphonates alone. However, there are conflicting reports as to whether bisphosphonates adversely influence skeletal uptake of the bone-seeking radiotracers used for therapy. Recent studies analyzing influence of Zoledronic acid on total bone uptake of Samarium-153 EDTMP (Sm-153 EDTMP) by measuring cumulative urinary activity of Sm-153 on baseline study, as well as in combination with bisphosphonates (administrated 48 hours prior to Sm-153) did not provide any statistically significant difference in urinary excretion of Sm-153 between the two groups. It may be noted that the exact temporal sequence of bisphosphonate administration vis a vis radionuclide therapy has not yet been studied. One of the side effects of bisphosphonates is transient flare effect on bone pain. Radionuclide therapy may also have similar side effect. Keeping in view the above the current study was designed with the main objective of determining the exact timing of bisphosphonate administration in patients receiving combined therapy so as to achieve optimal efficacy of bone pain palliation. Ninety-three patients suffering from metastatic bone pain who received combination therapy with Sm-153 oxabifore (an analog of Sm-153 EDTMP) and Zoledronic acid were divided into three groups according to the timing of Zoledronic acid administration: Group I: 39 patients who received Zoledronic acid 7 or more days prior to Sm-153 oxabifore treatment; Group II: 32 patients who received Zoledronic acid 48-72 hours prior to Sm-153 oxabifore treatment and Group III: 22 patients who received Zoledronic acid 7 days after Sm-153 oxabifore treatment. Sm-153 oxabifore was administered to all patients at the standard bone palliation dose of 37 MBq/kg body weight. All patients received Zoledronic acid before and after treatment in standard dosage of 4 mg every 28 days. WB bone scan, CT, and MRI were performed before treatment in all patients to exclude cord compression and vertebral fractures. Pain scores and quality of life (QOL) measurements were recorded meticulously in all patients. In groups I, II, and III, pain relief occurred in 10.4 ± 3.1 (Range = 5-15); 3.1 ± 1.1 (Range = 1-5) and 22 ± 5.1 (Range = 15-35) days, respectively, following radionuclide therapy. There was statistically significant difference between pain score in all groups before and after treatment as well as statistically significant difference in time to pain relief onset between Group II and other groups of patients (P < 0.0001). Based on our results we concluded that administration of Zoledronic acid 48-72 hours prior to Sm-153 oxabifore treatment helps in achieving better pain relief, as well as at the shortest time interval from the start of therapy.

Impact of ¹⁸F-fluoride PET-CT on implementing early treatment of painful bone metastases with Sm-153 EDTMP

This study evaluated the diagnostic impact of using skeletal (18)F-fluoride PET/CT on patients with painful bone metastases to schedule an early palliative radionuclide treatment.

METHODS

The skeletal involvement from prostate cancer metastases was assessed by both (99m)Tc-diphosphonate bone scan (BS) and (18)F-fluoride PET/CT within four weeks in 24 patients (67.7 ± 5.1 years) suffering from a borderline degree of bone pain for which radionuclide palliation was not shortly planned for administration. The BS and (18)F-fluoride PET/CT results were compared, assessing the number and extension of the skeletal sites involved. Afterward, the patients were randomly assigned either to the study group (N=12) receiving radionuclide therapy (Samarium-153 EDTMP) or to the control group (N=12) not receiving radionuclide therapy. The short-term results from the radionuclide palliation group (evaluated with a visual analogue scale) were compared with the controls.

RESULTS

Overall, at BS, 7.6 ± 1.4 sites were considered metastatic, involving at least 5 ± 1 body regions. At (18)F-fluoride PET/CT, 116 ± 19 sites presented metastatic involvement with 12/12 body regions concerned. No differences were found in regards to either the number of metastatic sites or regions at both BS and (18)F-fluoride PET/CT between the study group and controls (p=ns). At CT, 88 blastic metastases were identified, whereas 110 were mainly lytic. Most of mainly lytic lesions were not detectable at BS. The reduction in total discomfort and bone pain in the study group was significantly greater than in the controls (p<0.0001).

