Will virtual multidisciplinary team meetings become the norm for musculoskeletal oncology care following the COVID-19 pandemic? - experience from a tertiary sarcoma centre

Background

Like with all cancers, multidisciplinary team (MDT) meetings are the norm in bone and soft tissue tumour (BST) management too. Problem in attendance of specialists due to geographical location is the one of the key barriers to effective functioning of MDTs. To overcome this problem, virtual MDTs involving videoconferencing or telemedicine have been proposed, but however this has been seldom used and tested. The COVID-19 pandemic forced the implementation of virtual MDTs in the Oxford sarcoma service in order to maintain normal service provision. We conducted a survey among the participants to evaluate its efficacy.

Methods

An online questionnaire comprising of 24 questions organised into 4 sections was circulated among all participants of the MDT after completion of 8 virtual MDTs. Opinions were sought comparing virtual MDTs to the conventional face-to-face MDTs on various aspects. A total of 36 responses were received and were evaluated.

Results

72.8% were satisfied with the depth of discussion in virtual MDTs and 83.3% felt that the decision-making in diagnosis had not changed following the switch from face-to-face MDTs. About 86% reported to have all essential patient data was available to make decisions and 88.9% were satisfied with the time for discussion of patient issues over virtual platform. Three-fourths of the participants were satisfied (36.1% - highly satisfied; 38.9% - moderately satisfied) with virtual MDTs and 55.6% of them were happy to attend MDTs only by the virtual platform in the future. Regarding future, 77.8% of the participants opined that virtual MDTs would be the future of cancer care and an overwhelming majority (91.7%) felt that the present exercise would serve as a precursor to global MDTs involving specialists from abroad in the future.

Conclusion

Our study shows that the forced switch to virtual MDTs in sarcoma care following the unprecedented COVID-19 pandemic to be a viable and effective alternative to conventional face-to-face MDTs. With effective and efficient software in place, virtual MDTs would also facilitate in forming extended MDTs in seeking opinions on complex cases from specialists abroad and can expand cancer care globally.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-020-03925-8.

TH1579, MTH1 inhibitor, delays tumour growth and inhibits metastases development in osteosarcoma model

Background

Osteosarcoma (OS) is the most common primary malignant bone tumour. Unfortunately, no new treatments are approved and over the last 30 years the survival rate remains only 30% at 5 years for poor responders justifying an urgent need of new therapies. The Mutt homolog 1 (MTH1) enzyme prevents incorporation of oxidized nucleotides into DNA and recently developed MTH1 inhibitors may offer therapeutic potential as MTH1 is overexpressed in various cancers.

Methods

The aim of this study was to evaluate the therapeutic benefits of targeting MTH1 with two chemical inhibitors, TH588 and TH1579 on human osteosarcoma cells. Preclinical efficacy of TH1579 was assessed in human osteosarcoma xenograft model on tumour growth and development of pulmonary metastases.

Findings

MTH1 is overexpressed in OS patients and tumour cell lines, compared to mesenchymal stem cells. In vitro, chemical inhibition of MTH1 by TH588 and TH1579 decreases OS cells viability, impairs their cell cycle and increases apoptosis in OS cells. TH1579 was confirmed to bind MTH1 by CETSA in OS model. Moreover, 90 mg/kg of TH1579 reduces in vivo tumour growth by 80.5% compared to non-treated group at day 48. This result was associated with the increase in 8-oxo-dG integration into tumour cells DNA and the increase of apoptosis. Additionally, TH1579 also reduces the number of pulmonary metastases.

Interpretation

All these results strongly provide a pre-clinical proof-of-principle that TH1579 could be a therapeutic option for patients with osteosarcoma.

Funding

This study was supported by La Ligue Contre le Cancer, la SFCE and Enfants Cancers Santé.

