Microwave in situ inactivation in the treatment of bone giant cell tumor: a mid-term descriptive study.

AIM: To evaluate the mid-term clinical efficacy of microwave in situ inactivation combined with bone grafting or polymethyl methacrylate (PMMA) filling in the treatment of giant cell tumor of bone (GCTB). METHODS: This is a retrospective, descriptive, and analytical study. A total of 30 GCTB patients received microwave in situ inactivation from January 2012 to January 2020, whose clinical recurrence rate was evaluated at the last follow-up after microwave in situ inactivation surgery. The Musculoskeletal Tumor Society (MSTS) function score was used to evaluate the postoperative clinical panoramic results. RESULTS: All patients were followed up for 21 to 110 months, with an average of 63.79 months. Distal femur (40%) and proximal tibia (28%) had a higher rate of GCTB incidence. Seventeen percent of tumor patients suffered from associated pathologic fracture. The rate of Campanacci classification stage III was 60%. The average MSTS score was evaluated as 27.53 points overall at the last follow-up. In terms of complications, three, two, two and one cases developed fat liquefaction, controllable tissue rejection reaction, incision infection and degenerative changes around lesion joint, respectively, without in situ recurrences and reoperation as well as distant lung metastasis. CONCLUSIONS: The method of microwave in situ inactivation combined with bone grafting or PMMA filling is prudently recommended as one of the options for the limb salvage treatment of giant cell tumor of long and periarticular bone. LEVEL OF EVIDENCE: IV: case series.

Secondary Malignancy in Giant Cell Tumor: A Single-Center Study.

Giant cell tumor of bone (GCTB) undergoes a sarcomatous transformation. Secondary malignancy in giant cell tumor (MGCT) is associated with radiotherapy and has a dismal prognosis. We reviewed medical records to investigate the clinicopathological characteristics and prognosis of MGCT patients. The enrollment criterion was high-grade spindle-cell sarcoma, which developed at the site of prior GCTB treatment. Twelve patients were analyzed: six females and six males. The median age was 42.5 years. Benign recurrence occurred in five GCTB patients not treated with radiotherapy. No pulmonary implants were observed. The median latency to the malignant transformation was 63 months. Nine patients were AJCC stage IIB, and three were stage IVA. The median follow-up period after malignant transformation was 62.5 months. Five patients developed local recurrence, and six had distant metastasis. Five-year overall recurrence and metastasis-free survival rates were 61.9%, 66.7%, and 58.3%, respectively. Initial metastasis was a predictive factor for overall survival. Benign local recurrence of GCTB was also a negative factor for metastasis-free survival of MGCT patients. Differences in overall survival according to benign recurrence also showed a tendency toward significance. In our series, secondary MGCT did not occur after radiotherapy. The prognosis was better than previous findings. Benign recurrence of GCTB could reflect the prognosis of MGCT.

Giant cell tumor of the cervical spine treated by carbon ion radiotherapy: A case report.

INTRODUCTION: Giant cell tumor (GCT) of the bone is a benign-malignant intermediate tumor with locally destructive growth and a relatively high local recurrence rate. Neurological symptoms may develop in patients with GCT of the spine, and surgical treatment is prioritized in cases where resection is possible. However, the local recurrence rate of GCT of the bone is higher than that of GCT at other sites owing to the associated surgical challenges, and treatment is often difficult. No study to date has reported long-term remission of recurrent tumors for more than 5 years by treatment with carbon ion beam radiotherapy after resection of GCT of the cervical spine. PATIENT CONCERNS: A 14-year-old boy who experienced recurrence after surgery for GCT of the cervical spine. DIAGNOSIS: The patient presented with cervical pain, and computed tomography revealed a mass of the C2 vertebral body. He underwent surgery for tumor resection and autologous bone grafting, and the final pathological diagnosis was GCT. The transplanted bone exhibited gradual progression of resorption, and recurrent tumors were observed on computed tomography and magnetic resonance imaging 1 year and 4 months after surgery. INTERVENTIONS: The patient was started on denosumab at 15 years of age and received carbon ion beam therapy with 70.4 Gy administered in 32 sessions over 7 weeks. OUTCOMES: No progressive tumor growth was observed, there were no neurological symptoms such as paralysis or pain were noted, and the patient was in remission for 5 years after irradiation. CONCLUSION: These findings suggest that carbon ion radiotherapy is a safe and effective therapeutic option for patients with recurrent GCT of the cervical spine.

