Osteosarcoma (OS), the most common type of primary malignant bone tumor, is defined by the presence of malignant mesenchymal cells producing osteoid or immature bone. The peak incidence of the most frequent type of OS, i.e., high-grade central OS, occurs in the second decade of life during the adolescent growth spurt. Most patients suffer from the pain and swelling in the involved region and, usually, seek medical attention. Diagnosis is carried out by conventional radiographs, computed tomography, and magnetic resonance image (MRI). In addition, three-phase bone scans, thallium scintigraphy, dynamic MRI, and positron emission spectroscopy are new innovative promising tools. OS can be treated with surgery, radiotherapy, and chemotherapy. There is a clear need for newer effective agents for patients with OS, especially for patients who afflicted with metastatic and recurrence tumor. Monoclonal antibodies directed against OS may prove useful as treatment, either for drug delivery or for radiopharmaceuticals.

Medulloblastoma is one of the most common malignant tumours of the central nervous system in children. It affects two persons per million per year worldwide and is increasing. More than 70% of patients diagnosed with medulloblastoma are predominantly below age 10 years. Histological variants of medulloblastoma are recognized as classic, nodular-desmoplastic, large cell/anaplastic and medulloblastoma with extensive nodularity. Symptoms include headache, general malaise, failure to feed, vomiting, clumsiness and other presentations that mimic common and benign childhood pathologies seen in primary care. Study data suggested an inverse correlation between high-stage disease and duration of symptoms. Currently, medulloblastoma is classified clinically into high risk and standard (average) risk depending upon factors solely clinical - age, metastases and resection. The treatment strategies for medulloblastoma are maximal safe resection (plus/minus cerebrospinal fluid diversion), neuraxis radiotherapy and chemotherapy. Medulloblastoma is the first brain tumour to show efficacy of chemotherapy in large prospective trials. Effective chemotherapy regimens remain elusive for almost all patients with high-grade cortical or brainstem gliomas and for most young patients with residual or metastatic disease of any histology. Conventional chemotherapeutic agents continue to be developed to reduce toxicity and/or improve efficacy. Recent advances in tumour biology have changed the emphasis to novel agents that target molecular changes crucial for tumour proliferation or survival. The toxicity and efficacy of several of these novel agents are currently being assessed in children with brain tumours.