Extracorporeal Irradiation Research Articles

Reconstruction with biological methods following intercalary excision of femoral diaphyseal tumors.

The aim of this study was to assess outcomes of biological (nonvascularized fibula grafts and extracorporeal irradiated autologous bone grafts) methods used for reconstruction of intercalary defects after resection of femoral diaphyseal tumors. This study included 28 patients who had undergone intercalary resection in femoral diaphyseal tumors between 2011 and 2016. The mean follow-up period was 24 months (range 12-57 months). The mean union time for diaphyseo-diaphyseal union was 10.5 and 11 months in nonvascularized fibula group and extracorporeal radiotherapy (ECRT) group, respectively. The mean union time for metaphyseo-diaphyseal union was 6.5 months in both nonvascularized fibula and ECRT groups. Six patients had distant metastasis, and one patient had local recurrence. The mean Musculoskeletal Tumor Society score was 28 at the last follow-up. Two patients had surgical site infection in the nonvascularized fibula group. Implant failure was found in one patient of the ECRT group requiring revision surgery. Three patients had nonunion (two from the nonvascularized fibula group and one from the ECRT group). The present study indicates that the biological reconstruction modalities provide good functional outcomes in diaphyseal tumors of femur. Nonvasularized fibula and ECRT-treated autografts reconstruction provides good results, and union timing is comparable. The outcomes of the current study are promising as compared to the results in the reviewed literature. The reconstruction method depends on the resources available at the oncological center and the conversance with the method of the treating surgeon.

Surgical outcomes of extracorporeal irradiation and re-implantation in extremities for high grade osteosarcoma: A retrospective cohort study and a systematic review of the literature

PurposeTo assess the failure rate and mode failure of high-grade osteosarcoma patients who received extracorporeal irradiation and re-implantation (ECIR) in extremities. Patients and MethodsFor the cohort study, patients who had received ECIR at a single institution between January 1996 and December 2014 were retrospectively evaluated. Characteristics of failure and time to failure were recorded and analyzed. In addition, a systematically search of published literatures regarding the use of ECIR for osteosarcoma was conducted. Failure rates and modes of failure were determined from the pooled data. ResultsIn the cohort study, the overall reconstruction failure was 46% (23 of 50 cases) of which 6% were due to mechanical failure, and 40% were due to non-mechanical failure. In the systematic review, 164 cases reached the criteria for analysis (50 diaphysis, 97 osteochondral of lower extremity, 6 knee resection, and 11 proximal humerus resection). Among those cases, overall failure rate was 29.9% (49 of 164 cases) of which 7.9% were due to mechanical failure, and 22.0% to non-mechanical failure. Diaphyseal resection with intercalary re-implantation had a significantly lower failure rate than osteochondral reconstruction of lower extremity (OR: 2.7, p < 0.02), and knee extra-articular resection osteochondral re-implantation (OR: 10.5, p < 0.01). ConclusionsDiaphyseal resection and extracorporeal irradiation of intercalary re-implantation offer the most promising outcome among other type of reconstructions. Availability of graft, fewer structural complications, and biological permanence are advantages of this reconstruction method.

CORR Insights®: Does Extracorporeal Irradiation and Reimplantation After Acetabulum Resections Result in Adequate Hip Function? A Preliminary Report.

CORR Insights®: Does Extracorporeal Irradiation and Reimplantation After Acetabulum Resections Result in Adequate Hip Function? A Preliminary Report.

Error analysis of applicator position for combined internal/external radiation therapy in cervical cancer.

