Successful Treatment of Late Isolated Bone Metastasis in a Patient with Bilateral Retinoblastoma Using an Unconventional Method.

Though survival in bilateral retinoblastoma (RB) has improved due to advancement in diagnostics and treatment modalities, children require long-term follow-ups for recurrence and second malignancies. We report a case of bilateral RB in a 7-month-old baby who was treated with chemotherapy, transpupillary thermotherapy, and periocular carboplatin for both eyes following which there was complete regression of tumour. Six and a half years after treatment, the child presented with metastatic recurrence of tumour in the left ulna. He was treated successfully with chemotherapy, extracorporeal radiation and reimplantation therapy. A less aggressive treatment approach for isolated bone relapse may be considered in selected cases.

Extracorporeal irradiation: biological reconstruction following tumor resection with a large bone defect / Extracorporalis irradiatio: nagy csontdefektussal járó tumorresectiót követo biológiai rekonstrukció.

Összefoglaló. A malignus csonttumorok sebészi ellátása során kialakuló szegmentális csontdefektusok pótlása fontos szempont a végtagmegtartó sebészetben. Felnottkorban a megoldás rendszerint tumorprotézis beültetése, 10 évesnél fiatalabb gyermekeknél azonban ez nehezen alkalmazható módszer a kis csontméret és az igen magas várható szövodményarány miatt. A bemutatott, hazánkban még ritkán alkalmazott beavatkozás, a tumoros csontszegmentum mutét alatti sugárkezelése, visszaültetése megfelelo rekonstrukciós lehetoség a végtag funkciójának megtartása mellett, csökkentve a késobbi reoperációk, protézisrevíziók számát. Célkituzés: A hazánkban eddig az ismertetett módon végzett mutétek bemutatása, az eredmények összevetése nemzetközi irodalmi adatokkal. Módszer: Magyaroszágon eddig 12 alkalommal végeztünk végtagmegtartó mutétet malignus csonttumor miatt 12 évesnél fiatalabb gyermekeknél, és e mutétek során biológiai rekonstrukciós módszerként extracorporalis irradiatiót, autograft-reimplantatiót (ECRT, ECI) végeztünk. A mutétek mindegyike primer malignus csonttumor (Ewing-sarcoma 7 esetben, osteosarcoma 4 esetben, chondrosarcoma 1 esetben) miatt történt. Betegeink átlagéletkora 9 (3-12) év volt, az átlagos utánkövetési ido 32,5 (2-73) hónap. A felmérés során fizikális vizsgálat, valamint minden alkalommal röntgenfelvételek készítése történt, szükség esetén szövettani mintavétellel, vérelemzéssel vagy egyéb képalkotással kiegészítve. Eredményeinket nemzetközi irodalmi adatokkal hasonlítottuk össze. Eredmények: Lokális tumorkiújulást egyetlen esetben sem észleltünk, másik csontot érinto skip ('ugró') metastasis miatt egy alkalommal amputatiót végeztünk. A szövodmények tekintetében eredményeink megfelelnek a nemzetközi irodalomban leírtaknak. Két esetben jelentkezett szeptikus szövodmény (16,7%). A resectiós sík radiológiai átépülése 3-9 hónap alatt történt meg az esetek 60%-ában. Álízület, grafttörés, graft részleges elhalása miatt 3 esetben végeztünk reoperációt, kétszer újabb allograft felhasználásával, egy esetben pedig tumorprotézis beültetésével. Betegeink szubjektív véleménye a módszerrol pozitív, a legtöbb esetben megorizték jó fizikai aktivitásukat, az esetleges reoperációk ellenére végtagjukat terhelik, akár sporttevékenységet is végeznek. Következtetések: Vizsgálatunk alapján az extracorporalis irradiatio hasznos biológiai rekonstrukciós módszer 12 évesnél fiatalabb gyermekek esetében szegmentális csontdefektusok pótlására tumoros indikációval. A felmerülo szövodmények aránya alatta marad a hasonló korban beültetett tumorprotézisek szövodményarányainak, ideális esetben pedig több, további kiterjesztett mutét elkerülheto vele. Szövodmény esetén a késobbiekben tumorprotézis-beültetés mint végtagmegtartó vészmegoldás még mindig elvégezheto. Orv Hetil. 2020; 161(45): 1914-1919. INTRODUCTION: Reconstruction of massive segmental bone defects is a crucial point of limb salvage surgeries after malignant bone tumor resections. Megaendoprostheses implantation is a commonly used method for adult patients, but hardly usable for children below 12 years old, because of the small size of the host bone and multiple mechanic complications. OBJECTIVE: Extracorporeal irradiation and allograft reimplantation (ECRT, ECI) are promising methods for these young children for limb salvage, reducing the number of prostheses revisions, reoperations. METHOD: In Hungary, we performed limb salvage surgery for malignant bone tumor in 12 cases in children under 12 years old, using extracorporeally irradiated autografts as biological reconstruction. All cases were primary bone tumors (Ewing's sarcoma: 7, osteosarcoma: 4, chondrosarcoma: 1). The average age of our patients was 9 (3-12) years, the average follow-up was 32.5 (2-73) months. At follow-up, we performed physical examination, X-ray, and other imaging methods if they were necessary. Our results were compared to international publications. RESULTS: We observed no local recurrence, but in one case we had to perform above-knee amputation, due to a skip metastasis in the proximal tibia. The complication rates were similar to those reported in other papers. Septic complications were treated in two cases (16.7%). Total union of the resection lines was observed at 3-9 months in 60% of all cases. Reoperations were performed due to nonunion, or allograft fracture/partly desorganization in 3 cases, twice with new allograft, and with prostheses in one case. The subjective opinion of our patients is positive, they walk with full weightbearing, some of them do even light sporting activities. CONCLUSIONS: We found extracorporeal irradiation a useful and safe method for children under 12 years old for biological reconstruction after malignant bone tumor resection. Complication rate stays under the rate of growing prostheses complications, in optimal cases further radical, and extensive surgeries may be avoided. In the case of major complications, megaendoprostheses implantation later on is still an option as salvage procedure with limb salvage. Orv Hetil. 2020; 161(45): 1914-1919.

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

AIM: 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. MATERIALS AND METHODS: 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). RESULTS: 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). CONCLUSION: 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.

Irradiation-Induced Compositional Effects on Human Bone After Extracorporeal Therapy for Bone Sarcoma.

The present study investigates Raman scattering of human bone irradiated with 50 Gy single dose during therapeutic treatment of Ewing and Osteosarcoma. Bone quality was evaluated via mineral-to-matrix ratio, degree of crystallinity, change in amount of calcium, and carbonate substitution. Alteration in collagen and its cross-links was quantified through second-derivative deconvolution of Amide I peak. A dose of 50 Gy radiation leads to almost 50% loss of mineral content, while maintaining mineral crystallinity, and small changes in carbonate substitution. Deconvolution of Amide I suggested modifications in collagen structure via increase in amount of enzymatic trivalent cross-linking (p < 0.05). Overall irradiation led to detrimental effect on bone quality via changes in its composition, consequently reducing its elastic modulus with increased plasticity. The study thus quantifies effect of single-dose 50 Gy radiation on human bone, which in turn is necessary for designing improved radiation dosage during ECRT and for better understanding post-operative care.

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.