Strontium-89 for palliation of pain from bone metastases in patients with prostate and breast cancer

We have used strontium-89 chloride (89Sr) for the palliative treatment of metastatic bone pain. Seventy-six patients (50 males with prostate carcinoma and 26 females with breast cancer) were treated with 148 MBq of 89Sr. Sixteen patients were retreated, receiving two or three doses; the total number of injected doses was consequently 95. The Karnofsky performance status was assessed and pain and analgesia were scored on scales of 9 and 5 points, respectively. The efficacy of 89Sr was evaluated at 3 months of treatment. Three levels of response were considered: good - when there was an increase in the Karnofsky status and a decrease in the pain score (equal to or higher than 4) or analgesic score (equal to or higher than 1); partial - when there was an increase in the Karnofsky status and a decrease in the pain score (2 or 3 points) without significant changes in the analgesic score; no response - if no variation or deterioration in these parameters was observed. In prostate cancer patients, the response was good in 64% of cases and partial in 25%, and there was no response in the remaining 11%. In breast cancer patients, the response was good in 62% of cases and partial in 31%, and there was no response in the remaining 8%. Duration of the response ranged from 3 to 12 months (mean 6 months). In the patients who were retreated the effectiveness was as good as after the first dose of 89Sr. A decrease in the initial leucocyte and platelet counts was observed after the 1st month of treatment, with a gradual partial to complete recovery within 6 months. It is concluded that 89Sr is an effective agent in palliative therapy for metastatic bone pain in patients with prostate or breast carcinoma. If required, retreatment can be administered safely and with the same efficacy as is achieved by the first dose.

The role of strontium-89 systemic radiotherapy in the management of osseous metastases from prostate cancer

Strontium-89 systemic radiotherapy can play a significant role in the palliation of symptomatic osseous metastases from prostate cancer. Given as a single injection, strontium's affinity for osteoblastic activity draws it to all sites of osseous involvement simultaneously. The metastases are bathed with beta-particles whose short range in tissues spares the surrounding normal structures. This article will review the rationale, physiology, and patient selection criteria for its use. Approximately 80% of patients will respond to treatment as documented by the authors experience and by a review of the literature.

[Biological effects of acute external or internal irradiation of rats in the framework of nitrite intoxication]

The material presented provides evidence that high nitrite doses have a various effect under the condition of external or internal radiation. Thus, nitrite protector properties were observed in male rats exposed to external radiation using the LD50/30 while following 90Sr exposure male rats of the same age showed a higher sensitivity to the radionuclide. The nitrite combined with optimum carcinogenic 90Sr dose had a potentiating effect on both life-span shortening and increase in osteosarcoma rate in the animals.

[Behavior of fuel hot particles in the body of cows at oral intake]

It was studied the behaviour of fuel hot particles (analogous to Chernobyl) in gastrointestinal tract of cows. The values of caesium and strontium radionuclides transfer to the cows organism and its transition parameters to milk after the single per oral intake to the organism of animals are estimated. It is shown, that the biological simplicity of radionuclides in the fuel hot particles at two parameters lower, than the same radionuclides in washed phases.

Dosimetric considerations for catheter-based beta and gamma emitters in the therapy of neointimal hyperplasia in human coronary arteries

PURPOSE

Recent data indicate that intraluminal irradiation of coronary arteries following balloon angioplasty reduces proliferation of smooth muscle cells, neointima formation, and restenosis. We present calculations for various isotopes and geometries in an attempt to identify suitable source designs for such treatments.

METHODS AND MATERIALS

Analytical calculations of dose distributions and dose rates are presented for 192Ir, 125I, 103Pd, 32P, and 90Sr for use in intracoronary irradiation. The effects of source geometry and positioning accuracy are studied.