The aim of this study was to analyze the error variation in the applicator placement during the first and second radiotherapy session for cervical cancer. We recruited 22 patients with cervical cancer treated with radiotherapy. According to the image output in the first and second CT-Sim inspection, we conducted comparative analysis of image fusion to accurately measure the errors in applicator position in the horizontal (X-), longitudinal (Y-) and vertical (Z)-axes. The calibration processing was implemented in accordance with the data error measured and the location parameters, such as the angle and depth of the applicator. Electronic portal imaging technology (EPID) was used to calibrate posture change amplitude for the extracorporeal irradiation of patients, and dynamic measurement with applicator position was used to describe the error of the parameters. Finally, the data from two measurements in CT-Sim, digital reconstruction radiography (DRR) and EPID were compared. After calibration, the mean value of error of the applicator were significantly smaller. Image registration planning for error parameter calibration of applicator position can effectively reduce the applied horizontal spatial position error in radiotherapy treatment, and improve the accuracy and effectiveness during treatment.

Reconstructing diaphyseal tumors using radiated (50 Gy) autogenous tumor bone graft.

Establish oncologic safety using 50 Gy to sterilize tumor bearing bone before reimplantation in primary diaphyseal high grade extremity tumors, determine extracorporeal radiotherapy (ECRT) graft survival, and analyze factors that affect union at osteotomy sites. Seventy non metastatic patients underwent reconstruction with intercalary ECRT grafts sterilized with 50 Gy. Diagnosis included osteosarcoma (38) and Ewing's sarcoma (32). At last follow-up-49 patients were alive, 19 had died and 2 were lost to follow up. Survivors had minimum follow up of 3 years (range 39-127 months). Ninty one percent metaphyseal osteotomies united without additional intervention compared to 71% diaphyseal osteotomies. Additional small plate at diaphyseal osteotomy apparently reduced incidence of non-union (17% vs 31%) (P = 0.49). Addition of morsellised allograft did not help union. There were seven (10%) local recurrences, all in soft tissue. Seventeen of 69 patients (25%) needed removal of ECRT graft. Five year survival for ECRT graft (removal for all causes) was 79% and 84% (excluding removal for local recurrence). Reimplanting sterilized tumor bone using 50 Gy for tumor ablation is an easily applicable, oncologically safe, biological reconstruction option for primary diaphyseal extremity tumors.

Does Extracorporeal Irradiation and Reimplantation After Acetabular Resections Result in Adequate Hip Function? A Preliminary Report.

Pelvic resections are challenging, and reconstruction of the resected acetabulum to restore mobility and stability is even more difficult. Extracorporeal radiation therapy (ECRT or extracorporeal irradiation) of autograft bone and reimplantation allows for a perfect size match and has been used with some success in the extremities. Although the risk of wound complications in pelvic surgery has discouraged surgeons from using ECRT of autografts in that anatomic site, we believe it may be a reasonable option. In a small series, we asked: (1) What was the median surgical time and blood loss for these procedures, and what early complications were observed? (2) Is there evidence of osteonecrosis or cartilage loss at a minimum of 2 years after ECRT of acetabular autografts, and what functional scores were achieved? (3) What were the oncologic outcomes after ECRT? Between March 2007 and September 2016, one surgeon performed 12 ECRT acetabular autografts and reimplantations after resections of pelvic or acetabular tumors. Of those, 10 with minimum 2-year followup are reported on here with respect to oncologic, functional, and radiographic assessment; all 12 are reported on for purposes of surgical parameters and early complications. During that period, we generally performed this approach when we judged it possible to achieve a tumor-free margin, adequate bone stock, and sufficient remaining hip musculature to allow use of the bone as an autograft with restoration of hip mobility. We generally did not use this approach when we anticipated a difficult resection with uncertain margins or where remaining bone was judged of poor strength for use as a graft or if both iliopsoas and abductors were sacrificed. Since 2010, this series represents seven of the 21 pelvic resections with reconstruction that we performed (five patients in this series had the procedure performed before 2010). Followup was at a median of 65 months (range, 33-114 months) for nine patients whose functional outcomes were evaluated. The median patient age was 30 years (range, 10-64 years). Clinical parameters were recorded from chart review; radiographic analysis for assessment of cartilage was performed by looking for any obvious loss of joint space when compared with the opposite side. Functional scoring was done using the Musculoskeletal Tumor Society score, which was obtained from chart review. Oncologic assessment was determined for local recurrence as well as metastases. Median surgical time was 8.6 hours and median blood loss was 2250 mL. There were no perioperative wound-related complications. Two patients underwent a second surgical procedure during the postoperative period, one for a femoral artery thrombus and another for a complete sciatic nerve deficit. No patients developed avascular necrosis of the femoral head. None of the patients who underwent osteoarticular grafting showed radiographic evidence of joint space narrowing. The median Musculoskeletal Tumor Society score was 28 (range, 17-30). No fractures in the radiated segment of reimplanted bone were seen in this small series. Results from this small series suggest that ECRT is a potential option in selected patients who have good bone stock and adequate soft tissue coverage. Although technically challenging, ECRT is a low-cost alternative to prostheses in providing a mobile and stable hip. Although we did not observe cartilage wear on plain radiographs, followup here was short term; it may appear as we continue to follow these patients. Future studies from retrieval specimens may shed light on the actual status of cartilage on the acetabulum. Level IV, therapeutic study.

