Effect of Irradiation Doses < 10 Gy and of Irradiated Bone Volume on the Variation of Blood Elements of the Complete Blood Count During and After Pelvic Irradiation

Patients will be identified as potentially eligible for inclusion once radiotherapy has been decided upon at the multidisciplinary consultation meeting. During the radiotherapy consultation, the study will be offered to the patient if they also meet the other inclusion criteria. As soon as the consent is signed and before the first radiotherapy session, a first biological check-up including a blood count and renal function will be performed. This biological investigation will serve as a reference.

During the dosimetric computer-tomography scan for radiotherapy, bony structures will be delineated, iliac bones, lower pelvis, femoral heads, lumbosacral spine and entire pelvis.

Dosimetry will be performed in the same way whether patients are included in the study or not, they will receive between 25Gy in 5 fractions and 78Gy in 39 fractions, depending on the primary tumor. The dose volume histograms will be received.

During treatment, patients will have a weekly blood test starting from the second week of treatment. At one months and three months after the end of the radiotherapy, patients will be seen in consultation and will also have a blood test.

For inclusion in the study, patients must be affiliated to the national or local social security, and must meet all the following criteria :

Inclusion criteria

• Patients must be ≥ 18 years old and < 80 years old
• Performance Status 0 to 2
• Histologically-confirmed diagnosis of : prostate cancer ; cervical cancer ; vaginal cancer ; endometrial cancer ; middle or low rectal cancer ; anal duct carcinoma
• At inclusion, patients must have : Haemoglobin > 10 g/dL ; Leucocytes 4.0-11.0 g/L ; Neutrophils 1.5-7.7 g/L ; Platelets 150-400 g/L
• Signed informed consent from the patient

Exclusion criteria

• History of haematologic disorders, leucopathia or imune system diseases
• At inclusion, patients must not have : Haemoglobin < 10 g/dL or > 18 g/dL (men) > 16 g/dL (women) ; Leucocytes < 4.0 or > 11.0 g/L ; Neutrophils < 1.5 or > 7.7 g/L ; Platelets < 150 or > 400 g/L
• Patients previously treated with radiation therapy or with chemotherapy
• Patients with metastatic cancer
• Patients presenting tumor classified histologically as sarcomatoid
• Patients placed under judicial protection, guardianship, or supervision
• Women that are pregnant or breast-feeding