RESULTS

Accurate source centering, high dose rate, well-defined treatment volume, and radiation safety are all of concern; 15-20 Gy are required to a length of 2-3 cm of vessel wall (2-4 mm diameter). Dose must be confined to the region of the angioplasty, with reduced doses to normal tissues. Beta emitters have radiation safety advantages, but may not have suitable ranges for treating large diameter vessels. Gamma emitters deliver larger doses to normal tissues and to staff. Low energy x-ray emitters such as 125I and 103Pd reduce these risks but are not available at high enough activities. The feasibility of injecting a radioactive liquid directly into the angioplasty balloon is also explored.

CONCLUSIONS

Accurate source centering is found to be of great importance. If this can be accomplished, then high energy beta emitters such as 90Sr would be ideal sources. Otherwise, gamma emitters such as 192Ir may be optimal. A liquid beta source would have optimal geometry and dose distribution, but available sources, such as 32P are unsafe for use with available balloon catheters.

The treatment of osseous metastases of hormone-refractory prostate cancer with external beam radiotherapy and Strontium-89

Metastatic bone disease from hormone-refractory prostate cancer can lead to significant morbidity such as pain, nerve compression and fractures which diminishes the quality of life of these patients substantially. Pain from osteoblastic metastases can significantly be improved by both external radiotherapy and Strontium-89 (89Sr), whereas lytic metastases are only responsive to external irradiation. Pain relief is obtained in approximately 80% of patients. Toxicity is mild and retreatment is usually possible. External beam radiotherapy is indicated when spinal cord or nerve root compression is demonstrated, or when osteolytic metastases with danger of fracture are visualized. External radiotherapy and Strontium-89 are important treatments to palliate patients suffering from metastatic prostate cancer. Because of their mild toxicity and highly effective analgesic effect, implementation of irradiation and 89Sr should be start of early in the disease process of these patients in order to keep them ambulatory and pain-free as long as possible.

[The results of strontium-90 contact therapy to prevent the recurrence of pterygium]

AIM

Aim of the study was the evaluation of the role of adjuvant radiation therapy in the prevention of recurrence after excision.

PATIENTS AND METHODS

Between July 1, 1985 and April 1, 1993, 64 patients (43 male, 21 female) were referred to radiation therapy after excision of a nasal pterygium. Radiation therapy was done with a strontium-90 eye applicator and a total dose of 30 Gy, fractionated in 6 fractions of 5 Gy each, 3 times a week. Forty-nine patients were treated primarily, 15 patients underwent radiation therapy for the first time in case of recurrent pterygium after multiple re-excisions. All patients had a following of 1 to 9 years with a median of 5.5 years.

RESULTS

In 8 of 64 irradiated patients recurrent pterygium was detected (12.5%). Differentiated into the 2 groups 4 of the primarily treated patients had recurrent pterygium (8.16%), the other 4 were in the group with multiple former re-excisions (26.7%). With regard to the initiation of the irradiation after surgery pterygium did not recur in any of the primarily treated patients who were irradiated in between 3 days after surgery. In contrary 3 of 7 primarily treated patients (42.9%) who started radiation therapy between 7 and 10 days after surgery had recurrent pterygium. For the patients with primarily recurrent pterygium no dependence of the initiation of radiation therapy after surgery could be detected.

CONCLUSIONS

Adjuvant radiation therapy after excision of pterygium lowers the rate of recurrence from about 40% to 12.5%, in a primarily adjuvant situation to 8.16%. In these patients radiation therapy should be initiated within 3 days after surgery. Patients with primarily recurrent pterygium have an elevated risk of recurrence independently of the initiation of radiation therapy.

Strontium-89 chloride (Metastron) for palliative treatment of bony metastases. The University of Minnesota experience

