590 likes | 900 Views
Radionuclide methods in oncology. Materials for medical students. Otto Lang, MD, PhD Otakar Bělohlávek, MD, CSc Dept Nucl Med Charles Univ, 3rd Med Fac. Role for Nuclear Medicine. Diagnosis Specific or non-specific Staging Important for proper therapy Follow-up
E N D
Radionuclide methods in oncology Materials for medical students Otto Lang, MD, PhD Otakar Bělohlávek, MD, CSc Dept Nucl Med Charles Univ, 3rd Med Fac
Role for Nuclear Medicine • Diagnosis • Specific or non-specific • Staging • Important for proper therapy • Follow-up • Early detection of recurrens • Treatment • Specific or non-specific
Tumors • Metabolically active tissues – many similar properties as inflammation • Increased vascularization • Increased capillary permeability • Newly proliferated capillaries • Increased blood flow • Metabolically active cells • Increased energy demand
Tumor cells • High density of some common receptors • Expression of several specific receptors • Expression of some specific tumor antigenes • All these properties could be used for imaging and therapy
Diagnostic radiopharmaceuticals • Non-specific - demonstrate tumor sites but are not specific for malignancy • PET or PET-CT • F-18 FDG – anaerobic metabolism • Planar, SPECT or SPECT-CT • Diphosphonates – bone scan • Ga-67 citrate – similar to FDG – localising agent • Colloids – liver-spleen scan • Leukocytes – bone marrow scan • MIBI – several tumors
Diagnostic radiopharmaceuticals • Specific – binds directly to special tumor antigens or receptors or are accumulated by special metabolic pathway • PET or PET/CT - no commercially available • Planar, SPECT or SPECT/CT • I-123/131 MIBG for neuroendocrine tumours • I-131 for differentiated thyroid carcinomas • In-111 octreotide for tumours expressing somatostatin receptors. • monoclonal antibodies labelled with In-111, I-123/131 or Tc-99m
Therapeutic radiopharmaceuticals • Non-specific • Sr-89, Sm-153, Re-189 • Bone pain palliation • Specific • I-131 • Thyroid cancer, as specific diagnostic if tumor significantly accumulates • Y-90 • Zevalin – monoclonal antibody for B-cell lymphomas
Ga-67 scan • Introduced in seventies of 20th century for lymphomas (prof. Dienstbier) • Mechanisms of accumulation • tumour viability • blood flow • capillary permeability • lymphatic drainage • transferrin receptors on the tumour cells
Ga-67 scan • Procedure • Patient preparation • Laxatives for bowel preparation post injection, nothing else • Several weeks post tumor therapy (FN) • radiation therapy and chemotherapy can alter the normal pattern of gallium distribution • 180 MBq is usually administered • imaging follows after 48 – 72 hours • WB + SPECT, middle-energy collimator
Ga-67 scan • Normal scan • Accumulates in bone marrow and liver. • Splenic uptake is variable. • The kidneys are usually visualized and also lacrimal, salivary, nasopharyngeal and genital activity is often present. • Female breasts can be visualized, but accumulation is physiologically symmetrical. • Radioactivity is commonly seen in the colon
Ga-67 scan • Clinical indications • lymphoma • staging and monitoring effect of therapy • melanoma • lung cancer • hepatoma • Combination with other imaging modalities is necessary (SPECT/CT)
Bone scan • Radiopharmaceuticals • Tc-99m MDP, HDP • Tissue accumulation depends on • blood flow • capillary permeability • metabolic activity of osteoblasts and osteoclasts • mineral turnover • 500 to 800 MBq, imaging 2 to 3 hours later – WB + SPECT
Bone scan • Clinical indications: • Diagnosis of metastases of different tumors – staging and follow-up • Positivity many months before an abnormality can be detected on X ray - method of choice to seek for bone metastases • Mainly • Bronchogenous carcinoma, prostate, breast, thyroid, and renal tumours
Bone scan • Scan pattern • increased accumulation in the surrounding bone - hot lesion • defect - cold lesion (some metastases –breast) - rare (very fast grow – no bone reaction) • flare phenomenon – increased number of lesions in the case of effective therapy • super-scan (spread malignancies) - diffusely increased uptake
Liver/spleen scan • Metastases of GI tumors • Replaced by sono and CT • Scan pattern – cold nodules, different number and size • Mainly • Colorectal, ovarian, breast, lung, lymphoma • Always poor prognosis
Thyroid scan • Non-specific test with pertechnetate • Mainly cold nodules – especially in children – must be biopsied!!!
Bone marrow scan • Colloids or leukocytes • Similar as bone scan • Better sensitivity
FDG PEThttp://www.homolka.cz/nm/ • For several tumors – staging and follow-up • Mainly lymphomas, lung cancers, melanoma, colorectal cancers and others • Not suitable for prostate cancer • Patient preparation • At least 1 w post chemo, 3 m radiotherapy • One hour before injection physical rest • Fasting, no milk, no sugar
Specific methods • Binding to receptors or antigens • I-123 MIBG – pheochromocytoma, neuroblastoma in children • In-111 Octreoscan – neuroendocrine tumors (insulinoma, vipoma, carcinoid), SCLC • I-131 – thyroid cancer – follow-up and treatment
Specific methods • Monoclonal antibodies • Anti-CEA – rather in detection of relaps • In the pelvis better than CT • In the liver CT better • In-111 Oncoscint – colorectal, ovarian • Melanoma – antibody against melanin • Ga scan is better
Thyroid cancer I-131 Tc-99m Tc-99m post surgery
Tc-99m sestamibiparathyroid adenoma early late
Neuroblastoma liver and bone involvment I-131 MIBG scan Bone scan
Palpable mass on the necklymphoma Tc-99m pertechnetate Ga-67 citrate
FDG PET Tumor of unknown origin Metastatic involvment of neck lymph nodes
FDG PET Tumor of unknown origin Pharyngeal cancer
FDG PET – brain tumor post thtwo foci on CT, only one viable tumor
Staging colorectal CA
Lung cancer Effect of therapy