MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor of the extremities.

PURPOSE: To determine diagnostic performance of MRI radiomics-based machine learning for classification of deep-seated lipoma and atypical lipomatous tumor (ALT) of the extremities. MATERIAL AND METHODS: This retrospective study was performed at three tertiary sarcoma centers and included 150 patients with surgically treated and histology-proven lesions. The training-validation cohort consisted of 114 patients from centers 1 and 2 (n = 64 lipoma, n = 50 ALT). The external test cohort consisted of 36 patients from center 3 (n = 24 lipoma, n = 12 ALT). 3D segmentation was manually performed on T1- and T2-weighted MRI. After extraction and selection of radiomic features, three machine learning classifiers were trained and validated using nested fivefold cross-validation. The best-performing classifier according to previous analysis was evaluated and compared to an experienced musculoskeletal radiologist in the external test cohort. RESULTS: Eight features passed feature selection and were incorporated into the machine learning models. After training and validation (74% ROC-AUC), the best-performing classifier (Random Forest) showed 92% sensitivity and 33% specificity in the external test cohort with no statistical difference compared to the radiologist (p = 0.474). CONCLUSION: MRI radiomics-based machine learning may classify deep-seated lipoma and ALT of the extremities with high sensitivity and negative predictive value, thus potentially serving as a non-invasive screening tool to reduce unnecessary referral to tertiary tumor centers.

Malignant Transformation of Giant Cell Tumour of Bone: A Review of Literature and the Experience of a Referral Centre.

Giant cell tumour of bone (GCTB) is a benign, locally aggressive primary bone neoplasm that represents 5% of all bone tumours. The principal treatment approach is surgery. Although generally GCTB is considered only a locally aggressive disease, it can metastasise, and lung metastases occur in 1-9% of patients. To date, only the use of denosumab has been approved as medical treatment for GCTB. Even more rarely, GCTB undergoes sarcomatous transformation into a malignant tumour (4% of all GCTB), but history of this malignant transformation is unclear and unpredictable. Considering the rarity of the event, the data in the literature are few. In this review, we summarise published data of GCTB malignant transformation and we analyse three cases of malignant transformation of GCTB, evaluating histopathology, genetics, and radiological aspects. Despite the rarity of this event, we conclude that a strict follow up is recommended to detect early malignant transformation.

[18F]FDG PET/CT quantitative parameters for the prediction of histological response to induction chemotherapy and clinical outcome in patients with localised bone and soft-tissue Ewing sarcoma.

OBJECTIVE: The application of [18F]FDG PET/CT in predicting histologic response to induction chemotherapy in patients with Ewing sarcoma (EWS) has been proposed using the values of pre-post treatment SUVmax as a referral parameter, although with heterogeneous results. The aim of this retrospective study was to evaluate the diagnostic accuracy of [18F]FDG PET/CT volumetric parameters (metabolic tumour volume (MTV) and total lesion glycolysis (TLG)) as compared to SUVmax to predict response to chemotherapy and clinical outcome in patients with localised EWS of bone and soft-tissue. METHODS: Twenty-eight patients with non-metastatic EWS of bone (n = 20) and soft tissues (n = 8) who underwent a [18F]FDG PET/CT scan before (PET1) and after induction chemotherapy (PET2) were enclosed in the analysis. Values of PET metrics (SUVmax, MTV, TLG) at diagnosis and after neoadjuvant chemotherapy as well as the percentage change between PET1 and PET2 (ΔSUV, ΔMTV and ΔTLG) were correlated to histological response and to progression-free survival (PFS). RESULTS: ΔTLG (cut-off: -60%) is the best predictor for histologic response with 100% sensitivity and 77.8% specificity. MTV1 > 33.4 cm3 and TLG1 > 112 were also associated with a favourable histologic response (sensitivity 80% and specificity 77.8% for both). On multivariate analysis, SUV2 (> 3.3) and ΔTLG (< -18%) were independent predictors of worse PFS. CONCLUSIONS: [18F]FDG PET/CT could accurately predict histologic response to neoadjuvant chemotherapy in patients with EWS, also showing a possible prognostic value for future disease relapse. KEY POINTS: • The variation of the PET parameter tumour lesion glycolysis (TLG) can predict the histologic response to induction chemotherapy (sensitivity 100%, specificity 77.8%), in patients with Ewing sarcoma. • The percentage variation of TLG and the value of the SUVmax at PET scan after chemotherapy show a prognostic role for future disease relapse. The combination of both the parameters identifies three prognostic classes of patients with low, intermediate and high risk of disease relapse.

