Evaluation of planning aims and dose prescription in image-guided adaptive brachytherapy and radiochemotherapy for cervical cancer: Vienna clinical experience in 225 patients from 1998 to 2008

Abstract

Results . In the PA ϩ group there were 77 (34%) and in the PA-group 148 (66%) patients. In the PA-group, CTV HR D 90 Ͻ 85 Gy was prescribed in 82 patients, D 2cm3 bladder Ͼ 90 Gy was prescribed in 80 patients and D 2cm3 Rectum Ͼ 70 Gy in 60 patients. Fulfi llment of the PA for dose prescription improved from 4% in the learning period to 48% in the protocol period. The fi ve-year event-free interval was 64% in the learning period and 84% in the protocol period (p ϭ 0.008). Conclusion . Fulfi llment of all PAs for dose prescription is challenging -especially in patients with more advanced tumors. However, with growing experience fulfi llment of PA for dose prescription can be signifi cantly increased (learning and protocol period). Such increase in fulfi lling PA for dose prescription is followed by a signifi cant improvement in clinical outcome.The gold standard in the treatment of locally advanced cervix cancer is radio-chemotherapy and brachytherapy [1]. Image-guided adaptive brachytherapy (IGABT) is an advanced method which is increasingly implemented in clinical practice [2,3]. By imaging of the applicator and tumor/target volume and the surrounding organs at risk (OAR), IGABT offers the possibility of dose optimization based on the individual high risk (HR) clinical target volumes (CTV) and OARs [4 -7]. First clinical results indicate a reduction in local recurrence and side effects in comparison to standard point A based brachytherapy [8 -11]. Recently, dose response relationships were described in IGABT for the target volume and OARs (bladder and rectum) based on the monoinstitutional Vienna cohort and also based on the large multi-center cohort RetroEMBRACE [12 -15].

A volumetric analysis of GTVD and CTVHR as defined by the GEC ESTRO recommendations in FIGO stage IIB and IIIB cervical cancer patients treated with IGABT in a prospective multicentric trial (EMBRACE)

“…Third, the feasibility of IGABT was simply evaluated based on the dose coverage of the CTV HR . However, reducing the doses to the different organs at risk is another aspect of IGABT that needs to be considered [20]. Such an analysis can be very complex as these dose constraints compete with target coverage and they carry a differential weight in different patient groups.…”

Brachytherapy: An overview for clinicians

“…The importance of individual expertise and the implementation of a specific brachytherapy workflow must be appraised . A learning period does exist, especially for sophisticated brachytherapy treatments, and a correlation between increased experience, ability to fulfill planning aims, and clinical outcome has been demonstrated . The possibility that the outcome after brachytherapy is affected by the skills of the center and the activity of the clinician (as for surgical procedures), as is frequently observed in oncological practice, should be considered but should not prevent the center from performing brachytherapy.…”

Providing Patients with Locally Advanced Cervical Cancer Access to Brachytherapy: Experience from a Referral Network for Women Treated in Overseas France

“…The therapeutic process is however complex and requires a health care structure with access to combined intracavitary/interstitial brachytherapy procedures. Adequate training of physicians, physicists and radiotherapy technicians is required, as published data showed a correlation between increased experience, ability to fulfill planning aims, and patient outcome [ 28 ]. The lack of radiotherapy-brachytherapy facilities is a major concern in many parts of the world.…”