Palliative therapy with bone seeking radiopharmaceuticals

WITHDRAWN: Radioisotopes for metastatic bone pain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.

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.

Three-dimensional imaging-based radiobiological dosimetry

Targeted radionuclide therapy holds promise as a new treatment for cancer. Advances in imaging are making it possible for researchers to evaluate the spatial distribution of radioactivity in tumors and normal organs over time. Matched anatomical imaging, such as combined single-photon emission computed tomography/computed tomography and positron emission tomography/computed tomography, has also made it possible to obtain tissue density information in conjunction with the radioactivity distribution. Coupled with sophisticated iterative reconstruction algorithms, these advances have made it possible to perform highly patient-specific dosimetry that also incorporates radiobiological modeling. Such sophisticated dosimetry techniques are still in the research investigation phase. Given the attendant logistical and financial costs, a demonstrated improvement in patient care will be a prerequisite for the adoption of such highly-patient specific internal dosimetry methods.

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.

Systemic radionuclide therapy in pain palliation

Several radiopharmaceuticals were investigated to determine their efficacy and toxicity in the palliation of painful bone metastases. Data on the influence of rhenium-188 hydroxyethylidene diphosphonate (188Re-HEDP), rhenium-186 hydroxyethylidene diphosphonate (186Re-HEDP), and strontium-89 (89Sr) on pain symptoms, quality of life, and bone-marrow function were obtained in 64 patients with breast and prostate cancer. Thirty-one patients were treated with 188Re-HEDP (3194 +/- 387 MBq), 15 patients with 186Re-HEDP (1358 +/- 158 MBq), and 18 patients with 89Sr (152 +/- 19 MBq). The 188Re-HEDP group included six breast cancer patients and 25 prostate cancer patients; the 186Re-HEDP group included three breast cancer patients and 12 prostate cancer patients; and the 89Sr group included three breast cancer patients and 15 prostate cancer patients. All subjects participated in an interview using a standardized sets of questions before and after the 12-week term of therapy. Blood counts were taken weekly for six weeks and after 12 weeks. Results showed that 77 percent of patients reported pain relief after treatment with 188Re-HEDP, 67 percent after treatment with 186Re-HEDP, and 72 percent after treatment with 89Sr. Sixteen percent of patients treated with 188Re-HEDP, 13 percent treated with 186Re-HEDP, and 17 percent treated with 89Sr were able to discontinue their analgesics and were pain-free. Patients described an improvement on Karnofsky performance status (KPS) from 73 +/- 7 percent to 85 +/- 8 percent 12 weeks after 188Re-HEDP (p < 0. 05), from 72 +/- 13 percent to 79 +/- 12 percent after 186Re-HEDP (p = 0.251), and from 62 +/- 14 percent to 69 +/- 16 percent after 89Sr (p = 0.415). Only three patients undergoing 188Re-HEDP therapy, one undergoing 186Re-HEDP therapy, and three undergoing 89Sr therapy had thrombocytopenia (platelet count below 100 x 10(3)/microl) following treatment. The maximum nadir of platelet and leukocyte counts was observed between the second and fifth week after treatment for all radionuclides and was reversible within 12 weeks. The nadir was earlier for 188Re-HEDP with a shorter physical half-life compared with 89Sr. There were no significant differences in bone marrow toxicity (p = 0.123-0.421). Results of this study indicate that all evaluated radiopharmaceuticals were effective in pain palliation without induction of severe side effects. The increase in KPS after 188Re-HEDP was the only statistically significant finding (p = 0.001).

The benefit of bone-seeking radiopharmaceuticals in the treatment of metastatic bone pain

PURPOSE

The surface bone-seeking radiopharmaceuticals rhenium-188-HEDP (188Re-HEDP) and samarium-153-EDTMP (153Sm-EDTMP) were investigated to determine the efficacy and toxicity in pain palliation in bone metastases.

