P1-088: 99mTcMDP Bone scintigraphy is gold standard in imaging, early diagnosis and staging of lung cancer.

Abstract

Lung cancer remains the leading cause of cancer death in men.Skeletal scintigraphy is exquisitely sensitive to the remodeling process and is typically abnormal months before or more prior to the appearance of radiographic changes in lung cancer patients.The characteristic scintigraphic appearance is intense uptake at the site of metastases and fracture site.Finding bone metastases is frequently important to clinical decisions affecting quality of life.Detection of such bone metastatic lesions before comlications allows radiation therapy or surgical intervenations to prevent pathologic fractures from disabling the patients of lung cancer.It also helps in the staging of the disease.We have investigated 47 patients of different types of Cancer refered by surgeons,radiotherapists and chemotherapists. Adsorption of 99mTc-MDP occurs on to the mineral phase of the bone.The uptake is significantly higher in amorphous calcium phosphate than in mature crystalline hydroxyappatite.This explain the avidity of tracer for areas of increased osteogenic activity.High sensitivity of bone scanning in determining the presence and extent of metastatic disease makes extremely important tool in decision making. Bone scans demonstrate metastatic lesions much earlier than X-ray, C.T., MRI. Skeletal radiopharmaceutical Tc99m-MDP distributed rapidly throughout the extracellular space.Uptake in bone is also rapid,clearance is via the kidneys. A total of 47 patients,all males,in the range of 45 to 82 years old was investigated before and after surgery, radiotherapy,chemotherapy and during followup. 22 to 25 mCi 0f Tc99m-MDP was injected IV, static Ant. and posterior views of entire skeleton was taken under the gamma camera. Total 47 patients was investigated. On visual analysis there was positive scan findings (bone mets) in 18 patients (38.29%) and negative scan findings (normal bone scan) in 29 patients (61.71%). 8/47 pts(17.02%) were cases of lung cancer. 4/47 pts(8.51%)were diagnosed as lung cancer with bone metastasis. (One case was diagnosed as Lung cancer with pathological fracture and multiple bone mets). Significance of bone mets is in the management of lung cancer when clinically and radiographically stage I and scintigraphically stage IV,here change of treatment is needed.Bone sacn are very sensitive for detecting the altered local metabolism in areas of skeletal remodeling associated with metastatic deposits. Sensitivity for detecting bone mets is quoted as 95% or above. Non-Invasive and a very sensitive and specific method.