Fig. 4

Two representative complete remission (CR) patients with oligometastases in stage IV. The first CR patient in stage IV is shown in a-g. A male in his 50s presented with dyspnea, and bilateral malignant pleural and pericardial effusions were observed on the chest X-ray (a) and the CT (b). He was diagnosed as stage IVA (cT1aN2M1a) adenocarcinoma. After pericardial drainage followed by chemotherapy, the pleural and pericardial effusions disappeared (c). He complained of left femoral pain, and bone scintigraphy revealed bone metastases in the left femoral bone and left hip joint (d). After radiation therapy, he underwent joint replacement surgery. The primary lesion, located in the right upper lobe, showed gradual enlargement (e) and was surgically removed (f). The CR has since been maintained, based on head MRI and PET/CT (g). The second patient with brain metastases achieving CR is shown in h-o. A male in his 30s consulted our hospital due to loss of consciousness. A tumor was detected in the right upper lobe (h, i). There was no lymph node swelling, while a solitary brain metastasis was observed in the right temporal lobe (j). He was diagnosed as stage IVA (cT2aN0M1b) large cell carcinoma. Cyber-knife therapy for this lesion and surgery for the primary lesion were performed. After 4 courses of a first-line chemotherapy, three new brain metastases were detected in the left cerebellum, the right occipital lobe, and the left parietal lobe by head MRI. Cyber-knife treatments for these lesions were done. He subsequently complained of headache. Brain metastases in the left occipital lobe (k), the left cerebellum, and the right occipital lobe (l) were demonstrated by head MRI. Brain surgeries were performed for these lesions. The brain tumors and the lung tumor ultimately disappeared, as shown by the head MRI (m, n) and the PET/CT (o)