CONCLUSION

Sm-153 EDTMP therapy should be considered for patients with early bone pain from prostate cancer even if their BS only indicates a few metastases before the initiation of a severe pain syndrome. (18)F-fluoride PET/CT may be helpful in deciding if the implementation of bone pain palliation using bone-seeking radionuclides at pain onset is necessary.

Clinical significance of zoledronic acid and strontium-89 in patients with asymptomatic bone metastases from non-small-cell lung cancer

BACKGROUND

The purpose of this study was to clarify the treatment value of zoledronic acid (ZA) and/or strontium-89 (Sr-89) in patients with non-small-cell lung cancer (NSCLC) with asymptomatic bone metastases (BMs).

PATIENTS AND METHODS

Eligible patients were those with resectable NSCLC and asymptomatic BMs. These candidates were randomized into 4 groups: group A was treated with ZA and Sr-89 simultaneously, group B was treated with ZA, group C was treated with Sr-89, and group D was untreated. Patients were monitored and analyzed for the first skeletal-related event (SRE), overall survival (OS), and annual incidence of SREs.

RESULTS

One hundred eighty patients were enrolled. Time to first SRE in group A was 15 months (95% confidence interval [CI], 14.0-16.0 months), in group B it was 12 months (95% CI, 11.1-13.0 months), in group C it was 9 months (95% CI, 8.5-9.5 months), and in group D it was 8 months (95% CI, 7.1-8.9 months) (P = .000). The overall survival (OS) in group A was 17 months (95% CI, 16.0-18.1 months); in group B, it was 16 months (95% CI, 14.2-17.8 months); in group C, it was 12 months (95% CI, 11.1-12.9 months); and in group D, it was 12 months (95% CI, 10.8-13.2 months). The annual incidence of SREs in group A was 24.4%; in group B, it was 55.6%; in group C, it was 75.6%; in group D, it was 91.1% (P = .000).

CONCLUSIONS

Treatment with ZA and/or Sr-89 significantly extended the time to first SRE as well as survival time and reduced the annual incidence of SREs. Treatment with the combined use of ZA and Sr-89 was safe and well tolerated and achieved the best effect on asymptomatic BMs of NSCLC.

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.

Patient-reported outcome instruments used to assess pain and functioning in studies of bisphosphonate treatment for bone metastases

Purpose

When treating metastatic bone disease, relief of bone pain is often a key outcome. Because pain cannot be quantified with objective clinical measures, patient-reported outcome (PRO) measures are required to assess patients' subjective experience. The goal of the current review was to examine measures used to assess pain, as well as the impact of pain on functional status and health-related quality of life (HRQL), in trials of bisphosphonates for the treatment of bone metastases.

Methods

A literature search focused on articles published from January 1999 to April 2009.

Results

A total of 49 articles were located that used PROs to assess pain-related outcomes of bisphosphonate treatment for bone metastases. The Brief Pain Inventory was the most commonly used multi-item instrument. However, the most common approach for assessing pain was to administer a single-item scale such as a visual analog scale, numerical rating scale, or verbal rating scale. Of the 49 studies, 19 included a PRO assessing functional status or HRQL.

Conclusions

Although pain is an important outcome of trials examining treatment for bone metastases, the current review suggests that there is little consistency in PRO measurement across studies. Furthermore, presentation of measures often lacked clear description, information on measurement properties, citations, clarity regarding method of administration, and consistent instrument names. Recommendations are provided for instrument validation within the target population, assessment of content validity, use of PRO instruments recently developed for patients with bone metastases, clear description of instruments, and implementation of measures consistent with recommendations from instrument developers.

Effective use of strontium-89 in osseous metastases

Bone is one of the organs to which cancer metastasizes most frequently. However, it is not a vital organ, therefore, survival after the occurrence of osseous metastasis is relatively favorable. Improvements of medical treatment bring prolonged survival to patients with osseous metastases. But this makes us to recognize the importance of quality of life (QOL) due to several factors, including pain. It is important for oncologists to know how to deal with such painful osseous metastases, as pain relief may enable patients to live their remaining lives to the fullest. Strontium-89 (89Sr) has been used worldwide as in Japan, while being reported to have positive effects on pain relief and QOL improvement in patients with osseous metastases. This review paper is aimed to present not only the history, roles, and medical characters of 89Sr, but also new aspects, such as how to use bone turnover markers, which location of osseous metastases is suitable for effective use of 89Sr.

