Physiologic Reactions After Proton Beam Therapy in Patients With Prostate Cancer: Significance of Urinary Autoactivation
| Autor: | Yusuke Demizu, Masakazu Shimizu, Kazuro Sugimura, Hidenobu Sakamoto, Ryohei Sasaki, Masao Murakami, Daisuke Miyawaki, Yoshio Hishikawa, Hideki Nishimura, Daisaku Suga, Takashi Akagi |
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| Rok vydání: | 2009 |
| Předmět: |
Male
Cancer Research medicine.medical_specialty Urinary system Urinary Bladder Context (language use) Urine urologic and male genital diseases Prostate cancer Prostate Proton Therapy medicine Humans Radiology Nuclear Medicine and imaging Radiometry neoplasms Proton therapy Aged Aged 80 and over Radiation Urinary bladder medicine.diagnostic_test Phantoms Imaging business.industry Radiotherapy Planning Computer-Assisted Rectum Prostatic Neoplasms Femur Head Radiotherapy Dosage Middle Aged medicine.disease Tumor Burden medicine.anatomical_structure Oncology Positron emission tomography Positron-Emission Tomography Radiology Tomography X-Ray Computed business Nuclear medicine therapeutics Emission computed tomography Half-Life |
| Zdroj: | International Journal of Radiation Oncology*Biology*Physics. 75:580-586 |
| ISSN: | 0360-3016 |
| DOI: | 10.1016/j.ijrobp.2009.02.085 |
| Popis: | Proton therapy is a sophisticated treatment modality for prostate cancer. We investigated how physiologic factors affected the distribution of autoactivation as detected by positron emission tomography (PET) after proton beam therapy.Autoactivation was evaluated in 59 patients treated with a 210-MeV proton beam. Data acquisition for autoactivation by PET started 5 minutes after proton irradiation to assess activation. In the first 29 patients, five regions of interest were evaluated: planning target volume (PTV) center, urinary bladder inside the PTV, urinary bladder outside the PTV, rectum (outside the PTV), and contralateral femoral bone head (outside the PTV). In the remaining 30 patients, urine activity was measured directly. In a phantom study autoactivation and its diffusion after proton beam irradiation were evaluated with water or an ice block.Mean activities calculated by use of PET were 629.3 Bq in the PTV center, 555.6 Bq in the urinary bladder inside the PTV, 332.5 Bq in the urinary bladder outside the PTV, 88.4 Bq in the rectum, and 23.7 Bq in the femoral bone head (p0.001). Mean urine activity was 679.4 Bq, recorded 10 minutes after therapy completion, and the half-life for urine autoactivation was 4.5 minutes.Urine is a major diffusion mediator of autoactivation after proton beam therapy. Our results indicate that physiologic factors can influence PET images of autoactivation in the context of proton beam therapy verification. |
| Databáze: | OpenAIRE |
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