Exploring the Proteomic Alterations from Untreated and Cryoablation and Irradiation Treated Giant Cell Tumors of Bone Using Liquid-Chromatography Tandem Mass Spectrometry.

Giant cell tumors of bone (GCT) are benign tumors that show a locally aggressive nature and affect bones' architecture. Recently, cryoablation and irradiation treatments have shown promising results in GCT patients with faster recovery and less recurrence and metastasis. Therefore, it became a gold standard surgical treatment for patients. Hence, we have compared GCT-untreated, cryoablation, and irradiation-treated samples to identify protein alterations using high-frequency liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS). Our label-free quantification analysis revealed a total of 107 proteins (p < 0.01) with 26 up-regulated (< 2-folds to 5-fold), and 81 down-regulated (> 0.1 to 0.5 folds) proteins were identified from GCT-untreated and treated groups. Based on pathway analysis, most of the identified up-regulated proteins involved in critical metabolic functions associated with tumor proliferation, angiogenesis, and metastasis. On the other hand, the down-regulated proteins involved in glycolysis, tumor microenvironment, and apoptosis. The observed higher expressions of matrix metalloproteinase 9 (MMP9) and TGF-beta in the GCT-untreated group associated with bones' osteolytic process. Interestingly, both the proteins showed reduced expressions after cryoablation treatment, and contrast expressions identified in the irradiation treated group. Therefore, these expressions were confirmed by immunoblot analysis. In addition to these, several glycolytic enzymes, immune markers, extracellular matrix (ECM), and heat shock proteins showed adverse expressions in the GCT-untreated group were identified with favorable regulations after treatment. Therefore, the identified expression profiles will provide a better picture of treatment efficacy and effect on the molecular environment of GCT.

Comprehensive molecular imaging of malignant transformation of giant cell tumour of bone reveals diverse disease biology.

Malignant transformation of giant cell tumour of the bone is extremely rare. In addition, bone transformation in giant cell tumour may occur in different phases. With conventional X-rays, CT scans or MRIs, it may be challenging to distinguish among different phases of bone transformation, normal bone, soft tissue disease and bone disease (benign vs malignant lesions) and changes in multiple organs such as lung, liver and lymph nodes unless every lesion is biopsied, which is not practical. Molecular imaging with different isotopes (Tc-99m phosphonate, 2-deoxy-2-(18F)fluoro-d-glucose and sodium fluoride-18) may help to better characterise the disease. We hypothesised that molecular imaging could offer qualitative and quantitative characterisation of all stages of bone formation, destruction, reactivity or neoplasia in a patient with giant cell tumour of the bone, and we present the first case of molecular imaging where bone formation was seen in multiple soft tissues, such as lungs, muscles, lymph nodes and liver.

Giant cell tumour of bone in the denosumab era.

