1. Department of Dermatology Venereology and Allergology University Hospital “Dr. Georgi Stranski” Faculty of Medicine Medical University Pleven Bulgaria
2. Department of Medical Oncology and Radiotherapy Oncology Diseases Hospital (SHATOD) “Dr. Marko Markov” Varna Bulgaria
3. Surgical Oncology Department University Hospital “Dr. Georgi Stranski” Faculty of Medicine Medical University Pleven Bulgaria
4. Department of Nuclear Medicine Radiation Therapy and Medical Oncology University Hospital “Tsaritsa Yoanna” Faculty of Medicine Medical University Sofia Bulgaria