Intraoperative radiotherapy in the multimodality approach to colorectal cancer

The role of intraoperative radiotherapy in advanced rectal cancer: a meta-analysis

AIM

Patients with locally advanced and locally recurrent rectal cancer (LARC/LRRC) experience higher rates of local recurrence (LR) and poorer overall survival than patients with primary rectal cancer restricted to the mesorectum despite improved neoadjuvant treatment regimens and radical surgical procedures. Intraoperative radiotherapy (IORT) has been suggested as an adjunctive tool in the surgical management of these challenging cases. However, clear evidence regarding the oncological benefit of IORT is sparse. The aim of this review was to update this evidence in the era of standardized neoadjuvant radiotherapy administration.

METHOD

A systematic review of patients who received IORT as part of multimodal treatment for advanced rectal cancer from 2000 to 2020 and an analysis of IORT and surgery/external beam radiotherapy (EBRT) groups was performed. The primary endpoint was the rate of LR between the two groups.

RESULTS

Seven papers met the predefined criteria. LR was reduced by the addition of IORT when compared with the surgery/EBRT alone group (14.7% vs. 21.4%; OR 0.55, 95% CI 0.27-1.14; p = 0.11). There was no increase in reported genitourinary morbidity, wound issues, pelvic collections or anastomotic leak in those patients who received IORT. Notably, there was no survival difference between the two groups.

CONCLUSION

The addition of IORT to current treatment strategies in the management of patients with LARC/LRRC is associated with a lower rate of locoregional recurrence without increased morbidity. However, this marks a highly selective group of patients, with heterogeneity regarding indications, prior neoadjuvant treatments and/or IORT dosing.

Modified simultaneous integrated boost radiotherapy for an unresectable huge refractory pelvic tumor diagnosed as a rectal adenocarcinoma

A clinical trial of radiotherapy with modified simultaneous integrated boost (SIB) technique against huge tumors was conducted. A 58-year-old male patient who had a huge pelvic tumor diagnosed as a rectal adenocarcinoma due to familial adenomatous polyposis was enrolled in this trial. The total dose of 77 Gy (equivalent dose in 2 Gy/fraction) and 64.5 Gy was delivered to the center of the tumor and the surrounding area respectively, and approximately 20% dose escalation was achieved with the modified SIB technique. The tumor with an initial maximum size of 15 cm disappeared 120 d after the start of the radiotherapy. Performance status of the patient improved from 4 to 0. Radiotherapy with modified SIB may be effective for patients with a huge tumor in terms of tumor shrinkage/disappearance, improvement of QOL, and prolongation of survival.

Partial–breast irradiation: towards a replacement for whole–breast irradiation?

Largely thanks to all of the investigators and patients who have participated in randomized breast-conservation trials, many women facing a diagnosis of breast cancer today can conserve their breast with the help of adjuvant radiation therapy. A standard course of radiation consists of 5-7 weeks of daily radiation treatments delivered to the whole breast. The success of this treatment has led investigators to attempt to determine whether the same control can be achieved while decreasing the volume of breast tissue irradiated, thus allowing treatment to be delivered in a shorter period of time. This approach could alleviate time and logistical problems faced by patients during their course of treatment as well as improving overall cost-effectiveness. It can also allow complete avoidance of the adjacent heart and lung tissue in the radiation treatment portal. Partial-breast irradiation (the delivery of radiation to the resection cavity, plus a safety margin) delivered in just hours or days, is currently under investigation. Although relatively new, its use is growing rapidly and many institutional and cooperative group trials are quickly enlisting patients, while physicians are gaining experience in a variety of partial-breast irradiation techniques.

Clinical review: surgical management of locally advanced and recurrent colorectal cancer

AIM

Recurrent and locally advanced colorectal cancers frequently require en bloc resection of involved organs to achieve negative margins. The aim of this review is to evaluate the most current literature related to the surgical management of locally advanced and recurrent colorectal cancer.

METHODS

A literature review was performed on the electronic databases MEDLINE from PubMed, EMBASE and the Cochrane library for publications in the English language from January 1993 to July 2013. The MeSH search terms 'locally advanced colorectal cancer', 'recurrent colorectal cancer' and 'surgical management' were used.

RESULTS

A total of 1,470 patients with recurrent or locally advanced primary colorectal cancer were included in 22 studies. Surgical removal of the tumour with negative margins (R0) offers the best prognosis in term of survival with a 5-year survival of up to 70 %. MVR is needed in approximately 10 % with the most commonly involved organ being the bladder. The mean post-operative morbidity is 40 %, mainly relating to superficial surgical site infection, pelvic collections and delayed wound healing. Most patients will undergo radiotherapy and/or chemotherapy pre- or post-operatively. The mean 5-year overall survival for R0 resection is 50 % for recurrent and locally advanced primary tumours while survival following R1 or R2 is 12 and <5 %, respectively.