The outcome of surgical treatment for peri-acetabular metastases

We reviewed the outcome of patients who had been treated operatively for symptomatic peri-acetabular metastases and present an algorithm to guide treatment. The records of 81 patients who had been treated operatively for symptomatic peri-acetabular metastases between 1987 and 2010 were identified. There were 27 men and 54 women with a mean age of 61 years (15 to 87). The diagnosis, size of lesion, degree of pelvic continuity, type of reconstruction, World Health Organization performance status, survival time, pain, mobility and complications including implant failure were recorded in each case. The overall patient survivorship at five years was 5%. The longest lived patient survived 16 years from the date of diagnosis. The mean survival was 23 months (< 1 to 16 years) and the median was 15 months. At follow-up 14 patients remained alive. Two cementoplasties failed because of local disease progression. Three Harrington rods broke: one patient needed a subsequent Girdlestone procedure. One 'ice-cream cone' prosthesis dislocated and was subsequently revised without further problems. We recommend the 'ice-cream cone' for pelvic discontinuity and Harrington rod reconstruction for severe bone loss. Smaller defects can be safely managed using standard revision hip techniques.

Survival patterns in teenagers and young adults with cancer in the United Kingdom: Comparisons with younger and older age groups

AIMS

We aimed to describe and compare survival in teenagers and young adults (TYAs) with cancer to that of younger children and older adults, to identify sub-populations at greater or lesser risk of death.

METHODS

We compared survival in cancer patients diagnosed in the United Kingdom aged 13-24 years (TYAs) to those aged 0-12 (children) and 25-49 years (adults) using the National Cancer Data Repository. All cases had a first cancer diagnosis between 1st January 2001 and 31st December 2005 with censor date 31st December 2010 or death if earlier.

RESULTS

We found six distinct statistically significant survival patterns. In pattern 1, the younger the age-group the better the 1- and 5-year survival (acute lymphoid leukaemia, carcinoma of ovary and melanoma). In pattern 2, TYAs had a worse 5-year survival than both children and young adults (bone and soft tissues sarcomas). In pattern 3, TYAs had a worse 1-year survival but no difference at 5-years (carcinoma of cervix and female breast). In pattern 4, TYAs had better 1-year survival than adults, but no difference at 5 years (carcinoma of liver and intrahepatic bile ducts, germ cell tumours of extra-gonadal sites). In pattern 5, the younger the age-group the better the 5-year survival, but the difference developed after 1-year (acute myeloid leukaemia, carcinoma of colon and rectum). In pattern 6, there was no difference in 1- and 5-year survival between TYAs and adults (testicular germ cell tumours, ovarian germ cell tumours and carcinoma of thyroid).

CONCLUSION

TYAs with specific cancer diagnoses can be grouped according to 1- and 5-year survival patterns compared to children and young adults. To further improve survival for TYAs, age-specific biology, pharmacology, proteomics, genomics, clinician and patient behaviour studies embedded within clinical trials are required.

The impact of curettage technique on local control in giant cell tumour of bone

INTRODUCTION

Although consensus has been reached regarding the main aspects of intralesional surgery for giant cell tumour of the bone (GCTB), debates continue about the most effective combination of local adjuvants. The purpose of study was to analyze the previous experience and determine the most effective curettage approach for GCTB.

METHODS

We summarized the findings from 89 papers published from 1962 to 2020 related to this subject. Database consisted of 137 treated groups that included 6441 patients who underwent different curettage techniques without pre-operative administration of bisphosphonates or RANKL inhibitors.

RESULTS

Recurrence rates after simple curettage ranged between 27 and 82% with a median value at 47%. The use of one or two local adjuvants reduced the incidence of recurrences approximately by 50% when compared with simple curettage. High-speed burring combined with chemical adjuvants or followed by poly(methyl methacrylate) cementation with or without bone grafting further improved the local control leading to good and excellent results; however, these were not documented in all studies. Simultaneous use of burring, chemical adjuvants, and cementation, which we named here as combined curettage, allowed to down local relapses to the range of 0-26%, with a median at 11%. Oncologic outcomes after combined curettage are significantly better when compared with simple curettage (p < 0.0001) and other variants of enhancement (p = 0.001).

CONCLUSIONS

Combined curettage appears to provide the most potent and comprehensive impact on residual tumour cells located in risk zones. This approach should be considered for locally advanced tumours when function-preserving surgery is planned. Additional comparative studies are required to define the optimal curettage enhancement for each individual patient.

