Outcomes of MR interstitial hybrid brachytherapy in Carcinoma Cervix with novel commercial intravaginal template – initial results from an Indian cancer center
Harjot Kaur Bajwa, Rajesh Natte, Sushil Beriwal, Suresh ChaudhariABSTRACT
Purpose:
To analyze the outcomes in carcinoma cervix patients treated with MR interstitial brachytherapy using the novel intravaginal template (Aarhus) applicator. The applicator has a vaginal template with channels for straight and oblique needles. There is no published outcome data using this applicator.
Materials and Methods:
Patients diagnosed with carcinoma cervix and treated with MR hybrid brachytherapy were retrospectively analyzed. The parameters analyzed were tumor response at 3 months, local control and toxicity.
Results:
Forty-four patients were included in the analysis. The most common stage was International Federation of Gynecology and Obstetrics (FIGO) stage IIB. All patients received definitive EBRT (external beam radiotherapy) (45–50 Gy). MRI (magnetic resonance imaging) was done before EBRT and at brachytherapy with an Aarhus applicator using 32 mm vaginal template. The median number of needles used was 5. The prescribed dose was 7–8 Gy in 3–4 fractions. The mean dose to 98% gross tumor volume (GTV) at brachytherapy (D98 GTV BT ) was 100.8 Gy (109.6-93.7 IQR). The mean HRCTV (high-risk clinical target volume) was 29.8cc (16-73.7cc). The mean dose to 90% CTV HR (D90 CTV HR ) was 89.9 Gy (93.6-85.9 IQR). The D2cc to bladder, rectum, and sigmoid were 75.1 Gy, 59.7 Gy and 62.2 Gy, respectively. Besides, 42 (95%) patients had a complete response at 3 months. At a median follow-up of 22 months, the crude local control rate was 95%. The most common toxicity was Grade 2 GI toxicity. The incidence of late grade 3 GI toxicity was 4.5%. None of the patients had late Grade 4 GI or Grade 3 and above GU toxicity.
Conclusion:
MR brachytherapy using a hybrid intra-vaginal template in carcinoma cervix resulted in good local control with minimal toxicities in our population.