CONCLUSION

Multimodal therapy and extended surgery to achieve clear margins offers good prognosis to patients with recurrent and locally advanced colorectal cancers.

The role of intraoperative radiotherapy in solid tumors

BACKGROUND

Combined multimodality therapy is becoming standard treatment for many solid tumors, but the role of intraoperative radiotherapy in the management of solid tumors remains uncertain. The aim is to review the indication, application, and outcomes of intraoperative radiotherapy in the management of nongynecological solid tumors.

METHODS

A literature search was performed using Medline, Embase, Ovid, and Cochrane database for studies between 1965 and 2008 assessing intraoperative radiotherapy, using the keywords "intraoperative radiotherapy," "colorectal cancer," "breast cancer," "gastric cancer," "pancreatic cancer," "soft tissue tumor," and "surgery." Only publications in English with available abstracts and regarding adult humans were included, and the evidence was critically evaluated.

RESULTS

Our search retrieved 864 publications. After exclusion of nonclinical papers, duplicated papers and exclusion of brachytherapy papers, 77 papers were suitable to assess the current role of intraoperative radiotherapy. The clinical application and evidence base of intraoperative radiotherapy for each cancer is presented.

CONCLUSIONS

Current studies in all common cancers show an additional benefit in local recurrence rates when intraoperative radiotherapy is included in the multimodal treatment. However, intraoperative radiotherapy may not improve overall survival and has significant morbidity depending on the site of the tumor. Intraoperative radiotherapy does have a role in the multidisciplinary management of solid tumors, but further studies are required to more precisely determine the extent of benefit.

Can unresectable colorectal cancer be cured?

A multimodality regimen that includes EBRT, chemotherapy, maximal surgical resection, and IORT, when used in patients with initially unresectable primary colon or rectal adenocarcinoma, is associated with excellent long-term local control, and a 5-year overall survival of 52%. Distant metastases account for most treatment failures, occurring in roughly 50%. Treatment-related morbidity is high, with a long-term complication rate that approaches 50%. These results suggest that selected patients with advanced unresectable disease benefit from an aggressive approach. Additional effort needs to focus on reducing the rate of systemic failure with more effective chemotherapy regimens and minimizing the frequency of long-term procedural complications.

A population-based study of radiotherapy in a cohort of patients with rectal cancer diagnosed between 1996 and 2000

AIMS

To study, in a population-based setting, the use of delayed radiotherapy (RT) in a cohort of 2008 unselected rectal cancer patients diagnosed between 1996 and 2000.

PATIENTS AND METHODS

Radiation within 6 months of diagnosis was considered part of the primary treatment (PRT). RT given 6 months or later after diagnosis or after PRT was considered as delayed or secondary RT (SRT). Number, percentage and cumulative proportion of patients receiving SRT were calculated. The odds for receiving SRT (total and for recurrent rectal cancer only) were studied by logistic regression analysis, taking into account age, gender, co-morbidity, socio-economic status, stage, prior PRT and RT department (2 departments, each serving general hospitals only).

RESULTS

Forty-six percent of all newly diagnosed patients received RT. Ten percent (n=203) received at least once SRT, either after PRT or as first RT, of which 96 patients for a relapsed rectal tumour (31 after PRT on the rectal tumour, 65 as a first radiation treatment). In a multivariate analysis of patients with rectal recurrence secondary pelvic irradiation was less often given after primary irradiation (OR: 0.7, 95% CI: 0.4-1.1). Patients with a stage III significantly more often received SRT on a recurrence (OR=2.5, 95% CI=1.4-4.5). Generally, patients in the eastern department received more often PRT and less often SRT for recurrence (OR: 0.5, 95% CI: 0.3-0.8).

CONCLUSIONS

Five percent of all patients with rectal cancer received SRT on a recurrent tumour, with a large variation between the two RT departments in the region.