Strontium-89 chloride (Metastron) is an FDA-approved treatment for palliation of cancer pain. We evaluated blood count changes and pain relief in 28 patients with widespread painful bony metastasis treated with strontium-89 at the University of Minnesota Hospital and Clinics. Eighteen patients had prostate cancer (all hormone-refractory cancer), seven patients had breast cancer, and three patients had lung cancer, all previously treated with either radiation, chemotherapy, or a combination of the two. Serial blood counts were performed weekly up to 8 weeks and at 12 weeks after administering Metastron. Pain scale and blood values were monitored simultaneously. The mean baselines of hemoglobin (Hgb), white blood count (WBC), and platelets (Plts) were 11.4, 5900, and 258,000, respectively. The mean dose of Metastron was 3 mCi (range 2.2-4.4). The median time (range) to nadir was about 6 weeks. The percentage reductions relative to baseline were 32% (range 0-72%) for WBC; 14% (range 0-50%) for Hgb; 15% (range 0-47%) for the red blood cell (RBC) count; and 40% (range 0-85%)for Plts. We did not find a close relationship among the baseline blood count, reduction of subsequent blood counts, or previously irradiated active bone marrow volume. The median time of survival was 23 weeks (range 2-66 weeks). At 12 weeks, 29% of patients had moderate to dramatic improvement of pain, 32% had some relief of pain, and 50% had no improvement in pain. Thirty-two percent of the treated patients required additional palliative external beam radiation to their bony lesions within the study period. Our results show that Metastron for palliation for bony metastases should be used with caution because of moderate to severe bone marrow toxicity, especially in platelets, associated with its use. Careful evaluation of patients given Metastron is needed to assess accurately its full benefit.

[Schematic model of genesis of osteosarcoma induced by Sr-90]

The development of radiation osteosarcoma genesis scheme induced by 90Sr was the subject of the present study. The production of cancer cells after exposure to a specific dose-rate of emitting 90Sr incorporated in the skeleton are typical for the initiation period. However not all the cells remain in the mutant DNA. In some of them DNA reparation occurs, other cells are killed in the process of the subsequent divisions, and only a few of them containing mutant DNA are preserved in the state of repression up to the end of life time. Disorders of homeostasis due to exhausted of physiological reserves - (natural or early aging) are manifested as a promoter. In that period the derepression of mutant DNA occurs and malignant growth of tumor starts.

Strontium 89 therapy for the palliation of pain due to osseous metastases

OBJECTIVE

To present the current state of systemic radiopharmaceutical therapy for the palliation of pain in individuals with metastatic cancer and to evaluate the palliative effect and degree of hemotoxicity of strontium chloride 89 (89Sr) in patients with painful osteoblastic metastases primarily from prostate and breast cancer.

DATA SOURCES AND STUDY SELECTION

A MEDLINE search through December 1994 was performed to identify English-language studies that met the following criteria. All eligible studies reported treatment of patients with painful osteoblastic bony metastases primarily from prostate or breast cancer treated with intravenous 89Sr. For study eligibility, evaluation of clinical response as assessed by the Karnofsky index, need for pain medication, or changes in mobility or sleep patterns was required. Hemotoxicity data were a requirement. A minimum of 10 prostate cancer cases was necessary for study inclusion. Only those studies assessing clinical response following one injection of 89Sr were included. Preliminary reports of cooperative studies were not included. Doses of 89Sr ranged from 0.6 MBq/kg (16 microCi/kg) to 400 MBq (10.8 mCi) per patient. Evaluation of patients for at least 3 months following 89Sr treatment was required. In addition, two studies examining issues of cost with regard to 89Sr treatment were identified.

DATA EXTRACTION

Baseline pain assessment and periodic pain estimates as measured by the Karnofsky index, medication diaries, changes in mobility, sleep patterns, and/or ability to work were the basis for assessment of response. Baseline and periodic complete blood cell counts were the basis for hemotoxicity evaluation.

DATA SYNTHESIS

Palliation and hemotoxicity data were analyzed separately for each study. Some improvement occurred in as many as approximately 80% of patients. Several studies demonstrated complete relief of pain in at least 10% of patients The nadir of platelet and white blood cell counts appears at approximately 4 to 8 weeks following injection, with a partial return to baseline by 12 weeks. As many as 10 injections spaced 3 months apart have been given to some patients with repeated palliative effect and without serious hemotoxicity. Reinjection may be limited by a platelet count below 60 x 10(9)/L, a white blood cell count below 2.4 x 10(9)/L, or the absence of osteoblastic skeletal metastasis as seen on bone scan. Studies examining treatment costs suggest that 89Sr may decrease costs associated with palliation of pain due to metastatic disease.

