Radiological evidence of lymphangioleiomyomatosis in female and male patients with tuberous sclerosis complex.

AIM: To determine the gender-specific prevalence of pulmonary cysts typical for lymphangioleiomyomatosis (LAM) in adult patients with known tuberous sclerosis complex (TSC). MATERIALS AND METHODS: A retrospective, cross-sectional study in a cohort of 206 adult TSC patients was performed. Institutional review board approval was obtained, and patient informed consent was waived. Patients had routinely undergone abdominal CT scanning between 1996 and 2006. All 186 patients (mean age 38 years; range 19-72 years; 91 (49%) male patients) in whom at least the lung bases were depicted on computed tomography (CT) were included. Images were reviewed for the presence of pulmonary thin-walled cysts. Descriptive statistics, two sample t-test to compare means, and χ(2)-test to compare proportions were applied. RESULTS: CT demonstrated pulmonary thin-walled cysts in the lung bases in 52 (28%) of 186 patients. Size varied from 2mm in diameter to more than 2 cm. Pulmonary cysts were detected in 40 (42%) of 95 female patients and in 12 (13%) of 91 male patients (p<0.001). In general, cysts were larger and more numerous in women than in men. Only minimal cystic changes were found in four women and two men, moderate cystic changes were seen in three women and seven men, but considerable cystic changes were seen almost exclusively in women (33 women versus three men). CONCLUSION: CT demonstrated thin-walled pulmonary cysts in the lung bases in 28% of 186 included patients with tuberous sclerosis complex. Female patients were more affected than male patients.

Holmium-166 poly(L-lactic acid) microsphere radioembolisation of the liver: technical aspects studied in a large animal model.

OBJECTIVE: To assess the accuracy of a scout dose of holmium-166 poly(L-lactic acid) microspheres ((166)Ho-PLLA-MS) in predicting the distribution of a treatment dose of (166)Ho-PLLA-MS, using single photon emission tomography (SPECT). METHODS: A scout dose (60 mg) was injected into the hepatic artery of five pigs and SPECT acquired. Subsequently, a 'treatment dose' was administered (540 mg) and SPECT, computed tomography (CT) and magnetic resonance imaging (MRI) of the total dose performed. The two SPECT images of each animal were compared. To validate quantitative SPECT an ex vivo liver was instilled with (166)Ho-PLLA-MS and SPECT acquired. The liver was cut into slices and planar images were acquired, which were registered to the SPECT image. RESULTS: Qualitatively, the scout dose and total dose images were similar, except in one animal because of catheter displacement. Quantitative analysis, feasible in two animals, tended to confirm this similarity (r(2) = 0.34); in the other animal the relation was significantly better (r(2) = 0.66). The relation between the SPECT and planar images acquired from the ex vivo liver was strong (r(2) = 0.90). CONCLUSION: In the porcine model a scout dose of (166)Ho-PLLA-MS can accurately predict the biodistribution of a treatment dose. Quantitative (166)Ho SPECT was validated for clinical application.

Multiple endocrine neoplasia type 1 (MEN1): its manifestations and effect of genetic screening on clinical outcome.

OBJECTIVE: Effect of genetic screening on outcome in multiple endocrine neoplasia type 1 (MEN1) remains unclear. Expression of MEN1 is described using currently available diagnostic techniques. Manifestations and outcome are compared in patients diagnosed because of clinical expression with those diagnosed by genetic screening. DESIGN: Retrospective cohort study. Patients are divided into two groups: patients with a (i) clinical MEN1 diagnosis and (ii) MEN1 diagnosis by genetic screening. PATIENTS AND MEASUREMENTS: Demographic and clinical data were collected on MEN1 patients treated in the UMCU up to 1 January 2008. Results of mutation analysis were obtained from the Department of Medical Genetics. RESULTS: A total of 74 patients was included (median follow-up 5.5 year); 78% had hyperparathyroidism, 46% a pancreatic neuro-endocrine tumour (NET), 38% a pituitary abnormality, 8% a NET of other origin and 16% an adrenal adenoma at the end of follow-up. Of the patients 18% had no manifestation. All five MEN1-related tumours were seen as first manifestation. Compared with patients identified by genetic screening, patients with a clinical MEN1 diagnosis had significantly more manifestations at diagnosis (P < 0.001) and at end of follow-up (P = 0.002). Eleven of 30 patients with a genetic MEN1 diagnosis (mean age at diagnosis 30.0 years) already had manifestations at diagnosis. No malignancy or death was seen in genetically diagnosed patients. CONCLUSIONS: MEN1 is a syndrome with high morbidity. Genetic diagnosis is associated with less morbidity at diagnosis and at follow-up. Early genetic diagnosis might therefore lead to improvement of long-term outcome.

