Endorectal Brachytherapy Boost After External Beam Radiation Therapy in Elderly or Medically Inoperable Patients With Rectal Cancer: Primary Outcomes of the Phase 1 HERBERT Study

Benefit of adaptive CT-based treatment planning in high-dose-rate endorectal brachytherapy for rectal cancer

“…The COIN parameter ranges from 0 to 1, with 0 representing no conformity and 1 representing full conformity. The HERBERT trial was a dose escalation study, and patients were treated with a prescription dose of 5e8 Gy (8). Therefore, for reporting of dose parameters, we chose to scale the dose distributions to a prescription dose of 7 Gy.…”

“…For the present study, we selected 11 patients from the HERBERT trial in whom repeat CT scans with applicator in situ were available at each fraction (the HERBERT trial, registered with the Dutch Central Committee on Research Involving Human Subjects; registration no. NL17037.031.07) (8,21).…”

“…All patients were treated with 13 Â 3 Gy EBRT at four fractions per week, followed by three weekly fractions of HDREBT using a prescription dose of 5e8 Gy starting 6 weeks after conclusion of EBRT. We adapted the brachytherapy equipment, application and positioning procedures from Devic et al as described in Rijkmans et al (8,11). Patients received an enema before the CT scan with applicator in situ at each fraction.…”

“…For patients unfit or unwilling to undergo surgery, definitive or palliative radiotherapy are alternatives. Rijkmans et al demonstrated the feasibility of an HDREBT boost after EBRT in inoperable patients (8). Compared with EBRT, HDREBT can deliver high doses to the tumor while sparing surrounding organs due to a steeper dose gradient (7).…”

Decision-Making Strategy for Rectal Cancer Management Using Radiation Therapy for Elderly or Comorbid Patients

“…Therefore, achieving comparable local control would require higher doses of radiation than the standard 45 to 50.4 Gy of EBRT. Several studies, mostly retrospective, have shown that dose escalation beyond the standard pelvic radiation with EBRT is viable using brachytherapy for attaining reasonable rates of local control (see also above, "CRT with dose escalation") (135)(136)(137)(138)(139)(140).…”