High-activity samarium-153-EDTMP therapy in unresectable osteosarcoma

Despite highly efficacious chemotherapy, patients with osteosarcomas still have a poor prognosis if adequate surgical control cannot be obtained. We applied high-activity Sm-153-EDTMP therapy within a multimodal therapy concept to improve local control of an unresectable osteosarcoma with poor response to initial polychemotherapy. A 21-year-old woman with an extended, unresectable pelvic osteosarcoma and multiple pulmonary metastases was treated with high-activity of Sm-153- EDTMP (150 MBq/kg BW, total 8.1 GBq). Afterwards external radiotherapy of the primary tumor site was performed and polychemotherapy was continued, followed by autologous peripheral blood stem cell reinfusion. Within 48 h after Sm-153-EDTMP application the patient had complete pain relief. After three weeks the response was documented by 3-phase Tc-99m-MDP bone scintigraphy (primary tumor and metastases: decreased tracer uptake), whole-body F-18-FDG-PET (primary tumor and metastases: diminution of glucose metabolism) and thoracic CT (metastases: reduction of size). The present case warrants further evaluation of feasibility and efficacy of this multimodal therapy combination of high-activity Sm-153-EDTMP therapy, external radiation, polychemotherapy and stem cell support for unresectable osteosarcomas.     

153Sm]EDTMP: a potential therapy for bone cancer pain.

Reactor-produced samarium-153 (153Sm) is both a beta and gamma emitter with a physical half-life of 46.3 hours. When complexed with EDTMP, more than 50% of the administered dose localizes in bone. A therapeutic trial on patients with painful bone metastases performed at the University of Missouri produced relief in 65.4% of the patients who were evaluable. Myelotoxicity was mild and transient. For [153Sm]EDTMP to attain clinical utility, studies demonstrating its efficacy as an analgesic must be performed to exclude a "ligand analgesic effect".     

Lack of effect of a bisphosphonate (pamidronate disodium) infusion on subsequent skeletal uptake of Sm-153 EDTMP

Patients who are candidates for samarium-153 ethylenediaminetetramethylenephosphonic acid (Sm-153 EDTMP) therapy often receive monthly infusions of pamidronate disodium or other bisphosphonates. Because both drugs are related compounds that concentrate in bone, it was advisable to determine whether previous bisphosphonate administration has blocked subsequent uptake of Sm-153 EDTMP. The authors compared skeletal uptake of Sm-153 EDTMP before and 1 to 4 days after pamidronate infusion in three patients with breast cancer metastatic to bone. In two of the patients, they continued to compare Sm-153 EDTMP uptake at approximately 1, 2, 3, and 4 weeks after pamidronate infusion. There was no difference in skeletal uptake of Sm-153 EDTMP before or at any time after pamidronate infusion. Pamidronate infusion did not interfere with skeletal uptake of Sm-153 EDTMP.     

~(153)Sm-EDTMP治疗骨转移癌疼痛的现状

以往骨转移癌病人疼痛治疗的常用方法是放疗和阶梯性使用止痛药物。随着核医学的发展 ,亲骨性放射性核素越来越多地用于癌症的治疗 ,尤其是骨转移癌的止痛治疗。其中 ,1 5 3　 Sm- EDTMP(1 5 3　 Sm-乙二胺四甲撑膦酸 )在缓解疼痛 ,改善生活质量 ,减少新的骨转移病灶发生 ,及降低治疗费用等方面都有很大优势     

Short- and long-term effects of 186Re-1,1-hydroxyethylidene diphosphonate in the treatment of painful bone metastases.

This study evaluates the short- and long-term therapeutic efficacy of 186Re-1,1-hydroxyethylidene diphosphonate (HEDP) in the palliation of painful bone metastases and the influence of variables before therapy in determining the characteristics of pain palliation. METHODS: Sixty patients with painful bone metastases from different tumor types were treated with 1406 MBq 186Re-HEDP. After treatment, the patients were followed up clinically at weekly intervals for the first month and monthly thereafter up to 1 y, until death or pain relapse. Pain response was graded as complete, partial, minimal, or absent using the Wisconsin test scoring system. Duration of pain relief, performance status, tumor markers, serum alkaline phosphatase levels, hematologic toxicity, and metastatic bone progression were also evaluated. RESULTS: Overall, 80% of individuals experienced prompt relief of pain, with 31% complete, 34% partial, and 15% minimal responses. Transient World Health Organization grade 1-2 hematologic toxicity was apparent, with a decrease in the mean platelet (32%) and mean leukocyte (18%) counts at 3 and 4 wk, respectively. The degree of pain response did not correlate with any pretreatment variable. The duration of pain relief ranged from 3 wk to 12 mo and correlated positively with the degree of response (P = 0.02) and negatively with pretreatment scintigraphic scores and alkaline phosphatase levels (P = 0.02). CONCLUSION: 186Re-HEDP is effective for fast palliation of painful bone metastases from various tumors. The effect tends to last longer if patients are treated early in the course of their disease.     

