The inverse square law: A basic principle in brachytherapy.

The purpose of this article is to remind the importance of the inverse square law in radiotherapy and especially in brachytherapy. Indeed, beyond the impact in radiation therapy with high energy beam, there is the use of radionuclides and low energy photons with short FSD where it is still more important. Comparisons between Iridium Brachytherapy and low energy X-rays brachytherapy show equivalent dose distributions in the first few centimeters.

Organ or sphincter preservation for rectal cancer. The role of contact X-ray brachytherapy in a monocentric series of 112 patients.

Background: Contact X-ray brachytherapy (CXB) has been used at Centre Antoine Lacassagne since 2002 to increase the chance of conservative treatment (organ or sphincter preservation) in rectal cancer. A consecutive series of 112 patients (pts) is reported.

Methods: Three protocols were used in selected rectal adenocarcinomas.

Combination of phosphotidylinositol-3-kinase targeting with cetuximab and irradiation: A preclinical study on an orthotopic xenograft model of head and neck cancer.

Background: The purpose of this study was to investigate the effects of combining the phosphotidylinositol-3-kinase (PI3K) inhibitor buparlisib (BKM)120 with the anti-epidermal growth factor receptor (EGFR) agent cetuximab and radiotherapy (RT) on an orthotopic model of head and neck squamous cell carcinoma (HNSCC).

Methods: We evaluated the antitumor efficacy of BKM120, cetuximab, and RT, administered alone or in combination, using the human PIK3CA-mutated HNSCC cell line, CAL33, injected into the floor of the mouth of nude mice.

Results: Compared with control, the BKM120-cetuximab and the BKM120-cetuximab-RT combinations led to the highest tumor inhibition (p < .

Assessment and quantification of patient set-up errors in nasopharyngeal cancer patients and their biological and dosimetric impact in terms of generalized equivalent uniform dose (gEUD), tumour control probability (TCP) and normal tissue complication probability (NTCP).

Objective: The aim of this study is to assess and quantify patients' set-up errors using an electronic portal imaging device and to evaluate their dosimetric and biological impact in terms of generalized equivalent uniform dose (gEUD) on predictive models, such as the tumour control probability (TCP) and the normal tissue complication probability (NTCP).

Methods: 20 patients treated for nasopharyngeal cancer were enrolled in the radiotherapy-oncology department of HCA. Systematic and random errors were quantified.