Symptoms and their implications on quality of life and psychological distress in sarcoma patients.

The aim of this study was to investigate symptoms, their variation over time and their relationship with quality of life (QoL)/psychological distress in sarcoma patients, as few data regarding QoL and psychological distress in this set of patients are currently available. A total of 188 sarcoma patients from an Italian referral center were involved. Symptoms and financial difficulties were evaluated with the European Organization for Research and Treatment of Cancer Quality of Life Questionnaire from the first treatment and over the follow-up period, up to 6 years. The authors found that patients with sarcoma experience several symptoms, especially fatigue and pain, which may dramatically worsen QoL and psychological distress. In conclusion, patients with sarcoma often experience fatigue, pain and financial difficulties, which negatively impacts QoL and psychological distress. To ameliorate overall QoL, proper control of symptoms is necessary.

Antibacterial hydrogel coating in joint mega-prosthesis: results of a comparative series.

PURPOSE: Joint mega-prosthesis after bone tumors, severe trauma or infection is associated with high rates of post-surgical septic complications. A fast-resorbable antibacterial hydrogel coating (DAC®, Defensive Antibacterial Coating) has previously been shown to be able to significantly reduce surgical site infection in various clinical settings. Aim of the present study was to evaluate the safety and efficacy of the DAC hydrogel coating to prevent early periprosthetic joint infection after joint mega-prosthesis. METHODS: In this three-centers, case-control study, 43 patients, treated with an antibacterial hydrogel coated mega-prosthesis for oncological (N = 39) or non-oncological conditions (N = 4), were retrospectively compared with 43 matched controls, treated with mega-implants without the coating. Clinical, laboratory and radiographic examinations were performed to evaluate the occurrence of post-surgical infection, complications and adverse events. RESULTS: At a mean follow-up of 2 years, no evidence of infection or adverse events were observed in the DAC-treated group, compared to six cases of post-surgical infection in the control group. CONCLUSION: This matched case-control study shows that a fast-resorbable, antibiotic-loaded coating can be safely used to protect joint mega-prosthesis, providing a reduction of early surgical site infections with no side effects. Larger prospective trials with longer follow-ups are warranted to confirm this report. TRIAL REGISTRATION: RS1229/19 (Regina Elena National Cancer Institute Experimental Registry Number).

Sarcoma patients' quality of life from diagnosis to yearly follow-up: experience from an Italian tertiary care center.

Aim: To investigate sarcoma patients' perception of quality of life and psychosocial distress across the different disease's stages. Patients & methods: Total 329 sarcoma patients were monitored from diagnosis up to a maximum of six consecutive follow-up visits. Results: Functional status worsened over time with the lowest value after surgery and a full recovery not earlier than the second follow-up visit. Married and single patients exhibited similar quality of life pattern. High levels of psychological distress were observed from diagnosis to active treatment periods with a progressive improvement during follow-up. Psychological distress pattern over time varied by marital status and age. Conclusion: Our study suggests the importance of integrating psychosocial care to medical therapy across the entire sarcoma journey.

Percutaneous management of bone metastases: state of the art, interventional strategies and joint position statement of the Italian College of MSK Radiology (ICoMSKR) and the Italian College of Interventional Radiology (ICIR).

Interventional radiology provides local management of bone metastases (BM) with a palliative intent in most cases, or with a curative intent in selected patients. Its role has rapidly expanded in the last decade, offering new treatment solutions often in combination with surgery, radiation therapy and medical treatments. The aim of the present paper is to increase awareness, acceptance and adoption of interventional radiology procedures for the treatment of BM; and to present the joint position of the Italian College of Musculoskeletal Radiology and the Italian College of Interventional Radiology.