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.     

Rhenium-188 HEDP to treat painful bone metastases

PURPOSE: Rhenium-188 hydroxyethylidine diphosphonate (HEDP) is a new and attractive radiopharmaceutical that localizes in skeletal metastases and emits beta particles that may be therapeutically beneficial. In this study, the therapeutic efficacy of Re-188 HEDP was investigated in an uncontrolled initial trial of 61 patients with different types of advanced cancer for the palliation of painful bone metastases. MATERIALS AND METHODS: Sixty-one patients with painful bone metastases of lung, prostate, breast, renal, rhinopharyngeal, and bladder cancers were treated with 1.1 GBq (31 mCi) to 6.9 GBq (188 mCi) Re-188 HEDP. After treatment, the patients were followed at weekly intervals for the first 2 months and monthly thereafter for as long as 1 year. Hematologic function tests were also performed before and after treatment for 6 weeks. Pain responses were scored according to a three-point pain-rating scale as complete, significant, and minimal. RESULTS: Prompt and significant relief of bone pain occurred in 80% of patients overall. Of the specific tumor types, pain relief was achieved in 77% of patients with lung cancer, in 80% with prostate cancer, in 83% with breast cancer, in 100% with bladder cancer, in 50% with renal cancer, in 50% with rhinopharyngeal cancer, and in 87% of patients with other tumor types, with no severe side effects or hematopoietic toxicity. CONCLUSION: This large clinical trial verified that Re-188 HEDP is a useful radiopharmaceutical agent to treat painful bone metastases from various tumor types.     

153Sm-EDTMP治疗转移癌性骨痛

目的 探讨影响^153Sm-乙二胺四亚甲基磷酸盐（EDTMP）治疗转移癌性骨痛疗效的相关因素。方法 按国际原子能机构区域合作计划组织中国多中心研究,3年内收集^153Sm-EDTMP治疗转移癌性骨痛234例,根据治疗响应分为有效及无效2组,比较其个人情况,临床特点,原发病种,骨转移特点及治疗方法等因素,以SAS软件进行分组与多因素分析。结果 183例治疗有效,51例治疗无效,2组间在年龄、非核素治疗、^153Sm-EDTMP用量、转移灶数目、占骨骼比重、放射性摄取程度等方面无明显差别。但无效组中男性（43例,84.3%）、肺癌（34例,66.7%）、脊柱、骨盆与下肢转移的比例明显不同于有效组。多因素分析证实患者性别、肿瘤类型和转移部位与治疗效果相关。结论 ^153Sm-EDTMP治疗对肺癌、男性和下半身转移者效果可能较差。     

Samarium-153 EDTMP therapy of disseminated skeletal metastasis

153Sm-EDTMP (ethylenediaminetetramethylene phosphonate), prepared from a kit, was administered to 28 patients in a clinical trial of therapy for painful skeletal metastases unresponsive to all conventional treatment. The 103 keV gamma emission of 153Sm was utilized for prospective individual estimation of beta radiation absorbed dose to red marrow to minimize myelotoxicity and provide optimum internal radiotherapy to skeletal metastases in each patient. Pain relief occurred within 14 days of administration of 153Sm-EDTMP in 15 of 19 patients (79%) who could be evaluated at 6 weeks, when clinical response was maximal. Duration of response ranged from 4 to 35 weeks. Recurrence of pain responded to retreatment with 153Sm-EDTMP in five of eight cases. No dose-response relationship was apparent for pain relief but reversible myelotoxicity was frequently observed at radiation absorbed doses to bone marrow greater than or equal to 270 cGy. Dosimetry calculation was based on pharmacokinetic studies of a tracer administration of 153Sm-EDTMP in each patient. Assumptions inherent in this prospective method of predicting dose to bone marrow were validated experimentally. Biodistribution studies in rats demonstrated rapid skeletal uptake and long term retention of 153Sm-EDTMP in bone over 5 days. Urinary clearance accounted for 40% of injected dose, and less than 1.0% of administered activity was retained in non osseous tissue. Microdensitometry of autoradiographs of sheep vertebra and femur confirmed surface uptake of 153Sm-EDTMP in cortical bone and demonstrated relatively high trabecular bone activity which is the major component of radiation absorbed dose to bone marrow. Haematological studies in rabbits showed 153Sm-EDTMP-induced myelotoxicity to be transient and no histopathological abnormalities were demonstrable with doses ten times greater than those administered to patients.     

