Application of Dynamic ¹⁸F-FDG PET/CT for Distinguishing Intrapulmonary Metastases from Synchronous Multiple Primary Lung Cancer

Figure 4

Representative sMPLC and IPM examples. (a–f) sMPLC examples. (a–c) FDG-PET of a patient (patient #1 in Table 3) with two synchronous primary lung tumors. Dynamic FDG PET/CT revealed an acinar adenocarcinoma in the right upper lobe (b) (white arrow, , , ) and a synchronous papillary adenocarcinoma in the left upper lobe (c) (black arrow, , , ). The values of and of both primary tumors were 0.05 and 0.0025, respectively. (d, e) HE staining. (f) The Patlak plot from lesions in (b) and (c), respectively. The slope of the Patlak plot represented the ¹⁸F-FDG net influx rate constant (, i.e. uptake rate constant). (g–m) IPM examples. (g–i) FDG-PET of a lung cancer patient (patient #24 in Table 4) with multiple intrapulmonary metastases. Dynamic FDG PET/CT demonstrated a lesion in the right upper lobe (h, i) (white arrow, , , ) and another lesion in the left lower lobe (h, i) (black arrow, , , ). The values of and of both tumors were 1.22 and 0.0076, respectively. Specifically, we only included and shown one lesion pair (two lesions: the largest and second-largest lesion) in this patient. (j–l) The HE and IHC (TTF-1 and Napsin A) staining of puncture biopsy tissue of left cervical lymph node ((g), black arrow), which indicated metastatic lung adenocarcinoma. (m) The Patlak plot from lesions in (h) and (i), respectively. According to the optimal cut-off value of , the first patient was in agreement with pathological examination to be sMPLC, and the second patient was IPM. AC: adenocarcinoma; RUL: right upper lobe; LLL: left lower lobe.

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