Giant cell tumour of bone (GCTB) is an intermediate locally aggressive primary bone tumour, occurring mostly at the meta-epiphysis of long bones. Overexpression of receptor activator of nuclear factor kappa-B ligand (RANKL) by mononuclear neoplastic stromal cells promotes recruitment of numerous reactive multinucleated osteoclast-like giant cells, causing lacunar bone resorption. Preferential treatment is curettage with local adjuvants such as phenol, alcohol or liquid nitrogen. The remaining cavity may be filled with bone graft or polymethylmethacrylate (PMMA) bone cement; benefits of the latter are a lower risk of recurrence, possibility of direct weight bearing and early radiographic detection of recurrences. Reported recurrence rates are comparable for the different local adjuvants (27-31%). Factors increasing the local recurrence risk include soft tissue extension and anatomically difficult localisations such as the sacrum. When joint salvage is impossible, en-bloc resection and endoprosthetic joint replacement may be performed. Local tumour control on the one hand and maintenance of a functional native joint and quality of life on the other hand are the main pillars of surgical treatment for this disease. Current knowledge and development in the fields of imaging, functional biology and systemic therapy are forcing us into a paradigm shift from a purely surgical approach towards a multidisciplinary approach. Systemic therapy with denosumab (RANKL inhibitor) or zoledronic acid (bisphosphonates) blocks, respectively inhibits, bone resorption by osteoclast-like giant cells. After use of zoledronic acid, stabilisation of local and metastatic disease has been reported, although the level of evidence is low. Denosumab is more extensively studied in two prospective trials, and appears effective for the optimisation of surgical treatment. Denosumab should be considered in the standard multidisciplinary treatment of advanced GCTB (e.g. cortical destruction, soft tissue extension, joint involvement or sacral localisation) to facilitate surgery at a later stage, and thereby aiming at immediate local control. Even though several questions concerning optimal treatment dose, duration and interval and drug safety remain unanswered, denosumab is among the most effective drug therapies in oncology.

Benign Tumors of the Spine: Has New Chemotherapy and Interventional Radiology Changed the Treatment Paradigm?

STUDY DESIGN: Clinically based systematic review. OBJECTIVE: To determine the role of (A) medical treatment and (B) interventional radiology as either adjuvant or stand-alone treatment in primary benign bone tumors of the spine. METHODS: A multidisciplinary panel of spine surgeons, radiation oncologists, and medical oncologists elaborated specific focused questions regarding aneurysmal bone cyst, giant cell tumor, and osteoid osteoma. Denosumab, bisphosphonate, interferon, bone marrow aspirate, doxycycline, thermal ablation, and selective arterial embolization were identified as areas of interest for the article. A systematic review was performed through MEDLINE and EMBASE. Recommendations based on the literature review and clinical expertise were issued using the GRADE system. RESULTS: The overall quality of the literature is very low with few multicenter prospective studies. For giant cell tumor, combination with Denosumab identified 14 pertinent articles with four multicenter prospective studies. Nine studies were found on bisphosphonates and six for selective arterial embolization. The search on aneurysmal bone cyst and selective arterial embolization revealed 12 articles. Combination with Denosumab, Doxycycline, and bone marrow aspirate identified four, two, and three relevant articles respectively. Eleven focused articles were selected on the role of thermal ablation in osteoid osteoma. CONCLUSION: Alternative and adjuvant therapy for primary benign bone tumors have emerged. Their ability to complement or replace surgery is now being scrutinized and they may impact significantly the algorithm of treatment of these tumors. Most of the data are still emerging and further research is desirable. Close collaboration between the different specialists managing these pathologies is crucial. LEVEL OF EVIDENCE: N/A.

Treatment and outcome of malignant giant cell tumor in the spine.

Malignant giant cell tumor (MGCT) in the spine is extremely rare and there is little published information regarding this subject in the literature. We attempted to correlate different treatment options and outcomes over time. A retrospective study of patients with spinal MGCT who were surgically treated in our center between 2006 and 2012 was performed. Overall, three surgical management strategies, including subtotal resection, piecemeal total resection, and total en bloc spondylectomy were applied. Postoperative radiotherapy was carried out in 4 cases. Clinical data and efficacy of surgical treatment strategy were analyzed via chart review. A total of 14 patients with spinal MGCT were included in the study. Three cases were diagnosed as primary MGCT (PMGCT), while the other 11 patients were secondary MGCT (SMGCT). The mean follow-up period was 41 (range 3-75) months. Recurrence was found in 7 patients after surgery in our center, while distant metastasis and death occurred in 4 and 6 cases, respectively. MGCT of bone is always a high-grade sarcoma with a poor prognosis and complete excision, while also preserving neural function, is recommended. In our study, patients who underwent total en bloc spondylectomy had significantly lower local recurrence rate for MGCT in the spine.

Therapeutic radiotherapy for giant cell tumor of the spine: a systemic review.

