ESTRO38 Congress Report

Brachytherapy

4. Contact X-Ray Brachytherapy (CXB) after local excision (LE) for early rectal adenocarcinoma (E38-0234) Gérard JP 1 , Sun Myint A2 , Falcoz A1 , Dhadda A3 . 1 Centre Antoine Lacassagne, University Côte d’Azur, Nice – France, 2 Clatterbridge Cancer Center, Clatterbridge – UK, 3 East Yorkshire Hospitals, Hull - UK

Context of the study Early rectal cancers (malignant polyp, Tis, T1 sm1-2 < 3cm diameter) are treated using standard local excision (LE) techniques and careful pathological analysis. When adverse pathological features are found (pT1 sm3, pT2, R1, fragmentation, budding, poor differentiation), radical TME surgery removing the rectum is the standard treatment. The hypothesis of this study was to evaluate the role of CXB with or without external beam (chemo) radiotherapy (EBRT) as adjuvant treatment after LE to avoid radical surgery. Overview of abstract Between 2009-2017, 197 patients with adverse pathological features after LE were treated in 3 institutions (Clatterbridge: 120, Hull: 35, Nice: 34) with a conservative strategy. CXB (Papillon 50) delivered a dose of 40 to 60 Gy in 2-3 fractions and was combined with EBRT (45-50 Gy over 5 weeks) in 170 patients oftenwith concurrent chemotherapy (capecitabine). Local relapse rate at 5 years was 8% and distant metastases 11%. Organ preservation was achieved in 95% of cases with good bowel function in most patients. Main toxicity was late rectal bleeding (radiation telangiectasia) easily treated if grade 3 using plasma argon coagulation. What were the three main findings? 1) This strategy provides a high rate of local control with rectal preservation. 2) Toxicity is low and bowel function good in most cases. 3) This simple treatment can be proposed at any age with good tolerance. What impact could your research have ? A randomized trial comparing TME vs CXB+ EBRT after local excision would be very difficult to propose to patients. These data may provide good evidence that CXB is a valid option as an alternative to TME radical surgery after LE in patients with adverse pathological features. Is this research indicative of a bigger trend in oncology? In oncology an important trend for clinical research is reduction of toxicity and organ preservation. It is well recognised that radical TME surgery is often responsible for poor bowel function and poor quality of life. The main advantage of CXB with EBR(C)T is organ preservation. It is highly probable that this trend in favour of conservative treatment in oncology will be of increasing interest in the future for patients as well as medical professionals.

1 The Papillon 50 machine which was at the origin of Contact X-Ray brachytherapy (CXB) renaissance in 2010.

2 The different steps of a CXB procedure for rectal cancer. The knee-chest position allows a good opening of the rectumand clear vision of tumor or scar after local excision.

3 An example of a T1 tumor treated using local excision and adjuvant CXB

Congress report | BRACHYTHERAPY

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