Reconstruction of the Scapula in Pediatric and Adolescent Patients After Total Scapulectomy. A Report of 10 Patients Treated by Extracorporeal Irradiation and Reimplantation of the Scapula.

Ewing sarcoma of the scapula is uncommon. Restoration of shoulder function after total scapulectomy is challenging. Extracorporeal irradiation and reimplantation is a well-known method of biological reconstruction in orthopaedic oncology; yet very few reports in the literature describe its specific use in tumors of the scapula. Ten patients with the diagnosis of Ewing sarcoma of the scapula were surgically treated by total scapulectomy and extracorporeal irradiation and reimplantation of the scapula. The mean age at presentation was 10 years (3 to 15 y). Six patients were male individuals and 4 were female individuals. An extracorporeal single dose of 5000 cGy was applied to each graft. At reimplantation, internal fixation was used in the first 2 cases, whereas, in the following 8 patients, stabilization was carried out by resuturing of the glenohumeral and acromioclavicular joint capsules without internal fixation. An ipsilateral Latissimus Dorsi muscle flap was used in all patients to cover the irradiated scapula. The mean follow-up duration was 29.2 months (13 to 50 m). At the latest follow-up, 8 patients were continuously disease free and 2 patients had systemic relapse. No patient had local recurrence. The mean musculoskeletal tumor society functional score was 87% (66.6% to 100%). Eight of the 10 patients (80%) could actively elevate the upper limb up to and beyond 90 degrees in both the forward and scapular planes. Complications included wound gaping in 2 patients (20%), dislocation of the acromioclavicular joint in 3 patients (30%), and partial resorption of the scapular graft in 5 patients (50%). No patient showed any progressive deterioration of his or her shoulder function throughout the follow-up period. The irradiated scapular graft provides a stable biological fulcrum for the reattached muscles of the shoulder joint after total scapulectomy, thereby providing an adequate postoperative range of shoulder elevation. A longer follow-up study is needed to evaluate the progression and effect of graft resorption on the functional outcome. Level IV.

Is extracorporeal irradiation and re-implantation a good enough alternative to implants in paediatric bone tumors?

Is extracorporeal irradiation and re-implantation a good enough alternative to implants in paediatric bone tumors?

Clinical, functional and radiological outcomes of extracorporeal irradiation in limb salvage surgery for bone tumours.