Yttrium-90 microsphere radioembolization for the treatment of liver malignancies: a structured meta-analysis.

Radioembolization with yttrium-90 microspheres ((90)Y-RE), either glass- or resin-based, is increasingly applied in patients with unresectable liver malignancies. Clinical results are promising but overall response and survival are not yet known. Therefore a meta-analysis on tumor response and survival in patients who underwent (90)Y-RE was conducted. Based on an extensive literature search, six groups were formed. Determinants were cancer type, microsphere type, chemotherapy protocol used, and stage (deployment in first-line or as salvage therapy). For colorectal liver metastases (mCRC), in a salvage setting, response was 79% for (90)Y-RE combined with 5-fluorouracil/leucovorin (5-FU/LV), and 79% when combined with 5-FU/LV/oxaliplatin or 5-FU/LV/irinotecan, and in a first-line setting 91% and 91%, respectively. For hepatocellular carcinoma (HCC), response was 89% for resin microspheres and 78% for glass microspheres. No statistical method is available to assess median survival based on data presented in the literature. In mCRC, (90)Y-RE delivers high response rates, especially if used neoadjuvant to chemotherapy. In HCC, (90)Y-RE with resin microspheres is significantly more effective than (90)Y-RE with glass microspheres. The impact on survival will become known only when the results of phase III studies are published.

Prevalence of subependymal giant cell tumors in patients with tuberous sclerosis and a review of the literature.

BACKGROUND AND PURPOSE: To investigate the prevalence of subependymal giant cell ependymomas (SEGA) in patients with tuberous sclerosis complex (TSC). METHODS: We performed a retrospective cross-sectional study in a cohort of 285 patients with known TSC. Institutional review board approval was obtained. We included all 214 TSC-patients who had received a contrast-enhanced computed tomography (CT) scan of the brain. The most recent scan was evaluated for SEGA and presence of hydrocephalus. Additionally, a literature search was performed, and pooled estimates of SEGA prevalence in TSC were calculated. We used descriptive statistics, two sample t-test, chi-squared-test, and meta-analysis as appropriate. RESULTS: Computed tomography showed radiological evidence of SEGA in 43 of the 214 TSC-patients (20%); 23 of 105 men (22%) and 20 of 109 women (18%; P = .52). Average maximum tumor size was 11.4 mm (range, 4-29 mm). Patients with SEGA (mean, 31 years; range, 16-58 years) were on average younger than patients without SEGA (mean, 37 years; range, 10-72 years; P = 0.007). No association between tumor size and patient age was detected. Nine patients had bilateral SEGA. Hydrocephalus was present in six of the 43 patients (14%). Meta-analysis of reported prevalence and our current study showed that studies using radiological evidence to diagnose SEGA gave a higher pooled estimate of the prevalence of SEGA in TSC (0.16; 95% CI: 0.12, 0.21) than studies using mainly histopathological evidence of SEGA (0.09; 95% CI: 0.07, 0.12). CONCLUSIONS: In our cohort, CT demonstrated evidence of SEGA in 20% of TSC-patients. Prevalence of SEGA in TSC is higher in studies using radiological evidence to diagnose SEGA than in studies using histopathological evidence.