Samarium-153-EDTMP: pharmacokinetic, toxicity and pain response using an escalating dose schedule in treatment of metastatic bone cancer.

Samarium-153 emits medium-energy beta particles and an imageable gamma photon with a physical half-life of 46.3 hr. When chelated to ethylenediaminetetramethylenephosphonic acid (EDTMP), it is remarkably stable in vitro and in vivo. In this study, we administered escalating amounts of 153Sm-EDTMP, from 0.1 to 1.0 mCi/kg (3.7-37 MBq/kg), to 22 patients with painful metastatic bone cancer. A complete concordance was found when the scintigrams of 153Sm-EDTMP were compared qualitatively to 99mTc-HDP bone images. Moreover, the skeletal uptake of the 153Sm-EDTMP related to the number of metastatic sites (r = 0.65; p = 0.001) showed an inverse proportion to the plasma radioactivity at 30 min following injection (r = -0.79; p = 0.0001) and was unaffected by the administered (mCi/kg), (r = 0.33; p = 0.13). Myelotoxicity was observed in 10 of the 29 treatment courses and leukopenia occurred in two. Thrombocytopenia occurred in patients who had low pretreatment platelet counts, albeit within the normal range (p = 0.001), most suffered from prostate cancer (p = 0.007) and retained a higher percentage of the 153Sm-EDTMP in their skeleton (p = 0.057). In four patients an exacerbation of the pre-existing pain ("flare reaction") was recorded. Pain palliation occurred in 65% of the treated patients (mean: 3.8 mo, range: 1-11 mo). Retreatment in first time responder patients was quite effective. Our preliminary results indicate that 153Sm-EDTMP is a promising radiotherapeutic agent for palliative treatment of metastatic bone cancer pain, and further study is necessary to ascertain its optimal dose, efficacy and toxicity.     

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 metabolic radiotherapy with samarium-153 EDTMP for the treatment of painful bone metastasis.

Various radioisotopes conjugated to pyrophosphate analogues have been developed for systemic metabolic radiotherapy. Samarium-153-EDTMP is a 1:1 complex of radioactive Samarium-153 and a Tetraphosphonate [ethylenediamine-tetramethylene phosphonic acid (EDTMP)]. Samarium Sm-153-EDTMP has a high affinity for skeletal tissue and concentrates by chemiabsorption in areas of enhanced metabolic activity, where it associates with the hydroxyapatite crystal. Samarium-153 Lexidronam [Quadramet (R)] has been approved for routine use by the FDA. This agent offers several advantages over other agents used for palliating bone pain. Due to its half-life of 46 hours and its beta emissions, a high dose rate can be delivered to regions adjacent to enhanced osteoblastic activity over a short period of time with little residual long term activity being left in the bone marrow. This paper summarizes both animal studies and clinical studies performed with this agent. Special emphasis will be given to the pivotal Phase-III clinical studies and subsequent studies performed since its approval by the FDA. Special considerations regarding appropriate selection of patients, preparation, follow-up of patients and adjustments to the usual recommended dose [1 mCi/kg (35 Mbq/kg)] will be discussed. Current and future treatment options utilizing Sm-153-EDTMP with other pharmaceuticals appear promising and will substantially extend its use into new areas. In addition, because it also emits a 103 keV gamma ray which makes it suitable for imaging and assessment of biodistribution, dosimetric applications are possible in the future.     