Joint-preserving tumour resection around the knee with allograft reconstruction using three-dimensional preoperative planning and patient-specific instruments

BACKGROUND

The region around the knee joint is a common location of malignant bone tumours. Limb salvage procedures, whenever possible, are preferred to amputation. Allograft reconstruction is an accepted procedure to restore large bone defects. Preoperative three-dimensional (3D) planning and patient-specific instruments (PSI) have already been introduced. The purpose of this study was to provide a technical guideline for joint preserving tumour resection and allograft reconstruction around the knee using 3D planning and PSI.

MATERIAL AND METHODS

3D triangular surface models are created based on computed tomography (CT) and magnetic resonance imaging (MRI) data, whereby tumour expansion in the bone and affection of the surrounding structures are assessed. We describe the preoperative 3D analysis and planning in tumours around the knee joint. In addition, we provide a description of different PSI as well as cutting-techniques to enlarge the toolkit and facilitate a broad range of joint preserving tumour resections with allograft reconstruction around the knee. The basic guide serves for the registration of the preoperative plan for the surgery. Reference pins facilitate the application of further guides. Different additional guide designs can be applied, such as "safety guides," "osteotomy guides," and "allograft adjustment guides."

DISCUSSION

The use of 3D planning and generation of PSI offers valuable tools in tumour resection and allograft reconstruction around the knee joint. To perform complex osteotomies and to preserve vital structures PSI seems to be helpful tools. A step-by-step guideline is provided for the use of 3D preoperative planning and sequentially applied patient-specific guides.

Surgical treatment of primary malignant tumours of the distal tibia: clinical outcome and reconstructive strategies

AIMS

We retrospectively report our experience of managing 30 patients with a primary malignant tumour of the distal tibia; 25 were treated by limb salvage surgery and five by amputation. We compared the clinical outcomes of following the use of different methods of reconstruction.

PATIENTS AND METHODS

There were 19 male and 11 female patients. The mean age of the patients was 19 years (6 to 59) and the mean follow-up was 5.1 years (1.25 to 12.58). Massive allograft was used in 11 patients, and autograft was used in 14 patients. The time to union, the survival time of the reconstruction, complication rate, and functional outcomes following the different surgical techniques were compared. The overall patient survival was also recorded.

RESULTS

Out of 14 patients treated with an autograft, 12 (86%) achieved union at both the proximal and distal junctions. The time to union at both junctions of the autograft was significantly shorter than in those treated with an allograft (11.1 vs 17.2 months, p = 0.02; 9.5 vs 16.2 months, p = 0.04). The complication rate of allograft reconstruction was 55%. The five patients treated with an amputation did not have a complication. Out of the 25 patients who were treated with limb salvage, three (12%) developed local recurrence and underwent amputation. The mean functional Musculoskeletal Tumor Society (MSTS) score after autograft reconstruction was higher than after allograft reconstruction (81% vs 67%; p = 0.06), and similar to that after amputation (81% vs 82%; p = 0.82). The two- and five-year overall rates of survival were 83% and 70%, respectively.

CONCLUSIONS

This consecutive case series supports the safety of limb salvage and the effectiveness of biological reconstruction after the resection of a primary tumour of the distal tibia. Autograft might be a preferable option. In some circumstances, below-knee amputation remains a valid option.

A diagnostic approach to bone tumours

In this review we discuss an approach to diagnosing primary bone tumours, namely the cartilaginous, bone-forming, giant cell-rich, fibro-osseous and round cell neoplasms. Less common lesions including chordoma are also discussed. The value of integrating clinical, histopathological and relevant radiological features is emphasised with a view to providing the general histopathologist with a methodical approach to reaching an accurate diagnosis.

Paediatric Strategy Forum for medicinal product development of multi-targeted kinase inhibitors in bone sarcomas: ACCELERATE in collaboration with the European Medicines Agency with participation of the Food and Drug Administration