Intraoperative radiotherapy for treatment of locally advanced and recurrent esophageal and gastric adenocarcinomas

Intraoperative radiotherapy (IORT) allows delivery of radiotherapy doses in excess of those typically deliverable with conventional external beam radiotherapy. IORT has potential utility in clinical situations, such as treatment of esophageal and gastric malignancies, in which the radiation tolerance of normal organs limits the dose that can be given with conventional radiotherapy techniques. We reviewed the records of 50 patients who received IORT for locally advanced primary or recurrent gastric or esophageal adenocarcinomas deemed unresectable for cure. IORT was given as a single fraction of electron beam radiotherapy (10-25 Gy) after maximal tumor resection: R0 in 42%, R1 in 46%, and R2 in 12%. Forty-eight patients also received external beam radiotherapy (8-55 Gy), 46 received radiosensitizing chemotherapy, and nine received systemic chemotherapy after radiotherapy. Outcomes were estimated with Kaplan-Meier analysis. Median survival was 1.6 years. Overall survival at 1, 2, and 3 years was 70%, 40%, and 27%. Of 42 patients who died, 37 died from cancer progression and three from multifactorial treatment toxicity. Median survival for patients with recurrent disease versus primary disease was 3.0 years versus 1.3 years (P < 0.05), with a delay of metastatic failure in patients with recurrent tumors (P = 0.06). At 3 years, distant metastatic failure was 79%, local failure was 10%, and regional failure was 15%. IORT for locally advanced primary or recurrent gastric malignancies effectively decreases the risk of local failure. For patients with isolated local recurrences, IORT may be effective salvage therapy. However, more effective systemic therapy is needed as a component of treatment.

Value of intraoperative radiotherapy in locally advanced rectal cancer

PURPOSE

This study was designed to analyze the results of a multimodality treatment using preoperative radiotherapy, followed by surgery and intraoperative radiotherapy in patients with primary locally advanced rectal cancer.

METHODS

Between 1987 and 2002, 123 patients with initial unresectable and locally advanced rectal cancer were identified in our prospective database, containing patient characteristics, radiotherapy plans, operation notes, histopathologic reports, and follow-up details. An evaluation of prognostic factors for local recurrence, distant metastases, and overall survival was performed.

RESULTS

All patients were treated preoperatively with a median dose of 50 Gy radiotherapy. Surgery was performed six to ten weeks after radiotherapy. Twenty-seven patients were treated with intraoperative radiotherapy because margins were incomplete or </=2 mm. Postoperative mortality was 2 percent. The median follow-up of all patients was 25.1 months. The overall five-year local control was 65 percent and the overall five-year survival was 50 percent. Positive lymph nodes and incomplete resections negatively influenced local control and overall survival. Intraoperative radiotherapy improved five-year local control (58 vs. 0 percent, P = 0.016) and overall survival (38 vs. 0 percent, P = 0.026) for patients with R1/2 resections.

CONCLUSIONS

The presented multimodality treatment is feasible with an acceptable mortality and a five-year overall survival of 50 percent. Addition of intraoperative radiotherapy for patients with a narrow or microscopic incomplete resection seems to overrule the unfavorable prognostic histologic finding.

intraoperative radiation therapy part 2. Clinical results

Intraoperative radiation therapy (IORT) has been used for over 30 years in Asia, Europe and America as a supplementary activity in the treatment of cancer patients with promising results. Modern IORT is carried out with electron beams (IOERT) produced by a linear accelerator generally used for external beam irradiation (EBRT) or a specialized mobile electron accelerator. HDR brachytherapy (HDR-IORT) has also been applied on selected locations. Retrospective analysis of clinical experiences in cancer sites such as operable pancreatic tumour, locally advanced/recurrent rectal cancer, head and neck carcinomas, sarcomas and cervical cancer are consistent with local tumour control promotion compared to similar clinical experiences without IORT. New emerging indications such as the treatment of breast cancer are presented. The IORT component of the therapeutical approach allows intensification of the total radiation dose without additional exposure of healthy tissues and improves dose-deposit homogeneity and precision. Results of the application of IORT on selected disease sites are presented with an analysis on future possibilities. To improve the methodology, clinical trials are required with multivariate analysis including patient, tumour and treatment characteristics, prospective evaluation of early and late toxicity, patterns of tumour recurrence and overall patient outcome.

Is En-Bloc Resection of Locally Recurrent Rectal Carcinoma Involving the Urinary Tract Indicated?

BACKGROUND

This study investigated morbidity, mortality, and long-term survival after multimodality management of locally recurrent rectal carcinoma involving the urinary tract.

METHODS

A total of 82 patients (63 males) were identified during 1987 to 2000. Data sources were a prospectively collected database of intraoperative radiotherapy, institutional tumor registry, and chart review. The median follow-up was 3.3 years and lasted until death or for at least 2 years on all patients.