Radiation safety considerations for the bone seeking radiopharmaceuticals. 89SrCl2, 186Re-HEDP and 153Sm-EDTMP.

UNLABELLED: The radiation exposure to bystanders from 89SrCl2, 186Re-HEDP and 153Sm-EDTMP, is generally thought to be caused by "bremsstrahlung" and gamma-radiation, with negligible contribution from beta-radiation. The latter assumption may be erroneous. The aim of this prospective study was the investigation of radiation safety after treatment with these radiopharmaceuticals. The radiation field around treated patients was characterized and the magnitude estimated. PATIENTS, METHODS: 33 patients (30 prostate carcinoma, 3 breast carcinoma) were treated with 150 MBq 89SrCl2 (9 patients), 1295 MBq 186Re-HEDP (12 patients) or 37 MBq/kg 153Sm-EDTMP (12 patients). External exposure rates at 30 cm from the patient were measured at times 0 to 72 h post-injection. To evaluate the respective contribution of Bremsstrahlung, beta- and gamma-radiation, a calibrated survey meter was used, equipped with a shutter. For each patient, the measured exposure rate-versus-time data were fit to a curve and the curve integrated (area under the curve) to estimate the total exposure. RESULTS: For 29/33 patients the total ambient equivalent doses (mean+/-1 standard deviation [SD]) based on the integral of the fitted curve were 2.1+/-1.2 mSv for 89SrCl2, 3.3+/-0.6 mSv for 186Re-HEDP and 2.8+/-0.6 mSv for 153Sm-EDTMP. Beta-radiation contributes significantly to these doses (>99% for 89SrCl2, 87% for 186Re-HEDP and 27% for 153Sm-EDTMP). The effective doses (at 30 cm) are <0.1 mSv for 89SrCl2, 0.3 mSv for 186Re-HEDP and 1.6 mSv for 153Sm-EDTMP. CONCLUSION: Patients treated with 89SrCl2, 186Re-HEDP or 153Sm-EDTMP emit a spectrum of radiation, including non-negligible beta-radiation. With specific instructions effective doses to bystanders are acceptable.

A phase II trial of imatinib therapy for metastatic medullary thyroid carcinoma.

CONTEXT: Medullary thyroid carcinoma (MTC) metastasizes early in its clinical course. No effective systemic therapy is available. Generally (somatic or germline), mutations in the rearranged during transfection gene are considered essential in the pathogenesis of MTC. OBJECTIVE: We investigated imatinib, a tyrosine kinase inhibitor, as a potential treatment in patients with disseminated MTC. DESIGN: A phase II study was initiated using 600 mg imatinib daily with a possible dose increase to 800 mg in case of progression. Standard Response Evaluation Criteria in Solid Tumors were used using computed tomography or magnetic resonance imaging every 2 months. RESULTS: There were 15 patients with disseminated MTC treated for up to 12 months. No objective responses were observed. Four patients had stable disease over 24 months. Three patients stopped treatment due to toxic effects [fatigue (n = 2) and nausea (n = 1)]. In four cases the dose of imatinib was decreased because of toxicity [rash and malaise (n = 2) and laryngeal swelling (n = 2)]. Emergency tracheotomy was performed in two cases due to mucosal swelling of the larynx in patients with recurrent nerve palsy and a narrow vocal cleft. In nine patients with a history of a thyroidectomy, the dose of supplemental thyroid hormone was increased because of serious hypothyroidism. CONCLUSIONS: Imatinib therapy yielded no objective responses and induced considerable toxicity in patients with MTC. A minority of patients had stable disease. Patients with supplemented hypothyroidism or with recurrent nerve palsy are specifically at risk for serious adverse events and need special attention when treated with imatinib.

Characterization of holmium loaded alginate microspheres for multimodality imaging and therapeutic applications.