Concurrent use of Sr-89 chloride with zoledronic acid is safe and effective for breast cancer patients with painful bone metastases

Our aim in this study was to examine the safety and efficacy of the concurrent use of the radiopharmaceutical strontium-89 (Sr-89) chloride with zoledronic acid in standard anticancer therapy for breast cancer patients with painful multifocal bone metastases. The study comprised 16 breast cancer patients with painful multifocal bone metastases detected by bone scintigraphy, computed tomography or magnetic resonance imaging. All patients were treated with Sr-89 and zoledronic acid concurrently between March 2007 and February 2011 as part of a standard therapeutic regimen comprising chemotherapy, endocrine therapy, molecular targeting therapy and targeted radiotherapy. Sr-89 was administered intravenously at 2 MBq/kg to a maximum of 141 MBq per person. Safety was evaluated according to myelotoxicity as measured by the Common Terminology Criteria for Adverse Events (v3.0). To assess treatment efficacy, we monitored changes in analgesic drug dosages. Furthermore, bremsstrahlung imaging after the administration of Sr-89 was utilized to examine the relationship between the accumulation of Sr-89 in metastatic sites and treatment efficacy. Based on the results, a total of 14 out of 16 patients (88%) reported bone pain relief, indicating a high efficacy of Sr-89 combined with zoledronic acid. In responsive cases, a strong uptake of Sr-89 was observed on bremsstrahlung imaging at the same sites indicated by (99m)Tc bone scintigraphy. Moreover, severe myelosuppression (> grade 3) was not observed, and adverse events were tolerable. In conclusion, the use of Sr-89 with zoledronic acid in breast cancer patients with painful bone metastases was safe and effective when administered concurrently with other standard therapies. In the future, the treatment with Sr-89 at the early stage should be considered, and a large-scale clinical study should be conducted.

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.

Bone metastases: assessment of therapeutic response through radiological and nuclear medicine imaging modalities

Radiological and nuclear medicine imaging modalities used for assessing bone metastases treatment response include plain and digitalised radiography (XR), skeletal scintigraphy (SS), dual-energy X-ray absorptiometry (DEXA), computed tomography (CT), magnetic resonance imaging (MRI), [(18)F] fluorodeoxyglucose positron emission tomography (FDG-PET) and PET/CT. Here we discuss the advantages and disadvantages of these assessment modalities as evident through different clinical trials. Additionally, we present the more established response criteria of the International Union Against Cancer and the World Health Organization and compare them with newer MD Anderson criteria. Even though serial XR and SS have been used to assess the therapeutic response for decades, several months are required before changes are evident. Newer techniques, such as MRI or PET, may allow an earlier evaluation of response that may be quantified through monitoring changes in signal intensity and standard uptake value, respectively. Moreover, the application of PET/CT, which can follow both morphological and metabolic changes, has yielded interesting and promising results that give a new insight into the natural history of metastatic bone disease. However, only a few studies have investigated the application of these newer techniques and further clinical trials are needed to corroborate their promising results and establish the most suitable imaging parameters and evaluation time points. Last, but not least, there is an absolute need to adopt uniform response criteria for bone metastases through an international consensus in order to better assess treatment response in terms of accuracy and objectivity.

Radiotherapy for metastatic bone disease: current standards and future prospectus

Changes in population dynamics will require increased end-of-life cancer care in the coming years. Palliative radiotherapy successfully relieves symptoms of advanced cancer, with the most common indication for its use being uncomplicated painful bone metastases. Single-fraction radiotherapy provides successful, time-efficient and cost-effective management of bone metastases. Newer technologies, such as stereotactic body radiotherapy, hold promise for some patients with spine metastases, although their niche has not been properly defined and their use outside of a protocol setting is inappropriate. Surgery should be considered for circumstances of completed or impending pathologic fracture, spinal instability, or spinal cord compression in patients who have adequate performance status and prognosis. Multiple sites of painful metastases may be treated with injectible radiopharmaceuticals or hemibody radiation. The future developments in palliative radiotherapy for bone metastases will mirror several forces affecting all of medicine, including resource allocation, the adoption of clinical guidelines and the integration of newer technologies.