METHOD

The effect of treatment with 188Re-HEDP and 153Sm-EDTMP on pain symptoms, life quality, and bone marrow function were obtained in 46 patients with prostate and breast cancer. There were 31 patients treated with 188Re-HEDP (3194+/-387 MBq) and 15 patients with 153Sm-EDTMP (2940+/-545 MBq). The 188Re-HEDP group included 6 patients and 25 patients, and the 153Sm-EDTMP group 6 patients and 9 patients with breast and prostate cancer, respectively. All patients had an interview using standardized sets of questions before and after therapy for 12 weeks. Blood counts were taken weekly for 6 weeks and after 12 weeks.

RESULTS

After treatment with 188Re-HEDP, 77% of patients reported pain relief and 73% after 153Sm-EDTMP. Sixteen percent of the patients treated with 188Re-HEDP and 13% of those given 153Sm-EDTMP could discontinue their analgesics and were pain free. Patients described an improvement on the Karnofsky performance scale from 73+/-7 to 85+/-8% 12 weeks after 188Re-HEDP (p<0.05) and from 68+/-9 to 74+/-9% after 153Sm-EDTMP (p=0.217). Only 3 patients post-188Re-HEDP and 2 patients post-153Sm-EDTMP showed a thrombocytopenia below 100 x 10(3)/microl. The maximum nadir of platelet and leukocyte counts were observed between the second to fourth week after treatment in both and was reversible within 12 weeks. There were no significant differences in pain palliation, Karnofsky performance scale and bone marrow toxicity between the lower beta energy 153Sm-EDTMP and the higher beta energy 188Re-HEDP (p=0.098-0.442).

CONCLUSION

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

Prostate cancer and bone metastases: medical treatment

Prostate cancer is the most common malignancy in men in the United States. With the long natural history of the disease, management of skeletal morbidity related to advanced prostate cancer becomes a major public health issue. The standard of care in advanced prostate cancer is androgen deprivation therapy. This may accelerate the development of osteoporosis and further exacerbate the risks of having adverse skeletal-related events develop. Recently, the use of bisphosphonates in men who have not responded to androgen deprivation therapy has been shown to reduce the incidence of skeletal-related events with time. Questions remain as to whether bisphosphonates should be broadly applied to earlier stages of the disease or tailored to men at higher risk of having bone-related morbidity. Work is ongoing to improve other approaches to the medical treatment of bone metastases in patients with advanced prostate cancer including the use of radiopharmaceuticals and combined chemotherapy.

Therapeutic efficiency of rhenium-188-HEDP in human prostate cancer skeletal metastases

Rhenium-188-HEDP ((188)Re-HEDP) is a new and attractive radiopharmaceutical for the treatment of metastatic bone pain. As a product of (188)W/(188)Re generator, it is convenient for clinical therapeutic use with a short physical half-life of 16.9 h and a maximal beta-energy of 2.1 MeV. We investigated the effect of (188)Re-HEDP on pain relief, analgesic intake and impairment of bone marrow function in 27 patients with bone metastases induced from prostate cancer. All patients were interviewed using a standardised set of questions before, and after therapy for 12 weeks. The patients were treated with 2700-3459 MBq of (188)Re-HEDP. Blood samples were taken weekly for 12 weeks, and a blood count was performed. Patients described an improvement on the Karnofsky performance scale from 74+/-7 to 85+/-9% 12 weeks after therapy (P=0.001). The pain score showed a maximum decrease from 44+/-18 to 27+/-20% in the third to the eight week after therapy (P=0.009). Seventy-six percent of the patients described a pain relief without increase of analgesic intake. Twenty percent of the patients could discontinue their analgesics and were pain free. Mean platelet count decreased from (286+/-75)*10(3) microl(-1) to (215+/-92)*10(3) microl(-1), and mean leucocyte count from (7.7+/-1.5)*10(3) microl(-1) to (6.0+/-1.9)*10(3) microl(-1) in the second to the fourth week after therapy. The maximal differences between the values of platelets and leucocytes before and after therapy were not statistically significant (P=0.021 and 0.094). In conclusion, (188)Re-HEDP is an effective radiopharmaceutical used in the palliative treatment of metastatic bone pain in prostate cancer and shows minimal bone marrow toxicity.

