Comparative benefit of interstitial needles in addition to intracavitary applicators in the treatment of locally advanced cervical cancer

Autor: Deidre Batchelar, Francois Bachand, Danielle Sherin, Juanita Crook, Jocelyn Moore, Dorothy Chilambe Lombe, Tracey Rose
Rok vydání: 2019
Předmět:
Zdroj: Journal of Clinical Oncology. 37:5528-5528
ISSN: 1527-7755
0732-183X
Popis: 5528 Background: Cervical cancer is the leading cause of cancer mortality of women in Low and Middle Income Countries (LMIC). Interstitial needles (IN) have improved outcomes but the resources required in comparison to intracavitary brachytherapy (IC) alone has impeded uptake in endemic regions. We conducted a retrospective review of the utilisation of IN in the management of locally advanced cervical cancer and simulated 2D planning by loading the applicators using standard Manchester loading (ML) to explore the magnitude of benefit that interstitial needles provide. Methods: 72 brachytherapy plans of 18 patients who had undergone treatment using tandem and ring and had interstitial brachytherapy between 04/2016 and 10/2018 were reviewed. ML plans prescribed to point A were generated to represent a 2D scenario but the known HR-CTV was taken into consideration and its dosimetric outcomes were compared to those of the 3D based plans. Results: The median tumour volume was 23 cm3. IN was used in 82 % of the insertions. The median number of IN was 2 (range 0 – 6) with median percentage of IN dwell time 6.6 % (range 0.68 – 38.5). V100 was excellent 98.2% for ML 97.3% for 3D IN and 98.7% for 3D non-IN plans. The median HRCTV D90 was 8.5 Gy/fraction (cumulative EQD210101.4 Gy) for ML plans and 8.0 Gy/fraction (cumulative EQD210 91.4 Gy) for 3D plans. The ML plans failed to meet the OAR goals except for the rectum, which was optimally distanced by the rectal paddle. The median bladder, sigmoid and small bowel doses were 24% above the recommended constraint in the individual plans and 15% cumulative EQD2. A statistically significant relationship was found between the number of needles utilised, tumour volume (p < 0.001) and coverage (p = 0.006) but not delivered dose (p < 0.068). Conclusions: 2D brachytherapy can provide adequate dose coverage for most tumours but IN provide a benefit in reducing the doses to OARs in a significant number of patients. This justifies investment in resources for uptake of interstitial needles to increase access to optimal treatment of cervical cancer for women in LMIC. This research was made possible an ASCO Conquer Cancer Foundation grant.
Databáze: OpenAIRE