We present a retrospective review of patients treated with extracorporeally irradiated allografts for primary and secondary bone tumours with the mid- and long-term survivorship and the functional and radiographic outcomes. A total of 113 of 116 (97.4%) patients who were treated with extracorporeally irradiated allografts between 1996 and 2014 were followed up. Forms of treatment included reconstructions, prostheses and composite reconstructions, both with and without vascularised grafts. Survivorship was determined by the Kaplan-Meier method. Clinical outcomes were assessed using the Musculoskeletal Tumor Society (MSTS) scoring system, the Toronto Extremity Salvage Score (TESS) and Quality of Life-C30 (QLQ-30) measures. Radiographic outcomes were assessed using the International Society of Limb Salvage (ISOLS) radiographic scoring system. There were 61 (54%) men with a mean age of 22 years (6 to 70) and 52 (46%) women with a mean age of 26 years (3 to 85). There were 23 deaths. The five-year patient survivorship was 82.3% and the ten-year patient survivorship was 79.6%. The mean follow-up of the 90 surviving patients was 80.3 months (2 to 207). At the last follow-up, 105 allografts (92.9%) were still in place or had been at the time of death; eight (7%) had failed due to infection, local recurrence or fracture. Outcome scores were comparable with or superior to those in previous studies. The mean outcome scores were: MSTS 79% (sd 8); TESS 83% (sd 19); QLQ 82% (sd 16); ISOLS 80.5% (sd 19). Pearson correlation analysis showed a strong relationship between the MSTS and ISOLS scores (r = 0.71, p < 0.001). This study shows that extracorporeal irradiation is a versatile reconstructive technique for dealing with large defects after the resection of bone tumours with good functional and radiographic outcomes. Functional outcomes as measured by MSTS, TESS and QLQ-30 were strongly correlated to radiographic outcomes. Cite this article: Bone Joint J 2017;99-B:1681-8.

En bloc resection, intraoperative extracorporeal irradiation and re-implantation of involved bone for the treatment of limb malignancies.

Reconstruction of the defect following limb-sparing resection of malignant bone tumors is controversial and extremely challenging. Extracorporeal irradiation (ECI) and re-implantation have been used for limb salvage surgery for patients, with major advantages, including biological reconstruction, ready availability and preservation of bone stock, over replacement with a megaprosthesis. The purpose of the present study was to present our experience and details of all patients treated with this surgery. Between June 2005 and December 2014, we followed-up 23 patients with limb malignancies who were treated with en bloc excision followed by 50-Gy single dose ECI and re-implantation of involved bone segments. All cases were evaluated based on clinical and radiological examinations, complications and Musculoskeletal Tumor Society (MSTS) score. Mean follow-up period was 77.6 months (range, 17-116 months). A total of 17 patients (73.9%) demonstrated no evidence of disease, 5 (21.7%) patients succumbed to the disease and 1 (4.3%) patient was alive with the disease at the final follow-up. Local recurrence occurred in 3 patients (recurrence rate, 13.0%) in the bed outside of the irradiated graft, and 4 of the 5 patients that lost their lives did so due to associated metastatic disease. The mean value of the MSTS score was 78.8% (50-93.3%). The majority of patients demonstrated solid bony union; however, 3 patients had non-union (13.0%) and 1 had a delayed union (4.3%). Early or late complications occurred in 11 patients (47.8%). Although the complication rate (47.8%) and re-operation rate (39.1%) were high, ECI and re-implantation may be a useful and cheap technique following en bloc resection for limb salvage in appropriately selected patients.

Vascularized fibula with and without extracorporeal radiotherapy for limb salvage surgery in Indian patients

BackgroundReconstruction of segmental bone defects following resection of bone sarcomas is a challenging procedure. Vascularised fibula grafts alone or in combination with extracorporeal radiotherapy and reimplantation of tumor bone have long been established as a method of reconstruction of such defects, with satisfying results. Prompted by paucity of data on Indian patients, we report our experience with vascularised fibula graft for patients undergoing limb salvage surgery for sarcomas of bone. Material and methodsA total of 25 patients underwent the procedure from December 2008 to December 2014. Femur was the commonest site and osteosarcoma was the commonest diagnosis. Intercalary resection was done in 19 patients and arthrodesis in 6 patients. Vascularised fibula was used in combination with extra corporeally irradiated bone in eight patients, and alone in 17 patients. ResultsAll but one limb could be salvaged, and all but three patients had united at final follow up. Combination of extracorporeal radiotherapy and reimplantation with vascularised fibula fared better than vascularised fibula alone in terms of time to union (9.6 months vs 12.2 months) and rate of graft related complications (14.2% vs 62.5%). ConclusionReconstruction with VFG with or without ECRT has a good and predictable functional outcome. Though manageable with active intervention, complications were more commonly seen with vascularised fibula alone than a combination of the two techniques.