The eighth Paediatric Strategy Forum focused on multi-targeted kinase inhibitors (mTKIs) in osteosarcoma and Ewing sarcoma. The development of curative, innovative products in these tumours is a high priority and addresses unmet needs in children, adolescents and adults. Despite clinical and investigational use of mTKIs, efficacy in patients with bone tumours has not been definitively demonstrated. Randomised studies, currently being planned or in progress, in front-line and relapse settings will inform the further development of this class of product. It is crucial that these are rapidly initiated to generate robust data to support international collaborative efforts. The experience to date has generally indicated that the safety profile of mTKIs as monotherapy, and in combination with chemotherapy or other targeted therapy, is consistent with that of adults and that toxicity is manageable. Increasing understanding of relevant predictive biomarkers and tumour biology is absolutely critical to further develop this class of products. Biospecimen samples for correlative studies and biomarker development should be shared, and a joint academic-industry consortium created. This would result in an integrated collection of serial tumour tissues and a systematic retrospective and prospective analyses of these samples to ensure robust assessment of biologic effect of mTKIs. To support access for children to benefit from these novel therapies, clinical trials should be designed with sufficient scientific rationale to support regulatory and payer requirements. To achieve this, early dialogue between academia, industry, regulators, and patient advocates is essential. Evaluating feasibility of combination strategies and then undertaking a randomised trial in the same protocol accelerates drug development. Where possible, clinical trials and development should include children, adolescents, and adults less than 40 years. To respond to emerging science, in approximately 12 months, a multi-stakeholder group will meet and review available data to determine future directions and priorities.

Periostin expression in neoplastic and non-neoplastic diseases of bone and joint

BACKGROUND

Periostin is a matricellular protein that is expressed in bone and joint tissues. To determine the expression of periostin in primary bone tumours and to assess whether it plays a role in tumour progression, we carried out immunohistochemistry and ELISA for periostin in a range of neoplastic and non-neoplastic bone and joint lesions.

METHODS

140 formalin-fixed paraffin-embedded sections of bone tumours and tumour-like lesions were stained by an indirect immunoperoxidase technique with a polyclonal anti-periostin antibody. Periostin expression was also assessed in rheumatoid arthritis (RA) and non-inflammatory osteoarthritis (OA) synovium and synovial fluid immunohistochemistry and ELISA respectively.

RESULTS

Periostin was most strongly expressed in osteoid/woven bone of neoplastic and non-neoplastic bone-forming lesions, including osteoblastoma, osteosarcoma, fibrous dysplasia, osteofibrous dysplasia, fracture callus and myositis ossificans, and mineralised chondroid matrix/woven bone in chondroblastoma and clear cell chondrosarcoma. Reactive host bone at the edge of growing tumours, particularly in areas of increased vascularity and fibrosis, also stained strongly for periostin. Vascular elements in RA synovium strongly expressed periostin, and synovial fluid levels of periostin were higher in RA than OA.

CONCLUSIONS

In keeping with its known role in modulating the synthesis of collagen and other extracellular matrix proteins in bone, strong periostin expression was noted in benign and malignant lesions forming an osteoid or osteoid-like matrix. Periostin was also noted in other bone tumours and was found in areas of reactive bone and increased vascularity at the edge of growing tumours, consistent with its involvement in tissue remodelling and angiogenesis associated with tumour progression.

A new parametric model-based technique in bone tumour analysis

The study presents a new statistical model based segmentation technique dedicated to inhomogeneous bone tumours structure analysis. The presented 3-D segmentation procedure applies a statistic description of the structure based on Gaussian mixture model and an adaptive model-based relative fuzzy connectedness technique. It has been tested on 94 different MR series of 38 young patients. The final segmentation results have been evaluated using two different verification techniques and compared with other segmentation methods. The developed technique yields higher bone tumours segmentation accuracy compared to results obtained with conventional fuzzy connectedness approach and different segmentation methods presented in the literature, and based on active contour models or statistical analysis.

An 8-YEAR analysis of bone tumours in a Caribbean island

BACKGROUND

An epidemiologic analysis of bone tumours in Trinidad & Tobago.

METHODS

A retrospective analysis of primary and secondary bone tumours, site of origin and demographic data was conducted.

RESULTS

63 bone tumours were analysed and included 27 primary benign (43%), 12 primary malignant (19%), 19 metastatic (30%) and 5 by contiguous spread (8%). The most common malignant primary tumour was the osteosarcoma (n = 7), originating from the femur in mostly males in the 11-20 age group. There was 1 chondrosarcoma, 2 fibrosarcomas and 2 plasmacytomas. Benign tumours consisted of 8 osteochondromas, 2 osteomas, 3 giant cell tumours, 3 bone cysts and 11 cases of fibrous dysplasia.