In this paper the preparation and characterization of holmium-loaded alginate microspheres is described. The rapid development of medical imaging techniques offers new opportunities for the visualisation of (drug-loaded) microparticles. Therefore, suitable imaging agents have to be incorporated into these particles. For this reason, the element holmium was used in this study in order to utilize its unique imaging characteristics. The paramagnetic behaviour of this element allows visualisation with MRI and holmium can also be neutron-activated resulting in the emission of gamma-radiation, allowing visualisation with gamma cameras, and beta-radiation, suitable for therapeutic applications. Almost monodisperse alginate microspheres were obtained by JetCutter technology where alginate droplets of a uniform size were hardened in an aqueous holmium chloride solution. Ho(3+) binds via electrostatic interactions to the carboxylate groups of the alginate polymer and as a result alginate microspheres loaded with holmium were obtained. The microspheres had a mean size of 159 microm and a holmium loading of 1.3 +/- 0.1% (w/w) (corresponding with a holmium content based on dry alginate of 18.3 +/- 0.3% (w/w)). The binding capacity of the alginate polymer for Ho(3+) (expressed in molar amounts) is equal to that for Ca(2+), which is commonly used for the hardening of alginate. This indicates that Ho(3+) has the same binding affinity as Ca(2+). In line herewith, dynamic mechanical analyses demonstrated that alginate gels hardened with Ca(2+) or Ho(3+) had similar viscoelastic properties. The MRI relaxation properties of the microspheres were determined by a MRI phantom experiment, demonstrating a strong R(2)* effect of the particles. Alginate microspheres could also be labelled with radioactive holmium by adding holmium-166 to alginate microspheres, previously hardened with calcium (labelling efficiency 96%). The labelled microspheres had a high radiochemical stability (94% after 48 h incubation in human serum), allowing therapeutic applications for treatment of cancer. The potential in vivo application of the microspheres for a MR-guided renal embolization procedure was illustrated by selective administration of microspheres to the left kidney of a pig. Anatomic MR-imaging showed the presence of holmium-loaded microspheres in the kidney. In conclusion, this study demonstrates that the incorporation of holmium into alginate microspheres allows their visualisation with a gamma camera and MRI. Holmium-loaded alginate microspheres can be used therapeutically for embolization and, when radioactive, for local radiotherapy of tumours.

Yttrium-90 radioembolization for colorectal cancer liver metastases: a prospective cohort study on circulating angiogenic factors and treatment response.

BACKGROUND: Yttrium-90 radioembolization (90Y-RE) as a treatment for liver tumours induces radiation damage and hypoxia in liver tissue, which is also a trigger for systemic release of angiogenic factors, potentially stimulating tumour growth. We examined changes in circulating angiogenic factors following 90Y-RE and investigated the association between response and angiogenic factors. In this prospective study, 42 patients with unresectable, chemorefractory metastatic colorectal cancer (CRCLM) were treated with 90Y-RE. Blood samples were collected pre-treatment and at 0, 1, 3, 7 and 30 days of follow-up. Response was measured with MRI according to RECIST 1.1 at 1 month and subsequently 3-month interval until progressive disease (PD) occurred. Associations between circulating angiogenic factors and response were examined with linear mixed model analysis. RESULTS: Following 90Y-RE, three angiogenic factors demonstrated an increase in plasma levels, i.e., vascular endothelial growth factor (VEGF), hepatocyte growth factor (HGF) and angiopoietin-2 (Ang-2). Non-responders (= PD at 1-month follow-up, n = 10) had a significant increase of Ang-2 and HGF at 3 and 7 days post treatment compared to responders (= stable disease or better, n = 32), who showed little to no changes in plasma levels (respectively p = 0.01 and p = 0.007). Median overall survival was 9.2 months (95% confidence interval 6.1-12.4). CONCLUSIONS: Significant increases in plasma levels of Ang-2 and HGF in the first week after treatment were associated with rapid progressive disease of liver lesions at 1 month after 90Y-RE. Combination of 90Y-RE with anti-angiogenic therapy may reduce these effects and result in better response.

