23. Anal Cancer - The GEC-ESTRO Handbook of Brachytherapy

Anal Cancer

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THE GEC ESTROHANDBOOKOF BRACHYTHERAPY | Part II Clinical Practice Version 1 - 01/03/2023

Figure 4: Imaging of a large anal canal tumour a. Clinical examination b. CT scan of the same tumour, axial cross-section c. MRI, T2, coronal cross-section d. MRI, T2, axial cross-section

6. INDICATIONS, CONTRA-INDICATIONS

Indications The intention of treatment for anal cancers is to achieve cure with locoregional control and preservation of anal function. For small Tis or T1N0M0 lesions, conventional (nowadays mostly Volumetric-Modulated Arc Therapy (VMAT) or Intensity- Modulated Radiotherapy (IMRT)) external beam radiation therapy (EBRT) demonstrated excellent rates of local control and survival [16,17]. Surgical excision prior to radiotherapy did not improve results [18]. Exclusive brachytherapy for these small lesions is not recommended due to a high risk of local recurrence and necrosis of the treated area [16]. For patients with locally advanced stages, combinations of radiotherapy and chemotherapy (mainly Mitomycin and 5-Fluorouracil) have been established as the standard of care [19–21]. After concurrent chemoradiation, a sequential boost to the primary tumour delivered by either EBRT or an interstitial brachytherapy boost (IBT) is recommended [22,23]. Brachytherapy has the capacity to deliver a high dose to the primary tumour, while sparing surrounding normal tissues and the contralateral mucosa, because of the rapid fall off in dose, thus limiting local adverse events. In nonrandomized studies, IBT shows

Figure 5: Same tumour as the previous figure, on CT scan (a.) a centimetric node was present. An FDG-PET (b.) was performed and showed a hypermetabolism of the node