Is Skeletal Imaging Essential in the Staging Workup for Conventional Chondrosarcoma?

BACKGROUND: Staging of a bone sarcoma before initiating treatment helps orthopaedic oncologists determine the intent of treatment and predicting the prognosis. As per National Comprehensive Cancer Network (NCCN) and European Society for Medical Oncology (ESMO) guidelines, there are no exclusive recommendations for chondrosarcoma staging. They are staged similar to other bone sarcomas even though skeletal metastases are extremely rare in chondrosarcomas. QUESTIONS/PURPOSES: We asked: (1) What proportion of patients with a chondrosarcoma present with detectable only skeletal metastasis? (2) What proportion of patients with chondrosarcoma present with skeletal metastasis with or without concurrent pulmonary metastases? METHODS: Between January 2006 to December 2017, 480 patients with histology-proven chondrosarcomas of the extremity, including clavicle, scapula, spine, and pelvis, presented to our institute. Fifty-three patients were excluded due to incomplete details about their staging. The remaining 427 were retrospectively analyzed and included in this study. Their clinical, radiological, and histopathological details were retrieved from patient files and electronic medical records. Of the 427 patients included, 53 had Grade 1 chondrosarcoma, 330 had Grade 2 chondrosarcoma, and 41 had Grade 3 chondrosarcoma. Grade was not available in three patients. All patients were staged with a thoracic CT scan and bone scan or a whole body fluorodeoxyglucose positron-emission tomography/CT (FDG PET/CT). Patients with a suspected or documented metastasis were reviewed again by an experienced radiologist and a nuclear medicine expert for the purpose of this study. A total of 8% (35 of 427) of patients with chondrosarcoma had isolated lung metastases at the time of initial staging. These included 9% (31 of 330) of patients with Grade 2 chondrosarcomas and 10% (4 of 41) of patients with Grade 3 chondrosarcomas. No patient with a Grade 1 chondrosarcoma had detectable lung metastases. The primary study endpoint was the number of patients who had a diagnosis of skeletal or skeletal and lung metastases as identified by the staging modalities. RESULTS: Three patients with Grade 2 chondrosarcoma had only skeletal metastasis. No patients with Grade 1 or Grade 3 chondrosarcoma had detectable bone metastases. Combined lung and bone metastases were seen in only two patients with Grade 2 chondrosarcoma. CONCLUSIONS: Our study found that the incidence of bony metastasis in conventional chondrosarcomas is extremely low. Considering the present results, we believe skeletal scanning may be overused in current staging algorithms. We do not have survival outcomes to know if detecting these few patients with skeletal lesions at initial presentation would be important in the absence of symptoms, but our data suggest that omitting skeletal imaging from the staging work-up of conventional chondrosarcomas should be considered. It may be reserved for patients with documented pulmonary metastases. LEVEL OF EVIDENCE: Level IV, diagnostic study.

First preclinical imaging of primary cartilage neoplasm and its local recurrence using 99mTc-NTP 15-5 radiotracer.