The dual mobility cup in muscular skeletal oncology: rationale and indications.

PURPOSE: Because of the improvement of medical therapy and the corresponding increase in life expectancy, orthopaedic surgeons are obliged to perform more wide resections rather than intramedullary stabilization nailing for patients affected by tumours of the hip compared to the past. Wide resection often causes joint instability, so prosthetic reconstruction presents a higher risk of dislocation than in primary osteoarthritis cases. The aim of the present paper is to classify the indications for the dual mobility cup (DMC) hip prosthesis based on the anatomic structures involved in the disease and to analyse the rationale to reduce the risk of dislocation. METHODS: Indications were analyzed and classified based on all the cases in which the DMC prosthesis was used for reconstruction after hip resection in an oncological research hospital. RESULTS: Four classes of indications were identified; for classes I and IV the indication for DMC prosthesis can be considered strong; for classes II and III the indications must be evaluated considering the specific case, based on life expectancy, performance status, presence of osteoarthritis, and availability of adjuvant local therapies. When the DMC prosthesis is indicated, the cup should always be cemented, either alone or with augmentation techniques, to decrease the risk of mobilization due to local disease progression. CONCLUSIONS: DMC can be a valid alternative in reconstruction of the hip after tumor removal; nevertheless, prospective, randomized studies are necessary to verify the real dislocation rate based on the entity of resection.

Development of a Patient-Derived Xenograft (PDX) of Breast Cancer Bone Metastasis in a Zebrafish Model.

Bone metastasis is a complex process that needs to be better understood in order to help clinicians prevent and treat it. Xenografts using patient-derived material (PDX) rather than cancer cell lines are a novel approach that guarantees more clinically realistic results. A primary culture of bone metastasis derived from a 67-year-old patient with breast cancer was cultured and then injected into zebrafish (ZF) embryos to study its metastatic potential. In vivo behavior and results of gene expression analyses of the primary culture were compared with those of cancer cell lines with different metastatic potential (MCF7 and MDA-MB-231). The MCF7 cell line, which has the same hormonal receptor status as the bone metastasis primary culture, did not survive in the in vivo model. Conversely, MDA-MB-231 disseminated and colonized different parts of the ZF, including caudal hematopoietic tissues (CHT), revealing a migratory phenotype. Primary culture cells disseminated and in later stages extravasated from the vessels, engrafting into ZF tissues and reaching the CHT. Primary cell behavior reflected the clinical course of the patient's medical history. Our results underline the potential for using PDX models in bone metastasis research and outline new methods for the clinical application of this in vivo model.

Sorafenib and everolimus for patients with unresectable high-grade osteosarcoma progressing after standard treatment: a non-randomised phase 2 clinical trial.

BACKGROUND: Results of previous study showed promising but short-lived activity of sorafenib in the treatment of patients with unresectable advanced and metastatic osteosarcoma. This treatment failure has been attributed to the mTOR pathway and might therefore be overcome with the addition of mTOR inhibitors. We aimed to investigate the activity of sorafenib in combination with everolimus in patients with inoperable high-grade osteosarcoma progressing after standard treatment. METHODS: We did this non-randomised phase 2 trial in three Italian Sarcoma Group centres. We enrolled adults (≥18 years) with relapsed or unresectable osteosarcoma progressing after standard treatment (methotrexate, cisplatin, and doxorubicin, with or without ifosfamide). Patients received 800 mg sorafenib plus 5 mg everolimus once a day until disease progression or unacceptable toxic effects. The primary endpoint was 6 month progression-free survival (PFS). All analyses were intention-to-treat. This trial is registered with ClinicalTrials.gov, number NCT01804374. FINDINGS: We enrolled 38 patients between June 16, 2011, and June 4, 2013. 17 (45%; 95% CI 28-61) of 38 patients were progression free at 6 months. Toxic effects led to dose reductions, or short interruptions, or both in 25 (66%) of 38 patients and permanent discontinuation for two (5%) patients. The most common grade 3-4 adverse events were lymphopenia and hypophosphataemia each in six (16%) patients, hand and foot syndrome in five (13%), thrombocytopenia in four (11%), and fatigue, oral mucositis, diarrhoea, and anaemia each in two (5%). One patient (3%) had a grade 3 pneumothorax that required trans-thoracic drainage, and that recurred at the time of disease progression. This was reported as a serious adverse event related to the study drugs in both instances. No other serious adverse events were reported during the trial. There were no treatment-related deaths. INTERPRETATION: Although the combination of sorafenib and everolimus showed activity as a further-line treatment for patients with advanced or unresectable osteosarcoma, it did not attain the prespecified target of 6 month PFS of 50% or greater. FUNDING: Italian Sarcoma Group.

