Radiation induced sarcoma of bone is a rare but challenging disease process associated with a poor prognosis. To date, series are limited by small patient numbers; data to inform prognosis and the optimal management for these patients is needed. We hypothesized that patients with radiation-induced pelvic bone sarcomas would have worse surgical, oncologic, and functional outcomes than patients diagnosed with primary pelvic bone sarcomas

This was a multi-institution, comparative cohort analysis. A retrospective chart review was performed of all patients diagnosed with a radiation-induced pelvic and sacral bone sarcoma between January 1st, 1985 and January 1st, 2020 (defined as a histologically confirmed bone sarcoma of the pelvis in a previously irradiated field with a minimum 3-year interval between radiation and sarcoma diagnosis). We also identified a comparison group including all patients diagnosed with a primary pelvic osteosarcoma/spindle cell sarcoma of bone (i.e. eligible for osteosarcoma-type chemotherapy) during the same time interval. The primary outcome measure was disease-free and overall survival.

We identified 85 patients with primary osteosarcoma of the pelvis (POP) and 39 patients with confirmed radiation induced sarcoma of the bony pelvis (RISB) undergoing surgical resection. Patients with RISB were older than patients with POP (50.5 years vs. 36.5 years, p67.7% of patients with POP underwent limb salvage as compared to 77% of patients with RISB; the type of surgery was not different between groups (p=.0.24). There was no difference in the rate of margin positive surgery for RISB vs. POP (21.1% vs. 14.1%, p=0.16). For patients undergoing surgical resection, the rate of surgical complications was high, with more RISB patients experiencing complications (79.5%) than POP patients (64.7%); this approached statistical significance (p=0.09).

15.4% of patients with RISB died perioperative period (within 90 days of surgery) as compared to 3.5% of patients with POP (p= 0.02). For patients undergoing surgical resection, 5-year OS was significantly worse for patients with RISB vs. POP (27.3% vs. 47.7%, p=0.02). When considering only patients without metastatic disease at presentation, a significant difference in 5-year survival remains for patients with RISB vs. POP (28.6% vs. 50%, p=0.03) was a trend towards poorer 5-year DFS for patients with RISB vs. POP (30% vs. 47.5%), though this did not achieve statistical significance (p=0.09).

POP and RISB represent challenging disease processes and the oncologic outcomes are similarly poor between the two; however, the disease course for patients with RISB appears to be worse overall. While surgery can result in a favorable outcome for a small subset of patients, surgical treatment is fraught with complications.

This text has been removed at the authors' request.

Introduction

Extensive bone loss and poor residual bone quality can make implant fixation difficult to achieve in revision of failed megaprostheses. While newer porous components are available to address various periarticular cavitary and segmental defects, diaphyseal fixation remains challenging without resorting to cemented techniques, or cementless fully-coated stems that achieve fixation over long segments of bone. In cases of previous infection, it may be advantageous to avoid the use of such devices as they can be difficult to remove and may result in even greater bone loss if the infection were to persist. Compressive osseointegration technology has been become a valuable device in the management of these challenging situations.

Curative treatment of malignancies in the sacrum and lower lumbar spine frequently requires en bloc spinopelvic resection. There is no standard classification of these procedures. We present outcomes and a classification scheme with oncologic and reconstructive guidelines for spinopelvic tumors based on an analysis of 30 cases of en bloc resection and reconstruction performed with curative intent.

Mean follow-up of surviving patients was 38 months. Tumors included osteosarcoma (n=9), chondrosarcoma (n=6), chordoma (n=5), other sarcomas (n=5), neurogenic tumors (n=4), and local extension of carcinoma (n=1). Resections could be divided into 4 types. Type 1 resections (n=12) included a total sacrectomy with lower lumbar spine and bilateral medial iliac resections. Type 2 resections (n=6) included hemisacrectomy, partial lumbar spine excision, and medial iliac resection. Type 3 resections (n=9) encompassed external hemipelvectomy with hemisacrectomy and partial lumbar spine excision. Type 4 resections (n=3) encompassed external hemipelvectomy, total sacrectomy, and lumbar spine excision.

For each resection type, we have developed staged surgical approaches to allow resection with wide margins and reconstruction of spinopelvic continuity. Tumor free margins were achieved in all cases. Perioperative mortality was 3/30. Seven additional patients have died of disease, two died of other causes, two are alive with disease, and 16 have no evidence of disease. 13/18 surviving patients are independent in their activities of daily living.

In our practice en bloc excision and reconstruction of spinopelvic neoplasms may be classified into four types. For each type, we have devised surgical treatment guidelines to allow for wide resection and reconstruction of spinopelvic continuity. Long term survival and independent function can be achieved in this challenging patient population. This represents the first standardised classification of oncologic spinopelvic resections and reconstructions.

The influence of advancements in imaging and chemotherapy on patient with dedifferentiated chondrosarcoma was determined. There were forty-two cases in which twenty-seven patients received adjuvant therapy. Median survival was eight months and five-year survival was 4.8%. There was no statistical difference (p=0.62) in survival between patients who did and did not receive chemotherapy, had wide versus radical resection, or had limb sparing versus sacrificing procedures. There were no statistically significant differences between patients treated prior to 1986 and those subsequently. Despite advances, dedifferentiated chondrosarcoma continues to carry a poor prognosis. The routine adjuvant chemotherapy in this population should be questioned

The long-term survival for patients that presented with dedifferentiated chondrosarcoma has historically been poor. A large clinical series has not been analyzed in the era of modern diagnostic and treatment modalities. The current study was performed to look at the influence of advancements in imaging and chemotherapy on patient outcome. A retrospective chart review of all cases of patients presenting with dedifferentiated chondrosarcoma at our institution from 1984–2000 was performed. This was done as an extension to a study published in 1986 prior to the era of modern chemotherapy.

There were forty-two cases in twenty-five men and seventeen women of average age fifty-six (range twenty-four-eighty-three years). MSTS grades at presentation were IIA(5), IIB(27), and III(10). Three patients underwent biopsy only, nineteen had limb sacrificing surgery, and twenty had limb sparing procedures. Surgical margins were intralesional in three, marginal in two, wide in twenty, and radical in fourteen. Twenty-seven patients received adjuvant therapy (twenty-two chemotherapy only, two radiotherapy only, three combined therapy). Median survival was eight months and five-year survival was 4.8%. There was no statistical difference (p=0.62) in survival between patients who did and did not receive chemotherapy, had wide versus radical resection, or had limb sparing versus sacrificing procedures. There were no statistically significant differences between patients treated prior to 1986 and those subsequently.

Despite advances in diagnostic modalities, surgical treatments, and adjuvant therapies, dedifferentiated chondrosarcoma continues to carry a poor prognosis. The routine use of current adjuvant chemotherapy and its inherent risks and benefits in this population should be questioned.