Correcting Effect of Therapeutic Doses of Optical Radiation on Hematological Parameters of Blood Irradiated In Vivo

We studied the effect of therapeutic doses of optical radiation on the hematological parameters of blood irradiated in vivo: hemoglobin concentration, hematocrit, and the number of erythrocytes in the peripheral blood of patients during courses of extracorporeal, overvein, and intravenous blood irradiation and after treatment. The reversible changes during the procedures were found to differ from the changes obtained after treatment completion. At the end of the treatment course, the hematological parameters had changed in different directions and became higher, the same, or lower than the initial parameters depending on the initial parameters and photoinduced changes in blood oxygenation. A compensatory effect was found for photohemotherapy on oxygen-dependent processes altering the oxygen inflow into cells as well as the generation of active oxygen species and their inhibition by antioxidant systems.

Topical vancomycin: Does it reduce surgical site infection in bone tumors?

Introduction:We retrospectively analyzed a consecutive group of patients operated for bone tumors of extremity and pelvis who received only perioperative antibiotics (Group A) against a similar group that had additional 1 g topical vancomycin sprinkled in the wound before closure (Group B). The aim was to determine if the addition of topical vancomycin decreases the incidence of deep surgical site infection (SSI).Materials and Methods:A total of 221 patients operated between January 2011 and December 2011 were analyzed in Group A and 254 patients operated between April 2012 and March 2013 were analyzed in Group B. Any patient who required operative intervention for wound discharge was considered to be infected. All patients had a 1 year follow-up to determine the incidence of SSI.Results:The overall rate of SSI was 7% (31 of 475 patients). Seventeen (8%) of Group A patients had SSI as against 14 (6 %) of Group B patients (P = 0.337). A subgroup analysis of endoprosthetic reconstructions, internal fixation implants (plates/intramedullary nails), extracorporeal radiation treated bones and strut allografts showed no difference between the two groups of patients.Conclusion:Our data suggest that the addition of topical vancomycin before wound closure in patients operated for bone tumors does not decrease the incidence of SSI. Further investigation of this technique using a case–controlled methodology with an increase in the dose of vancomycin may be warranted.

PO-0743: Retransplantation of bony autografts sterilized by extracorporal high dose irradiation

PO-0743: Retransplantation of bony autografts sterilized by extracorporal high dose irradiation

Resection of the ilium in patients with a sarcoma: should the pelvic ring be reconstructed?

The aim of the study was to investigate the controversial issue of whether the pelvic ring should be reconstructed following resection of the sarcomas of the ilium. From our database, we identified 64 patients who underwent excision of a tumour involving the ilium between 1976 and 2015. A total of 35 underwent complete resection, of whom 24 were reconstructed with a non-vascularised fibula graft, and four with extracorporeal irradiation and reimplantation. A total of 29 patients had a partial resection. The mean follow-up was 9.2 years (1.1 to 25.6). Functional outcomes were assessed using the Toronto Extremity Salvation Score (TESS) at final follow-up. In all, 32 patients (50%) had a chondrosarcoma. The mean TESS for all patients was 71.6% (17% to 100%). The mean TESS for those who underwent total resection with reconstruction was 72.0% (17% to 100%) and without reconstruction it was 53.3% (20% to 90%) and for those who underwent partial resection it was 76.3% (31.3% to 100%). The rate of local recurrence was 42.2% and this was more common in those treated by partial resection (p = 0.048). The risk of local recurrence was related to the margin achieved at resection. Given the high rate of local recurrence following excision of a tumour from the ilium, obtaining wide surgical margins should be a priority even if this requires more aggressive surgery. In young patients, where late recurrence may occur, more radical complete resection should be considered. When total resection of the ilium is considered, reconstruction should also be considered as it confers a higher functional outcome than total resection without reconstruction. Cite this article: Bone Joint J 2017;99-B:538-43.

