153Sm-EDTMP for bone pain palliation in skeletal metastases

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

PURPOSE

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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

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

AIMS

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

MATERIAL AND METHODS

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

RESULTS

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

CONCLUSIONS

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

Management of bone metastases in cancer: a review

The presence of bone metastases is indicative of disseminated disease and typically indicates a short-term prognosis in cancer patients. Palliation of symptoms is the primary goal of therapy, with multidisciplinary efforts yielding the best results. New classes of drugs, such as bisphosphonates that significantly increase the time to first skeletal-related event (SRE), represent useful tools for the treatment of bone metastases. While the optimal duration of therapy needs to be defined, there is clinical benefit derived from the use of this class of agents. A potential role for bisphosphonates in the prevention of bone metastases is under current evaluation in clinical trials encompassing different solid tumor types. In combination with ongoing clinical trials, basic research to identify potential novel targets in the tumor cells-bone microenvironment will further define future strategies in the treatment of bone metastases.

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.