Radiological and clinical findings following rectal contact X-ray brachytherapy (Papillon technique) – how to assess response

Abstract

PurposeRectal contact X-ray brachytherapy (Papillon radiotherapy) has recently received approval from the National Institute for Health and Care Excellence. In particular, it is suitable for elderly patients who are high-risk for a major operation, but it may also be undertaken for patients who wish to avoid a stoma. It is imperative to be able to identify clinical response or tumor regrowth on surveillance magnetic resonance imaging (MRI) and sigmoidoscopy. This article aims to help clinicians to interpret MRIs and endoscopic appearances following Papillon radiotherapy.Material and methodsMRI and sigmoidoscopy images are presented from a case series of seven non-consecutive, heterogeneously treated patients with T2 to 3C N0 rectal adenocarcinoma. Treatments included transanal excision, adjuvant or neoadjuvant chemo/radiotherapy, and Papillon radiotherapy. These patients wished to avoid a stoma or were high-risk for a major operation. These cases have been chosen to demonstrate response assessment alone.ResultsThe “black spider” sign of maturing, low signal fibrosis on MRI was found to be reassuring, as was the presence of a flat scar on endoscopy. Residual tumor mass or intermediate signal suggest equivocal response, which may necessitate transanal excision. Loss of low signal fibrosis, or the development of soft tissue nodularity or mass should prompt biopsy.ConclusionsMR scans should be used in combination with endoluminal mucosal assessment (and digital rectal examination) to determine response following Papillon radiotherapy. This is the first paper to describe both the endoscopic and imaging findings following Papillon radiotherapy.

Systematic Review of Intensity-Modulated Brachytherapy (IMBT): Static and Dynamic Techniques

“…22,23,[26][27][28][29][30][31][32][33] Studies of both these techniques have included steps toward clinical implementation such as computed tomography or magnetic resonance imaging compatibility, 27,33,34,78,137 optimal planning algorithms to decrease planning and delivery times, 23,26,32,67,75,77 and optimal sources and shielding materials. 4,[29][30][31][32]71,138 Commercially available IMBT techniques include staticshielded applicators 6,7,14,17,20,[35][36][37][38][39][40][41][42][43][44][46][47][48][49][50][51]…”

“…35,39,43,94 Static-shielded applicators can also be pressed against the breast, as with AccuBoost (Advanced Radiation Therapy, Inc, Billerica, MA), 37,41,42,44,47 or against colorectal tissue, as with Papillon devices (Ariane, Alfreton, UK). 36,38,40,45,46,48,49,[84][85][86][87][88]95,96 Leipzig applicators have been studied and used clinically for nonmelanoma skin cancer or Kaposi's sarcoma, 43 are conically shaped with tungsten or tungsten alloy shields of 10 to 30 mm in inner diameter, and use a 192 Ir source in either parallel or perpendicular orientation to the treated surface ( Fig. 1J).…”

“…25,107 Clinically, cup-or D-shaped static IMBT applicators with Papillon devices have been the most widely used to provide boosts to early-stage colorectal cancers for more than 30 years. 36,38,40,46,48,49,[84][85][86][87][88]95,96 Studies have demonstrated favorable incidence rates for 3-year local recurrence (6%-16.9%), clinical complete response (63.8%-96%), organ preservation (62%-96%), grade 3 acute toxicity (constipation/diarrhea or incontinence, 6.7%-9%) and late toxicity (bleeding, 9%-28%), and good-excellent bowel function (85%) at 2.5 to 3 years of median followup. 38,40,48,49 Other, multiple, or no specific disease site Studies of IMBT have also included other sites such as the pancreas, 63 multiple malignant sites (an ongoing clinical trial of any solid tumor of the abdomen or pelvis), 58 no specific disease sites, 55,62 and nonmalignant applications, such as intravascular BT for coronary artery disease.…”

“…"Static" IMBT approaches include those in which the shield does not move relative to the source or surrounding tissues during BT delivery, such as shielded applicators (eg, shielded cylinders, [3][4][5][6][7][8][9][10][11] shielded tandem and ovoids, [12][13][14][15][16][17][18][19][20] Strut-Adjusted Volume Implants [SAVI], 21 intracavitary mold applicators [ICMA], [22][23][24][25][26] direction-modulated brachytherapy [DirMBT], 21,25,[27][28][29][30][31][32][33][34] and cup or D-shaped applicators [35][36][37][38][39][40][41][42][43][44][45][46][47][48][49]…”

Treatment: the role of contact X‐ray brachytherapy (Papillon) in the management of early rectal cancer

“…Tumour is shaved off layer by layer (a few millimetres at a time) every 2 weeks, after which the next treatment is given. During the 2‐week interval between treatments, the normal tissues recover and the tumour regresses, usually centripetally . At the end of the third treatment, very little residual tumour can be seen or felt in a responsive tumour (Fig.…”