| 1. |
- Cederkrantz, Elin, et al.
(author)
-
Absorbed Doses and Risk Estimates of (211)At-MX35 F(ab')2 in Intraperitoneal Therapy of Ovarian Cancer Patients.
- 2015
-
In: International journal of radiation oncology, biology, physics. - : Elsevier BV. - 1879-355X .- 0360-3016. ; 93:3, s. 569-76
-
Journal article (peer-reviewed)abstract
- Ovarian cancer is often diagnosed at an advanced stage with dissemination in the peritoneal cavity. Most patients achieve clinical remission after surgery and chemotherapy, but approximately 70% eventually experience recurrence, usually in the peritoneal cavity. To prevent recurrence, intraperitoneal (i.p.) targeted α therapy has been proposed as an adjuvant treatment for minimal residual disease after successful primary treatment. In the present study, we calculated absorbed and relative biological effect (RBE)-weighted (equivalent) doses in relevant normal tissues and estimated the effective dose associated with i.p. administration of (211)At-MX35F(ab')2.
|
|
| 2. |
- Gustafsson-Lutz, Anna, 1981, et al.
(author)
-
Therapeutic efficacy of alpha-radioimmunotherapy with different activity levels of the Bi-213-labeled monoclonal antibody MX35 in an ovarian cancer model
- 2017
-
In: EJNMMI Research. - : Springer Science and Business Media LLC. - 2191-219X. ; 7
-
Journal article (peer-reviewed)abstract
- Background: The aim of this study was to compare the therapeutic efficacy of two different activity levels of the Bi-213-labeled monoclonal antibody MX35 in an ovarian cancer model. Sixty female BALB/c (nu/nu) mice were inoculated intraperitoneally with human ovarian cancer cells (OVCAR-3). Two weeks later, 40 mice were injected intraperitoneal (i.p.) with 1 ml of Bi-213-MX35, 3 MBq/mL (n = 20), or 9 MBq/mL (n = 20). An additional 20 mice received unlabeled MX35. Incidence of tumors and ascites was investigated 8 weeks after therapy. Body weight and white blood cell counts were monitored after treatment for possible signs of toxicity. Results: The tumor-free fraction of the animals treated with 3 MBq/mL of Bi-213-MX35 was 0.55, whereas that of animals treated with 9 MBq/mL of Bi-213-MX35 was 0.78. The control group treated with unlabeled MX35 had a tumor-free fraction of 0.15. No significant reduction in white blood cell counts or weight loss was observed. Conclusions: Tumor growth after i.p. treatment with Bi-213-MX35 was significantly reduced compared to treatment with unlabeled MX35. Treatment with 9 MBq/mL of Bi-213-MX35 resulted in higher tumor-free fraction compared with 3 MBq/mL of Bi-213-MX35, but this difference was not statistically significant. No signs of toxicity were observed in the treated animals.
|
|
| 3. |
|
|
| 4. |
- Hallqvist, Andreas, 1973, et al.
(author)
-
Intraperitoneal alpha-Emitting Radioimmunotherapy with At-211 in Relapsed Ovarian Cancer: Long-Term Follow-up with Individual Absorbed Dose Estimations
- 2019
-
In: Journal of Nuclear Medicine. - : Society of Nuclear Medicine. - 0161-5505 .- 2159-662X. ; 60:8, s. 1073-1079
-
Journal article (peer-reviewed)abstract
- Eliminating microscopic residual disease with alpha-particle radiation is theoretically appealing. After extensive preclinical work with alpha-particle-emitting At-211, we performed a phase I trial with intraperitoneal alpha-particle therapy in epithelial ovarian cancer using At-211 conjugated to MX35, the antigen-binding fragments-F(ab')(2)-of a mouse monoclonal antibody. We now present clinical outcome data and toxicity in a long-term follow-up with individual absorbed dose estimations. Methods: Twelve patients with relapsed epithelial ovarian cancer, achieving a second complete or nearly complete response with chemotherapy, received intraperitoneal treatment with escalating (20-215 MBq/L) activity concentrations of At-211-MX35 F(ab')(2). Results: The activity concentration was escalated to 215 MBq/L without any dose-limiting toxicities. Most toxicities were low-grade and likely related to the treatment procedure, not clearly linked to the alpha-particle irradiation, with no observed hematologic toxicity. One grade 3 fatigue and 1 grade 4 intestinal perforation during catheter implantation were observed. Four patients had a survival of more than 6 y, one of whom did not relapse. At progression, chemotherapy was given without signs of reduced tolerability. Overall median survival was 35 mo, with a 1-, 2-, 5-, and 10-y survival of 100%, 83%, 50%, and 25%, respectively. Calculations of the absorbed doses showed that a lower specific activity is associated with a lower single-cell dose, whereas a high specific activity may result in a lower central dose in microtumors. Individual differences in absorbed dose to possible microtumors were due to variations in administered activity and the specific activity. Conclusion: No apparent signs of radiation-induced toxicity or decreased tolerance to relapse therapy were observed. The dosimetric calculations show that further optimization is advisable to increase the efficacy and reduce possible long-term toxicity.