Impact of interpatient pharmacokinetic variability on design considerations for therapy with radiolabeled MAbs

Radionuclides provide biologically-distributed vehicles for radiotherapy of multifocal cancer. Two algorithms, fixed vs individualized, have been used to prescribe the therapeutic dose of radionuclide (GBq) for the patient. The individualized method for prescribing radionuclide dose takes variations in drug pharmacokinetics into consideration, whereas the fixed method depends, in part, on documentation that there is little interpatient pharmacokinetic variability for the radiolabeled drug. Two data bases, selected to compare iodine-131((131)I) and indium-111((111)In) labeled MAbs, were used to assess interpatient pharmacokinetic variability and its impact on radionuclide dose prescription. Pharmacokinetic data obtained over 7 days for non-Hodgkins lymphoma (NHL) patients given (131)I-Lym-1 (n = 46) or (111)In-Lym-1 (n = 13) were used to obtain cumulated activities. Although (131)I-Lym-1 often showed greater interpatient variability, (111)In-Lym-1 showed several-fold variability for many tissues. Both (131)I- and (111)In-Lym-1 had sufficient interpatient variability to be significant for radionuclide dose prescription, depending on the dose-limiting critical tissue. Interpatient variability exceeded intra- and interoperator variability and intrapatient variability over time for a single institution. In summary, the magnitude of interpatient pharmacokinetic variability for (131)I- and (111)In-Lym-1 suggested that an optimally safe and effective therapy can be best achieved when radionuclide dose is influenced by estimated radiation dose, if the latter is reproducible from institution to institution.

Radioisotopes for metastatic bone pain

BACKGROUND

Bone metastases manifest through pain, which can arise even before the injury is radiologically detected. Pain occurs as a result of bone destruction and, as more destruction ensues, more pain can be experienced. Radiculopathies, plexopathies and shrinkage of spinal nerves due to tumour growth and fractures are very frequent in these patients. Relief of pain from bone metastasis can be achieved by treating the cancer itself; radiotherapy; conventional analgesics; and specific drugs that work on the bone tumour-induced alteration: biphosphonates, calcitonin or radioactive agents.

OBJECTIVES

To determine the efficacy of radioisotopes to control metastatic pain in patients with bone metastases and complications due to bone metastases (hypercalcaemia, bone fracture and spinal cord compression) as well as its efficacy in terms of patient survival and adverse effects.

SEARCH STRATEGY

Randomised and controlled clinical trials related to this review were retrieved electronically using MEDLINE (1966-2003), EMBASE (1974-2003) and Cochrane Central Register of Controlled Trials (CENTRAL) (Issue 1 2003). general strategies to identify RCTs were combined with specific commands to identify trials of radioisotopes and metastatic bone pain.

SELECTION CRITERIA

The inclusion criteria were: randomised trials of patients with metastatic bone pain that compared treatment with radioisotopes and placebo, and where the major outcome was either pain or complications of bone metastases (eg, hypercalcaemia, bone fracture, spinal cord compression) assessed at least four weeks after treatment.

DATA COLLECTION AND ANALYSIS

The quality of included studies was assessed using the Jadad scale and the Oxford Pain Validity Score. Two independent reviewers extracted the data and completed a standard form designed for that purpose. An intention-to-treat analysis was performed, and global estimates of effect were calculated using a random effects model.

MAIN RESULTS

Four trials (325 patients) provided data that suggest a small effect of radioisotopes on pain control both at short and medium term (one to six months). No evidence was available to assess long-term effects (12 months). Only one study provided data on analgesia use and concluded that patients given either radioisotopes or placebo showed similar levels of analgesic use when compared to baseline use. Leukocytopenia and thrombocytopenia are secondary effects associated with the administration of radioisotopes. The incidence of leukocytopenia is significantly greater in patients treated with radioisotopes (RR=4.56, 95% CI (1.22,17.08)). There were also a greater number of thrombocytopenia events in the treatment group, without reaching statistical significance.