Lanthanide bearing microparticulate systems for multi-modality imaging and targeted therapy of cancer.

The rapid developments of high-resolution imaging techniques are offering unique possibilities for the guidance and follow up of recently developed sophisticated anticancer therapies. Advanced biodegradable drug delivery systems, e.g. based on liposomes and polymeric nanoparticles or microparticles, are very effective tools to carry these anticancer agents to their site of action. Elements from the group of lanthanides have very interesting physical characteristics for imaging applications and are the ideal candidates to be co-loaded either in their non-radioactive or radioactive form into these advanced drug delivery systems because of the following reasons: Firstly, they can be used both as magnetic resonance imaging (MRI) and computed tomography (CT) contrast agents and for single photon emission computed tomography (SPECT). Secondly, they can be used for radionuclide therapies which, importantly, can be monitored with SPECT, CT, and MRI. Thirdly, they have a relatively low toxicity, especially when they are complexed to ligands. This review gives a survey of the currently developed lanthanide-loaded microparticulate systems that are under investigation for cancer imaging and/or cancer therapy.

Radioimmunodiagnosis and therapy.

Although promising results with radioimmunotherapy and radioimmunodiagnosis in haematological diseases, have been reported, they are less encouraging results in solid tumours. Experimental mathematical models suggest that optimization of antibody-based therapy and diagnosis is possible and that further research towards improvement is warranted. In this review, the major problems of radioimmunotherapy and diagnosis are discussed. Particular items adressed include tumour uptake of antibodies and antibody-fragments, the target/non-target ratio, immunogenicity and the selection of radionuclides.

PCV chemotherapy for recurrent glioblastoma multiforme.

The authors evaluated response, time to progression (TTP), survival, prognostic factors, and toxicity in 63 patients with a recurrent glioblastoma multiforme treated with procarbazine, lomustine, and vincristine (PCV) chemotherapy. Complete and partial response was observed in two (3%) and five patients (8%). In 16 patients (25%), stable disease was observed. Median TTP and survival were 13 and 33 weeks. Age < 40 years and Karnofsky Performance Status > or = 90 were associated with longer TTP and survival. PCV treatment was generally well tolerated.

Response rate and prognostic factors of recurrent oligodendroglioma treated with procarbazine, CCNU, and vincristine chemotherapy. Dutch Neuro-oncology Group.

OBJECTIVES: To determine the response rate and factors correlated with response of oligodendroglial tumors to procarbazine, lomustine (CCNU), and vincristine (PCV) chemotherapy. DESIGN: Retrospective, observational multicenter study. METHODS: Patients treated with PCV or intensified PCV chemotherapy for a recurrent oligodendroglial tumor after surgery and radiation therapy with measurable disease were retrospectively evaluated for response. A 50% reduction in cross-sectional enhancing tumor area was considered a partial response. Stabilized or responding patients received six cycles of PCV unless unacceptable toxicity occurred. RESULTS: Fifty-two patients were included; median time to progression (MTP) for the entire group was 10 months. In 17% of patients a complete response (MTP, 25 months) was obtained, and in 46% a partial response (MTP, 12 months) was obtained. Median overall survival was 20 months. Although treatment was discontinued for toxicity in seven patients, it was generally well tolerated. The intensified PCV regimen was more toxic. Patients initially presenting with seizures and patients with tumor necrosis in histologic specimens had a better response rate in contrast to patients who had their first relapse within 1 year of first treatment (surgery and radiation therapy). CONCLUSIONS: Oligodendroglial tumors are chemosensitive, but most patients will have relapsed after 12 to 16 months. New studies must aim at improving initial treatment and second-line chemotherapy.

Acute liver necrosis induced by iodine-131-MIBG in the treatment of metastatic carcinoid tumors.

