Study to Evaluate the Safety, Biodistribution, Radiation Dosimetry and Tumor Imaging Potential of [131I]-SGMIB Anti-HER2 VHH1 in Healthy Volunteers and Breast Cancer Patients

Inclusion Criteria:

Subjects will only be included in the study if they meet all of the following criteria:

* Subjects who have given informed consent
* Subjects that agree not to drink alcoholic beverages or use any drugs during the study
* Subject with blood parameters within normal ranges
* Age: at least 18 years old

Patients will only be included in the study if they meet all of the following criteria:

* Patients who have given informed consent
* Patients that agree not to drink alcoholic beverages or use any drugs during the study
* Age: at least 18 years old
* Patients with local, locally advanced or metastatic HER2+ breast carcinoma as diagnosed on biopsied tissue by immunohistochemistry or fluorescence in situ hybridization (FISH).

Exclusion Criteria:

Patients will not be included in the study if one of the following criteria applies:

* Pregnant patients
* Breast feeding patients
* Patients with occupational exposure to ionizing irradiation
* Patients with previous thyroid disorders
* Patients that received radiolabeled compounds with a long half-life (\>7h) for diagnostic or therapeutic purposes within the last 2 days.
* Patients with absolute contra-indications for thyroid blockage with potassium iodide.
* Patients with abnormal liver: ALT/AST \> 2 times normal values; bilirubin \> 1.5 time normal values.
* Patients with abnormal kidney function: \< 50 ml/min/1,73 m2
* Patients with recent (\< 1 week) gastrointestinal disorders (CTCAE v4.0 grade 3 or 4) with diarrhea as major symptom
* Patients with any serious active infection
* Patients who have any other life-threatening illness or organ system dysfunction, which in the opinion of the investigator would either compromise patient safety or interfere with the evaluation of the safety of the test radiopharmaceutical
* Patients who cannot communicate reliably with the investigator
* Patients who are unlikely to cooperate with the requirements of the study
* Patients at increased risk of death from a pre-existing concurrent illness
* Patients who participated already in this study
* Patients who participated in a previous trial with Anti-HER2 VHH1

Subjects will not be included in the study if one of the following criteria applies:

* Pregnant subjects
* Breast feeding subjects
* Subjects with occupational exposure to ionizing irradiation
* Subjects with clinical significant disease or on concomitant therapy (except contraception)
* Subjects with previous thyroid disorders
* Subjects that received radiolabeled compounds with a long half-life (\>7h) for diagnostic or therapeutic purposes within the last 2 days.
* Subjects with absolute contra-indications for thyroid blockage with potassium iodide.
* Subjects with abnormal liver: ALT/AST \> 2 times normal values; bilirubin \> 1.5 time normal values.
* Subjects with abnormal kidney function: \< 50 ml/min/1,73 m2
* Subjects with recent (\< 1 week) gastrointestinal disorders (CTCAE v4.0 grade 3 or 4) with diarrhea as major symptom
* Subjects with any serious active infection
* Subjects who have any other life-threatening illness or organ system dysfunction, which in the opinion of the investigator would either compromise subject safety or interfere with the evaluation of the safety of the test radiopharmaceutical
* Subjects who cannot communicate reliably with the investigator
* Subjects who are unlikely to cooperate with the requirements of the study
* Subjects at increased risk of death from a pre-existing concurrent illness
* Subjects who participated already in this study
* Subjects who participated in a previous trial with Anti-HER2 VHH1