case_images: PMC11128599_01
case_images: Fusion FDG-PET/CT axial slices with a large lesion in the upper lobe infiltrating the thoracic wall with a small lung metastasis and pathologic high FDG-uptake in mediastinal, hilar lymph nodes.
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case_images: Further, workup in this former smoker included a CT scan of the thorax (not shown) followed by a PET-CT scan ( Figure 1 ), which revealed a pulmonary lesion in the right upper lobe.
case_images: Follow-up CT scans showing tumor progression with hepatic and pancreatic metastases. (A) Follow-up CT scan three months after the end of the initial chemotherapy showing new liver metastases and a new lesion in the pancreas, marked with an X. (B) Follow-up CT scan seven months after the end of initial chemotherapy at the time when increasing doses of tolvaptan were necessary to control hyponatremia. (C) CT scan nine months after the end of chemotherapy at a time when tolvaptan was not effective anymore, and one month later (D) when the patient had beginning signs of liver failure and died shortly after that. In all images, the pancreas is marked with an X.
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case_images: A CT scan of the thorax and abdomen revealed new nodules in the lung (not shown), multiple lesions in the liver, and one lesion in the pancreas ( Figure 2A ). We registered a peak copeptin value of 19'830 pmol/l ( Figure 4 ), and repeated CT scans showed further progression of the metastatic SCLC ( Figure 2B-D ).
case_images: Start of tolvaptan: Serum sodium, urine osmolality, urine output, and volume/solute management. Summary of critical data before and after the start of tolvaptan. Within a few hours after the first dose of tolvaptan, the urine volume increased, paralleled by a drop in urine osmolarity from 813 to 50 mOsm/kg, and substitution of electrolyte-free water (glucose 5%) was started at a serum sodium concentration of 124 mmol/l to prevent too fast correction of hyponatremia.
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case_images: In September 2020, the patient had a urine osmolality of 813 mOsm/kg and did not respond sufficiently to urea and hypertonic saline solution (NaCl 3%) ( Figure 3 ). Serum sodium increased from 124 mmol/l to 134 mmol/l within 24 hours ( Figure 3 ).
case_images: Copeptin values and tolvaptan doses. The figure shows the dramatic increase in copeptin over time. Treatment with tolvaptan was started with a dose of 15 mg per day. We needed to rapidly increase the dose to a maximum of 120 mg per day.
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case_images: In the follow-up, increasing doses of tolvaptan - paralleled with a rapid increase of copeptin levels ( Figure 4 ) - were necessary to control hyponatremia. We registered a peak copeptin value of 19'830 pmol/l ( Figure 4 ), and repeated CT scans showed further progression of the metastatic SCLC ( Figure 2B-D ).