Iodine-131-metaiodobenzylguanidine (MIBG) is used in the treatment of carcinoid tumors. Temporary palliation with complete subjective symptomatic response has been reported in these patients. This treatment is usually well tolerated and side-effects are generally limited to nausea, mild hepatic toxicity with spontaneous recovery and temporary myelosuppression. Our case report shows that repeated treatment with [131I]MIBG in a patient with extensive carcinoid liver metastasis may cause severe hepatic toxicity leading to death. Factors such as concomitant use of 5-fluorouracil and the progressive nature of the disease may have contributed to this event.

Pharmacokinetics of rhenium-186 after administration of rhenium-186-HEDP to patients with bone metastases.

The pharmacokinetics of 186Re-HEDP, a radiopharmaceutical for palliative treatment of metastatic bone pain, was investigated in 11 patients (17 studies) who suffered from metastatic breast or prostate cancer. Half-life times of 186Re in three blood fractions (whole blood, plasma and plasma water) were 40.1 +/- 5.0, 41.0 +/- 6.0 and 29.5 +/- 6.4 hr, respectively. Time-dependent increase in plasma-protein binding was observed, probably caused by in vivo decomposition of 186Re-HEDP. Total urinary 186Re excretion was 69% +/- 15%, of which 71% +/- 6% was excreted in the first 24 hr after injection. The BSI (i.e., fraction of the skeleton showing scintigraphic evidence of metastatic disease) closely correlated with the fraction of dose non-renally cleared (r = 0.98). This implies that the amount of radioactivity taken up by the skeleton and hence the bone marrow absorbed dose can be predicted from a diagnostic pre-therapy 99mTc-HDP scintigram. The pharmacokinetic behavior indicates that 186Re-HEDP has suitable properties to justify its application.

Phase 1 study of rhenium-186-HEDP in patients with bone metastases originating from breast cancer.

UNLABELLED: Rhenium-186-1,1-hydroxyethylidene diphosphonate (186Re-HEDP) has been used for the palliative treatment of metastatic bone pain. A Phase 1 dosage escalation study was performed using 186Re-HEDP in patients with metastatic breast cancer. METHODS: Twelve patients with metastatic breast cancer were studied. Each patient had at least four bone metastases and adequate hematological function. Groups of three consecutive patients were treated with dosages starting at 1295 MBq (35 mCi) and increasing to 2960 MBq (80 mCi) (escalated in increments of 555 MBq). RESULTS: A transient increase in pain ("flare" reaction) was observed in six patients. Two patients who received 2960 MBq 186Re-HEDP showed Grades 3 (platelets 25-50 x 10(9)/l) and 4 (platelets < 25 x 10(9)/l) platelet toxicity, which was defined as unacceptable. Prior to treatment, alkaline phosphatase levels were elevated in seven cases. These patients showed a transient decline in alkaline phosphatase levels during the first 4 wk. CONCLUSION: The maximum tolerated administered activity of 186Re-HEDP in patients with metastatic breast cancer is 2405 MBq (65 mCi). Thrombocytopenia proved to be the dose-limiting toxicity, which could not be predicted adequately by the administered activity. Changes of alkaline phosphatase levels suggest anti-tumor effects of 186Re-HEDP.

Bone marrow absorbed dose of rhenium-186-HEDP and the relationship with decreased platelet counts.

UNLABELLED: Rhenium-186(Sn)-1,1-hydroxyethylidene diphosphonate (186Re-HEDP) has been used for palliation of metastatic bone pain. The purpose of this study was to find a relationship between the bone marrow absorbed dose and the toxicity, expressed as the percentage decrease in the peripheral blood platelet count. METHODS: The bone marrow absorbed dose was calculated according to the MIRD model using data obtained from ten treatments of patients suffering from metastatic prostate cancer; noninvasive and pharmacokinetic methods were used. The bone marrow doses were related to toxicity using the pharmacodynamic sigmoid Emax model. RESULTS: The mean bone marrow absorbed doses using the noninvasive and pharmacokinetic methods were in a close range to each other (1.07 mGy/MBq and 1.02 mGy/MBq, respectively). There was a good relationship between the toxicity and the bone marrow absorbed dose (r = 0.80). Furthermore, the EDrm50 (i.e., the bone marrow absorbed dose producing a 50% platelet decrease) to bone marrow for 186Re-HEDP was on the order of 2 Gy. CONCLUSION: Although the function of normal bone marrow is affected by metastases in patients with metastatic bone disease, the MIRD model can be used to relate toxicity to the bone marrow absorbed dose after a therapeutic dosage of 186Re-HEDP.