BACKGROUND: Giant cell tumor of the bone (GCTB) is a benign but locally aggressive tumor. Giant cell tumor of the spine (GCTS) accounts for 3-6 % of GCTB. Surgery remains the treatment of choice. For those not suitable for surgery, therapeutic radiotherapy (RT) is one classic modality. Although there are several articles on therapeutic RT for GCTS therapy, few systemic reviews have been performed on effects of therapeutic RT on GCTS. METHODS AND MATERIALS: We searched EMBASE and Medline databases for papers reporting therapeutic radiotherapy for GCTS patients not suitable for surgical resection. The inclusion criteria and prognosis indicators have been defined prior to data extraction. Information of the included patients has been discreetly recorded. We analyzed the prognosis of therapeutic RT and multiple data concerning the GCTS patients. The indicators for prognosis were computed by SPSS software. The local control (LC) and overall survival (OS) rate was estimated by the Kaplan-Meier method. p values ≤0.5 were considered statistically significant. RESULT: We included 13 studies comprising 42 patients who received therapeutic radiotherapy with doses ranging from 21 to 80 Gy. The results suggested a response rate of 100 %, OS of 97.6 %, 1-year local control rate (LC) of 85.4 %, 2-year LC rate of 80.2 %, and overall LC of 79 %. No patient reported malignant transformation albeit four had post-RT neurological complications. Four had distant metastasis of the tumor. Patients with previously repeated recurrence had worse prognosis after RT (p = 0.028). No association between dosage and prognosis was found. CONCLUSION: Therapeutic RT could provide a satisfactory prognosis for GCTS patients according to this study, and can be an alternative treatment modality for GCTS patients not suitable for surgery.

The multidisciplinary management of giant cell tumor of bone.

Giant cell tumor of bone is a locally aggressive lesion with a predilection for local recurrence, and in a small proportion of patients, metastatic disease can develop. Surgery is the mainstay of management for extremity-based lesions. For tumors located in challenging anatomical locations such as the sacrum and spine however, surgery may be associated with unacceptable functional morbidity. There are limited data regarding other treatment modalities such as radiation therapy, cytotoxic chemotherapy, interferon and bisphosphonates. Serial arterial embolization can be effective in some cases. Recent evidence has demonstrated denosumab to be a promising agent in the treatment of unresectable or metastatic disease.

Retroperitoneal mass: a diagnostic challenge.

We report a case of retroperitoneal mass involving lumbar spine (L2 region) of eight months duration in a male aged 26 years. X ray of the lumbar spine was suggestive of tuberculosis. However, as there was no response to specific therapy, a CT scan was performed which was indicative of a soft tissue sarcoma. Subsequent biopsy of the tumor showed it to be a giant cell tumor of bone (GCT). The tumor was inoperable and the patient is presently undergoing radiotherapy. Giant cell tumors only rarely arise in the axial skeleton. GCT of the spine is uncommon, accounting for 1.3-6.5% of all cases in various series. The case is being presented because of its rarity, diagnostic dilemma encountered and to emphasize the role of surgical biopsy.

Analysis of risk factors for recurrence of giant cell tumor of the sacrum and mobile spine combined with preoperative embolization.

AIM: To investigate the factors related to the local recurrence-free survival time (LRFS) after surgical treatment of GCT of the sacrum and mobile spine combined with preoperative embolization. MATERIAL AND METHODS: We retrospectively reviewed 28 consecutive patients with GCT of the sacrum and mobile spine who underwent initial surgical excision combined with preoperative embolization between 1995 and 2011. Data regarding age, gender, tumor location, tumor size, tumor extension, radiation therapy, and local recurrences were reviewed and analyzed statistically. RESULTS: All patients underwent intralesional resection. The average duration of follow-up was 86.4 months (range, 15 - 193 months). 8 (28.6%) patients developed local recurrence. The average recurrence time was 35.6 months (range, 5 - 79 months), and the local recurrence-free survival rates at 3 and 5 years were 89.1% and 75.5%, respectively. LRFS was found statistically longer in intracompartmental (T1) tumors as compared with extracompartmental (T2) tumors (P < 0.05), but not for age, gender, tumor location, tumor size, or radiation therapy. CONCLUSION: Intralesional excision with preoperative embolization is a feasible choice for T1 tumors of the sacrum and mobile spine, but for T2 tumors, more aggressive treatment may be required. The choice of surgical treatment should be balanced between the complications and tumor recurrence.