|
|
| 5. |
|
|
| 6. |
- Hultborn, Ragnar, 1946
(author)
-
Blood flow, volume and arterio-venous passages in induced mammary tumours of the rat
- 2018
-
In: Microvascular Research. - : Elsevier BV. - 0026-2862. ; 116, s. 45-49
-
Journal article (peer-reviewed)abstract
- Objective To study blood flow, vascular volume and arterio-venous passages in induced mammary tumours of the rat to characterize parameters possibly responsible for tumour hyponutrition. Method Dimethylbenzanthracene-induced mammary tumours in Sprague-Dawley rats were studied. Regional blood flow was studied by use of the radioactive microsphere tracer technique using 141Cerium-labelled 15 μm spheres coinjected into the left cardiac ventricle with 125Iodine-labelled 25 μm spheres. Blood volume was studied by use of 125Iodine- or 99mTechnetium-labelled human serum albumin, the latter allowing autoradiography of tumour sections for visualization of flow and volume. Results Twenty-seven rats with 170 tumours had a mean tumour blood flow of 48 and 67 mL × min− 1 × 100 g− 1 using 15 and 25 μm sphere data, respectively, indicating a significant passage through vessels between 15 and 25 μm. The lungs showed a “nominal bronchial” blood flow of 260 and 135 mL × min− 1 × 100 g− 1 for the 15 and 25 μm spheres, respectively, indicating pulmonary trapping, particularly of small spheres passing the systemic circulation in vessels larger than 15 μm. There was a positive correlation between the total tumour blood flow within individual rats and trapped spheres of both dimensions in the lungs, indicating shunts also larger than 25 μm. Normal tissues disclosed only small differences in regional blood flow as measured by the two spheres. Blood volume was studied in 20 rats with 120 tumours, with a vascular volume of 3.6 mL × 100 g− 1 representing a blood turnover > 15 times/min. Blood volume co-localized with perfusion as seen in autoradiographs. Conclusion In induced rat mammary tumours, a high fraction of blood, 28%, passes arterio-venous vessels between 15 and 25 μm and there also exist passages > 25 μm. These findings indicate that the functional capacity of the tumour vascular bed might be impaired, adding to the abnormal microenvironment of tumours. © 2017 Elsevier Inc.
|
|
| 7. |
- Hultborn, Ragnar, 1946, et al.
(author)
-
Radiosensitivity: Gender and Order of Administration of G-CSF, An Experimental Study in Mice
- 2019
-
In: Radiation Research. - : Radiation Research Society. - 0033-7587. ; 191:4, s. 335-341
-
Journal article (peer-reviewed)abstract
- To elucidate the potential influence of stimulating bone marrow before cell-cycle-dependent irradiation, we sought to determine overall survival in mice receiving total-body irradiation (TBI) when administered granulocyte stimulating factor (G-CSF) at different time points. Gender differences were also studied. C57/BL/6J mice, aged 9-14 weeks, received 8 Gy TBI in a perspex cage using a linear accelerator. In each of five different experiments, three groups were studied: 1. one control group receiving TBI only; 2. one group treated with filgrastim [500 mu g/kg subcutaneously/intraperitoneally (s.c./i.p.)] the day before TBI, followed by daily filgrastim injections postirradiation (1-5 days); and 3. one group treated with daily filgrastim injections only post-TBI (1-5 days). Each experimental group included male and female mice. Survival of the mice was monitored daily, and mice were euthanized when their condition deteriorated. A total of 293 mice were monitored for at least 37 days post-TBI. Control mice that received 8 Gy TBI showed a significant gender difference, with a median survival of 22 days in females and 17 days in males. Addition of G-CSF, irrespective of pre- or postirradiation, significantly improved survival, but in males the improvement was significantly better when G-CSF was not given before TBI. Improved survival in females was independent of the order of administration of G-CSF. Multiple filgrastim injections were more effective than a single injection, and s.c. administration was not better than i.p. In conclusion, these findings indicate that male mice are more sensitive to TBI than females. Filgrastim improved survival in both genders irrespective of whether given pre- orpostirradiation, but in males the improvement was significantly less if an injection was given before irradiation. These results suggest that, to prevent toxicity most effectively, G-CSF should not be given before cytotoxic therapy. While a completely different experimental model was used here, these results may also be extrapolated to indicate that endocrine cell-cycle suppression therapy should not be given before or during cytotoxic therapy of hormone-dependent tumors (e.g., breast and prostate cancer), thus a reduction in the efficacy of cell-cycle-dependent therapy can be prevented. (C) 2019 by Radiation Research Society
|
|
| 8. |
- Högberg, Jonas, 1976, et al.