Evaluation of thrombocytopenia in patients treated with rhenium-186-HEDP: guidelines for individual dosage recommendations.

UNLABELLED: A potential limitation of rhenium-186-1,1-hydroxyethylidene diphosphonate (186Re-HEDP) therapy in patients with painful bone metastases is thrombocytopenia. Given the palliative character of this therapy, it is essential to be able to predict the degree of thrombocytopenia before therapy. METHODS: Thus far, 39 prostatic cancer patients with multiple painful bone metastases were treated. Twenty-one patients underwent the therapy twice, resulting in 60 therapies. From the pre-therapy 99mTc-HDP scintigram, the bone scan index (BSI) was determined as an index of the extent of bone involvement. RESULTS: The administered activity ranged from 1104 to 3479 MBq 186Re-HEDP. The platelet count was lowest 4 wk following therapy. From this value and the pretreatment level, the percentage decrease in the platelet count was determined (47% +/- 19%, range 14%-89%). The BSI ranged from 8 to 93. Regression analysis showed a functional relation (R = 0.78; p < 0.001) of the percentage of platelet decrease with BSI and administered activity normalized to standard body surface area. CONCLUSION: Using this relation, it is possible to predict thrombocytopenia by pretreatment bone scintigraphy and to adjust the dosage to each patient to avoid unacceptable toxicity.

Efficacy of rhenium-186-etidronate in prostate cancer patients with metastatic bone pain.

UNLABELLED: Rhenium-186-etidronate has been developed for pain relief of bone metastases and has previously been studied with regard to toxicity, pharmacokinetics and dosimetry. Its palliating effect on bone pain has not been studied extensively. To justify further efficacy investigations, patients participating in two toxicity studies were studied using a strict pain assessment methodology. METHODS: Forty-three patients entered the study, 37 of whom were evaluable for pain assessment. Administered dosages ranged from 1295 MBq (35 mCi) to 3515 MBq (95 mCi) 186Re-etidronate. Pain relief was assessed using a handwritten diary containing questions reflecting the multidimensional character of chronic pain. The diary was marked twice daily for a maximum of 10 wk (2 wk prior to and 6/8 wk after the injection). A response was determined using a specific decision rule, in which pain intensity, medication index and daily activities were core determinants. RESULTS: A response was reached in 54% (20 of 37) of the patients and varied from 33% (n = 6) in the "35-mCi" group to 78% (n = 7) in the "50/65-mCi" group to 70% (n = 7) in the "80/95-mCi" group. CONCLUSION: Pain assessment using the multidimensional pain model showed that 186Re-etidronate is an effective agent in the treatment of metastatic bone pain in prostate cancer and warrants further placebo-controlled studies.

Transient cranial neuropathy in prostatic cancer with bone metastases after rhenium-186-HEDP treatment.

Rhenium-186 (tin) hydroxyethylidene diphosphonate (186Re-HEDP), a bone-seeking radiopharmaceutical, has been successfully used in the treatment of patients with painful bone metastases. Toxicity is usually limited to reversible thrombocytopenia. An infrequent but clinically significant side effect is the occurrence of transient cranial neuropathy. We report on two prostatic cancer patients with metastatic bone cancer. Both patients developed transient cranial neuropathy shortly after treatment with 186Re-HEDP. Transient neuropathy of cranial nerves needs to be distinguished from neurological abnormalities caused by disease progression.