Biomechanical investigation of the effect of extracorporeal irradiation on resected human bone

Extra Corporeal irradiation and Reimplantation Therapy (ECRT) is an established biological reconstruction technique of limb salvage surgery for malignant bone tumor. Several studies have focused on clinical outcome of the procedure, but biomechanical changes post ECRT procedure are not well established. The present study investigates changes in strength, deformation, and composition of cortical bone obtained post en block resection from five patients suffering from ECRT, and the results are verified against age-match control specimen from cadaver. For pre-irradiated sample, average indentation modulus varied from 11.1GPa to 15.8GPa, and hardness from 0.36GPa to 0.48GPa. Post 50Gy irradiation, we observed an overall increase in deformation, viscous response, and energy dissipation across all samples, together with reduction in indentation modulus and hardness. These changes in strength and deformation were found to be consistent with compositional investigations via Raman spectroscopy, where mineralization and amount of calcium content was found to be decreased. The study thus quantifies the effect of extra corporeal irradiation on bone mechanical and compositional response, which in turn can provide clinicians much needed insight into the mechanism of bone healing and repair post ECRT to guide follow-up care and recovery.

703. Early challenges and outcome in extracorporeal irradiation and reimplantation for primary malignant bone tumours

703. Early challenges and outcome in extracorporeal irradiation and reimplantation for primary malignant bone tumours

Regulatory Effect of Low-Intensity Optical Radiation on Oxygenation of Blood Irradiated In Vivo and Metabolic Processes

For three series of blood samples, we have studied the effect of therapeutic doses of low-intensity optical radiation (LOR) on oxygenation parameters of blood irradiated in vivo, and also on the levels of some metabolites: lactate, glucose, cholesterol. The quality of blood oxygenation was assessed using three parameters: the partial pressure of oxygen pVO2, the oxygen saturation of hemoglobin SVO2, and the oxygen level in arterial and venous blood, varying under the infl uence of low-intensity optical radiation due to photodissociation of hemoglobin/ligand complexes. We have established that during photohemotherapy (PHT), including extracorporeal, supravascular, and intravenous blood irradiation, positive changes occur in the oxygenation parameters and the metabolite levels, while after the courses of PHT have been completed, the individual changes in such parameters in individual patients were both positive and negative. The regulatory effect of PHT was apparent in the tendency toward a decrease in high initial values and an increase in low initial values both for the oxygenation parameters and for the metabolites; but at the doses recommended for use, PHT had a regulatory but still not a normalizing effect. Introduction. Application of low-intensity optical radiation (LOR) for medical purposes has considerably outrun experimental and theoretical studies of its effect. Positive outcomes from application of LOR in treatment of various diseases have been mainly noted in the scientifi c literature. Generally phototherapy conditions, radiation sources, and wavelengths are selected empirically. In this case, differences in the photophysical processes initiated in biological tissues by absorption and scattering of radiation at different wavelengths as well as the individual sensitivity of patients to LOR procedures have not been considered. It is attempted to justify such an approach by the lack of accepted ideas about the primary photoacceptors (molecules absorbing radiation) and photoprocesses initiated by LOR in biological tissues, despite the undoubted progress in understanding these questions that has been achieved to date (1-4). At the same time, by now a fair amount is known about the mechanisms for realization of the therapeutic effects of phototherapy, which allows us to analyze the reasons for the contradictory nature of the data on the biological activity of LOR. The aim of this work was to use as a basis the theoretically and experimentally substantiated mechanism of action for photohemotherapy (PHT) to analyze the details of its effect on metabolic processes occurring in different patients, comparing the identifi ed patterns for photomodifi cation of blood and radiation-initiated changes in the levels of some metabolites under the infl uence of LOR at different wavelengths absorbed by blood. Materials and Methods. We studied changes in the blood oxygenation characteristics and metabolite concentrations, directly during individual procedures and also 20-30 min after completion of the course of treatment, in three series of blood samples from patients with cardiovascular diseases. The fi rst series of samples was obtained for extracorporeal UV blood irradiation (UBI) in patients (n = 30) using light from a mercury lamp (O = 254 nm, power density at the surface of the cuvet 1.5 mW/cm 2 ); the course of treatment consisted of fi ve daily procedures. The samples in the second series were blood from patients (n = 20) who had received intravenous blood irradiation (intravenous LBI) procedures daily for seven days in the ulnar vein using radiation from a semiconductor laser (O = 670 nm, 2 mW at the output of the optical fi ber, t = 20 min). The samples in the third series were obtained during supravascular blood irradiation (SLBI) in the patients (n