(author)
-
Increased absorbed liver dose in Selective Internal Radiation Therapy (SIRT) correlates with increased sphere-cluster frequency and absorbed dose inhomogeneity
- 2015
-
In: EJNMMI Physics. - : Springer Science and Business Media LLC. - 2197-7364. ; 2:1
-
Journal article (peer-reviewed)abstract
- Background The higher tolerated mean absorbed dose for selective internal radiation therapy (SIRT) with intra-arterially infused 90Y microspheres compared to external beam therapy is speculated to be caused by absorbed dose inhomogeneity, which allows for liver regeneration. However, the complex liver microanatomy and rheology makes modelling less valuable if the tolerance doses are not based on the actual microsphere distribution. The present study demonstrates the sphere distribution and small-scale absorbed dose inhomogeneity and its correlation with the mean absorbed dose in liver tissue resected after SIRT. Methods A patient with marginally resectable cholangiocarcinoma underwent SIRT 9 days prior to resection including adjacent normal liver tissue. The resected specimen was formalin-fixed and sliced into 1 to 2-mm sections. Forty-one normal liver biopsies 6-8 mm in diameter were punched from these sections and the radioactivity measured. Sixteen biopsies were further processed for detailed analyses by consecutive serial sectioning of 15 30-μm sections per biopsy, mounted and stained with haematoxylin-eosin. All sections were scrutinised for isolated or conglomerate spheres. Small-scale dose distributions were obtained by applying a 90Y-dose point kernel to the microsphere distributions. Results A total of 3888 spheres were found in the 240 sections. Clusters were frequently found as strings in the arterioles and as conglomerates in small arteries, with the largest cluster comprising 453 spheres. An increased mean absorbed dose in the punch biopsies correlated with large clusters and a greater coefficient of variation. In simulations the absorbed dose was 5–1240 Gy; 90% were 10-97 Gy and 45% were <30 Gy, the assumed tolerance in external beam therapy. Conclusions Sphere clusters were located in both arterioles and small arteries and increased in size with increasing sphere concentration, resulting in increased absorbed dose inhomogeneity, which contradicts earlier modelling studies.
|
|
| 9. |
-
IVIM reveals increased blood perfusion of liver metastases after oral intake of Salovum®
- 2015
-
In: Magnetic Resonance Materials in Physics, Biology and Medicine. - : Springer Science and Business Media LLC. - 0968-5243 .- 1352-8661.
-
Editorial proceedings (other academic/artistic)abstract
- Introduction Elevated interstitial fluid pressure (IFP) of tumours impairs perfusion, which hinders anti-cancer drugs and oxygen to reach tumour cells1-3. AF-16, a 16 amino acid long sequence from the amino terminal end of the endogenous protein Antisecretory Factor (AF), supresses IFP in animal models of solid tumours4, and could improve drug delivery to tumour cells. Salovum®, a spray-dried egg yolk powder with high content of antisecretory peptides, should be tested on humans, but requires non-invasive tumour IFP/perfusion assessment methods. The IntraVoxel Incoherent Motion (IVIM) model applied to multi-b DWI enables measurement of tissue diffusion (D), pseudo-diffusion (D*) and voxel volume fraction of actively perfused capillaries (f) 5. The aim of this study was to investigate if f could be used to monitor changes induced by Salovum® in colorectal liver metastases in vivo Subjects and Methods Previously untreated patients (n=6) with colorectal liver metastases were imaged before, and 24h after intake of Salovum®, using IVIM-MRI (3T Philips, 16‐channel receiver; Single-shot, SE‐EPI (breath-hold); FOV covering liver, 3x3x5mm3 voxels; TR/TE/NSA/SENSE=1900ms/50ms/2/2; 11 b‐values (0-600); acquisition~10 min. MATLAB-based images processing comprised 1) Inter-scan image registration (volume preserving free-form deformation6); 2) Voxelwise fitting of D and A [eq.2] to S(b200-600) (for b>200, [eq.1] reduces to [eq.2], assuming D<2cm) on DWI (b=600), transfer of ROIs to corresponding f-maps for calculation of median ROI f before and after Salovum® intake and 4) Mann-Whitney U-test for statistical significance (α-level=0.05). Results Liver and metastases were well visualised on DWIs and f-maps Median f in metastatic tissue increased after intake of Salovum® in 5/6 patients, but decreased in one patient (Fig.2) (p<0.0001). Discussion/Conclusion The increased perfusion fraction on day 2 may offer a “window of opportunity” for improved transport of drugs to tumour cells. The increase in f was small, and perhaps not clinically significant, suggesting that additional time points after Salovum® intake and dose escalation be investigated, as well as intra-tumour effect heterogeneity. The proposed IVIM approach is a promising, non-invasive method for studying Salovum® induced changes in liver metastases in vivo. Further optimisation and fractionation studies should be conducted, and IVIM derived parameters should be compared to other techniques for perfusion or IFP measurements. References 1Rofstad,E.K.,et al.,Neoplasia. 2009;11(11):1243-51. 2Milosevic,M.F.,et al.,1999;43(5):1111-23. 3Wiig, H.,et al.,1982;42(2):159-64. 4Al-Olama, M.et al., 2011;50(7):1098-104. 5Le Bihan, D., et al., 1988;168(2):497-505. 6Rueckert, D., et al., 1999;18(8):712-21.
