High-dose rate endorectal brachytherapy for rectal cancer: A state-of-the-art review

Rectal cancer is a common malignancy that requires multidisciplinary treatment. By utilizing the dose-response relationship in rectal cancer radiotherapy, increasing the radiotherapy dose can improve clinical complete remission rates. High-dose rate endorectal brachytherapy (HDREBT) is a novel technique that delivers high doses of radiotherapy directly to the tumor via an endorectal applicator, sparing the adjacent normal tissues from excessive radiation exposure. HDREBT includes contact X-ray brachytherapy and high-dose-rate intracavitary brachytherapy. We introduce the latest developments in applicators and imaging techniques for HDREBT in rectal cancer and summarize the current evidence on the efficacy, safety, and feasibility of HDREBT as a neoadjuvant, definitive, or palliative treatment option for all stages of rectal cancer patients. We also discuss the potential advantages and challenges of HDREBT in achieving organ preservation and improving the quality of life of rectal cancer patients. HDREBT has shown promising results in achieving high complete response rates, enabling nonoperative management, improving organ preservation rates, and providing effective palliation in rectal cancer patients. More studies are needed to optimize its dose and fractionation schemes in different clinical scenarios.

Long-Term Results of One-Stage Laparoscopic-Assisted Endorectal Pull-Through for Rectosigmoid Hirschsprung's Disease in Patients Aged Above 5 Years

Purpose: Despite the fact that the laparoscopic-assisted endorectal pull-through (LAEPT) for Hirschsprung's disease (HD) was introduced over 20 years ago, published outcomes in older children and adolescent are lacking. To address this, we studied the long-term results of LATEP for rectosigmoid HD in patients above 5 years of age. Materials and Methods: A retrospective review was conducted on all nonsyndromic patients above 5 years of age and who underwent one-stage LAEPT for rectosigmoid HD between January 2002 and December 2017. Late Hirschsprung-associated enterocolitis (HAEC) was defined as HAEC occurring 1 year after the pull-through operation. Postoperative bowel function was assessed using the Krickenbeck classification. Results: Forty-one patients (37 males and 4 females) were included in this study with a median follow-up of 9.0 years. The median age at surgery was 55 days. Two patients had anastomotic leakage. No patient had late HAEC, rectal prolapse, anastomotic stricture, or intestinal obstruction. According to the Krickenbeck classification, all patients had voluntary bowel movements without constipation. Overall, 65.8% of patients had no soiling. However, on subgroup analysis, only 45.4% of patients younger than 11 years of age had no soiling compared with 89.5% in patients at or older than 11 years of age (P = .003). Conclusions: Our results showed that LAEPT for rectosigmoid HD was a safe procedure. Nearly 90% of patients had normal bowel function by puberty. Further studies are needed to address the problem of soiling in patients younger than 11 years of age.

High-dose-rate pre-operative endorectal brachytherapy for patients with rectal cancer

High-dose-rate endorectal brachytherapy (HDREBT) is an image guided brachytherapy treatment for patients with rectal cancer. It is based on tumor imaging with magnetic resonance in particular, which is used to choose eligible patients and improve tumor visualization. Treatment planning is performed using 3D CT simulation and treatment planning. The treatment is given on an outpatient basis and requires minimal local anesthesia. The validation of the technique was carried out through a preoperative study and is now explored as part of a radical treatment for early rectal cancer or as a boost modality.

We describe technical aspects of the HDREBT and we discuss the ongoing institutional review board approved studies exploring the clinical applications of this treatment modality for patients with rectal cancer: 1) as a neoadjuvant treatment for patients with operable rectal tumor; 2) as a option to improve local control in patients with newly diagnosed rectal cancer but with previous pelvic radiation.

Incorporating endorectal MR elastography into multi-parametric MRI for prostate cancer imaging: Initial feasibility in volunteers

PURPOSE

To investigate the tolerability and technical feasibility of performing endorectal MR elastography (eMRE) in human volunteers within the representative age group commonly affected by prostate cancer.

MATERIALS AND METHODS

Endorectal MRE was conducted on seven volunteers in a 1.5 Tesla (T) MR imager using a rigid endorectal coil. Another five volunteers were imaged on a 3T MR imager using an inflatable balloon type endorectal coil. Tolerability was accessed for vibration amplitudes of ±1-50 μm and for frequencies of 100-300 Hz.

RESULTS

All 12 volunteers tolerated the displacements necessary to successfully perform eMRE. Shear waves with frequencies up to 300 Hz could propagate across the entire prostate using both coil designs.

CONCLUSION

The results of this study motivate further investigation of eMRE in prostate cancer patients to help determine if there is an added value of integrating eMRE into existing multi-parametric prostate MRI exams.