Reirradiation with local-field radiotherapy for painful bone metastases

PURPOSE: The purpose of this study was to evaluate retrospectively the effectiveness, prognostic factors, and sequelae of the first course of local-field reirradiation for painful bone metastases. PATIENTS AND METHODS: From 1994 to 2000, a total of 30 patients were reirradiated for painful bone metastases. The most commonly used initial treatment regimen was 30 Gy/10 Fr/2 wk. An additional dose in the range from 10 Gy/5 Fr to 26 Gy/13 Fr was reirradiated. RESULTS: Fifteen patients (50%) showed some type of pain relief after reirradiation. Patients with initial CR were more likely to respond than those with previous PR (100% vs. 41%). The median duration of pain relief was five months. The duration of response was longer in initial CR than initial PR. The median survival time of responders after retreatment was 11 months. No patient developed radiation myelopathy. Prognostic factors for pain relief were duration from initial treatment, performance status (PS), and status of bone metastases. CONCLUSION: Reirradiation for patients with a long duration from initial treatment (> or = 4 months), good PS (ECOG: 1-2), or solitary bone metastases was effective for pain relief. The appropriate indications, optimal dose, fractions, and technique for reirradiation to painful bone metastases should be further explored in randomized study.     

153Sm-EDTMP-纳米羟基磷灰石的生物学性能

目的研究^153Sm-乙二胺四甲撑膦酸(EDTMP)-纳米羟基磷灰石(HA)的体内外生物学性能。方法采用溶胶-凝胶法合成纳米HA并用电镜和X线衍射进行鉴定，采用独立变数法研究^153Sm-EDTMP-纳米HA的最佳标记条件并对产物进行体外稳定性分析，进行^153Sm-EDTMP-纳米HA新西兰兔显像，比较纳米HA、^153Sm-EDTMP和^153Sm-EDTMP-纳米HA对肝癌SMMC-7721和乳腺癌MCF-7细胞的体外抑制作用。结果①纳米HA为针状结晶，结晶度较好，径向10～30nm，轴向70～100nm，X线衍射证明产物为HA。②^153Sm-EDTMP-纳米HA的标记率均在95％以上。体外稳定性好，在生理盐水中放置48h后放化纯仍大于95％。③正常新西兰兔^153Sm-EDTMP-纳米HA显像对比度较好，骨骼系统显示清晰，肾脏显影，血清中放射性下降较快。④^153Sm-EDTMP-纳米HA对肝癌SMMC-7721和乳腺癌MCF-7细胞的半抑制率质量浓度分别为1．98mg／L和0．075mg／L，而纳米HA分别为3．31mg／L和0．52mg／L，^153Sm-EDTMP分别为4．32mg／L和0．67mg／L，^153Sm-EDTMP-纳米HA对肿瘤生长的抑制率明显高于纳米HA和^153Sm-EDTMP。结论^153Sm-EDTMP-纳米HA的骨组织摄取好，有明显的体外抑制肿瘤生长的作用。     

^89SrCl2与^153Sm-乙二胺四亚甲基膦酸治疗骨转移癌的对比研究

目的对比研究^89SrCl2和^153Sm-乙二胺四亚甲基膦酸（^153Sm-EDTMP）治疗骨转移癌疗效。方法120例骨转移患者随机分为SOSrCl2治疗组和^153Sm-EDTMP治疗组,分别为69例和51例,^89SrCl2剂量为1．11-2．22MBq／kg,^153Sm-EDTMP剂量为25．9～37．0MBq／kg,3-6月复查SPECT,对止痛效果、转移灶变化及不良反应进行比较分析。结果^89SrCl2组总有效率、显效、有效、无效分别为92．8％、69．6％、23．3％、7．2％;^153Sm-EDTMP组的总有效率、显效、有效、无效分别为94．2％、66．7％、27．5％、5．8％,两组比较的差异无统计学意义（χ^2=4．98,P〉0．05）;^89SrCl2治疗组骨转移病灶Ⅰ级（变淡,缩小或消失,无新增病灶出现）为56．5％,^153Sm-EDTMP组为54．9％,两组比较的差异无统计学意义（χ^2=4．81,P〉0．05）;骨髓抑制情况（白细胞和血小板中任一项降低）分别为40．8％和59．2％,两组比较的差异有统计学意义（r=7．45,P〈0．05）。结论^153sm-EDTMP和^89SrCl2控制乳腺癌、前列腺癌及大多数肺癌骨转移疼痛有效,可根据经济条件选择相应药物。^89SrCl2疗效持久,相对骨髓抑制较小,更安全可靠,可作为早期骨转移患者的首选药物。     

