Advances in Physics Theories and Applications www.iiste.org ISSN 2224-719X (Paper) ISSN 2225-0638 (Online) Vol.25, 2013 76 The enhancement of prostate cancer treatment using gold nanoparticles and high energy photons Talib A. Abdulwahid 1 *, Imad K. Alsaberi 2 , Ali A. Abojassim 3 , B.A. Almayahi 4 1. Department of Physics, College of Science, University of Kufa, Iraq 2. Cancer Research Unit ,College of Medicine, University of Kufa, Iraq 3. Department of Physics, College of Science, University of Kufa, Iraq 4. Department of Environment, College of Science, University of Kufa, Iraq * E-mail of the corresponding author: taliba.jabir@uokufa.edu.iq Abstract Gold nanoparticles (AuNPs) are widely used for medical applications, because it ability to convert as colloidal solution, have no interaction with biotic tissue, low toxicity, easy in the detection, and thermally stabile. This study focuses on the treatment of prostate cancer by interaction the gamma ray (6 MeV) with Gold nanoparticles, without the extirpation of prostate. This method occurs in a minimum dose given for the patient for the improvement of radiotherapy that is used in prostate cancer treatment by depended on pair production phenomenon. Keywords: gold nanoparticles(AuNPs), gamma photons, prostate cancer, pair production. 1. Introduction The prostate gland sits in the pelvis, surrounded by the rectum, the bladder, and it is fixed to the bladder floor, the urethra communicates between the bladder and the prostate into the penis (Kantarjian et al. 2007). Prostate cancer is the most common cancer in men and the second after lung cancer leading cause of cancer death among men in the world (Jemal et al. 2010). In most men, the cancer grows slowly, many men with the disease will never know they had the condition. Early prostate cancer is confined to the prostate gland itself and the majority of patients can live for years with no problems (Christopher et al. 2010). This cancer is characterized by both grade and stage. The size and extent of the tumor determine its stage. The physician can be divided the treatment options according to risk (Christopher et al. 2010). Local treatment is composed of surgery and radiotherapy (External beam radiotherapy: EBRT or Brach therapy: BT). Systemic treatment is hormonal therapy (LHRH agonist or anti androgen) or systemic chemotherapy (Barrett et al. 2009). Radiotherapy consists of external beam radiotherapy (EBRT) and brachytherapy (BT). These treatments can be used as mono therapy or combined with each other. Radiotherapy can be used as radical treatment (EBRT or BT or both of them), adjuvant treatment after radical prostatectomy (EBRT) and palliative treatment (EBRT). Radiotherapy has been developed for a long time in giving the dose directly to the target lesion (prostate gland, seminal vesicles, and lymph nodes) (Bentzen et al. 2008 ). To increase the absorbed dose in cancer tumor inserting a material with a high atomic number (gold Z=79) locally in the region of the malignant cells (Hainfeld et al. 2008). In vivo this would be achieved by injecting gold nanoparticles. The injection of gold nanoparticles to enhance dose has already been proven to be viable using an animal model together with high energy photon beams (Hainfeld et al. 2004). Gold nanoparticles (AuNPs) are used in therapeutics because their unique properties of small size, high reactivity to the living cells, stability over high temperatures, and translocation into the cells (Pooja et al. 2011). AuNPs are the colloidal suspension of gold particles of nanometer sizes (Roa et al. 2009) .The size of AuNPs is determined by the gold salt concentration, temperature, and rate of addition of reactants resulting in size range of 10 nm to 25 nm (Grzelczak et al. 2008). Therapy combined with metallic nanoparticles is a new way to treat cancer, in which gold nanoparticles (AuNPs) are injected and bound to tumor sites. When an external photon-ray source hits these nanoparticles, particles can subsequently generate free radicals that damage cancer cells and induce cell apoptosis, AuNPs were used to enhance prostate cancer apoptosis by radiotherapy with little or no increase in harm to normal surrounding tissues (Liu et al. 2010). 2. Theoretical Calculations and Results Photons may undergo various possible interactions with atoms of an attenuator (photo electric effect, Compton scattering, and pair production). The probability (cross-section) for each interaction depends on the energy of the incident photon and on the atomic number Z of the matter. When the energy of photon 6 MeV and the attenuator