CONCLUSION

Bone tumours are rare with a low incidence of 1.125 per 100,000 population annually and malignant tumours being even rarer at an incidence of 0.18 per 100,000 population annually. There is need for better documentation and data registries in Trinidad and Tobago.

The History of Bone Tumour Treatment and the State of the Art in Vienna

PURPOSES

Bone tumours have been a tragedy for the patient in any time period. In the majority of the cases it occurs in children or young adults. In the past the affected limbs could not be spared and the overall prognosis was poor.

METHODS

Chemotherapy successfully introduced for the purpose of overcoming the poor overall prognosis (Rosen and Jaffe) and tumour prostheses were invented for the purpose of salvaging the affected limbs (Marcove, Scales, Campanacci, Sivas, Salzer). According to the Vienna Tumour Registry in 1968, the first custom-made Vitallium prosthesis for the proximal femur was implanted in a parosteal osteosarcoma.

RESULTS

In Vienna, as a result of the successful chemotherapy the surgical methods for bone tumours changed to limb sparing methods also. A modular ceramic prosthesis for the proximal humerus was introduced by Salzer. From 1975 -1982 16 custom-made endoprosthesis (1) for the knee region were implanted which were replaced by the KMFTR in 1982 (2, Kotz modular femur tibia reconstruction system) which was introduced at the "2nd ISOLS" to an international group of experts. The successful system was followed by the HMRS (Howmedica modular resection system) in 1988. At that time, especially in children, the rotation-plasty of Borgreve was adopted for tumours of the knee region (2). A scientific survey of 70 patients with rotation-plasty until 1991 showed excellent clinical and oncologic results. Later a similar approach was used in upper extremity tumours as "resection replantation" with surprisingly good results. Sophisticated technologies with growing mechanisms allowed the use of endoprostheses even in children (3) for the purpose of substitution since the mutilating rotation-plasty in 1996.

CONCLUSION

For almost 100 years efforts have been undertaken to improve the treatment of bone tumours. Surgery was aiming to keep the function of the limbs by tumour resection instead of amputation. Together with successful chemotherapy, which saves lives, an adequate surgery could stepwise salvage the function of the limb. Body integrity was the final aim for the diseased. Finally, by the effort of the International Societies like ISOLS and EMSOS the survival of malignant bone tumour patients improved from 20% to 80 % with good function quality by sophisticated operative techniques and improved tumour prostheses.

Pre-operative Embolization of Primary and Secondary Bone Tumours is Safe and Effective: a Retrospective Study

Background

The surgical treatment of bone tumours can result in large peri-operative blood loss, due to their large sizes and hypervascularity. Pre-operative embolisation has been successfully used to downgrade vascularity, thus reducing peri-operative blood loss and its associated complications.

Methods

Pre-operative embolisation was successfully undertaken on twenty-six patients with a variety of primary and secondary bone tumours.

Results

Mean blood loss was 796 mL and we experienced no complications.

Conclusion

Pre-operative arterial embolisation of large, richly vascular bone tumours in anatomically difficult positions, is a safe and effective method of downstaging vascularity and reducing blood loss.

Dry bone histology of bone tumours

This article focuses on the application of dry bone histology in the diagnosis of a series of different bone tumours. It provides a short introduction on bone tumour classification and how tumours may affect the skeleton. To illustrate the value of dry bone histology in the diagnostic process we studied the 'fresh' and 'dry' bone histology of a series of well-documented, recent clinical cases of various benign and malignant bone tumours. We show that histology is a valuable instrument to assess bone tissue architecture, which provides information on the biological behaviour of a tumour. Though histology may reveal the specific 'tumorous' bone deposition of high-grade conventional osteosarcomas, all other bone tumours display common, unspecific features. This holds for the following tumours: osteochondroma, hyperostotic meningioma, high-grade angiosarcoma, grade 2 chondrosarcoma, myoepithelial carcinoma, high-grade osteosarcoma and four carcinoma metastases. We conclude that histology is useful in cases where the biological behaviour of a tumour is to be defined, and is particularly an aide in the diagnosis of high-grade conventional osteosarcomas. Nevertheless, the differential diagnosis on the bone tumours in our series should primarily be based on a combination of physical anthropological patient data (age, sex), gross anatomy (e.g. tumour morphology and location), and radiography.