Der Einfluss palliativer Strahlentherapie auf Schmerz und Lebensqualität bei Patienten mit Knochenmetastasen

BACKGROUND AND PURPOSE: Palliative irradiation is used to provide pain relief and to increase quality of life. Most studies exclude patients with advanced cancer disease and, therefore, a positive selection results. This prospective clinical study investigates the effect of palliative radiotherapy on pain and quality of life of patients with painful bone metastases. PATIENTS AND METHODS: 263 patients with bone metastases due to advanced cancer were observed with respect to pain and quality of life during a 2-month course of radiotherapy. Missing data were substituted by the LOCF method (last observation carried forward) to prevent a biased reduction of data. RESULTS: Radiotherapy resulted in pain relief. In the complete group, pain medication was not increased. Quality of life was not affected positively. Side effects of radiotherapy increased remarkably. CONCLUSION: Radiotherapy leads to pain relief. However, risks and benefits must be considered critically due to side effects.     

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

A multicentre trial was organized in China as part of an international coordinated research project to study the efficacy and toxicity of single-dose samarium-153 ethylene diamine tetramethylene phosphonate (EDTMP) as a palliative treatment for painful skeletal metastases. One hundred and five patients with painful bone metastases from various primaries were treated with ¹⁵³Sm-EDTMP at a dose of 37 MBq/kg(group I) or 18.5 MBq/kg (group II). The effects were evaluated according to change in daily analgesic consumption, pain score, sum of effect product (SEP), Physician’s Global Assessment (PGA), blood counts, and organ function tests conducted regularly for 16 weeks. Fifty-eight of 70 patients in group I and 30 of 35 in group II had a positive response, with SEPs of 22.29±14.47 and 20.13±13.90 respectively. Of 72 patients who had been receiving analgesics, 63 reduced their consumption. PGA showed that the Karnofsky score (KS) increased from 58.54±25.90 to 71.67±26.53, indicating improved general condition, but the difference was not significant. Among subgroups of patients, only those with breast cancer showed a significant change in the Karnofsky score after treatment. Inter-group differences were found for net change in KS between patients with lung and patients with breast cancer, and between patients with lung and patients with oesophageal cancer. Seventeen patients showed no response. No serious side-effects were noted, except for falls in the white blood cell (nadir 1.5×10⁹/l) and platelet (nadir 6.0×10¹⁰/l) counts in 44/105 and 34/105 cases, respectively. Ten patients had an abnormal liver function test. Response and side-effects were both independent of dose. In conclusion, ¹⁵³Sm-EDTMP provided effective palliation in 83.8% of patients with painful bone metastases; the major toxicity was temporary myelosuppression. Further studies are needed to identify better ways of determining the appropriate dose in the individual case and the efficacy of treatment. Received 4 July and in revised form 6 September 1998     

Role of palliative and symptomatic radiotherapy in bone metastasis]

INTRODUCTION: The presence of bone metastases is a common event in the natural history of nearly all neoplasms which often affects the patient's quality of life greatly. Bone metastases may cause pain and pathologic fractures, or even a cord compression syndrome with severe neurologic symptoms. We tried to assess the optimal irradiation schedule for these patients and to discuss the use of radiopharmaceuticals. MATERIALS AND METHODS: We reviewed the literature focusing on studies investigating the efficacy of hypofractionated radiotherapy for bone metastases. We also addressed the problem of treating multiple skeletal lesions with half-body irradiation and radionuclides. RESULTS: External beam irradiation achieves pain palliation in more than 75% of patients with bone metastases, even with hypofractionation down to a single-dose administration. The results of exclusive radiotherapy in the cord compression syndrome depend on a prompt diagnosis, patient presentation and the intrinsic radiosensitivity of tumor cells. Palsy can always be avoided in these patients. Half-body irradiation can achieve complete pain relief in over 20% of patients and decrease pain markedly in the remaining cases with only a single-dose fraction (6-10 Gy), within 48 hours of irradiation and with little side-effects. Better results in terms of pain relief (80% complete responses) and duration of palliation come from fractionated half-body irradiation (up to 17.5 Gy in 7 fractions), which however has a more delayed response (1-2 weeks) and higher toxicity. The use of radiopharmaceuticals has been recently reevaluated after the introduction of new nuclides: results are similar to those of external beam irradiation (up to 80% responses), but cost and hematologic toxicity are both high. Radiopharmaceuticals can be used within an integrated treatment with external beam irradiation, chemotherapy and biphosphonates. DISCUSSION: The efficacy of external beam irradiation in the palliation of bone metastasis-related symptoms is confirmed by this literature review, even with short treatments and single-dose administrations. This is important for both patient expectations and the necessity for improved resource allocation with reference to the territorial distribution and waiting lists of radiotherapy centers. Finally, as for the role of radiopharmaceuticals, the best nuclides are not widely used yet for the high cost of the treatment, even though they provide similar results to external beam irradiation. The issue of their efficacy in combination with antiblastic drugs and/or external beam irradiation remains open and will be clarified only with further randomized clinical trials.     

