ABSTRACT
OBJECTIVE: Treatment of chondrosarcomas is grade based; intralesional curettage for grade 1 and resection for grade 2 or more. Currently used methods to determine grades before surgery are not highly accurate and create a dilemma for the surgeon. We have used a PET-CT combined with imaging to answer the following study questions: (1) Does SUVmax value from an 18F-FDG PET/CT correlate with the grade of chondrosarcoma? (2) Can a cutoff SUVmax value be used to differentiate between various grades of chondroid neoplasms with sufficient sensitivity and specificity? (3) Does SUVmax guide the clinician and add value to radiology in offering histologic grade-dependent management? METHODS: SUVmax values of patients with suspected chondrosarcoma were retrospectively correlated with the final histology grade for the operated patients. Radiologic parameters and radiology aggressiveness scores (RAS) were reevaluated and tabulated. RESULTS: Totally 104 patients with chondroid tumors underwent 18F-FDG PET/CT assessment. In total 73 had tissue diagnosis available as a pretreatment investigation. Spearman correlation indicated that there was a significant positive association between SUVmax and the final histology grading of chondroid tumors (correlation coefficient = 0.743; P < 0.01). SUVmax cutoff of 13.3 was 88.9% sensitive and 100% specific for diagnosing dedifferentiated chondrosarcomas. An RAS cutoff value of 3 or more could diagnose IHGCS with a sensitivity of 80.7% and specificity of 93.75%. Adding an SUVmax cutoff of 3.6 improves the sensitivity to 89.5%. CONCLUSION: SUVmax value can reliably help diagnose dedifferentiated chondrosarcoma and when added to the radiology score can improve the accuracy of grading chondrosarcoma.
Subject(s)
Positron Emission Tomography Computed TomographyABSTRACT
INTRODUCTION: Traditionally, centralization of the fibula with fusion across the tibiotalar joint has been used to reconstruct distal tibial defects. Although effective, it requires long periods of protected weight-bearing. The fibula or the fixation often fails before fibular hypertrophy necessitating multiple additional surgeries. A method of using ECRT with the available ipsilateral fibula (nonvascularized) to reconstruct the distal tibia defect with the aim of early return to weight-bearing was evolved. This paper documents our early experience. Patients and Methods. Four patients; with the diagnosis of osteosarcoma in 3 patients and recurrent giant cell tumor of the bone in 1 patient, underwent resection of the distal tibia for tumors between 2017 and 2019. Extracorporeally irradiated (50 Gy) distal tibia along with ipsilateral nonvascularized fibula was used to bridge the defect and fuse the tibiotalar joint. A plate was used to rigidly hold the construct. The final outcome was compared to the historical control group that underwent only pedicled ipsilateral fibula transposition and ankle arthrodesis without recycled autograft or allograft between 2009 and 2017. Oncological reconstruction and functional outcomes were compared for each group. Patient reported outcomes on the acceptability of ankle fusion; cosmesis and function were analyzed and compared between the two groups. RESULTS: The mean resection length in the study group (4 patients) was 7.75 cm (7 to 8.5 cm). As compared to the historical cohort of 7 patients, the study population showed statistically superior results in all reconstruction, functional, and patient-reported outcomes except time to proximal junction union (p=0.068). There were no reconstruction failures, infection, or nonunions in the study group, whereas the control comparative group had 2 proximal junction nonunions and a mean time to fibular hypertrophy of 143 weeks (82 to 430 weeks) with fibula centralization. Earlier weight-bearing was allowed (mean 26.75 weeks; median 27 weeks) compared to (mean 80.75 weeks; median 80 weeks) in the control group. CONCLUSION: We think that ECRT with ipsilateral vascularized fibula is a promising method of reconstructing the distal tibia. The recycled autograft tibia added strength to the distal tibia construct in our study and aided the anatomical reconstruction of the distal tibia. The patient-reported outcomes for cosmesis and acceptability add to the benefits of performing this procedure. Consistent early union across the proximal junction and earlier weight-bearing were clear advantages of this method.
ABSTRACT
BACKGROUND: Joint reconstruction following resection of malignant bone tumors is challenging in itself in spite of several options in hand. Ability to restore joint anatomy, function and mobility while achieving optimal oncological outcomes are the requirement of reconstructions today. While biological reconstructions (allograft or recycled tumor autografts) following tumor bone surgery are popular for intercalary resections not involving the joint, their use for osteo-articular reconstructions are associated with concerns over cartilage and joint health. We have used extracorporeal radiation therapy (ECRT) and re-implantation of the osteoarticular segment as a size matched recycled tumor autograft reconstruction after complex acetabular and proximal ulnar resections; owing to the lack of significantly superior reconstruction alternatives in these locations and also review the current literature on other biological/non-biological reconstruction options. QUESTIONS/PURPOSES: (1) What are the oncological, reconstruction and functional outcomes with osteo-articular reconstruction using ECRT and re-implantation of recycled tumor autograft for the acetabulum and olecranon? (2) Is there an evidence of cartilage loss, joint damage or avascular necrosis resulting from irradiation of the articular autograft? METHODS: 19 patients with primary bone tumors underwent limb salvage surgery with en-bloc resection and reconstruction using the resected articular tumor bone after treating it with extra-corporeal irradiation of 50-60Gy. These included 16 acetabular and 3 proximal ulnar. While all patients were included for oncological assessment; minimum follow-up of 24 months was considered for final outcome assessment of function and joint status. RESULTS: MSTS scores of the 16 acetabular reconstruction patients with minimum 2 years follow-up was 87% (26/30). Neither delayed union, non-union at osteotomy sites nor was any fractures reported in the irradiated graft. There was no local recurrence within the irradiated graft and only 1 patient required graft excision for uncontrolled infection. All 3 patients of proximal ulna reconstruction achieved healing and full range of movement of the elbow. Scores of MSTS: 100% (30/30), MEPS: 100 and DASH: zero was achieved. Two patients developed osteonecrosis of the femoral head; one requiring a joint replacement and one awaiting replacement. One patient of acetabular reconstruction has joint space narrowing on radiographs with mild clinical symptoms. CONCLUSIONS: Extracorporeal radiotherapy and re-implantation after osteo-articular resection is an oncologically safe option offering promising outcome in our small series. The availability of size-matched graft, thus avoiding inherent problems of allograft also provides a better economic option over endoprosthesis and its associated complications in select sites. The results can deteriorate over time that may require secondary reconstructive procedures like joint replacement. LEVEL OF EVIDENCE: Level IV, Therapeutic Study.
