Clinical and dosimetric predictors of late rectal bleeding of prostate cancer after TomoTherapy intensity modulated radiation therapy.

INTRODUCTION: Rectal bleeding after radiotherapy impacts the quality of life of long-term surviving prostate cancer patients. We sought to identify factors associated with late rectal bleeding following intensity modulated radiation therapy (IMRT) using TomoTherapy for prostate cancer. METHODS: We retrospectively analysed 82 patients with localised prostate cancer treated with TomoTherapy. Most patients (95.1%) received neoadjuvant and concurrent hormone therapy. Forty-two patients (51.2%) graded as high risk using D'Amico's classification underwent radiotherapy involving the pelvic nodal area. Late bleeding complications were quantified using the Common Terminology Criteria for Adverse Events v4.0. Multiple clinical and dosimetric factors were considered with reference to rectal bleeding. RESULTS: The median follow-up period was 538 (range, 128-904) days. Grades 1, 2 and 3 rectal bleeding were observed in 14 (17.1%), four (4.9%) and one (1.2%) patient respectively. In multivariate analysis, the following factors were significantly associated with Grade ≥1 late rectal bleeding: volume, mean dose (P = 0.012) and rectal V30 (P = 0.025), V40 (P = 0.011), V50 (P = 0.017) and V60 (P = 0.036). When exclusively considering Grade 2-3 rectal bleeding, significant associations were observed with the use of anticoagulants or antiaggregates (P = 0.007), rectal V30 (P = 0.021) and V40 (P = 0.041) in univariate analysis. CONCLUSIONS: Our results suggested that the intermediate rectal dose-volume (V30-V60) was a significant predictor for mild to severe late rectal bleeding (Grade ≥1). Rectal dose-volumes >V70, which represented the volume of the highest doses, were not predictive in this study.

Definitive chemo-radiotherapy for squamous cell carcinoma of the pharynx: impact of baseline low hemoglobin level (<12 g/dL) and post-radiation therapy F-18 FDG-PET/CT.

OBJECTIVE: To identify reliable predictors of overall survival (OS), locoregional control (LC), and metastasis-free survival (MFS) after definitive concurrent chemo-radiotherapy (CCRT) for squamous cell carcinoma (SCC) of the pharynx (nasopharynx, oropharynx and hypopharynx), we examined 16 potential prognostic factors, including pre-treatment hemoglobin level and pre- and post-treatment [(18)F]fluorodeoxyglucose positron emission tomography CT (F-18 FDG-PET/CT) maximum standardized up-take values (SUVmax) of primary sites and lymph node (LN) regions. METHODS: We retrospectively reviewed records of 70 patients treated with definitive CCRT for pharyngeal cancer in our institution during July 2006-April 2012, with particular regard to 16 prognostic factors: age, sex, T stage, N stage, retropharyngeal LN (RPLN) involvement, existence of multiple primary cancer, treatment interruptions, overall treatment time, chemotherapy type, pre-treatment hemoglobin level, pre-treatment body mass index, enteral feeding period, and pre- and post-treatment F-18 FDG-PET/CT SUVmax of primary site and LN region. All patients in our cohort underwent pre- and post-treatment F-18 FDG-PET/CT. RESULTS: Multivariate analysis associated improved OS with pre-treatment hemoglobin level (≥12 g/dL; hazard ratio [HR] 3.902; 95 % confidence interval [CI] 1.244-12.236; P = 0.020) and post-treatment SUVmax (primary site) (SUVmax <5.00; HR 4.237; 95 % CI 1.072-16.747; P = 0.039). Improved LC was associated with pre-treatment hemoglobin level (≥12 g/dL; HR 2.983; 95 % CI 1.123-7.920; P = 0.028), and post treatment SUVmax (primary site) (SUVmax <5.00; HR 5.233; 95 % CI 1.582-17.309; P = 0.007). No variable was found to be significant for improved MFS. CONCLUSIONS: Significant predictors for outcome in pharyngeal SCC treated with definitive CCRT were pre-treatment baseline hemoglobin level and post-treatment F-18 FDG-PET/CT SUVmax for primary site. Patients who have hemoglobin level lower than 12 g/dL may tend to have dismal prognosis. Additional treatment should be considered in those who have higher SUVmax at primary site in post-treatment F-18 FDG-PET/CT finding.