Long-Term Follow-up of a Randomized Controlled Trial on Accelerated Radiation Therapy Versus Standard Fractionated Radiation Therapy for Early Glottic Cancer (JCOG0701A3).

PURPOSE: We previously reported the primary results of JCOG0701, a randomized, multicenter, phase 3, noninferiority trial comparing accelerated fractionation (Ax) to standard fractionation (SF) for early glottic cancer. In the primary results, although the similar efficacy of 3-year progression-free survival and toxicity of Ax compared with SF was observed, the noninferiority of Ax was not confirmed statistically. To evaluate the long-term follow-up results of JCOG0701, we conducted JCOG0701A3 as an ancillary study of JCOG0701. METHODS AND MATERIALS: In JCOG0701, 370 patients were randomly assigned to receive SF of 66 to 70 Gy (33-35 fractions; n = 184) or Ax of 60 to 64.8 Gy (25-27 fractions; n = 186). The data cutoff date for this analysis was in June 2020. Overall survival, progression-free survival, and late adverse events including central nervous system ischemia were analyzed. RESULTS: With a median follow-up period of 7.1 years (range, 0.1-12.4), progression-free survival of the SF and Ax arms were 76.2% and 78.2% at 5 years and 72.7% and 74.8% at 7 years (P = .44). OS of the SF and Ax arms were 92.7% and 89.6% at 5 years and 90.8% and 86.5% at 7 years (P = .92). Among 366 patients with a protocol treatment, the cumulative incidence of late adverse events of the SF and Ax arms were 11.9% and 7.4% at 8 years (hazard ratio, 0.53; 95% CI, 0.28-1.01; P = .06). Central nervous system ischemia of grade 2 or higher was observed in 4.1% for the SF arm and 1.1% for the Ax arm (P = .098). CONCLUSIONS: After long-term follow-up, Ax showed comparable efficacy to SF and a tendency for better safety. Ax may be suitable for early glottic cancer because of its convenience in minimizing treatment time, cost, and labor.

Prediction of Results of Radiotherapy With Ku70 Expression and an Artificial Neural Network.

Background/Aim: Accurate prediction of radiotherapy results is indispensable for the individualized selection of treatment modalities of cancer. We examined the application of the artificial neural network (ANN) model in predicting radiotherapy results using clinical factors and immunohistochemical staining of Ku70 as inputs. Patients and Methods: We analyzed 79 prostate cancer patients with localized adenocarcinoma treated with radiotherapy between August 2001 and October 2010. We also analyzed 46 hypopharyngeal cancer patients with squamous cell carcinoma treated with radiotherapy between March 2002 and December 2009. The properly trained ANN analysis using a standard feedforward, back-propagation neural network was used to predict the radiotherapy treatment results. Results: The areas under the receiver-operating characteristic curve (AUC) were 0.939 for patients treated with intensity modulated radiotherapy (IMRT)+androgen deprivation therapy (ADT), 0.803 for IMRT alone, and 0.960 for 3D-conformal radiotherapy (CRT) alone in prostate cancer. Sensitivity and specificity were 85.7% and 90.4% for IMRT+ADT, 75.0% and 88.5% for IMRT alone, and 92.3% and 100% for 3D-CRT alone. The AUC was 0.901 for hypopharyngeal cancer. Sensitivity and specificity were 66.7% and 88.2%, respectively. Conclusion: We demonstrated a possibility to predict the radiotherapy treatment results in prostate and hypopharyngeal cancer using ANN in combination with Ku70 expression and clinical factors as inputs.

Evaluation of the urethral α/ß ratio and tissue repair half-time for iodine-125 prostate brachytherapy with or without supplemental external beam radiotherapy.

