**3. Staging**

*Recent Advances in Bone Tumours and Osteoarthritis*

static spread as well as a worse prognosis overall [14].

Osteosarcomas most commonly occur in the metaphysis of long bones, for the most part around the knee in the distal femur (43%0 or proximal tibia (23%), followed in frequency by the humerus (10%) (**Figure 1**) [10]. One in ten patients has a tumor of axial location, most commonly in the pelvis. Tumors of axial location tend to have a worse prognosis with higher recurrence rates and more advanced stages at presentation [10–12]. Patients complaint about intermittent pain and swelling, the pain is known to be severe enough to awake the patient during sleep hours [13]. Pain of a high intensity can potentially be an indication of an impending pathological fracture, fact that occurs in up to 10% of these patients [14]. A pathological fracture may represent a more aggressive tumor and the microRNA profile of tumors that fractured have been shown to be different that those without a break. Additionally, tumors that presented with a fracture were associated with a higher risk of meta-

About 20% of osteosarcoma patients have metastatic disease at presentation. Most of those secondary lesions are in the lung, bone being the second most common spread location [10]. Tumor size has been implicated as a risk factor for lung spread [15]. When osteogenic sarcoma presents in older population, there is a more frequent axial location compared to younger patients, being almost 40% of the elderly patients versus 10% in children and teenagers [16]. Additionally, the older patients tend to have larger tumors, more frequency of metastatic disease at presentation and a worse general prognosis with less opportunity for limb salvage procedures and inability to receive the full systemic treatment protocol as compared to younger patients [17]. Moreover, when the chemotherapy response seems to

*Fifteen-year-old patient with a left proximal tibia osteosarcoma, presented with local pain and swelling.*

**2. Clinical presentation**

**74**

**Figure 1.**

The assessment of osteosarcoma patients usually begins with orthogonal plain radiographs of the site of pain or mass. Plain films usually reveal an aggressive appearing lesion that prompts more advanced imaging studies such as a CT scan or ideally an MRI with and without contrast of the entire affected bone. On radiographic imaging the lesions may be more blastic, lytic or mixed pattern depending on the osteosarcoma subtype. In more advanced cases, there will be cortical permeation and an associated soft tissue component, although this is a more common finding in Ewing's sarcomas [19]. For purely lytic lesions, radiographic evidence is only present when a substantial percentage of the bone has been affected (30–50%), thus the recommendation in cases of persistent symptoms is to proceed with an MRI even with a negative plain film [20]. Additional findings on radiographs include a wide area of transition, cortical destruction and a periosteal reaction such as Codman's triangle or a sunburnt pattern (**Figure 2**) [21].

The next imaging study should be a full bone length MRI with and without contrast of the affected area, this will serve diagnostic and staging purposes as well, since it has the ability of detecting skip lesions. MRI studies provide information regarding the complete extent of the tumor within the bone, and its closeness to surrounding structures such as vessels and nerves. Additionally, it provides information regarding joint invasion, and, extremely important in the pediatric population, physis involvement by the tumor [22]. This information will dictate the proposed surgical intervention (**Figure 3**). After neoadjuvant chemotherapy and prior to the definitive surgical treatment a new MRI with and without contrast of the affected bone must be obtained for tumor re-assessment.

Following the initial images, usually proceeds a close or open biopsy of the lesion for pathology confirmation of the diagnosis and grading of the tumor. It is

#### **Figure 2.**

*Radiographic images of a patient with a distal femur conventional, central, osteoblastic, high grade osteosarcoma. The tumor presents a mixed, blastic and lytic, moth-eaten pattern.*

#### **Figure 3.**

*MRI of the tibia of a 15-year-old patient with an osteoblastic osteosarcoma of the proximal tibia respecting the physis (D, E). T1-weighted sequence (A), stir sequence (B) and T1-fat suppressed post contrast sequence (C).*

paramount that the biopsy is performed by a surgeon specialized and with experience in bone tumors, so that it can be done following important principles inherent to the specialty and have those not be respected it can potentially hinder the possibility of a limb salvage procedure for the patient [23].