CONCLUSIONS

As many as 80% of selected patients with painful osteoblastic bony metastases from prostate or breast cancer may experience some pain relief following 89Sr administration. In addition, as many as 10% or more may become pain free. Duration of clinical response may average 3 to 6 months in some cases. Hemotoxicity is mild. A decrease in treatment costs with administration of 89Sr to patients with painful osteoblastic bony metastases from prostate cancer may occur. These observations reflect the preliminary nature of knowledge in this field and point to the need for larger clinical trials of the use of 89Sr palliation.

Preparation and biodistribution of yttrium-90 Lipiodol in rats following hepatic arterial injection

In this study, we labelled Lipiodol with yttrium-90 and analysed the biodistribution in rats after intrahepatic arterial injection. An RP-18 column (E. Merck) was used to separate 90Y from strontium-90. 90Y was retained on the column, which had been pretreated with yttrium-selective extraction reagent, di(2-ethylhexyl) phosphate, while 90Sr was washed out. A hexadentate nitrogen-donor chelating ligand N,N,N',N'-tetrakis(2-benzymidazolylmethyl)-1,2-ethanediamine (EDTB) was synthesized by condensation of 1,2-benzenediamine and ethylene diamine tetra-acetic acid (EDTA). Lipiodol was covalently conjugated with EDTB. The final product was obtained by eluting the retained 90Y from the RP-18 column with EDTB-Lipiodol. Sixteen male rats (Sprague-Dawley) were sacrificed at 1 h, 24 h, 48 h and 72 h (four rats at each time) after injection of approximately 0.1 mCi 90Y-Lipiodol via the hepatic artery. Samples of liver, spleen, muscle, lung, kidney, bone, whole blood and testis were obtained and counted to calculate the tissue concentrations. In addition, labelling efficiency and in vitro stability were determined by ITLC methods. We found that at 1 h after intrahepatic injection, most of the radiotracer was retained in the liver, but it was eliminated gradually over a few days. The radioactivity level in the lung was fair at 1 h and remained at roughly the same level throughout the study. Radioactivity in the kidney and spleen reached a relatively high level at 24 h, but declined rapidly.(ABSTRACT TRUNCATED AT 250 WORDS)

Eye tumors and other lesions among beagles given 90Sr or 226Ra

Analysis of eye tumors and other eye lesions among beagles given either 90Sr or 226Ra, and among control animals, indicated that intraocular tumors in excess of the rate for our control animals were not associated with radiation from incorporated 90Sr + 90Y. It is unequivocal that eye melanomas were produced by injected 226Ra. Intraocular neoplasia, hyperplasia, hyperpigmentation, and melanosis in the eye all occurred in our control beagles given no radioactivity; however, tumor experience as currently reported for different beagle colonies may not be directly comparable because of differing rates of discovery, nonuniform nomenclature, and varying criteria for classification of lesions with their discordant interpretation by different pathologists.

Dietary intake evaluation and dosimetric modelling for the Techa River residents based on in vivo measurements of strontium-90 in teeth and skeleton

Explanations are given for the models and algorithms that are utilised to reconstruct the doses due to the incorporation of 90Sr in the inhabitants of the Techa riverside villages. A model for the 90Sr accumulation and excretion in the tooth enamel is employed to derive the relative intakes of 90Sr in the years 1950-1959. The measurements of beta-ray activity on the surface of the front teeth of persons born between 1940-1959 are used to derive the relative intakes in different calendar years and the transfer functions to the tooth enamel as a function of age. This derivation is based on a non-linear optimisation algorithm, to fit the observed average count rates for different birth cohorts in a village. The data for the village of Muslyumovo are used as the reference data set. Absolute values of the strontium intake are derived from the relative values by a fit to the measurements of the 90Sr body burdens that were performed after 1974. A model has been developed for the age-dependent metabolism of strontium in the skeleton. The computations in terms of this model are in reliable agreement with experimental data on strontium in man.