The giant cell tumour of the proximal phalanx of the thumb treated by a 2-stage operation

We present a 29-year-old woman who was treated for a giant-cell tumour of her thumb. Surgical treatment was performed in two stages. In the first stage, the tumour was removed and the first metacarpal and distal phalanges were fixed by an external fixator. In the second stage of reconstruction of the thumb, a cortico-cancellous bone graft from the iliac crest, an external fixator and double arthrodesis were used. This two-stage procedure provides the possibility for confirming the diagnosis and appropriate treatment choice and minimizes the risk of recurrence.

[Protocol for the study of bone tumours and standardization of pathology reports]

Primary bone neoplasms represent a rare and heterogeneous group of mesenchymal tumours. The prevalence of benign and malignant tumours varies; the latter (sarcomas) account for less than 0.2% of all malignant tumours. Primary bone neoplasms are usually diagnosed and classified according to the criteria established and published by the World Health Organization (WHO 2013). These criteria are a result of advances in molecular pathology, which complements the histopathological diagnosis. Bone tumours should be diagnosed and treated in referral centers by a multidisciplinary team including pathologists, radiologists, orthopedic surgeons and oncologists. We analyzed different national and international protocols in order to provide a guide of recommendations for the improvement of pathological evaluation and management of bone tumours. We include specific recommendations for the pre-analytical, analytical, and post-analytical phases, as well as protocols for gross and microscopic pathology.

Solitary enchondroma in a metatarsal bone, an incidental discovery

•

Benign tumours in the lower extremities found incidentally.

•

Many types of bone tumour exist, and accurate classification is important for adequate treatment.

•

Early detection and proper treatment are fundamental for a better prognosis.

•

Definitive histopathological diagnosis is key for better decision making and thus for a better outcome.

Introduction

Enchondromas are rare benign bone tumours and their discovery is usually incidental, since in most cases it presents with no symptoms.

Presentation of case

A 30 year old male who comes to the office after suffering a forced inversion of the left foot, he has edema of the left lateral malleolus, pain and is unable to walk; no deformities or other alterations are observed and palpable pulses of adequate intensity and frequency are recorded. The radiography shows soft tissue edema and no bone lesions.

A tumour is found in the first metatarsal, which was afterwards corroborated by an MRI; once the diagnosis was confirmed, curettage of the lesion was performed with good outcome.

Discussion/conclusion

Multiple enchondromas and solitary enchondromas, left untreated, can transform into malignant bone tumours like chondrosarcomas, so early detection and treatment, in most cases with lesion curettage and bone grafting, become fundamental for a good prognosis.

The risk for complications and reoperations with the use of mega prostheses in bone reconstructions

Background

Despite a relatively high risk for complications and reoperations, mega prostheses are considered a useful method for reconstruction of bone defects after tumour resections. The total number of reoperations has not previously been described, and little is known about the complication rate of mega prostheses used for other indications than primary bone tumours.

Questions/purposes

The current retrospective observational study aimed to describe the patient population treated with mega prostheses at Sahlgrenska University Hospital, Sweden, during 14 consecutive years, reports the complications leading to reoperation and the number and type of reoperations for different kinds of complications, and reports on implant survival.

Methods

All patients treated with a mega prosthesis, regardless of surgical indication and anatomical location, at Sahlgrenska University Hospital during the period 2006–2019 were identified. The medical records for all patients were reviewed. Data regarding age, sex, diagnosis, site of disease, bone resection length, chemotherapeutical treatment and postoperative complications including infections and oncological outcome, were collected and evaluated.

Results

One hundred and fourteen patients treated with 116 mega prostheses were included in the study. The predominant indication for primary surgery with a mega prosthesis was sarcoma of either bone or soft tissue (53.5% of the patients). In total 51 prostheses (44%) did not require any reoperation after the primary surgery. The most common reason for reoperation was infection (22%) followed by soft tissue failure (13%). The risk for prosthetic infection was significantly higher in the group of patients operated due to sarcoma compared with all other indications for surgery regardless of surgical site (p = 0.004).