How do we estimate survival? External validation of a tool for survival estimation in patients with metastatic bone disease-decision analysis and comparison of three international patient populations.

BACKGROUND: We recently developed a clinical decision support tool, capable of estimating the likelihood of survival at 3 and 12 months following surgery for patients with operable skeletal metastases. After making it publicly available on www.PATHFx.org , we attempted to externally validate it using independent, international data. METHODS: We collected data from patients treated at 13 Italian orthopaedic oncology referral centers between 2010 and 2013, then applied to PATHFx, which generated a probability of survival at three and 12-months for each patient. We assessed accuracy using the area under the receiver-operating characteristic curve (AUC), clinical utility using Decision Curve Analysis (DCA), and compared the Italian patient data to the training set (United States) and first external validation set (Scandinavia). RESULTS: The Italian dataset contained 287 records with at least 12 months follow-up information. The AUCs for the three-month and 12-month estimates was 0.80 and 0.77, respectively. There were missing data, including the surgeon's estimate of survival that was missing in the majority of records. Physiologically, Italian patients were similar to patients in the training and first validation sets. However notable differences were observed in the proportion of those surviving three and 12-months, suggesting differences in referral patterns and perhaps indications for surgery. CONCLUSIONS: PATHFx was successfully validated in an Italian dataset containing missing data. This study demonstrates its broad applicability to European patients, even in centers with differing treatment philosophies from those previously studied.

Bone metastases of unknown origin: epidemiology and principles of management.

UNLABELLED: Metastases are the most common malignancies involving bone; breast, prostate, lung and thyroid are the main sites of primary cancer. However, up to 30 % of patients present with bone metastases of unknown origin, where the site of the primary neoplasm cannot be identified at the time of diagnosis despite a thorough history, physical examination, appropriate laboratory testing and modern imaging technology (CT, MRI, PET). Sometimes only extensive histopathological investigations on bone specimens from biopsy can suggest the primary malignancy. At other times, a bone lesion can have such a highly undifferentiated histological appearance that a precise pathological classification on routine hematoxylin-eosin-stained section is not possible. The authors reviewed the relevant literature in an attempt to investigate the epidemiology of the histological primaries finally identified in patients with bone metastases from occult cancer, and a strategy of management and treatment of bone metastases from occult carcinomas is suggested. Lung, liver, pancreas and gastrointestinal tract are common sites for primary occult tumors. Adenocarcinoma is the main histological type, accounting for 70 % of all cases, while undifferentiated cancer accounts for 20 %. Over the past 30 years, lung cancer is the main causative occult primary for bone metastases and has a poor prognosis with an average survival of 4-8 months. Most relevant literature focuses on the need for standardized diagnostic workup, as surgery for bone lesions should be aggressive only when they are solitary and/or the occult primaries have a good prognosis; in these cases, identification of the primary tumor may be important and warrants special diagnostic efforts. However, in most cases, the primary site remains unknown, even after autopsy. Thus, orthopedic surgery has a mainly palliative role in preventing or stabilizing pathological fractures, relieving pain and facilitating the care of the patient in an attempt to provide the most appropriate therapy for the primary tumor as soon as possible. LEVEL OF EVIDENCE: 5.

X-rays radiomics-based machine learning classification of atypical cartilaginous tumour and high-grade chondrosarcoma of long bones.