Radiotherapy in the management of giant cell tumor of bone.

OBJECTIVES: To evaluate the long-term treatment outcomes for patients with giant cell tumor of bone (GCTB) treated with radiotherapy with or without surgical resection. METHODS: This retrospective review includes 34 patients with GCTB treated with megavoltage radiotherapy between January 1973 and January 2008 at the University of Florida. Patients' ages ranged from 16 to 85 years (median, 29). Tumor sizes ranges from 2.5 to 12 cm (median, 4.8 cm) in the maximum dimension. Twenty-one patients received radiation for gross disease, either de novo (22 patients) or recurrent (12 patients). Thirteen patients were treated with postoperative radiation after gross total resection. The median dose was 45 Gy in both the definitive and adjuvant settings. RESULTS: The median follow-up was 16.8 years. The 5- and 10-year local-control (LC) rates were 85% and 81%, respectively. Six patients developed an isolated local recurrence (2/13 treated postoperatively and 4/21 who were treated for gross disease). All 6 patients who developed a local recurrence were successfully salvaged with surgery; therefore, the ultimate LC rate was 100%. Both the 5- and 10-year freedom from distant metastasis rates were 91%. Three patients developed lung metastases, including 1 patient who experienced GCTB transformation into a high-grade sarcoma. The 5- and 10-year progression-free survival rates were both 78%. CONCLUSIONS: Moderate-dose radiotherapy for GCTB provides a long-term LC >80%, justifying its role as an alternative to morbid surgery.

Radiotherapy for giant cell tumors of the bone: a safe and effective treatment modality.

BACKGROUND: Giant cell tumor of the bone (GCTB) is a benign or sometimes semi-malignant neoplasm accounting for 5% of all primary bone tumors. This type of tumor has been historically considered as radioresistant, but nowadays radiotherapy (RT) is used in unresectable, recurrent or incompletely resected cases. Since the value of RT is not well defined, a national cohort study was conducted. PATIENTS AND METHODS: Six German institutions collected data from 35 patients treated during the last 35 years and analyzed them. RESULTS: From 1975-2010 16 male and 19 female patients with 39 lesions were irradiated for GCTB. The median age was 30 years and the median follow-up 65 months. Nineteen patients had undergone RT for recurrent or unresectable disease and 16 patients for non-in-sano resection. The actuarial 5-year overall and disease-free survival rates were 90% and 59%, respectively. CONCLUSION: RT is an easy, safe and effective method for the treatment of GCTB. It may provide an attractive alternative to mutilating surgery.

Giant cell tumor of the odontoid in an adolescent male: radiation, chemotherapy, and resection for recurrence with 10-year follow-up.

Giant cell tumors (GCTs) are rare lesions of the cervical spine, with only 14 previously reported pediatric cases in the literature, all occurring in females. The authors present the case of a 15-year-old boy with neck pain who was found to have a lytic GCT of the odontoid process. Following resection, recurrent disease was treated with radiotherapy and chemotherapy and then a final resection. He has remained tumor free for more than 10 years. The rarity of GCTs can make their diagnosis difficult in the cervical spine. Because of their aggressive behavior and relative resistance to adjuvant therapy, GCTs must be monitored diligently and treated aggressively.

Recurrence after and complications associated with adjuvant treatments for sacral giant cell tumor.