PURPOSE: To assess the correlation between postimplant dosimetric quantifiers and the genitourinary (GU) toxicity of low-dose rate brachytherapy for prostate cancer. METHODS AND MATERIALS: The minimum urethral dose (UD10, 30, and 90) and the percent volume of the urethra receiving the prescription dose (V100, V150) were calculated from the postimplant dose-volume histograms of 182 patients. We then calculated various urethral biologically equivalent doses (uBEDs) using different values of the α/ß ratio and tissue repair half-time (t1/2) and examined the correlations with GU toxicity. RESULTS: Common dosimetric quantifiers, such as UD90 (brachytherapy) + UD50 (external beam radiotherapy), showed no correlation with Grade ≥ 2 GU toxicity. There was a significant correlation between Grade ≥2 GU toxicity and uBED when the α/ß value was 0.5 or 1 Gy and t1/2 was 0.5-2.5 h. An uBED (α/ß = 1.0, t1/2 = 0.5) had the largest hazard ratio for GU toxicity, and it was also significantly correlated with Grade ≥ 2 GU toxicity according to multivariate analysis. CONCLUSIONS: We observed a significant correlation of uBED with GU toxicity when α/ß was 0.5 or 1.0 Gy and t1/2 was 0.5-2.5 h. As the simple formula we used has not been verified in basic experiments, more data are needed to validate our results.

Retrospective DVH analysis of point A based intracavitary brachytherapy for uterine cervical cancer.

Combining external beam radiotherapy (EBRT) with intracavitary brachytherapy (ICBT) is important for definitive treatment of cervical cancer. In cervical cancer patients receiving radiotherapy, we evaluated treatment outcomes in relation to dose-volume histogram parameters, including the computed tomography (CT)-based high-risk clinical target volume (HR-CTV) for ICBT. Between 2010 and 2015, 89 consecutive cervical cancer patients were mostly treated with 40 Gy of EBRT in 20 fractions and 18 Gy of ICBT prescribed to point A in 3 fractions. CT scans were obtained during ICBT. The HR-CTV D90 was calculated and the total doses of ICBT and EBRT were converted to the equivalent dose in 2 Gy fractions (EQD2). When the patients were divided into four groups according to EQD2 of the HR-CTV D90, the 3-year local recurrence-free survival rates were 95.2, 78.4, 52.7 and 42.9% for patients receiving >80 , 70-80 , 60-70 and <60 Gy, respectively. There was a significant negative correlation between EQD2 of the HR-CTV D90 and the HR-CTV volume at first ICBT (r = -0.713). Local recurrence was more frequent when the HR-CTV volume was ≥22 cc and EQD2 of the HR-CTV D90 was <70 Gy. Multivariate analysis showed that EQD2 of the HR-CTV D90 and concurrent chemotherapy (≥4 cycles) were significant determinants of overall survival. HR-CTV D90 was an important prognostic indicator for local recurrence. HR-CTV D90 >70 Gy is required for the better local control, especially in patients with a larger HR-CTV (≥22 cc at initial ICBT).

Prediction of acute gastrointestinal and genitourinary radiation toxicity in prostate cancer patients using lymphocyte microRNA.

BACKGROUND: To search for novel biomarkers that can predict acute radiation toxicity, we conducted microRNA expression analysis of peripheral blood lymphocytes (PBLs). METHODS: The discovery cohort was 69 patients with localized adenocarcinoma of the prostate who received intensity-modulated radiation therapy between October 2007 and October 2010. The validation cohort was 72 patients treated with low-dose-rate brachytherapy between May 2008 and March 2014. After13 microRNAs were selected by TaqMan® Array analysis in a preliminary experiment, expression of these microRNAs in all samples was analyzed by RT-PCR. RESULTS: In the discovery cohort, the average prostate volume, the rectal volume receiving 70 Gy, and expression of miR-410 and miR-221 were significant risk factors for Grade 1-2 gastrointestinal toxicity. Receiver operating characteristic analysis showed that the area under the curve (AUC) was 0.807. The maximum dose to the urinary bladder, prostate volume, pretreatment urinary function score, and miR-99a and miR-221 expression were risk factors for Grade 2 genitourinary toxicity. The corresponding AUC was 0.796. In the validation cohort, reproducibility of these markers was confirmed for gastrointestinal toxicity, but not for genitourinary toxicity. CONCLUSION: Combining radiation dose parameters with microRNA expression in PBLs may be useful for predicting acute gastrointestinal toxicity of radiation therapy, thus contributing to personalized treatment of prostate cancer.