BACKGROUND: Atypical cartilaginous tumour (ACT) and high-grade chondrosarcoma (CS) of long bones are respectively managed with active surveillance or curettage and wide resection. Our aim was to determine diagnostic performance of X-rays radiomics-based machine learning for classification of ACT and high-grade CS of long bones. METHODS: This retrospective, IRB-approved study included 150 patients with surgically treated and histology-proven lesions at two tertiary bone sarcoma centres. At centre 1, the dataset was split into training (n = 71 ACT, n = 24 high-grade CS) and internal test (n = 19 ACT, n = 6 high-grade CS) cohorts, respectively, based on the date of surgery. At centre 2, the dataset constituted the external test cohort (n = 12 ACT, n = 18 high-grade CS). Manual segmentation was performed on frontal view X-rays, using MRI or CT for preliminary identification of lesion margins. After image pre-processing, radiomic features were extracted. Dimensionality reduction included stability, coefficient of variation, and mutual information analyses. In the training cohort, after class balancing, a machine learning classifier (Support Vector Machine) was automatically tuned using nested 10-fold cross-validation. Then, it was tested on both the test cohorts and compared to two musculoskeletal radiologists' performance using McNemar's test. FINDINGS: Five radiomic features (3 morphology, 2 texture) passed dimensionality reduction. After tuning on the training cohort (AUC = 0.75), the classifier had 80%, 83%, 79% and 80%, 89%, 67% accuracy, sensitivity, and specificity in the internal (temporally independent) and external (geographically independent) test cohorts, respectively, with no difference compared to the radiologists (p ≥ 0.617). INTERPRETATION: X-rays radiomics-based machine learning accurately differentiates between ACT and high-grade CS of long bones. FUNDING: AIRC Investigator Grant.

Clinical recommendations for treatment of localized angiosarcoma: A consensus paper by the Italian Sarcoma Group.

Angiosarcoma (AS) represents a rare and aggressive vascular sarcoma, posing distinct challenges in clinical management compared to other sarcomas. While the current European Society of Medical Oncology (ESMO) clinical practice guidelines for sarcoma treatment are applicable to AS, its unique aggressiveness and diverse tumor presentations necessitate dedicated and detailed clinical recommendations, which are currently lacking. Notably, considerations regarding surgical extent, radiation therapy (RT), and neoadjuvant/adjuvant chemotherapy vary significantly in localized disease, depending on each different site of onset. Indeed, AS are one of the sarcoma types most sensitive to cytotoxic chemotherapy. Despite this, uncertainties persist regarding optimal management across different clinical presentations, highlighting the need for further investigation through clinical trials. The Italian Sarcoma Group (ISG) organized a consensus meeting on April 1st, 2023, in Castel San Pietro, Italy, bringing together Italian sarcoma experts from several disciplines and patient representatives from "Sofia nel Cuore Onlus" and the ISG patient advocacy working group. The objective was to develop specific clinical recommendations for managing localized AS within the existing framework of sarcoma clinical practice guidelines, accounting for potential practice variations among ISG institutions. The aim was to try to standardize and harmonize clinical practices, or at least highlight the open questions in the local management of the disease, to define the best evidence-based practice for the optimal approach of localized AS and generate the recommendations presented herein.

Pelvic ring reconstruction with tibial allograft, screws and rods following enneking type I and IV resection of primary bone tumors.