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.

Influence of human biokinetics of strontium on internal ingestion dose of 90Sr and absorbed dose of 89Sr to organs and metastases

The objective of the present work is to apply the plasma clearance parameters to strontium, previously determined in our laboratory, to improve the biokinetic and dosimetric models of strontium-90 ((90)Sr) used in radiological protection; and also to apply this data for the estimation of the radiation doses from strontium-89 ((89)Sr) after administration to patients for the treatment of the painful bone metastases. Plasma clearance and urinary excretion of stable strontium tracers of strontium-84 ((84)Sr) and strontium-86 ((86)Sr) were measured in GSF-National Research Center for Environment and Health (GSF) in 13 healthy German adult subjects after intravenous injection and oral administration. The biological half-life of strontium in plasma was evaluated from 49 plasma concentration data sets following intravenous injections. This value was used to determine the transfer rates from plasma to other organs and tissues. At the same time, the long-term retention of strontium in soft tissue and whole body was constrained to be consistent with measured values available. A physiological urinary path was integrated into the biokinetic model of strontium. Parameters were estimated using our own measured urinary excretion values. Retention and excretion of strontium were modeled using compartmental transfer rates published by the International Commission on Radiological Protection (ICRP), the SENES Oak Ridge Inc. (SENES), and the Urals Research Center for Radiation Medicine (TBM). The results were compared with values calculated by applying our GSF parameters (GSF). For the dose estimation of (89)Sr, a bone metastases model (GSF-M) was developed by adding a compartment, representing the metastases, into the strontium biokinetic model. The related parameters were evaluated based on measured data available in the literature. A set of biokinetic parameters was optimized to represent not only the early plasma kinetics of strontium but also the long-term retention measured in soft tissue and whole body. The ingestion dose coefficients of (90)Sr were computed and compared with different biokinetic model parameters. The ingestion dose coefficients were calculated as 2.8 x 10(-8), 2.1 x 10(-8), 2.5 x 10(-8) and 3.8 x 10(-8) Sv Bq(-1) for ICRP, SENES, TBM and GSF model parameters, respectively. Moreover, organ absorbed dose for the radiopharmaceutical of (89)Sr in bone metastases therapy was estimated based on the GSF and ICRP biokinetic model parameters. The effective doses were 3.3, 1.8 and 1.2 mSv MBq(-1) by GSF, GSF-M, and ICRP Publication 67 model parameters, respectively, compared to the value of 3.1 mSv MBq(-1) reported by ICRP Publication 80. The absorbed doses of red bone marrow and bone surface, 17 and 21 mGy MBq(-1) calculated by GSF parameters, and 7.1 and 8.8 mGy MBq(-1) by GSF-M parameters, are comparable to the clinical results of 3-19 mGy MBq(-1) for bone marrow and 16 mGy MBq(-1) for bone surface. Based on the GSF-M model, the absorbed dose of (89)Sr to metastases was estimated to be 434 mGy MBq(-1). The strontium clearance half-life of 0.25 h from the plasma obtained in the present study is obviously faster than the value of 1.1 h recommended by ICRP. There are no significant changes for ingestion dose coefficients of (90)Sr using different model parameters. A model including the metastases was particularly developed for dose estimation of (89)Sr treatment for the pain of bone metastases.

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.

Management of painful bone metastases

PURPOSE OF REVIEW

This review examines recent data on the pathophysiology and mechanisms of bone pain; it highlights the use of multiple and interdisciplinary treatments rather than sole use of traditional analgesics.

