Influence of intraoperative radiotherapy (IORT) on perioperative outcome after surgical resection of rectal cancer

Intraoperative electron radiotherapy (IOERT) in colorectal cancer: Updated systematic review of techniques, oncological outcomes and complications

BACKGROUND

Intra-operative electron radiotherapy (IOERT) directly delivers a large fraction of radiation to at-risk margins during surgery. However, the precise benefit of IOERT in patients with locally advanced and locally recurrent colorectal cancer (LACC/LRCC) is unclear. This study aimed to provide an updated summary of the current evidence available regarding IOERT as part of multi-modality treatment of LACC and LRCC.

METHOD

This systematic review update was prospectively registered on PROSPERO (CRD42023438184). An electronic literature search was carried out using Ovid (MEDLINE), EMBASE, Web of Science, and the Cochrane Library databases for studies from July 2011 to April 2024. The inclusion criteria were adult patients who received IOERT as part of multi-modal treatment for LACC or LRCC. The primary outcome was overall survival (OS), disease free survival (DFS) and local control (LC) at 5 years. Secondary outcomes included post-operative complications.

RESULTS

16 new studies were identified since the previous analysis, and included (study population 1912 patients) of which two were prospective. High heterogeneity prevented meta-analysis of outcomes except for 5-year OS which suggested a non-significant benefit favouring IOERT. Significant methodological concerns were identified making interpretations challenging, however patients with LACC or LRCC with an R1 resection margin showed a favourable 5-year OS (40 % and 18 % respectively) when compared to current evidence.

CONCLUSION

Although limited by a lack of appropriately conducted randomised evidence, IOERT-containing multi-modality treatment may improve oncological outcomes in LACC and LRCC patients with R1 resections.

Efficacy and safety of intraoperative radiotherapy in rectal cancer: A systematic review and meta-analysis

BACKGROUND

In recent years, intraoperative radiotherapy (IORT) has been increasingly used for the treatment of rectal cancer. However, the efficacy and safety of IORT for the treatment of rectal cancer are still controversial.

AIM

To evaluate the value of IORT for patients with rectal cancer.

METHODS

We searched PubMed, Embase, Cochrane Library, Web of Science databases, and conference abstracts and included randomized controlled trials and observational studies on IORT vs non-IORT for rectal cancer. Dichotomous variables were evaluated by odds ratio (OR) and 95% confidence interval (CI), hazard ratio (HR) and 95%CI was used as a summary statistic of survival outcomes. Statistical analyses were performed using Stata V.15.0 and Review Manager 5.3 software.

RESULTS

In this study, 3 randomized controlled studies and 12 observational studies were included with a total of 1460 patients, who are mainly residents of Europe, the United States, and Asia. Our results did not show significant differences in 5-year overall survival (HR = 0.80, 95%CI = 0.60-1.06; P = 0.126); 5-year disease-free survival (HR = 0.94, 95%CI = 0.73-1.22; P = 0.650); abscess (OR = 1.10, 95%CI = 0.67-1.80; P = 0.713), fistulae (OR = 0.79, 95%CI = 0.33-1.89; P = 0.600); wound complication (OR = 1.21, 95%CI = 0.62-2.36; P = 0.575); anastomotic leakage (OR = 1.09, 95%CI = 0.59-2.02; P = 0.775); and neurogenic bladder dysfunction (OR = 0.69, 95%CI = 0.31-1.55; P = 0.369). However, the meta-analysis of 5-year local control was significantly different (OR = 3.07, 95%CI = 1.66-5.66; P = 0.000).

CONCLUSION

The advantage of IORT is mainly reflected in 5-year local control, but it is not statistically significant for 5-year overall survival, 5-year disease-free survival, and complications.

ESTRO/ACROP IORT recommendations for intraoperative radiation therapy in locally recurrent rectal cancer

Multimodal strategies have been implemented for locally recurrent rectal cancer scheduled for complete surgical resection. Irradiation and systemic therapy have been added to improve the oncological outcome, as surgery alone was associated with a poor prognosis. Intraoperative irradiation (IORT) is a component of irradiation intensification. Long-term cancer control and a higher survival rate were consistently reported in patients who had IORT as a component of their multidisciplinary treatment. The experience reported by expert IORT groups is reviewed and recommendations to guide clinical practice are explained in detail.