Extracorporeal Irradiation and Reimplantation with Total Hip Arthroplasty for Periacetabular Pelvic Resections: A Review of 9 Cases.

We report the early results of nine patients with periacetabular malignancies treated with Enneking and Dunham type 2 resection and reconstruction using extracorporeally irradiated (ECI) tumour bone combined with total hip arthroplasty (THA). Diagnosis was chondrosarcoma in six patients, osteosarcoma in two patients, and metastatic renal cell carcinoma in one patient. All patients underwent surgical resection and the resected specimen was irradiated with 50 Gy in a single fraction before being prepared for reimplantation as a composite autograft. The mean follow-up was 21 months (range, 3–59). All patients were alive at latest follow-up. No local recurrence was observed. One patient serially developed three pulmonary metastases, all of which were resected. One experienced hip dislocation due to incorrect seating of an acetabular liner. This was successfully treated with revision of the liner with no further episodes of instability. There were no cases of deep infection or loss of graft. The average Musculoskeletal Tumor Society (MSTS) score was 75% (range, 57–87%). Type 2 pelvic reconstruction with ECI and THA has shown excellent early oncological and functional results in our series. Preservation of the gluteus maximus and hip abductors is important for joint stability and prevention of infection.

High-dose irradiation of bone chips preserves the in vitro activity of bone-conditioned medium.

Extracorporeal irradiation sterilizes resected tumor bone used as autografts in reconstruction surgery. Therapeutic irradiation is a standard technique in head and neck cancer therapy that aims to preserve organ function. Bone irradiation has a complex, mostly inhibitory, effect on remodeling and regeneration, although the underlying mechanisms are still not fully understood. It remains unclear if extracorporeal irradiation affects the paracrine-like activity of the corresponding autografts. We recently reported that bone-conditioned medium from autogenous bone chips contains a number of factors that might affect cell activity. In the present study, we investigated the effects of extracorporeal irradiation of porcine cortical bone chips on the activity of the corresponding bone-conditioned medium. The effects of bone-conditioned medium on the expressions of transforming growth factor-beta (TGF-β) target genes in oral fibroblasts were assessed. Bone-conditioned medium from bone chips exposed to a total radiation dose up to 120 Gy did not affect expressions of TGF-β target genes, including adrenomedullin, BTB/POZ domain-containing protein 11, proteoglycan 4, NADPH oxidase 4, and interleukin 11, in oral fibroblasts. In conclusion, bone irradiation does not alter the capability of the corresponding bone-conditioned medium to provoke a robust fibroblastic cell response in vitro. (J Oral Sci 58, 325-331, 2016).