BACKGROUND: The best treatment of giant cell tumor of the sacrum is controversial. It is unclear whether adjuvant treatment with intralesional surgery reduces recurrences or increases morbidity. QUESTIONS/PURPOSES: We therefore asked whether adjuvants altered recurrence rates and complications after intralesional surgery for sacral giant cell tumors. METHODS: We retrospectively studied 31 patients with sacral giant cell tumors treated with intralesional surgery with and without adjuvants. Survival to local recurrence was evaluated using Kaplan-Meier analysis. The differences in survival to local recurrence with and without adjuvants were evaluated using multivariate Cox regression analysis. Complications were recorded from clinical records and images. The minimum followup was 36 months (median, 108 months; range, 36-276 months). RESULTS: Overall survival to local recurrence was 90% at 60 and 120 months. Survival to local recurrence with and without radiation was 91% and 89%, with and without embolization was 91% and 86%, and with and without local adjuvants was 88% and 92%, respectively. Adjuvants had no influence on local recurrence. Mortality was 6%: one patient died at 14 days postoperatively from a massive pulmonary embolism and another patient had radiation and died of a high-grade sarcoma. Fifteen of the 31 patients (48%) had one or more complications: eight patients (26%) had wound complications and seven patients (23%) had massive bleeding during curettage with hemodynamic instability. L5-S2 neurologic deficits decreased from 23% preoperatively to 13% postoperatively; S3-S4 deficits increased from 16% to 33%. CONCLUSIONS: Adjuvants did not change the likelihood of local recurrence when combined with intralesional surgery but the complication rate was high.

Intensity modulated radiotherapy (IMRT) in benign giant cell tumors--a single institution case series and a short review of the literature.

BACKGROUND: Giant cell tumors are rare neoplasms, representing less than 5% of all bone tumors. The vast majority of giant cell tumors occurs in extremity sites and is treated by surgery alone. However, a small percentage occurs in pelvis, spine or skull bones, where complete resection is challenging. Radiation therapy seems to be an option in these patients, despite the lack of a generally accepted dose or fractionation concept. Here we present a series of five cases treated with high dose IMRT. PATIENTS AND METHODS: From 2000 and 2006 a total of five patients with histologically proven benign giant cell tumors have been treated with IMRT in our institution. Two patients were male, three female, and median age was 30 years (range 20-60). The tumor was located in the sacral region in four and in the sphenoid sinus in one patient. All patients had measurable gross disease prior to radiotherapy with a median size of 9 cm. All patients were treated with IMRT to a median total dose of 64 Gy (range 57.6 Gy to 66 Gy) in conventional fractionation. RESULTS: Median follow up was 46 months ranging from 30 to 107 months. Overall survival was 100%. One patient developed local disease progression three months after radiotherapy and needed extensive surgical salvage. The remaining four patients have been locally controlled, resulting in a local control rate of 80%. We found no substantial tumor shrinkage after radiotherapy but in two patients morphological signs of extensive tumor necrosis were present on MRI scans. Decline of pain and/or neurological symptoms were seen in all four locally controlled patients. The patient who needed surgical salvage showed markedly reduced pain but developed functional deficits of bladder, rectum and lower extremity due to surgery. No severe acute or late toxicities attributable to radiation therapy were observed so far. CONCLUSION: IMRT is a feasible option in giant cells tumors not amendable to complete surgical removal. In our case series local control was achieved in four out of five patients with marked symptom relief in the majority of cases. No severe toxicity was observed.

Giant cell tumour of the sacrum: a suggested algorithm for treatment.

To investigate the outcome of our management of patients with giant cell tumour of the sacrum and draw lessons from this. A retrospective review of medical records and scans for all patients treated at our unit over the past 20 years with a giant cell tumour of the sacrum. Of the 517 patients treated at our unit for giant cell tumour over the past 20 years, only 9 (1.7%) had a giant cell tumour in the sacrum. Six were female, three male with a mean age of 34 (range 15-52). All, but two tumours involved the entire sacrum and there was only one purely distal to S3. The mean size was 10 cm and the most common symptom was back or buttock pain. Five had abnormal neurology at diagnosis, but only one presented with cauda equina syndrome. The first four patients were treated by curettage alone, but two patients had intraoperative cardiac arrests and although both survived all subsequent curettages were preceded by embolisation of the feeding vessels. Of the seven patients who had curettage, three developed local recurrence, but all were controlled with a combination of further embolisation, surgery or radiotherapy. One patient elected for treatment with radiotherapy and another had excision of the tumour distal to S3. All the patients are alive and only two patients have worse neurology than at presentation, one being impotent and one with stress incontinence. Three patients required spinopelvic fusion for sacral collapse. All patients are mobile and active at a follow-up between 2 and 21 years. Giant cell tumour of the sacrum can be controlled with conservative surgery rather than subtotal sacrectomy. The excision of small distal tumours is the preferred option, but for larger and more extensive tumours conservative management may well avoid morbidity whilst still controlling the tumour. Embolisation and curettage are the preferred first option with radiotherapy as a possible adjunct. Spinopelvic fusion may be needed when the sacrum collapses.