Strontium-89--precursor targeted therapy for pain relief of blastic metastatic disease

Strontium-89 is a radioactive calcium analog that provides an energetic beta particle for radiation therapy of osteoblastic disease. Strontium-89 is used as palliative therapy with the primary goal being pain relief. More than 500 patients with painful blastic metastatic disease were treated at University of Kansas Medical Center since the initiation of the first clinical trial there 15 years ago. Most patients have had metastatic prostate cancer to bone or breast cancer, as these tumors are commonly associated with bone pain as their primary clinical management problem. Improvement (decrease in pain, increase in physical activity level) was noted in 80% of patients with prostate carcinoma and 81% of patients with metastatic breast cancer to bone. Marrow toxicity levels were acceptable. The therapy can be repeated at 3-month intervals. Strontium-89 is a safe and effective systemic therapy for painful blastic metastatic disease. There is no longer any reason why the vast majority of persons with painful blastic metastatic disease should continue to hurt.

Optimal use of beta irradiation in the treatment of pterygia

Beta irradiation with strontium 90 has been associated with significant iatrogenic disease, causing such complications as ptosis, symblepharon, iridic and scleral atrophy, cataracts, and endophthalmitis. We studied 171 eyes in 140 patients treated and followed up during a 17-year period from 1973 to 1990. We sought to show that a single small dose of radiation administered immediately after surgical excision not only prevents decrease recurrence, but also avoids significant complication. Pterygia recurred in 14 (8%) of the 171 eyes treated. Six of these recurrences were corneal and eight were conjunctival. Complications were seen in five (3%) of the 171 eyes treated. All were minor except for one case of scleral thinning in a diabetic patient. Optimal radiation dosage to avoid significant recurrence in this adult population is a single dose of 2,000 rads using a bare sclera technique that vaults the limbus.

[Evaluation of the use of sea products in nutrition of population inhabiting regions under rigid radiation control]

Noninbred female white rats were fed for 30 days with diets containing 137Cs and 85Sr in indicative doses. After that the animals received some sea products to investigate their radioprotective properties. Natural sea products proved able to influence the kinetics of the radionuclides metabolism. Laminaria salad "Dalnevostochny" given in the dose 20 g per animal reduced the accumulation of radioactive Cs and Sr by 76.7 and 57.6%, respectively. Moreover, sea products stabilize functional activity of peripheral blood natural killers which are important in immunological defense of the body.

Skeletal uptake and lifetime retention of 90Sr and 226Ra in beagles

Skeletal uptake and retention of graded doses of ingested or injected 90Sr and injected 226Ra have been studied in 863 beagles; measurements of skeletal burden were made up to a maximum lifetime of 18.5 years. Doses ranged from 0 in 162 controls to levels that markedly reduced life span. Skeletal uptake of the administered doses averaged 2 to 2.3% for 90Sr fed to 388 beagles from midgestation to age 540 days, 33 to 35% for 45 dogs that were given single intravenous injections of 90Sr at age 540 days, and 37 to 45% for 226Ra given in eight fortnightly intravenous injections to 253 dogs from age 435 to 540 days. Skeletal retention was evaluated from the time when uptake ended until death, which occurred, on the average, at 14 to 14.5 years for the lower levels. Simple two-parameter power functions of the form SB(t) = at-b, with SB the skeletal burden, t the time after beginning of intake, and a and b fitted parameters, but corrected for radioactive decay, were used to describe the whole-skeleton retention of deposited 90Sr or 226Ra, as well as in 17 skeletal subgroups. The negative logarithmic slope, b, of these power functions for whole skeleton was about the same for both 90Sr and 226Ra, with an average value of 0.30 +/- 0.05 SD, indicating a common clearance mechanism. The lifetime average cumulative absorbed dose to irradiated skeleton varied from 0.38 to 107 Gy for beta rays in the 90Sr studies and from 0.94 to 167 Gy for alpha particles in the 226Ra studies. Daily dose rates to the skeleton for singly injected 90Sr fell rapidly after injection and declined to about 10% of the peak values late in life. Rates declined more slowly to 40-50% of peak values in other treatment groups. The time-weighted average dose rate for fed 90Sr and injected 226Ra was a robust measure that declined only about 20% late in life compared to peak values. The lifetime average dose rate varied from 0.08 to 133 mGy day-1 for the 90Sr studies and from 0.21 to 162 mGy day-1 for the 226Ra studies. Lifetime doses to mandible and cervical vertebrae for the intermediate dose levels of fed 90Sr were calculated to be about 40% higher than the skeletal average.

