MRI and PET Guided Interstitial Brachytherapy for post-surgical vaginal recurrences of cervical cancer: Results of phase II study.

Abstract

AIM\nThis phase II study evaluated the utility of MRI and PET for planning radiation and brachytherapy in patients with post-surgical recurrence of cervical cancer.\n\n\nMETHODS\nThe study (NCT XXXXXXX) recruited patients with residual or recurrent disease after hysterectomy. Patients underwent baseline T2W MRI, 18 F-FDG, 18 F-FLT and 18 F-F Miso PET and received external radiation (50 Gy/ 25#/ 5 weeks) and weekly cisplatin (40mg/m2)). MRI was performed at brachytherapy and utilized for delineation of clinical target volume (CTV). While patients with parametrial disease at baseline received interstitial brachytherapy (16-20Gy/ 4-5#) those with vaginal disease received intra-cavitary brachytherapy (12-14 Gy/ 2-4#). Kaplan Meier Analysis was performed to evaluate loco-regional relapse, disease free and overall survival. CTCAE v4.1 was used for toxicity scoring and EORTC QLQC30 and Cx 24 for quality of life reporting.\n\n\nRESULTS\nBetween January,2011- February,2016 sixty patients were included of which 50 received study treatment. The mean gross tumour volume (GTV) on T2 W MR was 20 (IQR 3.6-90) cc. The metabolic tumour volume was 15 (IQR 2.1-56.1) cc. The median FLT volume was 10 (IQR 0-48) cc. A total of 8 patients had 18-F F Miso uptake. The median CTV at brachytherapy was 38(12- 85) cc. The median CTVD90 and D 98 was 71 (53-74) and 74 (53-74) Gy. At a median follow up of 60 (5-93) months, the 5-year local control, disease free and overall survival were 84%, 73% and 74.5% respectively. Grade III and IV proctitis and cystitis were observed in 4% and 2% patients. On multivariate analysis baseline tumour volume, on T2 W MR impacted disease free (91% vs 65%, p=0.03) and overall survival (96% vs 77%, p=0.06).\n\n\nCONCLUSION\nImage guided assisted radiation and brachytherapy is associated with good to excellent local control and survival in patients with vaginal recurrences of cervical cancer.