|
|
| 10. |
- Lindegren, Sture, 1960, et al.
(author)
-
Binding Affinity, Specificity and Comparative Biodistribution of the Parental Murine Monoclonal Antibody MX35 (Anti-NaPi2b) and Its Humanized Version Rebmab200.
- 2015
-
In: PloS one. - : Public Library of Science (PLoS). - 1932-6203. ; 10:5
-
Journal article (peer-reviewed)abstract
- The aim of this preclinical study was to evaluate the characteristics of the monoclonal antibody Rebmab200, which is a humanized version of the ovarian-specific murine antibody MX35. This investigation contributes to the foundation for future clinical α-radioimmunotherapy of minimal residual ovarian cancer with 211At-Rebmab200. Here, the biodistribution of 211At-Rebmab200 was evaluated, as was the utility of 99mTc-Rebmab200 for bioimaging. Rebmab200 was directly compared with its murine counterpart MX35 in terms of its in-vitro capacity for binding the immobilized NaPi2B epitope and live cells; we also assessed its biodistribution in nude mice carrying subcutaneous OVCAR-3 tumors. Tumor antigen and cell binding were similar between Rebmab200 and murine MX35, as was biodistribution, including normal tissue uptake and in-vivo tumor binding. We also demonstrated that 99mTc-Rebmab200 can be used for single-photon emission computed tomography of subcutaneous ovarian carcinomas in tumor-bearing mice. Taken together, our data support the further development of Rebmab200 for radioimmunotherapy and diagnostics.
|
|
| 11. |
|
|
| 12. |
- Palm, Stig, 1964, et al.
(author)
-
Model of Intraperitoneal Targeted α-Particle Therapy Shows That Posttherapy Cold-Antibody Boost Enhances Microtumor Radiation Dose and Treatable Tumor Sizes.
- 2018
-
In: Journal of nuclear medicine : official publication, Society of Nuclear Medicine. - : Society of Nuclear Medicine. - 1535-5667. ; 59:4, s. 646-651
-
Journal article (peer-reviewed)abstract
- Intraperitoneally administered radiolabeled monoclonal antibodies (mAbs) have been tested in several clinical trials, often with promising results, but have never proven curative. Methods: We have previously presented simulations of clinically relevant amounts of intraperitoneal 90Y-mAbs for treatment of minimal disease and shown that such treatments are unlikely to eradicate microtumors. Our previous model simulated the kinetics of intraperitoneally infused radiolabeled mAbs in humans and showed the benefit of instead using α-emitters such as 211At. In the current work, we introduce penetration of mAbs into microtumors with radii of up to 400 μm. Calculations were performed using dynamic simulation software. To determine the radiation dose distribution in nonvascularized microtumors of various sizes after intraperitoneal 211At-radioimmunotherapy, we used an in-house-developed Monte Carlo program for microdosimetry. Our aim was to find methods that optimize the therapy for as wide a tumor size range as possible. Results: Our results show that high-specific-activity radiolabeled mAbs that are bound to a tumor surface will penetrate slowly compared with the half-lives of 211At and shorter-lived radionuclides. The inner-core cells of tumors with radii exceeding 100 μm may therefore not be sufficiently irradiated. For lower specific activities, the penetration rate and dose distribution will be more favorable for such tumors, but the dose to smaller microtumors and single cells will be low. Conclusion: Our calculations show that the addition of a boost with unlabeled mAb 1-5 h after therapy results in sufficient absorbed doses both to single cells and throughout microtumors up to approximately 300 μm in radius. This finding should also hold for other high-affinity mAbs and short-lived α-emitters.
|
|