The Impact of Novel Radiation Treatment Techniques on Toxicity and Clinical Outcomes In Rectal Cancer

Purpose of review

Three-dimensional conformal radiation therapy (3DCRT) has been the standard technique in the treatment of rectal cancer. The use of new radiation treatment technologies such as intensity-modulated radiation therapy (IMRT), proton therapy (PT), stereotactic body radiation therapy (SBRT) and brachytherapy (BT) has been increasing over the past 10 years. This review will highlight the advantages and drawbacks of these techniques.

Recent findings

IMRT, PT, SBRT and BT achieve a higher target coverage conformity, a higher organ at risk sparing and enable dose escalation compared to 3DCRT. Some studies suggested a reduction in gastrointestinal and hematologic toxicities and an increase in the complete pathologic response rate; however, the clinical benefit of these techniques remains controversial.

Summary

The results of these new techniques seem encouraging despite conclusive data. Further trials are required to establish their role in rectal cancer.

Post operative stereotactic radiosurgery for positive or close margins after preoperative chemoradiation and surgery for rectal cancer

BACKGROUND

The incidence of positive margins after neoadjuvant chemoradiation and adequate surgery is very low. However, when patients do present with positive or close margins, they are at a risk of local failure and local therapy options are limited. We evaluated the role of stereotactic body radiotherapy (SBRT) in patients with positive or close margins after induction chemoradiation and total mesorectal excision.

METHODS

This is a retrospective evaluation of patients treated with SBRT after induction chemoradiation and surgery for positive or close margins. Seven evaluable patients were included. Fiducial seeds were place at surgery. The Cyberknife(TM) system was used for planning and treatment. Patients were followed 1 month after treatment and 3-6 months thereafter. Descriptive statistics and Kaplan-Meir method was used to repot the findings.

RESULTS

Seven patients (3 men and 4 women) were included in the study with a median follow-up of 23.5 months. The median initial radiation dose was 5,040 cGy (in 28 fractions) and the median SBRT dose was 2,500 cGy (in 5 fractions). The local control at 2 years was 100%. The overall survival at 1 and 2 years was 100% and 71% respectively. There was no Grade III or IV toxicity.

CONCLUSIONS

SBRT reirradiation is an effective and safe method to address positive or close margins after neoadjuvant chemoradiation and surgery for rectal cancer.

Evidence-Based Operative Details in Esophageal Cancer Treatment: Surgical Approach, Lymphadenectomy, Anastomosis

Background

This review depicts surgical treatment strategies in the management of esophageal cancer under the focus of evidence-based medicine. The main emphasis lies on technical details, i.e. surgical approach, lymphadenectomy, and current techniques of anastomosis.

Methods

The current literature on operative details in esophageal cancer treatment was reviewed. Surgical approaches and different techniques of anastomotic reconstruction utilizing a gastric tube were compared. The grade of evidence regarding the necessity and extent of lymphadenectomy was discussed.

Results

There is no level-1 evidence-based difference regarding the surgical approach for esophagectomy. The preferred anastomosis site is intrathoracic compared to the neck. Extended lymphadenectomy is still imperative in esophagectomy although neoadjuvant protocols might also result in a downstaging effect of lymph nodes. Neoadjuvant regimens have no negative influence on complication rate and anastomotic integrity.

Conclusion

A tailored interdisciplinary approach to the patients' physiology and esophageal cancer stage is the most important factor that influences operative outcome and oncological results after esophagectomy.

Stereotactic body radiotherapy (SBRT) reirradiation for pelvic recurrence from colorectal cancer

BACKGROUND AND OBJECTIVES

When surgery is not adequate or feasible, stereotactic body radiotherapy (SBRT) reirradiation has been used for recurrent cancers. We report the outcomes of a series of patients with pelvic recurrences from colorectal cancer reirradiated with SBRT.

METHODS

The Cyberknife(TM) Robotic Stereotactic Radiosurgery system with fiducial based real time tracking was used. Patients were followed with imaging of the pelvis.

RESULTS

Four women and 14 men with 22 lesions were included. The mean dose was 25 Gy in median of five fractions. The mean prescription isodose was 77%, with a median maximum dose of 32.87 Gy. There were two local failures, with a crude local control rate of 89%. The median overall survival was 43 months. One patient had small bowel perforation and required surgery (Grade IV), two patients had symptomatic neuropathy (1 Grade III) and one patient developed hydronephrosis from ureteric fibrosis requiring a stent (Grade III).

CONCLUSIONS

Local recurrence in the pelvis after modern combined modality treatment for colorectal cancer is rare. However it presents a therapeutic dilemma when it occurs; often symptomatic and eventually life threatening. SBRT can be a useful non-surgical modality to control pelvic recurrences after prior radiation for colorectal cancer.