Development and validation of a practical score to predict 3-year distant metastatic free survival in nasopharyngeal carcinoma incorporating the number of lymph node regions.

INTRODUCTION: The improvement in diagnosis and treatment for nasopharyngeal carcinoma (NPC) has shifted the pattern of failure toward distant metastasis. This study aimed to develop a simplified prognostic scoring model to predict distant metastatic free survival (DMFS) for NPC patients. MATERIALS AND METHODS: Patients with non-metastatic NPC were identified from a retrospective cohort diagnosed between 2010 and 2018. Flexible parametric survival analysis was used to identify potential predictors for DMFS and establish a scoring model. The prognostic accuracy between the 8th AJCC system and the scoring model was compared using Harrell's C-index. RESULTS: Of the total 393 patients, the median follow-up time was 85 months. The 3-year DMFS rate was 83.3%. Gender, T-stage, pre-EBV (cut-off 2300 copies/ml), and the number of metastatic lymph node regions were identified as independent risk factors for distant metastasis and were included in the final scoring model. Our established model achieved a high C-index in predicting DMFS (0.79) and was well-calibrated. The score divided patients into two categories: low-risk (score 0-4) and high-risk (score 5-7), corresponding with the predicted 3-year DMFS of 96% and 64.5%, respectively. CONCLUSIONS: A feasible and applicative prognostic score was established and validated to discriminate NPC patients into low- and high-risk groups.

Postoperative radiotherapy timing, molecular subgroups and treatment outcomes of Thai pediatric patients with medulloblastoma.

INTRODUCTION: Medulloblastoma (MB) is the most common childhood malignant brain tumor worldwide. Recently, molecular classification was established and started to play a role in the management of MB; however, studies involving molecular defined MB in Southeast Asia have been limited. We aimed to describe, and correlate clinical characteristics and molecular subgroups with therapeutic outcomes of Thai pediatric patients with MB. MATERIALS AND METHODS: Pediatric MB patients treated at King Chulalongkorn Memorial Hospital in Thailand from 2006 to 2018 were recruited. Patients were classified by clinical characteristics into standard- and high-risk groups, which determined treatment regimen. Retrospectively, available tumor tissues were classified into 3 molecular subgroups using immunohistochemistry: 1) WNT, 2) SHH, and 3) non-WNT/non-SHH. The primary outcome was 5-year overall survival (OS). Risk factors associated with OS were analyzed using cox regression analysis. RESULTS: Fifty-three Thai pediatric patients with MB were enrolled. The median follow-up time was 60 months. The 5-year OS for all patients, and patients with standard-risk and high-risk were 74.2%, 76.3% and 71.4%, respectively. Tumor tissues of 24 patients were available, of which 23 could be molecularly classified. Two, one and 20 were in the WNT, SHH and non-WNT/non-SHH subtypes with 5-year OS of 100%, 100% and 78.9%, respectively. Using multivariate analysis, the interval of more than 8 weeks between surgery and radiotherapy was significantly correlated with a decrease in the 5-year OS. CONCLUSION: Interval between surgery and radiotherapy within 8 weeks was associated with good therapeutic outcomes among Thai pediatric patients with MB. Simplified molecular subtyping combined with clinical characteristics is practical in risk classification of patients with MB in institutes with limited resources.

Long-term results of hypofractionation with concomitant boost in patients with early breast cancer: A prospective study.

AIM: To report the long-term local control and survival of patients with early breast cancer who had hypofractionated whole breast irradiation with concomitant boost (Hypo-CB). METHODS AND MATERIALS: Between October 2009 and June 2010, 73 patients with early breast cancer (T1-3N0-1M0) who underwent breast conserving surgery were enrolled into the study. Thirty-six of these participants received 50 Gy of conventional irradiation in 25 fractions over 5 weeks to the whole breast with a sequential boost to the tumor bed with 10-16 Gy in 5-8 fractions (Conv-SEQ). The other 37 participants received a hypofractionated dose of 43.2 Gy in 16 fractions with an additional daily concomitant boost (CB) of 0.6 Gy over 3 weeks (Hypo-CB). RESULTS: At a median follow-up time of 123 months, ipsilateral local recurrence (ILR) was found in 3 participants, 1 of whom was in the hypofractionated group. All 3 ILR were true local recurrence (TR). There were no significant differences in the 10-year disease free survival (DFS) and 10-year overall survival rates (OS) between the conventional and hypofractionated groups (93.9% vs. 94.4%, p = 0.96 and 91.9% vs. 91.6%, p = 0.792, respectively). CONCLUSION: This study showed that the effectiveness, DFS and OS were comparable between hypofractionated whole breast irradiation with a CB and the conventional irradiation with a sequential boost.

Flattening filter free stereotactic body radiation therapy for lung tumors: outcomes and predictive factors.

BACKGROUND: Stereotactic body radiation therapy (SBRT) using flattening filter free (FFF) has been commonly used, however, its outcomes and predictive factors in lung tumors are limiting. Thus, we aim to assess the clinical outcomes of this approach and identify factors associated with outcomes in patients with early stage non-small cell lung cancer (NSCLC) and oligometastatic/oligoprogressive lung tumor (OLT). METHODS: Patients who underwent lung SBRT with FFF were retrospectively reviewed. All patients were delivered using volumetric modulated arc therapy (VMAT) technique. The primary outcome was local control (LC). The secondary outcomes were overall survival (OS) and toxicities. We assessed the association between LC and various factors in OLT. RESULTS: From February 2014 to July 2019, ninety-four patients and 129 lesions with median follow-up time of 30 months were included in the analysis. Twenty-six patients with 26 lesions were early NSCLC, while 68 patients with 103 lesions were OLT, 41.7% of which were from colorectal cancers (CRC) and 18.5% were from primary lung cancers. Two-year LC was 88.9% and 85.7% for early NSCLC and OLT, respectively. Two-year OS was significantly higher for early NSCLC than OLT (83.3% vs. 68.7%, P=0.035). In the multivariate analysis for OLT, CRC origin (hazard ratio, HR 10.59, 95% CI: 2.29-48.95, P=0.003) and gross tumor volume (GTV) mean BED10 ≤147 Gy (HR 5.16, 95% CI: 1.13-23.59, P=0.034) were significantly associated with higher local failure (LF). Most of the acute grade 1-2 toxicities were radiation pneumonitis (26.5%). No grade 3-5 event was observed. CONCLUSIONS: This study confirmed the clinical efficacy and safety of lung SBRT using FFF-technique. Our findings support the role of using a high BED10 regimen to achieve good LC for OLT and the potential role for dose escalation for primary CRC.