RECENT FINDINGS

Bone pain has been shown to have a unique pathophysiology. Recent experimental (animal) models have revealed that, parallel to increased bone destruction, ipsilateral spinal cord segments that receive primary input from the cancerous femur exhibit several notable neurochemical changes. These mandate the use of opioid doses sufficient to inhibit the observed nociceptive behaviours; these doses are greater than those required to alleviate pain behaviours of comparable magnitude generated by inflammatory pain. Several substances have been tested in this animal model.

SUMMARY

According to new preclinical data, treatment of bone cancer pain requires multidisciplinary therapies such as radiotherapy applied to the painful area along with systemic treatment (hormone therapy or chemotherapy) and supportive care (analgesic therapy and bisphosphonates). In some selected cases use of radioisotopes and other noninvasive or minimally invasive techniques may be useful in the management of metastatic bone pain. The treatment should be individualized according to the patient's clinical condition, life expectancy, and quality of life.

A novel study investigating the therapeutic outcome of patients with lytic, mixed and sclerotic bone metastases treated with combined radiotherapy and ibandronate

PURPOSE

To investigate the therapeutic response of patients with different types of bone metastases treated with combined radiotherapy and bisphosphonates.

PATIENTS AND METHODS

By using computed tomography 52 patients were grouped into groups of lytic, mixed and sclerotic bone lesions. All patients were treated with concomitant radiotherapy and ibandronate (10 monthly cycles) and underwent clinical and radiological evaluations prior to therapy and at 3, 6 and 10 months of follow up.

RESULTS

At baseline there were statistically significant differences between the three groups for all the evaluated parameters. From 3 months onwards differences were leveled out. Statistically significant improvements were noted at all time points of evaluation for all groups in parameters such as pain (0-10), quality of life (QOL-physical functioning, 0-100) and Karnofsky performance status (KPS). The average pain score for the lytic group was reduced from 8.1 to 1.5 points at 3 months. The corresponding reductions for the mixed and sclerotic groups were from 6.2 to 0.5 and from 4.4 to 0.3 points respectively. Complete pain responses were >76.4% at all time points for all groups. Opioid consumption was also markedly reduced. Overall, the highest clinical response was noted for the lytic group, even though the mean values of pain, QOL and KPS were worse than those of the two other groups at all time points (apart from pain score at 10 months). The percentage of patients of the lytic group experiencing a complete pain response was the least of the three groups during follow up. At 10 months bone density was almost tripled for the lytic and almost doubled for the mixed group.

CONCLUSIONS

Even though the therapeutic outcome for the three groups was similar, the degree of clinical response and reossification differed.

Clinical and radiological evaluation of patients with lytic, mixed and sclerotic bone metastases from solid tumors: is there a correlation between clinical status of patients and type of bone metastases?

PURPOSE

To investigate the association between the clinical status of patients with metastatic bone disease and the type of bone metastases.

PATIENTS AND METHODS

80 patients with skeletal metastases underwent both clinical and radiological assessments. Bone lesions were evaluated with computed tomography (CT), and patients were separated into three groups: lytic, mixed, sclerotic. Bone density of each lesion was measured in Hounsfield units (HU).

RESULTS

Patients with osteolytic lesions had the highest mean pain score with 8.1 +/- 2.2 points, the least mean scores for quality of life (QoL) and performance status (PS) with 31.4 +/- 14.6 and 58.6 +/- 9.7 points respectively, the highest percentage and mean opioid consumption (100% and 220.9 mg of oral daily morphine equivalent respectively), and the least mean bone density (116.3 +/- 40.4 HU). On the contrary, the group with sclerotic metastases had the least mean pain score with 4.6 +/- 1.3 points, the highest mean scores of QoL and PS (61.1 +/- 15.5 and 66.6 +/- 10 points respectively), the least percentage and mean opioid requirement (55.5% and 170.6 mg respectively), and the highest mean bone density (444 +/- 86.6 HU). The differences between the three groups were statistically significant for all parameters evaluated, apart from performance status between the sclerotic and mixed groups. The correlation coefficients were statistically significant between all parameters investigated. Bone density had a strong negative correlation with pain.

