Preoperative Helical Tomotherapy and Megavoltage Computed Tomography for Rectal Cancer: Impact on the Irradiated Volume of Small Bowel

Three-Dimensional Analysis of Recurrence Patterns in Rectal Cancer: The Cranial Border in Hypofractionated Preoperative Radiotherapy Can Be Lowered

“…Due to this change, the dose to the small bowel has already significantly decreased. Modern RT techniques, such as intensity-modulated radiotherapy (IMRT), can be used to create conformal dose distributions, reducing the exposure even further (16,17).…”

Advances in radiotherapy delivery for rectal cancer: a European perspective

“…To do so, 3D-conformal RT, IMRT (helical tomotherapy) and IMRT-IGRT (helical tomotherapy with reduced CTV-PTV margins) were compared in a dosimetric evaluation. This study demonstrated a synergism between IMRT and IGRT in decreasing the normal tissue complication probability for developing symptomatic diarrhea to 18%, as opposed to a calculated risk of 27 and 40% for IMRT and 3D-conformal RT, respectively [8] clinical implementation of preoperative IMRT-IGRT in a Phase II trial in 108 patients with locally advanced rectal cancer confirmed this favorable toxicity profile, with 16 patients developing symptomatic diarrhea and one patient a grade 3 acute toxic effect only [9,10]. This is considerably lower than the 15% acute grade 3+ toxicity reported using 3D-conformal RT with concomitant 5-FU (1,2).…”

Helical Tomotherapy in Cervical Cancer Patients

“…In rectal cancer patients with preoperative irradiation, HT and daily MV-CT led to a reduced small bowel volume (V 15 ), which correlated with a decreased normal-tissue complication probability (NTCP) of 18% for grade ≥ 2 diarrhea [10]. Although the V 15 is comparable to that of the above-mentioned study, we saw no grade 2 diarrhea but one patient (5%) experienced grade 3 diarrhea, which is less than could be expected from this NTCP model.…”

“…The on-board megavoltage (MV) computed tomography (CT) allows daily setup verification. While reducing setup errors, the margins of the planning target volume (PTV) can be reduced and, as a result, reduce the dose to the small bowel [10].…”