Induced membrane technique for malignant bone tumours of the humerus.

PURPOSE: The aim of this study was to report on mid- to long-term results following large humeral tumoral resection and reconstruction with the induced-membrane technique in skeletally immature patients suffering from primary malignant bone tumours. METHODS: A retrospective analysis identified all children who underwent the two stages of a humeral reconstruction using the induced-membrane technique for primary malignant humerus tumours between 2002 and 2020. Functional assessment was conducted by an independent observer using the Musculoskeletal Tumor Society (MSTS) scoring system for the upper limb. Radiological assessment was performed by two independent observers and the healing index was calculated (i.e., months/cm). RESULTS: Eight adolescents (5 osteosarcomas and 3 Ewing sarcoma), with a mean age of 14.2 years (SD = 2.7), were included. The mean length of the bone resection was 17.4 cm (SD = 3.8), and the mean delay of the resection and reconstruction stages was 9.4 months (SD = 4). The mean follow-up was 6.6 years (SD = 4.3). The mean MSTS score was 77.4% and the global average healing index was 1.04 months/cm (SD = 2.2). Four complications (i.e., prominence device, fracture, aseptic pseudarthrosis, radial palsy) and one local recurrence were observed in four patients, requiring four unplanned surgical procedures in three patients. One patient died fourteen years after the initial treatment due to a lung recurrence. CONCLUSION: The induced-membrane technique is an effective and safe alternative for reconstructing large humeral bone defects after tumour resection in adolescents. Although this is a two-stage technique, it gives good functional results comparable to other strategies found in the literature. LEVEL OF EVIDENCE: IV.

Reconstruction with antibiotic loaded single-side gore-tex "Tartine" methyl-methacrylate cementoplasty for pediatric chest wall reconstruction: A 10-case series.

INTRODUCTION: Chest wall reconstruction in children after large resection of tumors may be performed with rigid or soft materials. Cementoplasty is commonly used with the "Sandwich" method i.e. gore-tex meshes surrounding both faces of the cement. HYPOTHESIS: Is antibiotic loaded single-side gore-tex "Tartine" methyl-methacrylate cementoplasty an interesting alternative to the double-side "sandwich" method for chest wall reconstruction? MATERIAL AND METHODS: Consecutive patients who were treated from 2011 to 2023 in our hospital were included. RESULTS: Among the ten children treated with a median 5.6 years follow-up, there were no surgical complications related to the reconstruction, loss of function, infections, post operative complications (versus 22.7% in meta-analysis encompassing the 50 rigid reconstructions reported worldwide) nor scoliosis (versus 25%). Three patients have an asymmetric chest wall appearance. DISCUSSION: "Tartine" cementoplasty is a simple, low-cost technique for pediatric chest wall reconstruction. It is well tolerated and checks key demands for chest wall reconstructions. LEVEL OF EVIDENCE: IV; retrospective case series.

The carbon footprint of external beam radiotherapy and its impact in health technology assessment.

Background: The major drivers of carbon dioxide (CO2eq) emissions of external beam radiation therapy (EBRT) are not well known and limit our ability to initiate mitigation strategies. Material and methods: We describe the carbon footprint of four typical centers. We explore direct EBRT associated factors such as the impact of fractionation and use of MRI-LINAC, as well as indirect factors (e.g. patient rides). Treatment strategy related CO2eq emissions are included in a health technology assessment analysis that takes into account CO2eq emissions. Results: A typical EBRT treatment emits from 185 kgCO2eq to 2066 kgCO2eq. CO2eq emissions are mostly driven by (i) accelerator acquisition and maintenance (37.8 %), (ii) patients and workers rides (32.7 %), (iii) drugs and medical devices (7.3 %), (iv) direct energy consumption (6.1 %), and (v) building and bunker construction (5.6 %) with a substantial heterogeneity among centers. Hypofractionation has a strong impact to mitigate emissions. MRI-LINAC is associated with a substantial increase in CO2eq emissions per fraction and requires ultra hypofractionation in 5 fractions to achieve a similar carbon footprint compared to 20 fractions treatment schemes. The expected limited small increase in toxicities due to hypofractionation (when existing) are in the same range as avoided detrimental effects to future people's health thanks to CO2eq mitigation. Conclusion: Carbon footprint of EBRT is not neglectable and could be mitigated. When safely feasible, hypofractionation is one of the main factors to decrease this impact. Taking into account CO2eq emissions has a substantial impact on the health technology assessment of EBRT, favoring hypofractionated regimens.

Hybrid extracellular vesicles for drug delivery.

Extracellular vesicles (EVs) are expected to serve as interesting drug delivery vectors as they may offer unique and new properties for drug delivery. Their natural origin, protein and nucleic acid composition, and intrinsic pleiotropic therapeutic effects could enable new possibilities in the field of drug delivery. Here, we aimed to review the methods used to produce Hybrid EVs, a recently emerged type of EV-based vector made from both EVs and synthetic vectors to exploit their respective properties. Hybrid EV/synthetic objects can be obtained by incubation, electrostatic interactions, polyethylene glycol (PEG)-mediated fusion, co-extrusion, freeze-thawing, or simple EV surface modification, leading to different types of objects. We also opted to review the properties of these vectors, and specifically compared them with those of other drug delivery vectors. It has to be noticed that only a limited number of study report loading metrics that allow cross article comparison. Based on this critical analysis, we attempted to draw the pith and marrow from these relatively difficult-to-compare studies and integrate them into the more general context of opportunities in drug delivery and drug development, with a particular focus on oncology.

Epiphyseal-sparing biological reconstruction of bone sarcoma in children: Focus on articular function and growth.

INTRODUCTION: Epiphyseal preservation surgery and biological reconstruction after resection of metaphyseal bone sarcoma in children is a surgical challenge which can only be justified if future joint function is maintained. HYPOTHESIS: The main hypothesis of this work was that long-term function was maintained. The secondary hypotheses were that local control of the disease and growth restoration were achieved, at the cost of an acceptable number of complications. MATERIAL AND METHOD: This was a retrospective study of 14 children with a median age of 8 years [2-14] at the time of surgery. The tumors (Ewing's sarcoma or osteosarcoma) were mostly situated at the knee (n=9) and hip (n=3). The reconstruction used an induced membrane (n=7) or an allograft (n=7). We studied joint function, mechanisms contributing to loss of growth, surgical complications and survival at the last follow-up. RESULTS: At the median follow-up of 76 months [24-130], 9 out of 14 patients required revision for non-union, and 4 of them required a second revision. At the last follow-up, 82% of the length had been restored, due to 3 bone lengthenings and 7 contralateral epiphysiodeses. Preserved joint function was excellent with an average modified MSTS score of 28.3/30 [24-30]. No local recurrence was reported. DISCUSSION: Our experience of epiphyseal preservation allows local control of the disease and very good function but at the cost of a cumbersome surgical program (12 out of 14 patients were reoperated on, with an average of 1.2 interventions per patient). The main difficulty is the growth management, most often by complex programs of alternating bone lengthening and shortening. LEVEL OF EVIDENCE: IV, retrospective study.