CONCLUSION

Our results show a clear correlation between the type of bone metastases and the clinical status of patients. Patients with excessive bone resorption suffer the most, and may be given priority in treatment. CT proved to be a practical and efficient method to investigate and classify metastatic bone lesions.

Clinical benefit of bone-targeted radiometabolic therapy with 153Sm-EDTMP combined with chemotherapy in patients with metastatic hormone-refractory prostate cancer

BACKGROUND

Bone metastases are responsible for most of the morbidity associated with hormone-refractory prostate cancer (HRPC). 153Sm-ethylenediaminetetramethylene phosphonate (153Sm-EDTMP) has been approved for palliation of painful skeletal metastases. We retrospectively investigated the possible synergistic effect on survival of 153Sm-EDTMP (given to HRPC patients for bone pain palliation) and chemotherapy.

METHODS

Forty-five HRPC patients were evaluated, with a median age of 71 years. The number of metastatic bone sites was <or=10 in 25 patients and >10 in 20 patients. Median serum PSA was 224 ng/ml. Bone pain was mild in 6 patients, moderate in 16, severe in 22 and intolerable in 1. Fifteen patients were only treated with 153Sm-EDTMP (group A), while 30 patients also received chemotherapy (estramustine phosphate or mitoxantrone plus prednisone) at variable times: between 3 and 5 months after 153Sm-EDTMP (14 patients, group B) or within 1 month after 153Sm-EDTMP (16 patients, group C).

RESULTS

Haematological toxicities observed after either regimen were in general mild, consistent with common observations after either 153Sm-EDTMP or chemotherapy, and without any additive adverse effects in the patients receiving both 153Sm-EDTMP and chemotherapy. Bone pain palliation to some degree was induced by 153Sm-EDTMP in 32/45 patients (71.1%), the proportion of patients with a favourable clinical response being significantly higher in group C than in group A (87.5% vs 53.3%, p = 0.0388). Also in terms of biochemical response (serum PSA levels), patients of group C performed significantly better than patients of group A (p = 0.0235). Overall median survival from the time of administration of 153Sm-EDTMP was 15 months in the total cohort of 45 patients, and was significantly longer in group C than in either group B (30 months vs 11 months, p = 0.023) or group A (30 months vs 10 months, p = 0.008).

CONCLUSION

The results of this study confirm that 153Sm-EDTMP is effective in terms of pain relief and PSA response, with minimal toxicity. When it was administered in combination with chemotherapy, prolonged survival indicated actual clinical benefit, while there were no additive toxicities. These results provide the rationale for future prospective evaluation of combined therapeutic strategies.

Radiopharmaceutical therapy of bone metastases with 89SrCl2, 186Re-HEDP and 153Sm-EDTMP: a dosimetric study using Monte Carlo simulation

PURPOSE

The aim of the paper is to calculate the dose to bone surface and bone volume using a Monte Carlo particle transport model and to give quantitative arguments for activity prescription.

METHODS

This study simulates the dose delivery process to skeletal metastases by bone surface- and bone volume-seeking radiopharmaceuticals. Dose distributions for three radiopharmaceuticals, 186Re-HEDP, 153Sm-EDTMP and 89SrCl2, frequently used for pain palliation therapies, were calculated using the EGSnrc Monte Carlo code. The model simulates a cylindrical geometry with regions of different constant density compositions and radioactivity distribution consistent with known biodistribution features of the three radiopharmaceuticals: superficial for phosphonates (186Re-HEDP and 153Sm-EDTMP) and volumetric for 89SrCl2. After 3D dose distribution calculation, dose-volume histogram reduction was carried out using the "preferred Lyman" method, which yields effective uniform dose (D(eff)) equivalent to the inhomogeneous dose distributions to the reference region (volume and surface).

RESULTS

Our simulations showed that to obtain a delivered dose to bone surface equivalent to that obtained from 89SrCl2, the administered activities of 153Sm-EDTMP and 186Re-HEDP should be increased by 37% and 48%, respectively, in comparison with those usually administered.

CONCLUSION

These results prove theoretically the empirical results from clinical observations and show that improvement in bone pain palliation by means of radiopharmaceutical therapy should be expected for dose-guided prescription.