INTRODUCTION: Surgery of primary malignant tumors involving the sacroiliac joint requires wide resection, which often interrupts the pelvic ring. Nowadays, restoration of the pelvic ring to provide stability and which technique is most fitting remain subject to debate. The aim of this study is to evaluate the results of pelvic reconstruction with pedicle screw instrumentation and tibial allograft following Enneking Type I-IV resections. PATIENTS AND METHODS: All patients who underwent reconstruction with tibial allograft, screws and rods after resection of areas I and IV for primary bone tumors between 2017 and 2022 were reviewed. Clinical and radiological characteristics, fusion rate and functional results were analyzed. The MSTS score and the TESS were used to evaluate functional results. RESULTS: Seven patients were included in the study. Chondrosarcoma was the most common histology. Only four patients reported pain. No fractures were observed at tumor diagnosis. Computer-assisted navigation was used in six cases. Reconstruction was performed in four cases with a screw inserted in the homolateral L5 pedicle and in the ischium, in two cases with a screw in the homolateral L4 pedicle and another in the homolateral L5 pedicle, in the last case with two screws inserted in L4 and L5, one screw in the ischium and another one in the residual iliac wing. In this case a contralateral stabilization was also carried out. The spine screws and the iliac screws were connected with a rod. The mean follow-up for all 7 patients was 37 months. One patient (16.6%) died due to general complications not directly related to the surgery; while the others are alive and apparently free of disease. Complete fusion was obtained in four out of seven patients and the average time for fusion was 9 months. The average MSTS score and TESS were 58.7% and 57.8%, respectively. DISCUSSION: The need for reconstruction is thoroughly debated in literature. The advantages of restoring posterior pelvis stability are the prevention of long-term pain associated with limb shortening and secondary scoliosis. Re-establishment of the pelvic ring can be achieved through synthetic, biologic or hybrid reconstructions. CONCLUSIONS: More studies that assess the surgical consequences at long-term follow-up and help clarify the indications for reconstruction and the specific technique are necessary to confirm our preliminary results.

Quality of life and emotional distress in sarcoma patients diagnosed during COVID-19 pandemic: a supplementary analysis from the SarCorD study.

Background: The COVID-19 outbreak had a negative psychological impact on cancer patients. In this study, we analyzed emotional distress and quality of life in patients diagnosed with sarcoma during the first year of the pandemic compared to the previous year. Methods: We retrospectively enrolled patients with soft tissue, bone sarcoma, and aggressive benign musculoskeletal diseases diagnosed during the pandemic (COVID group) or the year before (control group) at the IRCCS Regina Elena National Cancer Institute in Rome. Patients who had undergone a psychological assessment with the EORTC QLQ-C30 and the Distress Thermometer at diagnosis were included in the final analysis. We analyzed whether there is a difference in the various domains of quality of life between the two groups and whether there are changes over time in each group. Results: We enrolled 114 patients (72 control group; 42 COVID group), affected by soft tissue (64%), bone sarcoma (29%), and aggressive benign musculoskeletal diseases (7%). We did not observe significant differences in the health-related quality of life domains in the control and COVID groups, except for the financial domain (p = 0.039), with 9.7% vs. 23.8% of patients with a score > 0 in the control and COVID groups, respectively. We observed emotional distress at diagnosis in 48.6% of patients in the control group vs. 69.0% in the COVID group (p = 0.034). In the control group, we observed an improvement in physical function (p = 0.043) and in QoL (p = 0.022), while in the COVID group, we observed a deterioration in role function (p = 0.044) during follow-up. In the COVID group, 22.2% of patients were concerned about COVID-19, 61.1% by tumor, 91.1% stated that the pandemic worsened their subjective perception of cancer, and 19.4% perceived that their quality of care had worsened. Conclusion: We observed a higher level of distress among patients diagnosed during the pandemic compared to the year before, probably due to the increased concern for both infection and cancer, the worsened perception of health status, and the perception of a poorer quality of health care.

Narrative Medicine: A Digital Diary in the Management of Patients with Bone and Soft Tissue Sarcoma-A Multidisciplinary Pilot Study.

Although patient narratives have been increasingly introduced in various fields of medicine, a standard method in clinical practice is still lacking. The objectives of this pilot study were to evaluate the feasibility and usefulness of a digital narrative diary integrated into the care pathway of patients with bone sarcoma and limb soft tissue sarcoma both from the patients' and the healthcare professionals' (HCPs) perspectives. A digital platform, DNMLAB, was designed to obtain guided narratives from patients during their pathway of care in compliance with confidentiality and data protection laws. The diary was used for patients, often young, facing a rare and impactful disease that is difficult to manage and with few opportunities to share experiences. The multidisciplinary team shared the narratives and integrated them into the patient's treatment pathway. Narrative prompts were adequate for the care pathway. Patients correctly considered the diary as a shared area to think about their condition, and HCPs considered it "a shared area growing at each meeting with the patient". The main advantages reported by patients were increased awareness, the opportunity to express their opinion on cures and important personal needs and the perception of better taking charge (score ≥ 4.6). The main advantages of HCP were improved communication, therapeutic alliance, and deeper knowledge of patients. This study confirmed the authors' previous experiences, showing that a digital narrative process is feasible and useful for oncology clinical practice according to patients and HCPs.

