MRI-guided adaptive brachytherapy for locally advanced cervix cancer: Treatment outcomes from a single institution in Hong Kong.

BACKGROUND: Paradigm has shifted from 2D to image-guided adaptive brachytherapy (IGABT) for locally advanced cervix cancer (LACC). Increasing reports from pioneering institutions and large retrospective multicenter series have demonstrated improvements in outcome and reduction in toxicity with IGABT. However, there is scarcity of data on magnetic resonance (MR)-IGABT in Chinese patients. PURPOSE: To evaluate the clinical outcome of MR-IGABT for LACC in a single institution in Hong Kong. MATERIAL AND METHODS: Patients with FIGO stage IB-IVA LACC treated with definitive external beam radiotherapy +/- concurrent cisplatin followed by MR-IGABT from January 2015 to January 2018 were included. Brachytherapy planning and dose reporting followed the GEC-ESTRO recommendations. Dosimetric and clinical outcomes including local control (LC), pelvic control (PC), cancer-specific survival, overall survival (OS), and toxicity were analyzed. RESULTS: Forty-two consecutive patients were included. 71% were FIGO stage IIB or above; 52% had pelvic node involvement. Median high-risk clinical target volume (HRCTV) was 34.7 cm3 (12.3-155.1 cm3). Median dose to HRCTV D90 was 88.5 Gy (63.4-113.4 Gy) (EQD210). Median doses to the D2cc of bladder, rectum, sigmoid, and small bowel were 83.1 Gy, 67.5 Gy, 69.0 Gy, and 68.9 Gy (EQD23), respectively. Median followup was 20.3 months (4.0-35.1 months). 24-month actuarial LC, PC, cancer-specific survival, and OS were 90%, 84%, 90%, and 90%, respectively. Stratification by clinical variables showed that FIGO stage had significant impact on LC and dose to HRCTV on both LC and PC. Treatment was well tolerated without any severe late toxicity. CONCLUSIONS: Intermediate-term results from systematic MR-IGABT for LACC demonstrate very promising outcomes with minimal toxicity. This fills the gap in evidence for MR-IGABT in Chinese patients.

An analysis of the efficacy of serial screening for familial nasopharyngeal carcinoma based on Markov chain models.

Treatment of nasopharyngeal carcinoma (NPC) can be improved by early detection of the disease as treatment outcome worsens with disease's progression. This can be achieved with a mass screening program using Epstein Barr virus (EBV) serology and nasopharyngoscopy. The efficacy of any screening strategy should be evaluated before putting it into practice. Such evaluation is ideally performed with simulation as time and cost often preclude the evaluation by randomized trial. This study simulated and compared the outcomes of 4 screening strategies over a period of 12 years: (A) Annual screening, (B) biennial screening, (C) triennial screening, and (D) triennial screening for participants tested EBV negative and annual screening once the participants are tested EBV positive. Progression of the disease was divided into 4 phases and calculated by applying Markov chain model. Parameters of the transition matrix and probabilities were estimated using data from previous screening results of 1,072 family members of NPC patients. The early detection rates with strategies A, B, C and D are 88, 79, 71 and 87% respectively. The 5-year overall survival with screening is 10-12% higher than that without and is the highest with strategies A and D. Strategy D, however, requires only 64% screening tests compared with strategy A and has almost identical resultant disease stage distribution to strategy A. We concluded that strategy D offered the highest efficacy for NPC screening of family members of NPC patients among the four strategies studied.

Outcomes of nasopharyngeal carcinoma screening for high risk family members in Hong Kong.

We undertook a large retrospective study to evaluate the impact of screening family members of NPC patients with Epstein Barr Virus (EBV) serology. 1,199 asymptomatic family members of NPC patients were entered into the annual screening program with EBV serology and nasopharyngoscopy between 1994 and 2005. Eighteen participants of our screening program developed NPC; 17 of them were treated in our institute, of whom 16 were detected in screening. The sensitivity and specificity of EBV serology were 83.3 and 87.0%, respectively, and for the program they were 88.9 and 87.0%, respectively. Stage distributions and survival outcomes of the 17 cases were compared with that of 1,185 consecutive symptomatic patients diagnosed in the same period through general referral. It was found that the screening program resulted in early detection of cancer, with 59% presenting at early stage (stage I: 41%, stage II: 18%) compared to 24% (stage I: < 1%, stage II: 23%) of symptomatic cancers (P < 0.001), and a significant improvement in disease-free survival (P = 0.04). The cancer specific survival and overall survival rate at 5-year are also higher (92 vs. 77% and 92 vs. 70%, respectively), though they fail to reach statistical significance. In conclusion, screening asymptomatic family members of NPC patients annually leads to earlier detection of NPC and clinically valuable survival advantage among these family members. A larger sample size is needed to confirm its full potential in survival benefit.