Inger-Karine Kolkman-Deurloo

Prospective evaluation of AI-based BiCycle autoplanning for advanced cervical cancer brachytherapy

Rule-based AI BiCycle autoplanning compared favorably with manual planning in retrospective planning studies. In this study, we prospectively evaluated BiCycle's 'real life' impact by running it in parallel to current manual planning. Apart from dosimetric evaluations, treating physicians scored plans, and planning times were recorded. Following clinical routine, in each brachytherapy fraction, an RTT manually generated a plan which was then optionally adjusted by the treating physician, yielding the Man_Adj plan that was delivered. After treatment, a plan was automatically generated using BiCycle, followed by optional adjustment by the treating physician in the clinical TPS (Auto_Adj plan). Man_Adj and Auto_Adj plans were mutually compared and all planning time recorded. Physicians scored plan quality differences. For 28 of 37 evaluated fractions, the treating physician scored a higher quality for the Auto_Adj plan, in 7 fractions there was parity, and for 2 fractions Man_Adj was preferred. With comparable CTV For 95% of fractions, the treatment plan based on autoplanning was either preferred by the involved physician (76% of fractions) or considered similar in quality as the clinical plan (19%). Planning time reduced from 44.1 min for the manual workflow to 9.4 min. The system has recently been clinically introduced, following with the EU Medical Device Regulation.

Automated planning of curved needle channels in 3D printed patient-tailored applicators for cervical cancer brachytherapy

Abstract Purpose. Patient-tailored intracavitary/interstitial (IC/IS) brachytherapy (BT) applicators may increase dose conformity in cervical cancer patients. Current configuration planning methods in these custom applicators rely on manual specification or a small set of (straight) needles. This work introduces and validates a two-stage approach for establishing channel configurations in the 3D printed patient-tailored ARCHITECT applicator. Methods. For each patient, the patient-tailored applicator shape was based on the first BT application with a commercial applicator and integrated connectors to a commercial (Geneva) intrauterine tube and two lunar ring channels. First, a large candidate set was generated of channels that steer the needle to desired poses in the target region and are contained in the applicator. The channels’ centrelines were represented by Bézier curves. Channels running between straight target segments and entry points were optimised and refined to ensure (dynamic) feasibility. Second, channel configurations were selected using geometric coverage optimisation. This workflow was applied to establish patient-tailored geometries for twenty-two patients previously treated using the Venezia applicator. Treatment plans were automatically generated using the in-house developed algorithm BiCycle. Plans for the clinically used configuration, T P clin , and patient-tailored configuration, T P arch , were compared. Results. Channel configurations could be generated in clinically feasible time (median: 2651 s, range 1826–3812 s). All T P arch and T P clin plans were acceptable, but planning aims were more frequently attained with patient-tailored configurations (115/132 versus 100/132 instances). Median CTVIR D 98 and bladder D 2 c m 3 doses significantly improved ( p < 0.001 and p < 0.01 respectively) in T P arch plans in comparison with T P clin plans, and in approximately half of the patients dosimetric indices improved. Conclusion. Automated patient-tailored BT channel configuration planning for 3D printed applicators is clinically feasible. A treatment planning study showed that all plans met planning limits for the patient-tailored configurations, and in selected cases improved the plan quality in comparison with commercial applicator configurations.

Afterloader integrated EMT enables improved dwell position model definition and quality assurance in Venezia gynaecological brachytherapy applicators

Abstract Objective. In brachytherapy for gynecological cancers using intracavitary applicators, implant reconstruction is commonly performed using applicator libraries. These libraries contain applicator geometry models as well as dwell position (DP) models defined in respect to the applicator geometry. In this study, we investigate whether an afterloader integrated electromagnetic tracking (EMT) system can be utilized for DP model definition and quality assurance in such applicators. Approach. DPs in four sets of two configurations of the Elekta Venezia Advanced Gynaecological Applicator (22 mm ovoids/40 mm intrauterine (IU) and 26 mm ovoids/70 mm IU) were measured using an afterloader integrated EMT system. Measurements were evaluated for reproducibility and compared against manufacturer-specified (MS) DPs and a computed tomography (CT)-corrected DP model. Main Results. Excellent EMT measurement reproducibility was observed, with values of ⩽0.2 mm for both configurations. The overall reproducibility, including applicator geometry reproducibility, was ⩽0.4 mm for both configurations. Significant discrepancies from the manufacturer’s DP model were observed, with a mean ± sd deviation of 1.13 ± 0.66 mm (22/40) and 1.37 ± 0.63 (26/70), particularly in the IU channel, where MS DPs were not experimentally defined. Discrepancies were reduced to 0.89 ± 0.41 mm (22/40) and 0.81 ± 0.33 mm (26/70) when the CT-corrected DP model was used as baseline, highlighting the need for experimentally defined DP models. The overall uncertainty of single measurements was below the clinically acceptable 2 mm limit. Significance. This study confirms that afterloader integrated EMT can accurately reconstruct source paths in gynecological brachytherapy applicators and supports its incorporation into clinical workflows for improved quality assurance and treatment precision. The importance of EMT for quality assurance was highlighted by measured deviations from manufacturer’s DP model in a clinical relevant part of the IU channel.

Clinical Feasibility of the ARCHITECT Applicator in Cervical Cancer Brachytherapy

This prospective, non-randomised, single centre, phase I trial assesses the clinical feasibility of the use of the patient-tailored ARCHITECT applicator in locally advanced cervical cancer brachytherapy.