UNLABELLED: This study on a rat model of grade II chondrosarcoma aimed to determine whether the radiotracer N-(triethylammonium)-3-propyl-[15]ane-N5 radiolabeled with (99m)Tc ((99m)Tc-NTP 15-5), which binds to cartilage proteoglycans, has pathophysiologic validity for in vivo imaging of cartilage tumoral tissue. METHODS: We used 2 experimental approaches with the Swarm chondrosarcoma rat model: that is, a primary paratibial location and local recurrence after intralesional curettage. (99m)Tc-NTP 15-5 scintigraphy and (99m)Tc-hydroxymethylenediphosphonate ((99m)Tc-HMDP) scanning were performed at regular intervals during 50 d after tumor implantation in a paratibial location (primary model; n = 12 animals) and after intralesional curettage in a femoral condyle location (recurrence model; n = 9 animals). For each animal, positive scans were analyzed at each time point using the target-to-background ratio (TBR), with the target region of interest delineated over the tumor and the background region of interest over muscle. In each model, the TBR time course was followed against primary tumoral growth or recurrence. Tumor volume was monitored for 2 mo by measuring the 2 perpendicular diameters. At study end, animals were sacrificed for histopathologic analysis. RESULTS: For both models, (99m)Tc-NTP 15-5 scans showed tracer accumulation at the site of implantation or curettage. For the primary tumor model, the mean TBR was 1.6 +/- 0.14 by day 4 after implantation and increased over time as the disease progressed, with a mean TBR of 4.25 +/- 0.25 on day 45. For the recurrence model, mean TBR was 3.27 +/- 0.24 by day 4 after curettage and increased with recurrence, with a mean value of 5.25 +/- 0.49 on day 50. (99m)Tc-HMDP bone scans were negative for both models throughout the study; at a later stage of the study, an area of (99m)Tc-HMDP accumulation was seen in the diaphysis of the bone adjacent to the tumor and was attributed to remodeling. CONCLUSION: These experimental results in 2 preclinical models of grade II chondrosarcoma bring forward data in favor of (99m)Tc-NTP 15-5 radiotracer for imaging primary growth of chondrosarcoma and its local recurrence after surgery.

[Breast carcinoma and bone chondrosarcoma: a new syndrome?]. / Cancer du sein et chondrosarcome osseux: un nouveau syndrome?

We report the case of a fifty three years old woman who has developed in the same time a breast carcinoma and a bone chondrosarcoma. The mean of this article is to underline the strong link (statistical and phenotype) between those two cancers and to discuss the possibility of a syndrome associating breast carcinoma and bone chondrosarcoma.

Unresolving hip tendonitis leads to discovery of malignant tumor.

OBJECTIVE: To discuss a case of malignant bone tumor in the left hip of a patient who sought treatment following a tennis injury. CLINICAL FEATURES: A 27-year-old male patient visited a chiropractic clinic 6 months after a twisting injury to his left hip which occurred while playing tennis. His pain had remained moderate in intensity and intermittent to frequent in frequency since it originated but became more intense the week prior to his visit. INTERVENTION AND OUTCOME: The patient was diagnosed with a tendonitis/bursitis and received 3 weeks of treatment. Care consisted of various forms of passive modalities to reduce pain and inflammation, as well as hip mobilization and tissue stretching. Plain film examination was then performed, due to lack of progress, and revealed a possible chondroblastoma of the femoral head. The patient was referred to his primary care physician (PCP) for follow-up imaging. Surgical resection of the lesion occurred approximately 2 months later. Biopsy of the resected cells confirmed a new diagnosis of clear cell chondrosarcoma. A computed tomography (CT) scan of the chest was performed to rule out metastasis to the lungs. Regular follow-up care and imaging continued and revealed, 9 months following, that the femoral head lesion had returned and hip replacement surgery would be needed. CONCLUSION: Tendonitis, bursitis, and sprains commonly occur following sports-related trauma to the appendicular skeleton. A conservative trial of care should be performed on suspected soft tissue injuries. However, when lack of improvement occurs within the first month, further examination, special studies, or referral are warranted to ensure a proper diagnosis and to rule out a pathological condition.

Bone tumors of the extremities or pelvis treated by microwave-induced hyperthermia.

From July 1992 through March 1999, 213 patients with malignant bone tumors of the extremities (176 patients) and pelvis (37 patients) were treated by microwave-induced hyperthermia. Osteosarcoma and chondrosarcoma were the most common diagnoses. The limb-salvage procedure was done as follows: After separating the tumor-bearing bone and the extraosseous mass from surrounding normal tissues with a proper margin, microwave energy was delivered into the tumor while the healthy tissues were protected carefully from overheating. Restrengthening of the devitalized bone was necessary in many cases. The eschar resulting from the heat necrosis was curettaged. Most patients can walk early with a partial weightbearing brace for support. The survival rate was 73.9%. Fracture, local recurrence, and infection were the main complications although the majority of complications occurred early in the study. Thermotherapy is a novel and effective way to treat bone tumors in selected patients.