Once the diagnosis of osteosarcoma has been confirmed, the next step is to proceed with staging of the patient. Approximately, 20% of patients debut with stage IV cancer [24]. Osteosarcomas are known to spread most commonly to lungs, 80% of the metastases, followed by bones (10%) [25, 26]. Therefore, the next imaging studies will be directed to assess the most common sites of spread. The lung assessment is performed with a non-contrasted chest CT and the bone staging can be performed by a bone scan or, more recently, with a PET-CT scan (**Figures 4** and **5**).

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**4. Treatment**

*Osteosarcoma*

**Figure 4.**

**Figure 5.**

*DOI: http://dx.doi.org/10.5772/intechopen.96765*

and an overall survival of 13% [26].

Patients with metastatic disease at presentation have a worse prognosis than those with localized disease having an overall survival at 5 years of 40% or less [27]. Bone metastases have a particularly worse prognosis with higher rates of local recurrences

*Tecnecium-99 bone scan of a patient with a distal femur osteosarcoma. No other bone lesions were present.*

*Non-contrasted chest CT depicting peripheral lung nodules (circled) consistent with metastatic osteosarcoma.*

Additional studies prior to the start of treatment, will be oriented at making a basal assessment of organs potentially affected by chemotherapy. Consequently, the patient will obtain an echocardiogram, kidney function studies, hemogram and complete metabolic panel as well as an audiology test [13]. Additionally, patients should be referred for fertility counseling since the systemic treatment is known to decrease the chances of conceiving even many years after the finalization of chemotherapy. Male patients present with particularly worse chances of conceiving than females and the cumulative dose of the drugs used seem to be the most important

determinant factor to predict the ability to conceive after treatment [28].

Currently, the treatment of localized osteogenic sarcoma is the same, independent of subtype and despite its different behaviors and genetic profiles, and includes a plan of neoadjuvant chemotherapy, followed by local treatment with

**Figure 4.**

*Recent Advances in Bone Tumours and Osteoarthritis*

paramount that the biopsy is performed by a surgeon specialized and with experience in bone tumors, so that it can be done following important principles inherent to the specialty and have those not be respected it can potentially hinder the

*MRI of the tibia of a 15-year-old patient with an osteoblastic osteosarcoma of the proximal tibia respecting the physis (D, E). T1-weighted sequence (A), stir sequence (B) and T1-fat suppressed post contrast sequence (C).*

Once the diagnosis of osteosarcoma has been confirmed, the next step is to proceed with staging of the patient. Approximately, 20% of patients debut with stage IV cancer [24]. Osteosarcomas are known to spread most commonly to lungs, 80% of the metastases, followed by bones (10%) [25, 26]. Therefore, the next imaging studies will be directed to assess the most common sites of spread. The lung assessment is performed with a non-contrasted chest CT and the bone staging can be performed by a bone scan or, more recently, with a PET-CT scan (**Figures 4** and **5**).

possibility of a limb salvage procedure for the patient [23].

**76**

**Figure 3.**

*Non-contrasted chest CT depicting peripheral lung nodules (circled) consistent with metastatic osteosarcoma.*

**Figure 5.** *Tecnecium-99 bone scan of a patient with a distal femur osteosarcoma. No other bone lesions were present.*

Patients with metastatic disease at presentation have a worse prognosis than those with localized disease having an overall survival at 5 years of 40% or less [27]. Bone metastases have a particularly worse prognosis with higher rates of local recurrences and an overall survival of 13% [26].

Additional studies prior to the start of treatment, will be oriented at making a basal assessment of organs potentially affected by chemotherapy. Consequently, the patient will obtain an echocardiogram, kidney function studies, hemogram and complete metabolic panel as well as an audiology test [13]. Additionally, patients should be referred for fertility counseling since the systemic treatment is known to decrease the chances of conceiving even many years after the finalization of chemotherapy. Male patients present with particularly worse chances of conceiving than females and the cumulative dose of the drugs used seem to be the most important determinant factor to predict the ability to conceive after treatment [28].
