Ojedinělý případ akumulace osteotropního radiofarmaka 99mTc-metylen-difosfonátu v místě talkové pleurodézy zobrazený při scintigrafii skeletu a SPECT/CT u pacientky s diseminací osteosarkomu do plic

Aim: to present a rare case of non-osseous uptake of the bone-seeking radiopharmaceutical 99mTc-methylene diphosphonate in the area of talc pleurodesis in osteosarcoma patient with multiple pulmonary metastases. Method: A 17-year-old woman underwent left transfemoral amputation due to the tibial osteosarcoma. Unfortunately, subsequent chemotherapy was ineffective and interim CT revealed multiple lung metastases. Moreover, as a consequence of recurrent bilateral pneumothoraces the talc pleurodesis had to be performed. Two month later, patient suffered from a low-back pain, therefore the bone scan (including both planar imaging and SPECT/CT) was indicated to rule-out osseous metastases. Results: Whole body scan and additional SPECT/CT of the chest disclosed intensive nonosseous uptake of the bone-seeking radiopharmaceutical in the thickened, calcified pleura as well as osseous metastasis in the sacrum. Regrettably, metastatic involvement of the ribs and thoracic wall could not be ruled-out due to the intensive pleural uptake and subsequent Compton scattering. Conclusion: Bone scintigraphy with additional SPECT/CT disclosed rare 99mTc-methylene diphosphonate uptake in a talc pleurodesis and metastatic bone involvement. [ABSTRACT FROM AUTHOR]