ObjectivesTo investigate the safety and outcomes of elective para-aortic (PA) nodal irradiation utilizing modern treatment techniques for patients with node positive cervical cancer.MethodsPatients with pelvic lymph node positive cervical cancer who received radiation were included. All patients received radiation therapy (RT) to either a traditional pelvic field or an extended field to electively cover the PA nodes. Factors associated with survival were identified using a Cox proportional hazards model, and toxicities between groups were compared with a chi-square test.Results96 patients were identified with a mean follow up of 40 months. The incidence of acute grade ≥ 2 toxicity was 31% in the elective PA nodal RT group and 15% in the pelvic field group (Chi-square p = 0.067. There was no significant difference in rates of grade ≥ 3 acute or late toxicities between the two groups (p>0.05). The KM estimated 5-year OS was not statistically different for those receiving elective PA nodal irradiation compared to a pelvic only field, 54% vs. 73% respectively (log-rank p = 0.11).ConclusionsElective PA nodal RT can safely be delivered utilizing modern planning techniques without a significant increase in severe (grade ≥ 3) acute or late toxicities, at the cost of a possible small increase in non-severe (grade 2) acute toxicities. In this series there was no survival benefit observed with the receipt of elective PA nodal RT, however, this benefit may have been obscured by the higher risk features of this population. While prospective randomized trials utilizing a risk adapted approach to elective PA nodal coverage are the only way to fully evaluate the benefit of elective PA nodal coverage, these trials are unlikely to be performed and instead we must rely on interpretation of results of risk adapted approaches like those used in ongoing clinical trials and retrospective data.

Purpose: For cervical brachytherapy planning, magnetic resonance imaging (MRI) is preferable to computed tomography (CT) for target delineation. However, due to logistical and financial restrictions, in-room MRI is sometimes not routinely available in brachytherapy centers. Our institution has created a workflow that integrates MRI-based target delineation with an in-room CT scanner, with the aim of improving target coverage and conformality. This study reports the initial dosimetric results with using this workflow. Material and methods: A retrospective review was performed on 46 consecutive patients who received definitive chemoradiation with 5 fraction intracavitary high-dose-rate (HDR) brachytherapy for cervical cancer. Fraction 1 was planned from CT only. Outpatient MRI was obtained after Smit sleeve placement and first insertion to assess concurrent chemoradiotherapy tumor response. This MRI was registered to the CT for planning fractions 2-5. The median prescription dose for the cohort was 25 Gy (range, 25-29 Gy). Results: The D 90 to the high-risk clinical target volume (HR-CTV) and D 2cc rectal dose were increased from fraction 1 to fraction 2-5 averaged (p < 0.05). Among the 18 patients with complete volumetric data, there was no significant difference in HR-CTV size, with an average decrease of 1.73 cc (p > 0.05) with MRI fusion. Eleven out of 18 patients had changes in high-risk target volume greater than 20%, with an absolute average change in volume of 31.5%. Conclusions: The use of asynchronous MRI for target delineation, with co-registration to CT for each fraction of brachytherapy was associated with higher D 90 to the HR-CTV. We observed slightly higher D 2cc rectal doses with MRI, but cumulative rectal doses were within accepted thresholds. High-risk target volumes were not consistently increased or decreased, but MRI fusion was associated with target volume changes greater than 20% in over half of the treated patients.