Late rectal toxicity determined by dose-volume parameters in computed tomography-based brachytherapy for locally advanced cervical cancer.

The aim of this study was to observe the relationship between dose-volume histogram (DVH) parameters and rectal late side effects (LSE) in computed tomography (CT)-based brachytherapy (BT) for patients with locally advanced cervical cancer. In total, 144 cervical cancer patients received external beam radiotherapy and CT-based BT. The data from 111 survival cases with pelvic local control (LC) were used to analyze the relationship between DVH parameters and rectal LSE. The total doses, manifesting 2, 1, and 0.1 cm(3) (D2cc , D1cc , and D0.1cc ) of the rectum, and D90 for high-risk clinical target volume (HR CTV) were computed and normalized to 2 Gy fractions (EQD2) using a linear-quadratic model. The rectal LSE were evaluated by the late effects in normal tissues-subjective, objective, management, and analytic (LENT-SOMA) scale. A dose-response relationship was evaluated by probit analyses. For all patients, the total rate of rectal LSE was 56%, and the rate of ≥Grade 2 LSE was 27.4%. For the 111 survival cases with pelvic LC, the total mean for D2cc was 71.23 ± 5.54 Gy for the rectum, and the D2cc , D1cc , and D0.1cc values for Grades 2 and 3 were higher than those for Grades 0 and 1. In addition, the number of complications increased, and the complications became more severe as the dose increased, with a dose of 73.5 Gy resulting in a 10% probability of ≥Grade 3 LSE. In conclusion, DVH parameters could predict the incidence and grades of rectal LSE in CT-based BT. D2cc showed an excellent predictive value, and 73.5 Gy for D2cc of the rectum might be considered as an alternative dose limit.

Determination of an optimal standardized uptake value of fluorodeoxyglucose for positron emission tomography imaging to assess pathological volumes of cervical cancer: a prospective study.

PURPOSE: To determine the optimal standardized uptake value (SUV) of (18)F-fluorodeoxyglucose ((18)F-FDG) for positron emission tomography (PET) imaging, at which the PET-defined gross tumor volume (GTVPET) best matches with the pathological volume (GTVPATH) in the cervical cancer. MATERIALS AND METHODS: Ten patients with the cervical cancer who underwent surgery were enrolled in this study. The excised specimens were processed for whole-mount serial sections and H-E staining. The tumor borders were outlined in sections under a microscope, histopathological images were scanned and the GTVPATH calculated. The GTVPET was delineated automatically by using various percentages relative to the maximal SUV and absolute SUV. The optimal threshold SUV was further obtained as the value at which the GTVPET best matched with the GTVPATH. RESULTS: An average of 85 ± 10% shrinkage of tissue was observed after the formalin fixation. The GTVPATH was 13.38 ± 2.80 cm(3) on average. The optimal threshold on percentile SUV and absolute SUV were 40.50% ± 3.16% and 7.45 ± 1.10, respectively. The correlation analysis showed that the optimal percentile SUV threshold was inversely correlated with GTVPATH (p<0.05) and tumor diameter (p<0.05). The absolute SUV was also positively correlated with SUVmax (p<0.05). CONCLUSION: The pathological volume could provide the more accurate tumor volume. The optimal SUV of FDG for PET imaging by use of GTVPATH as standard for cervical cancer target volume delineation was thus determined in this study, and more cases are being evaluated to substantiate this conclusion.

Clinical outcome observation of preoperative concurrent chemoradiotherapy/radiotherapy alone in 174 Chinese patients with local advanced cervical carcinoma.

OBJECTIVE: To study outcomes of concurrent chemoradiotherapy (CCRT) or radiotherapy (RT) alone followed by radical surgery in patients with local advanced cervical cancer. METHODS: A retrospective approach was carried out in 174 Chinese patients with International Federation of Obstetricians and Gynaecologists stage IB2-IIIB cervical carcinoma. A total of 121 patients were treated with CCRT, while the remaining 53 patients received RT alone, and the regimen of chemotherapy was weekly cisplatin (40 mg/m2). Pathological response, overall survival (OS), progression-free survival (PFS), and complications were analyzed. RESULTS: The median age was 45 years and the mean primary tumor diameter was 4.8 ± 1.0 cm. Pathological complete response (CR) was achieved in 53 patients (30.5%). The CR rate was relatively higher in the CCRT group (31.4% vs 28.3%, P = 0.724), particularly when tumor diameter was less than 5 cm (38.2% vs 30.8%, P = 0.623). With median follow-up of 24 months, patients with CR had improved 3-year OS (100% vs 83.6%, P = 0.018) and 3-year PFS (93.1% vs 83.2%, P = 0.035) compared to patients with residual disease. CCRT was associated with significantly improved 3-year PFS (92.0% vs 76.5%, P = 0.032) compared to RT alone in patients with tumor diameter less than 5 cm. Thirty-seven patients (21.3%) experienced more than grade 2 toxicity, and one patient (0.6%) developed grade 3 uronephrosis. Data thus indicated that pathologic response, tumor size, and lymph-node involvement were highly correlated with clinical outcomes of the local advanced cervical disease. CONCLUSION: Preoperative CCRT achieved outcomes superior to RT alone, depending on the pathologic response, tumor size and lymph-node involvement as major prognostic factors.