RESULTS

A total of 20 (24%) of 82 patients had resection of urogenital tract structures without reconstruction. Sixty-two patients (76%) underwent reconstruction with ileal conduit (43%), ureteroneocystostomy (15%), or miscellaneous (18%). The mean number of fixation sites was 2.8 (SD, 1.5), and the mean number of organs at least partially resected was 2.6 (SD, 1.3). Eighty percent of patients underwent intraoperative radiotherapy among adjuvant treatments. Postoperative mortality was 2% (2 of 82), and morbidity was 39% (32 of 82), most frequently consisting of neuropathy and urinary leak (6% each). The overall 1-, 3-, and 5-year survival rates were 82%, 45%, and 19%, respectively. The median survival was 2.6 years. The number of sites involved was the only survival predictor at multivariate analysis (P < .001).

CONCLUSIONS

A multimodality approach for locally recurrent rectal carcinoma involving the urinary tract carries acceptable morbidity, mortality, and potential for long-term survival. The number of fixation sites correlates with a poorer prognosis.

Treatment Strategy for Locally Recurrent Rectal Cancer

Despite radical surgery, up to 33% of patients with rectal cancer will develop locoregional relapse. The management of these patients is particularly challenging. Surgery is the mainstay of treatment for those with a mobile recurrence. However, the majority of patients develop recurrence involving the pelvic wall. In these patients, multimodality therapy including radical surgery and intraoperative radiotherapy have been reported with 5-year survival of up to 31% and local control rates of 50-71%. The most important factor for obtaining long-term local control and survival is R0 resection. Extended surgery such as abdomino-sacral resection has not been popular because of 5-year survival rates of 16-31%, and significant postoperative morbidity. Re-recurrence following surgery occurs locally and in the lung, and remains a significant problem. In surgical treatment for local recurrence, surgeon-related factors are crucial. A staging system using degree of fixation and other prognostic factors should be developed so that appropriate treatment modalities are applied to each case.

Assessment of quality of life outcomes in the treatment of advanced colorectal malignancies

QOL assessment in oncology has made great strides in recent years. There was a difficult time initially, during which QOL tools were "thrown in" to many clinical trials as an afterthought, without a pre-specified scientific question. As expected from such a scattershot approach, the results were underwhelming and disappointing. The disappointing results from this period led many practitioners to question the value added by QOL assessment in oncology clinical trials. This healthy skepticism has led to a renaissance period, in which situation-specific and disease-specific QOL assessments have been developed and have contributed substantial information to the cause of the disease, the effects of treatments, and the experiences of cancer patients. Today, there is a dawning recognition that asking the patient directly about their QOL using the same scientific rigor required of other clinical outcomes can provide valuable data for prognosis, treatment, symptom management, and supportive care. With time and further successful experiences like those cited in this article, QOL assessment may eventually become as routinely collected and integrated into oncology clinical practice as pain and blood pressure assessments are today.

Radiosensitivity of human colon cancer cell enhanced by immunoliposomal docetaxel

AIM: To enhance the radiosensitivity of human colon cancer cells by docetaxel.

METHODS: Immunoliposomal docetaxel was prepared by coupling monoclonal antibody against carcinoembryonic antigen to cyanuric chloride at the PEG terminus of liposome. LoVo adenocarcinoma cell line was treated with immunoliposomal docetaxel or/and irradiation. MTT colorimetric assay was used to estimate cytotoxicity of immunoliposomal docetaxel and radiotoxicity. Cell cycle redistribution and apoptosis were determined with flow cytometry. Survivin expression in LoVo cells was verified by immunohistochemistry. D801 morphologic analysis system was used to semi-quantify immunohistochemical staining of survivin.

RESULTS: Cytotoxicity was induced by immunoliposomal docetaxel alone in a dose-dependent manner. Immunoli-posomal docetaxel yielded a cytotoxicity effect at a low dose of 2 nmol/L. With a single dose irradiation, the relative surviving fraction of LoVo cells showed a dose-dependent response, but there were no significant changes as radiation delivered from 4 to 8 Gy. Compared with liposomal docetaxel or single dose irradiation, strongly radiopotentiating effects of immunoliposomal docetaxel on LoVo cells were observed. A low dose of immunoliposomal docetaxel could yield sufficient radiosensitivity. Immunoliposomal docetaxel were achieved both specificity of the conjugated antibody and drug radiosensitization. Combined with radiation, immunoliposomal docetaxel significantly increased the percentage of G₂/M cells and induced apoptosis, but significantly decreased the percentage of cells in G₂/G₁ and S phase by comparison with liposomal docetaxel. Immunohistochemical analysis showed that the brown stained survivin was mainly in cytoplasm of LoVo cells. Semi-quantitative analysis of the survivin immunostaining showed that the expression of survivin in LoVo cells under irradiation with immunoliposomal docetaxel was significantly decreased.

CONCLUSION: Immunoliposomal docetaxel is strongly effective for target radiosensitation in LoVo colon carcinoma cells, and may offer the potential to improve local radiotherapy.