SPECT/CT with 99mTc-Technetryl in Staging, Planning of External Radiotherapy and Follow-up in Lung Cancer: a Clinical Case and Case – Addressed Review of Literature

Abstract

The case of a patient with newly diagnosed peripheral cancer of the right lung, involving the pleura, in whom the local extent of the process initially detected by X-ray CT was significantly extended from the data of the SPECT with 99mTc-technetryl. In particular, with SPECT/CT before the start of radiation therapy (RT), involved lymph nodes were detected both in the lower edge of the root of the right lung, and in paraaortic and paratracheal location. The SPECT/CT with 99mTc-technetryl was carried out with dual-detector gamma-camera GE Discovery NM/CT 670 DR (GE Medical) in a quantitative mode, with calibration and calculation of indexes of standardized uptake values (SUV) and % uptake of the administered activity by the primary tumor and metastatically involved lymph nodes. The values of the volume of tumor tissue were, respectively, for the tumor and the largest proximal metastatically involved lymph node 154.2 cm3 and 12.9 cm3, % of the activity absorbed by the tumor tissue − 0.498 and 0.030 %, and SVP ‒ 2.19 and 2.5.With subsequent external radiation therapy (in total 40 Gy, 2 Gy 5−6 times a week) the irradiation fields were planned in such a way that all affected lymph nodes were within their borders. A control SPECT/CT study carried out immediately after the RT showed a decrease in the volume of tumor tissue in the primary node down to 58 cm3, % of the activity absorbed by the tumor tissue to 0.090 %, and SVP ‒ to 1.15. Reliable imaging of lymph nodes after LT was not observed. After 6.5 months, no evidencies for relapse or continued tumor growth were detected with a control X-ray CT performed on an outpatient visit with contrast enhancement. Thus, SPECT/CT with 99mTc-technetryl in lung cancer is a vital method for clarifying the diagnosis and assessment of the extent of the tumor process, as well as monitoring the patient. A broad inter-center assessment of abilities of the SPECT/CT with 99mTc-technetryl in lung cancer is advisable, especially when planning RT.