Long-term longitudinal study on swine VML model.

BACKGROUND: Volumetric Muscle Loss (VML), resulting from severe trauma or surgical ablation, is a pathological condition preventing myofibers regeneration, since skeletal muscle owns the remarkable ability to restore tissue damage, but only when limited in size. The current surgical therapies employed in the treatment of this pathology, which particularly affects military personnel, do not yet provide satisfactory results. For this reason, more innovative approaches must be sought, specifically skeletal muscle tissue engineering seems to highlight promising results obtained from preclinical studies in VML mouse model. Despite the great results obtained in rodents, translation into human needs a comparable animal model in terms of size, in order to validate the efficacy of the tissue engineering approach reconstructing larger muscle mass (human-like). In this work we aim to demonstrate the validity of a porcine model, that has underwent a surgical ablation of a large muscle area, as a VML damage model. RESULTS: For this purpose, morphological, ultrasound, histological and fluorescence analyses were carried out on the scar tissue formed following the surgical ablation of the peroneus tertius muscle of Sus scrofa domesticus commonly called mini-pig. In particular, the replenishment of the damaged area, the macrophage infiltration and the vascularization at different time-points were evaluated up to the harvesting of the scar upon six months. CONCLUSION: Here we demonstrated that following VML damage, there is an extremely poor regenerative process in the swine muscle tissue, while the formation of fibrotic, scar tissue occurs. The analyses performed up to 180 days after the injury revealed the development of a stable, structured and cellularized tissue, provided with vessels and extracellular matrix acquiring the status of granulation tissue like in human.

Custom Massive Allograft in a Case of Pelvic Bone Tumour: Simulation of Processing with Computerised Numerical Control vs. Robotic Machining.

The use of massive bone allografts after the resection of bone tumours is still a challenging process. However, to overcome some issues related to the processing procedures and guarantee the best three-dimensional matching between donor and recipient, some tissue banks have developed a virtual tissue database based on the scanning of the available allografts for using their 3D shape during virtual surgical planning (VSP) procedures. To promote the use of future VSP bone-shaping protocols useful for machining applications within a cleanroom environment, in our work, we simulate a massive bone allograft machining with two different machines: a four-axes (computer numerical control, CNC) vs. a five-axes (robot) milling machine. The allograft design was based on a real case of allograft reconstruction after pelvic tumour resection and obtained with 3D Slicer and Rhinoceros software. Machining simulations were performed with RhinoCAM and graphically and mathematically analysed with CloudCompare and R, respectively. In this case, the geometrical differences of the allograft design are not clinically relevant; however, the mathematical analysis showed that the robot performed better than the four-axes machine. The proof-of-concept presented here paves the way towards massive bone allograft cleanroom machining. Nevertheless, further studies, such as the simulation of different types of allografts and real machining on massive bone allografts, are needed.

Cross-sectional evaluation of FGD-avid polyostotic fibrous dysplasia: MRI, CT and PET/MRI findings.

A 42-year-old male with left hip pain was diagnosed of several right femoral and tibial bone tumours. All lesions were osteolytic with sclerotic margins. The symptomatic lesion in the proximal femur also showed bone expansion and focal cortical thinning. Whole-body [18F]-fluorodeoxyglucose (FDG) PET/CT and segmental PET/MRI of the left hip and femur were performed for metabolic characterization of the lesions and for biopsy guidance. The lesions showed a heterogenous degree of FDG uptake corresponding to different metabolic stages of the disease. A biopsy of the tumour portion showing the highest FDG uptake revealed a fibrous dysplasia (FD). In conclusion, although generally affecting paediatric and adolescent subjects, polyostotic FD may be detected in the adulthood. Despite the benign nature of the disease, increased glucose metabolism can be seen in some lesions. Hybrid imaging combining morphological and functional information may help guide biopsy and better define the treatment strategy.