Strontium-89 and low-dose infusion cisplatin for patients with hormone refractory prostate carcinoma metastatic to bone: a preliminary report

Strontium-89 has been used for the treatment of painful bony metastases in patients suffering from disseminated adenocarcinoma of the prostate, with a variable proportion of patients obtaining clinically significant reductions in analgesic requirements. Based on data revealing enhancement of continuous low-dose rate irradiation by low-dose cisplatin in murine models, a protocol using 148 MBq (4 mCi) of 89Sr and 35 mg/m2 of cisplatin infused over 2 days, 1 and 4 wk after administration of the radioisotope was undertaken. Preliminary data suggest good pain relief with 55% of 18 patients entered thus far obtaining at least a 50% reduction in analgesic requirements. Improvements in total alkaline phosphatase and serum lactate dehydrogenase have consistently been seen, with some patients exhibiting improvements in hemoglobin, tumor markers and bone scans. Toxicity appears to be mild, with no life-threatening complications. In particular, myelosuppression after one course of treatment was modest, but retreatments in two patients has resulted in grade 3 hematologic toxicity. Two patients developed a "pain flare" after administration of cisplatin. Further accrual to this study will allow more accurate determination of pain response rate, and improved evaluation of parameters of objective response.

89Strontium in bone metastases from hormone resistant prostate cancer: palliation effect and biochemical changes

Hematological and biochemical parameters were evaluated in 31 patients receiving 150 MBq 89Strontium (89Sr) intravenously due to painful skeletal metastases from hormone resistant prostate cancer. Two and 3 months after the injection prostate specific antigen (PSA) had increased by a median of 36% and 100%, respectively, as compared to the pretreatment value whereas alkaline phosphatase (APHOS) had decreased by about 20% (median). The leucocyte and platelet counts were reduced by about 20-35%, without reaching grade greater than or equal to 2 toxicity. Pain relief was reported in 14 of 29 evaluable patients at 2 months and in 11 of 23 patients at 3 months. It is concluded that 89Sr represents a worthwhile therapeutic modality in the palliation treatment of patients with hormone resistant prostate cancer, though the biological significance of frequently increasing PSA and decreasing APHOS is not yet completely understood.

[Estimation of current maximum permissible levels of total specific activity of radionuclide mixture in the liquid forms of drugs and medicinal raw materials]

Algorithm of assessment of allowable levels of the total specific activity of radionuclides in liquid medicaments and medical raw materials was worked up. The key radionuclides were Strontium-90, Caesium-134 and -137.

[Validation of the use of brachytherapy in uveal melanomas of juxtapapillary localization]

Forty-two patients with juxtacapillary melanomas of the choroid were treated by brachytherapy. The treatment was carried out in two stages: Stage I--separating laser coagulation, Stage II--irradiation with ophthalmologic applicators (90Sr, 90I). Complete resorption was achieved in 12 patients, partial regression with the process stabilization in 17, no effect in 13, in 11 of these enucleation had to be performed. The mean follow-up period has made up 6.8 years. Analysis of brachytherapy results has lead the authors to a conclusion that this treatment modality may be considered as enucleation alternative in patients with juxtacapillary melanomas located by the optic disk and covering not more than 1/3 of its perimeter, with the prominence of less than 3 mm; brachytherapy applicator in this case should be US monitored.