REVIEWER'S CONCLUSIONS

The efficacy of radioisotopes has been assessed in clinical trials with small sample sizes and short-term evaluations of the outcomes. There is some evidence indicating that radioisotopes may give complete reduction in pain over one to six months with no increase in analgesic use, but adverse effects, specifically leukocytopenia and thrombocytopenia, have also been experienced.

Efficacy and safety of repeated samarium-153 lexidronam treatment in a patient with prostate cancer and metastatic bone pain

A patient with stage D3 prostate cancer was given 11 separate doses of samarium-153 lexidronam (Sm-153 ethylenediaminetetramethylene phosphonate) of 1 mCi/kg (37 MBq/kg) in a period of 28 months for bone pain from metastases. With the first five doses, Sm-153 lexidronam clearly reduced his bone pain and improved his quality of life, as determined by pain-assessment scores and the patient's self-assessment of its effect on his ability to perform activities of daily living. With doses 6 through 11, pain at baseline was on average less, and as a result beneficial effects after treatment were not as apparent. Samarium-153 lexidronam produced transient decreases in the leukocyte and platelet counts, but these never became low enough to cause clinical concern. This case shows both the efficacy and the safety of Sm-153 lexidronam in repeated treatments for metastatic bone pain in patients with prostate cancer.

Systemic radiopharmaceutical therapy of painful osteoblastic metastases

Bone pain from osteoblastic metastases can be ameliorated 40% to 80% of the time. Although we can predict nonresponders, we cannot predict responders; however, patients with a better performance scale may have a better chance of pain relief. Radiopharmaceuticals containing phosphorus 32, strontium 89, samarium 153, rhenium 186, and tin 117m are effective, but we do not know which is the most efficacious and the safest. Toxicity includes the flare phenomenon and mild to moderate pancytopenia, but disseminated intravascular coagulation can cause severe, life-threatening thrombocytopenia. This treatment may be repeated at about 9- to 12-week intervals, perhaps earlier with (153)Sm lexidronam, (186)Re etidronate, and (117m)Sn pentetate, with a success rate approaching that of the initial injection. The duration of action of pain reduction ranges from 2 weeks to many months. Tumorical effects are probably not the only mechanism of pain relief.

Use of radionuclides for the palliation of bone metastases

Pain palliation with bone-seeking radiopharmaceuticals is an effective and cost-effective management tool in patients with advanced cancer metastatic to bone. Strontium-89 ((89)Sr) (Metastron) and samarium-153 ((153)Sm) EDTMP (Lexidronam) are licensed for use in patients in the United States. Patients with a positive bone scan using technetium 99m methylene diphosphonate ((99m)Tc MDP) are eligible for treatment, and indications and contraindications for use are now well defined. The evidence in the literature now suggests that the radiopharmaceuticals can significantly reduce pain and analgesic requirements, can improve quality of life, can reduce lifetime radiotherapy requirements and management costs, and may slow the progression of painful metastatic lesions. Retreatment is safe and effective. Rhenium-186 ((186)Re) HEDP and Tin-117m diethylenetriaminepenta-acetic acid (DTPA) are in phase II/III trials to evaluate efficacy and compare efficacy with the licensed agents. Phosphorus-32 ((32)P) has been reassessed in two trials evaluating efficacy in comparison with (89)Sr and safety. Toxicity is reversible myelosuppression, which may be significant, and the treatments should not be given to patients with suspected disseminated intravascular coagulation.

Radionuclides as conditioning before stem cell transplantation

Targeted radiotherapy using either radiolabeled monoclonal antibodies or bone-seeking radiopharmaceuticals can potentially result in delivery of high radiation doses to tumor or bone marrow with less toxicity to normal organs. High-dose radioimmunotherapy has produced encouraging results in lymphoma and leukemia. The use of alternative radionuclides and new combinations of radioimmunotherapy with chemotherapy may improve patient outcomes. Comparative trials will be necessary to confirm an improved therapeutic benefit with this approach.