Proton alone therapy is performed

-> 5 times a week, 7200 cGy / 15 fractions for 3 weeks total

This clinical trial is a prospective, single-organ, phase II clinical trial to evaluate the efficacy of curative proton therapy for pulmonary metastasis of colon cancer diagnosed histologically as adenocarcinoma.

Patients who meet the selection criteria should be selected, signed for consent, and treated 5 times a week for 7200 cGy / 15 fractions alone for 3 weeks.

Inclusion Criteria:

1. Histologically diagnosed colon adenocarcinoma in primary or metastatic lesions..
2. If there is no other remote metastasis other than lung, or if there is, control is possible
3. If there are less than 2 lung metastatic lesions
4. If they refuse lung surgery or surgery is inappropriate (medically unsuitable for surgery due to surgery refusal, diabetes mellitus, high blood pressure, pulmonary disease, heart disease, etc., repeated surgery, poor systematic function, short disease-free period, etc.)

Exclusion Criteria:

1. Other histologic cancer other than adenocarcinoma of the colorectal
2. Colorectal cancer without primary lesion resection
3. If there is another remote metastasis and is not completely resected or regulated
4. If the patient has experience of other invasive cancer diagnosis within 5 years of colorectal cancer diagnosis
5. Pregnancy and women under lactation