Fig 1.
Experimental design and workflow.
Micro computer tomography (μCT); radiofrequency ablation treatment (RF Tx); radiofrequency ablation (RFA); hematoxylin and eosin (H&E); human epithelium growth factor receptor (hEGFr); polarization-in, polarization-out (PIPO) second harmonic generation (SHG); backscatter electron (BSE).
Fig 2.
Backscatter electron images of rat femur.
Representative sagittal cross-sectional BSE acquisitions. Regions of osteoblast proliferation, indicative of new bone formation, is seen post RFA (yellow arrows). Green arrows indicate probe insertion channels. a-c) Femora from healthy controls. d-f) Femora from ZR-75-1 cell injected rats: Osteoblastic-induced new bone formation is visualized identified inside the dashed rectangle box. g-i) Femora from HeLa cell injected rats: Osteolytic lesions in trabecular bone tissue demonstrate tumor involvement (i.e. dashed rectangular overlay).
Fig 3.
Histopathology of healthy bone tissue.
Histology section of the femur of healthy control rats and rats with osteoblastic lesions: a) Mid-sagittal section of a distal femur in a healthy control rat stained with haematoxylin and eosin (BM: bone marrow; TR: trabeculae) b) Mid-sagittal section of a distal femur 4-week post RFA. Fibrous tissue (F) has formed within the treated region with the newly formed bone (NB) visible on the border of the treated area. c) Tumor cells (T; ZR-75-1) in the mid-sagittal section of a distal femur inducing osteoblastic bone formation (BM: bone marrow; TR: trabeculae; OB: osteoblastic bone formation) d) Mid-sagittal section of a distal femur 4 weeks post RFA. Tumor cells are necrotic (N) and fibrous tissue (F) has formed within the treated area.
Fig 4.
Histopathology of metastatic bone tissue.
Histology section of the femur with osteolytic metastases: a) Tumor cells (T; HeLa) in the mid-sagittal section of a distal femur (BM: bone marrow; TR: trabeculae; OC: osteoclast; BV: blood vessel) b) Mid-sagittal section of a distal femur 1-week post RFA. Tumor cells are necrotic (N); osteocytes (OC) are dead within the trabeculae of the treated area surrounded by RFA-induced fibrous tissue (F) formation. c) Tumor cells (T) are staining positive for the hEGFr antibody in the mid-sagittal section of a distal femur (BM: bone marrow; TR: trabeculae; OC: osteoclast; BV: blood vessel) d) Mid-sagittal section of a distal femur 1 week post RFA. Tumor cells are necrotic (N), no longer stain positively and fibrous tissue (F) is formed within the treated area.
Table 1.
Susceptibility Ratio (R).
Fig 5.
Mineralization profile of bone tissue.
RFA-induced bone mineral density distribution (BMDD) changes in healthy femora and femora with metastatic lesions calculated from BSE images. The mineralization profile (a) Calcium Width (CaWidth) b) Calcium Mean (CaMean) and c) Calcium Peak (CaPeak)) of healthy and bone with metastatic lesions is modified post treatment. * Represents a significant difference between indicated groups (p < 0.05).