Dose escalation using contact X-ray brachytherapy (Papillon) for rectal cancer: does it improve the chance of organ preservation?

Myint, Arthur Sun; Smith, F. H.; Gollins, Simon; Wong, Helen; Rao, Christopher; Whitmarsh, Karen; Sripadam, Raj; Rooney, Paul; Hershman, M. J.; Fekete, Zsolt; Perkins, Kate; Pritchard, D. Mark

doi:10.1259/bjr.20170175

Cited by 45 publications

(60 citation statements)

References 25 publications

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“…We adopt a careful watch‐and‐wait policy for patients who achieve cCR after CXB . Regular DRE, endoscopy and MRI are carried out at local referring hospitals alternating with the CXB centres at the following intervals: every 3‐4 months in the first 2 years (when the risk of regrowth is highest); at 6‐month intervals in the third year; and annually up to the fifth year.…”

Section: Follow‐upmentioning

confidence: 99%

“…In an early-stage large rectal tumour with size > 3 cm at maximum diameter (cT1) or more advanced stage cancer of any size (cT2), EBRT is usually offered to downsize or downstage the tumour and to address possible lymph node spread, and CXB is considered as a boost either before or after, depending on the size of the tumour (< 3 cm) [5]. The option for CXB boost is only possible in larger tumours (> 3 cm) if there is a good response (more than 60% reduction in size) to initial external beam chemoradiotherapy (EBCRT) or EBRT.…”

Section: Cxb As a Boost In Addition To External Beam Chemoradiotherapmentioning

confidence: 99%

“…We adopt a careful watch-and-wait policy for patients who achieve cCR after CXB [5,12]. Regular DRE,…”

Section: Follow-upmentioning

confidence: 99%

“…In an early‐stage large rectal tumour with size > 3 cm at maximum diameter (cT1) or more advanced stage cancer of any size (cT2), EBRT is usually offered to downsize or downstage the tumour and to address possible lymph node spread, and CXB is considered as a boost either before or after, depending on the size of the tumour (< 3 cm) .…”

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

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

Myint

Stewart

Mills³

et al. 2019

Colorectal Disease

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Section: Follow‐upmentioning

confidence: 99%

Section: Cxb As a Boost In Addition To External Beam Chemoradiotherapmentioning

confidence: 99%

“…We adopt a careful watch-and-wait policy for patients who achieve cCR after CXB [5,12]. Regular DRE,…”

Section: Follow-upmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

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

Myint

Stewart

Mills³

et al. 2019

Colorectal Disease

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“…CXB is a highly targeted treatment and most of the additional radiation (if not all) is deposited mainly on the tumour with very little collateral damage to normal surrounding tissues. There is published evidence that the additional boost with CXB after EBCRT increases the initial clinical complete response (cCR) and also reduces local regrowth after achieving cCR . This is currently being investigated in the European Phase 3 randomized OPERA trial (ID: NCT02505750) which is recruiting well.…”

mentioning

confidence: 99%

Re: Evaluating the incidence of pathological complete response in current international rectal cancer practice: the barriers to widespread safe deferral of surgery

et al. 2018

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E‐Brachy: New dosimetry package for electronic brachytherapy sources

Esmaelbeigi,

Kalinowski,

Tomic

et al. 2024

Medical Physics

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BackgroundLarge reported variability in the material composition and geometrical components of the Xoft electronic high‐dose‐rate brachytherapy Causes inter‐source discrepancy in the source output. This variability is due to the manual manufacturing and assembly of the sources.PurposeThis study aimed to develop a dosimetry software tool called E‐Brachy to characterize the Xoft source and quantify the discrepancies in its photon spectrum and dosimetric properties.MethodsE‐Brachy is based on the Geant4 Monte Carlo toolkit and consists of two parts. In part one, the geometry and material composition for the source received in the computer‐aided design format from the vendor were converted to the geometry description markup language format using the GUIMesh Python tool and integrated into the E‐Brachy software. There was a large variation in material composition and thickness for some of the tube components. The simulation started from electrons and resulted in x‐ray generations in the anode region. Multithreading, a track length estimation, and the uniform bremsstrahlung splitting variance reduction techniques were used to decrease the simulation time and increase the x‐ray production. The photon energy, position, and momentum were saved into a phase space file as the photon exited the source, but before interacting with the external environment. The obtained x‐ray energy spectrum was compared with measurements from the National Institute of Standards and Technology (NIST). In part two, by sampling from the generated photons, the dose rates and dosimetric parameters according to the TG‐43 protocol were calculated for model S7500 and compared to the ones previously calculated for model S700 source, which were deemed identical by the manufacturer.ResultsThe material composition that resulted in the most similar spectrum as the measured NIST spectrum with Pearson's correlation coefficient of 0.99 and a calculated Euclidean difference of keV was chosen for further dosimetric analysis of the model S7500 source. Characteristic peaks showed the presence of tungsten, yttrium, and silver in the source components. Differences in dose rates between the two source models surpassed 20% for polar angles , reaching a peak at cm and . The differences in the radial dose function values were within 5%. The relative difference in percentage between the anisotropy function values of the two models was closer to 0 for smaller values, but at higher polar angles, they increased to 300%.ConclusionsA software package called E‐Brachy was successfully developed for the characterization and dosimetry of Xoft electronic brachytherapy sources. E‐Brachy can be combined with spectral measurements to investigate the inter‐ and intra‐source variability. The software package was tested by comparing the simulated spectra from the S7500 Xoft source model with NIST measurements and its TG‐43 parameters with the S700 model. The TG‐43 parameters between the two sources significantly exceed the recommendations of TG‐56.

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Dose escalation using contact X-ray brachytherapy (Papillon) for rectal cancer: does it improve the chance of organ preservation?

Cited by 45 publications

References 25 publications

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

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

Re: Evaluating the incidence of pathological complete response in current international rectal cancer practice: the barriers to widespread safe deferral of surgery

E‐Brachy: New dosimetry package for electronic brachytherapy sources

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