Conclusion

The study reveals a total reoperation rate of 56% after reconstructive surgery using mega prostheses. Despite the high reoperation rates, at the end of the study period, 83% of the patients had still a functioning prosthesis. Therefore, the use of mega prostheses can be considered a reliable method for reconstruction of large bone defects in selected patients.

Level of Evidence

Level IV, therapeutic study.

CT-Guided RFA for Management of Surgical Relapses of Giant Cell Tumour of Bone

OBJECTIVES

This retrospective study describes a pilot experience in CT-guided RadioFrequency Ablation (RFA) treatment of 5 Giant Cell Tumour of the bone (GCT) recurrences after surgery.

METHODS

After biopsy to confirm the diagnosis of GCT recurrences, all patients were treated with RFA in a single session. A close follow-up was scheduled with contrast-enhanced MRI starting 1 months after treatment.

RESULTS

Five lesions were treated in 5 patients. The length of the observation period was between 4 and 100 months. One lesion relapsed 4 months after the RFA treatment, and the patient underwent a second surgical treatment which included the en-block resection and prosthetic implant. No complications were recorded.

CONCLUSIONS

The management of GCT relapses with RFA could be an interesting and innovative field. However, the results of this limited series need to be confirmed by further investigations of larger patient cohorts.

Bone sarcomas and cancer predisposition syndromes

Bone sarcomas, constituting less than 1% of malignant neoplasms across all age groups, are rare tumours possibly associated with genetic susceptibility syndromes. This review aims to provide recommendations for the detection of cancer predisposition syndromes associated with bone sarcomas and managing affected patients. Recommendations were formulated by a multidisciplinary working and reviewing group from GROUPOS and SFCE oncogenetic's group, including geneticists, oncologists, and radiologists. For various bone sarcomas including osteosarcomas, chondrosarcomas and Ewing sarcomas, we delineate tumour presentation, management strategies, and follow-up within the context of cancer predisposition syndromes. The inherited predisposition syndrome, associated with germline TP53 variants, known as the Li-Fraumeni syndrome, is the most frequent implicated in osteosarcoma cases. Other cancer predisposition syndromes, such as RB1, RECQ or CDKN2A disorders in osteosarcomas and Ollier and Maffucci diseases in chondrosarcomas, are also recognized. Additionally, we discuss rarer cancer predisposition syndromes associated with bone sarcomas and suggest tailored treatment approaches in some cancer predisposition syndromes to mitigate severe toxicities or secondary oncological events. Furthermore, we emphasize the role of identification somatic molecular variations in identifying constitutional germline variants and describe national and international screening programs, reference networks and molecular tumour boards available for collegial and collaborative management discussion. This comprehensive review provides insights into the intricate interplay between genetic predisposition, tumour biology, and therapeutic interventions in bone sarcoma patients with cancer predisposition syndrome.

Robot-assisted implantation of additively manufactured patient-specific orthopaedic implants: evaluation in a sheep model

PURPOSE

Bone tumours must be surgically excised in one piece with a margin of healthy tissue. The unique nature of each bone tumour case is well suited to the use of patient-specific implants, with additive manufacturing allowing production of highly complex geometries. This work represents the first assessment of the combination of surgical robotics and patient-specific additively manufactured implants.

METHODS

The development and evaluation of a robotic system for bone tumour excision, capable of milling complex osteotomy paths, is described. The developed system was evaluated as part of an animal trial on 24 adult male sheep, in which robotic bone excision of the distal femur was followed by placement of patient-specific implants with operative time evaluated. Assessment of implant placement accuracy was completed based on post-operative CT scans.

RESULTS

A mean overall implant position error of 1.05 ± 0.53 mm was achieved, in combination with a mean orientation error of 2.38 ± 0.98°. A mean procedure time (from access to implantation, excluding opening and closing) of 89.3 ± 25.25 min was observed, with recorded surgical time between 58 and 133 min, with this approximately evenly divided between robotic (43.9 ± 15.32) and implant-based (45.4 ± 18.97) tasks.

CONCLUSIONS

This work demonstrates the ability for robotics to achieve repeatable and precise removal of complex bone volumes of the type that would allow en bloc removal of a bone tumour. These robotically created volumes can be precisely filled with additively manufactured patient-specific implants, with minimal gap between cut surface and implant interface.