Radiofrequency Ablation Therapy Combined with Cementoplasty for Painful Bone Metastases: Initial Experience

The purpose of this study was to assess the efficacy and safety of percutaneous radiofrequency (RF) ablation therapy combined with cementoplasty under computed tomography and fluoroscopic guidance for painful bone metastases. Seventeen adult patients with 23 painful bone metastases underwent RF ablation therapy combined with cementoplasty during a 2-year period. The mean tumor size was 52 × 40 × 59 mm. Initial pain relief, reduction of analgesics, duration of pain relief, recurrence rate of pain, survival rate, and complications were analyzed. The technical success rate was 100%. Initial pain relief was achieved in 100% of patients (n = 17). The mean VAS scores dropped from 63 to 24 (p < 0.001) (n = 8). Analgesic reduction was achieved in 41% (7 out of 17 patients). The mean duration of pain relief was 7.3 months (median: 6 months). Pain recurred in three patients (17.6%) from 2 weeks to 3 months. Eight patients died and 8 patients are still alive (a patient was lost to follow-up). The one-year survival rate was 40% (observation period: 1–30 months). No major complications occurred, but one patient treated with this combined therapy broke his right femur 2 days later. There was transient local pain in most cases, and a hematoma in the psoas muscle (n = 1) and a hematoma at the puncture site (n = 1) occurred as minor complications. Percutaneous RF ablation therapy combined with cementoplasty for painful bone metastases is effective and safe, in particular, for bulky tumors extending to extraosseous regions. A comparison with cementoplasty or RF ablation alone and their long-term efficacies is needed.     

Samarium — 153 EDTMP therapy of disseminated skeletal metastasis

¹⁵³Sm-EDTMP (ethylenediaminetetramethylene phosphonate), prepared from a kit, was administered to 28 patients in a clinical trial of therapy for painful skeletal metastases unresponsive to all conventional treatment. The 103 keV gamma emission of ¹⁵³Sm was utilized for prospective individual estimation of beta radiation absorbed dose to red marrow to minimize myelotoxicity and provide optimum internal radiotherapy to skeletal metastases in each patient. Pain relief occurred within 14 days of administration of ¹⁵³Sm-EDTMP in 15 of 19 patients (79%) who could be evaluated at 6 weeks, when clinical response was maximal. Duration of response ranged from 4 to 35 weeks. Recurrence of pain responded to retreatment with ¹⁵³Sm-EDTMP in five of eight cases. No dose-response relationship was apparent for pain relief but reversible myelotoxicity was frequently observed at radiation absorbed doses to bone marrow 270 cGy. Dosimetry calculation was based on pharmacokinetic studies of a tracer administration of ¹⁵³Sm-EDTMP in each patient. Assumptions inherent in this prospective method of predicting dose to bone marrow were validated experimentally. Biodistribution studies in rats demonstrated rapid skeletal uptake and long term retention of ¹⁵³Sm-EDTMP in bone over 5 days. Urinary clearance accounted for 40% of injected dose, and less than 1.0% of administered activity was retained in non osseous tissue. Microdensitometry of autoradiographs of sheep vertebra and femur confirmed surface uptake of ¹⁵³Sm-EDTMP in cortical bone and demonstrated relatively high trabecular bone activity which is the major component of radiation absorbed dose to bone marrow. Haematological studies in rabbits showed ¹⁵³Sm-EDTMP-induced myclotoxicity to be transient and no histopathological abnormalities were demonstrable with doses ten times greater than those administered to patients.