The esophageal squamous cell carcinoma (ESCC) has high prevalence and mortality in China, which become a severe challenge for public health. The molecular imaging technology has been developed for visualization and precise diagnosis of the tumors. Integrin αvβ3 is a specific marker for tumor. Noninvasive visualization and quantitative analysis of integrin αvβ3 expression provide new opportunities for tumor diagnosis, identification and efficacy monitoring. The peptide containing Arg-Gly-Asp (RGD) can specifically bind to integrin αvβ3 receptor with high selectivity and affinity to achieve the detecting tumor .The SPECT/CT with 99mTc-3PRGD2 has a high specificity in the diagnosis of mediastinal lymphnode metastasis and a greater value in the decision-making of lymphnode dissection.

This study is a single-center self-controlled study, It is planned to enroll 30 patients with esophageal cancer , preliminarily confirmed by endoscopic biopsy, . After intravenous injection of 0.3 mCi/kg of 99mTC-3PRGD2, patients underwent single-photon emission computed tomography/computed tomography (SPECT/CT) examination.Subsequently, the patients received chest/abdomen enhanced CT and 18F fluorodeoxyglucose (18F-FDG) positron emission computed tomography /CT (PET/CT) for diagnosis. According to the determination of the researcher, patients who were suitable for surgery received surgery to obtain surgical pathology; For patients who were not suitable for surgery, ultrasound-guided lyphnode biop was performed .In this study, pathological specimens were obtained from gastroscopy, surgical pathology, or ultrasound-guided lymph node biopsy. The diagnostic accuracy, sensitivity , specificity and safety of SPECT/CT with 99mTc-3PRGD2 were evaluated and compared with PET-CT and enhanced CT.

Screening period All patients will be during the screening screening assessment, specific include: the signing of the ICF, demographic data, drug allergy history and history, height, weight, physical examination, vital signs, electrocardiogram (ECG) examination, laboratory examination, blood pregnancy test records (if applicable), endoscopic biopsy, AE and drug combination, check into/standard. Qualified patients will enter the administration period after screening and confirmation. Administration period (from Administration to safety follow-up) day of administration (study day 1): before administration of the experimental drug, 12-lead ECG, laboratory test (fasting) and vital signs were measured. Subsequently, the experimental drug was injected intravenously at 0.3 ± 20% mCi/kg, and subjects underwent urination and SPECT/CT examination 40 min after administration. AE and combined medication were recorded. The next day after administration (day 2 of the study): 12-lead ECG, laboratory examination (fasting), vital signs were measured, AE and combined medication were recorded. Between the administration of 99mTc-3PRGD2 and the safety follow-up, the investigator determined that chest/abdomen enhanced CT and PET/CT were performed at an optional date.

Safety follow-up (day 14±2 of the study or before the next clinical intervention, whichever is shorter) :

12 lead ECG, laboratory test (fasting), measurement of vital signs, blood pregnancy (women of childbearing age only), AE and combined medication were recorded.Lymph node histopathology was obtained by surgery in patients suitable for surgery, and by ultrasound-guided lymph node biopsy in patients unsuitable for surgery.

Inclusion Criteria:

• Age ≥ 18 years
• Esophageal cancer was confirmed by Endoscopic biopsy
• Clinical laboratory tests (heart, liver, kidney, blood) and other indicators are in the normal range, or the abnormalities have no clinical significance (NCS), or the abnormalities have clinical significance (CS) but do not affect the implementation of surgery or lymph node puncture;
• The patient being able to follow scheduled visits, treatment plans and laboratory tests.

Exclusion Criteria:

• Female patients who plan to become pregnant within 6 months, or are pregnant or breastfeeding;
• Allergic to test drugs, allergic constitution or multiple drugs;
• Weight over 100 kg;
• Claustrophobia;
• Cannot tolerate both arms raised and supine for 15-30 minutes;
• The investigator considers it inappropriate to participate in this clinical trial;
• The patient participated in or participating in other clinical trials within the past 3 months.