The megavoltage radiation therapy in treatment of patients with advanced or difficult giant cell tumors of bone.

PURPOSE: To assess the outcomes of radiotherapy, in terms of local control and treatment complications, of advanced or difficult giant cell tumors of bone (GCTB) that could not be treated by surgery. METHODS AND MATERIALS: Among 122 consecutive patients with confirmed GCTB from 1985 to 2007, 77 patients were treated by megavoltage radiotherapy because they were inappropriate candidates for surgery. We have performed analysis of all data in terms of progression-free survival (PFS) and treatment morbidity. Median follow-up time was 58 months. RESULTS: In the irradiated group, maximal tumor size ranged from 5 to 18 cm (median, 8.5). Anatomic distribution was as follows: femur, 27 cases; tibia, 19; radial/ulnar bone, 12; sacrum, 9; pelvic bones, 5; other, 5. Twenty-one patients (27%) were referred for local recurrence after ≥1 other treatment procedures. The radiation doses ranged from 26 to 89 Gy (median, 56; administered 1.8-2.0 Gy/fraction with average total duration of treatment of 5-7 weeks); 8 patients (10%) received <50 Gy. All patients tolerated treatment well without acute or late complications. All patients except two are alive. Local control was achieved in 65 patients (84%; bone recalcification/restitution of joint functions), 12 patients showed signs of local progression, all within irradiated fields (9 were treated successfully with salvage surgery). Five- and 10-year local PFS were 83% and 73%, respectively. Three patients developed lungs metastases. Malignant transformation of GCTB occurred in two patients. CONCLUSIONS: GCTB can be safely and effectively treated with megavoltage radiotherapy with local control rate >80% at 5 years. Our study confirms that radiotherapy of GCTB offers an alternative to difficult or complex surgery and may be an option of choice in the treatment of inoperable patients.

Treatment and outcome of giant cell tumors of the pelvis.

BACKGROUND AND PURPOSE: Giant cell tumors (GCTs) of bone rarely affect the pelvis. We report on 20 cases that have been treated at our institution during the last 20 years. METHODS: 20 patients with histologically benign GCT of the pelvis were included in this study. 9 tumors were primarily located in the iliosacral area, 6 in the acetabular area, and 5 in the ischiopubic area. 8 patients were treated by intralesional curettage and 6 by intralesional resection with additional curettage of the margins. 3 patients with iliacal tumors were treated by wide resection. 2 patients were treated by a combination of external beam irradiation and surgery, and 1 patient solely by irradiation. In addition, 9 patients received selective arterial embolization one day before surgery. Of the 6 patients with acetabular tumors, 1 secondarily received an endoprosthesis and 1 was primarily treated by hip transposition. The patients were followed for a median time of 3 (1-11) years. RESULTS: 1 patient with a pubic tumor developed a local recurrence 1 year after intralesional resection and additional curettage of the margins. The recurrence presented as a small soft tissue mass within the scar tissue of the gluteal muscles and was treated by resection. No secondary sarcoma was detected and none of the patients developed pulmonary metastases or multicentricity. No major complication occurred during surgery. INTERPRETATION: We conclude that most GCTs of the pelvis can be treated by intralesional procedures. For tumors of the iliac wing, wide resection can be an alternative. Surgical treatment of tumors affecting the acetabular region often results in functional impairment. Pre-surgical selective arterial embolization appears to be a safe procedure that may reduce the risk of local recurrence.