Image-guided brachytherapy in cervical cancer: Experience in the Complejo Hospitalario de Navarra.

ABSTRACT

PURPOSE: To evaluate dosimetric and clinical findings of MRI-guided HDR brachytherapy (HDR-B) for cervical carcinoma. MATERIAL AND METHODS: All patients had a CT, MRI and pelvic-paraaortic lymphadenectomy. Treatment pelvic (+/-)para-aortic3D/IMRT radiotherapy (45 Gy), weekly cisplatin and HDR-B and pelvic node/parametrial boost 60 Gy until interstitial brachytherapy was done. Two implants 2008-2011 5 fractions of 6 Gy, 2011 2016, 4 fractions of 7 Gy. MRI/TAC were done in each implant. The following were defined GTV, CTH-HR, CTV-IR; OAR rectum, bladder and sigmoid. RESULTS: From 2007 to 2016 57 patients. Patients T1b2-T2a 4p, T2b 41p, T3a 2p; T3B 8p T4a 2p; N0 32p, N1 21p, no lymphadenectomy 4p. Median follow up 74.6 m (16-122 m), recurrence 5p local, 6p node, 9p metastasis and 37p without recurrence.Local control 5 years 90.1%; Ib2-IIB 94.8%, III-IVa 72.2%. (p0.01). RDFS 5y was 92.5%; IB2-IIB 93%, III 85% (p0.024); for pN0 100%; pN+ iliac-paraaortic 71.4% (p 0.007). MFS 5y was 84.1%. Overall survival (OS) at 5y 66.6% and the cancer specific survival (CEOS) was 74%. Univariate analysis survival stage Ib2-II 83% vs. III-IVa 41% (p = 0.001); histology squamous 78%, adenocarcinoma 59.7% (p ns); lymph node N0 85% vs. PA+P- 72%, and PA+P+ 35% (p = 0.010). In relation with HR-CTV dose > 85 Gy, CEOS 82.5% vs. 77%, and volume CTV-HR < 30 cc 81.8% and >30 cc 67%; p ns. Acute grade 2-3 toxicity rectal 15.7%, intestinal 15.7% and vesical 15.5%. CONCLUSION: Use of interstitial HDR-BQ guided by RM increased CTV-HR dose and local control, like EMBRACE results. Nodal boost improves RDFS and perhaps OS.