Conventionally fractionated radiation therapy versus stereotactic body radiation therapy for locally advanced pancreatic cancer (CRiSP): An international systematic review and meta-analysis

Investigate the Dosimetric and Potential Clinical Benefits Utilizing Stereotactic Body Radiation Therapy With Simultaneous Integrated Boost Technique for Locally Advanced Pancreatic Cancer: A Comparison Between Photon and Proton Beam Therapy

Purpose

To investigate the potential clinical benefits of using stereotactic body radiation therapy (SBRT) with simultaneous integrated boost (SIB) technique for locally advanced pancreatic cancer (LAPC) among different treatment modalities and planning strategies, including photon and proton.

Method

A total of 19 patients were retrospectively selected in this study: 13 cases with the tumor located in the head of the pancreas and 6 cases with the tumor in the body of the pancreas. SBRT-SIB plans were generated using volumetric modulated arc therapy (VMAT), two-field Intensity Modulated Proton Therapy (IMPT), and three-field IMPT. The IMPT used the robust optimization parameters of ± 3.5% range and 5-mm setup uncertainties. Root-mean-square deviation dose (RMSD) volume histograms were used to evaluate the target coverage robustness quantitatively. Dosimetric metrics based on the dose-volume histogram (DVH), homogeneity index (HI), and normal tissue complication probability (NTCP) were analyzed to evaluate the potential clinical benefits among different planning groups.

Results

With a similar CTV and SIB coverage, two-field IMPT provided a lower maximum dose for the stomach (median: 18.6GyE, p<0.05) and duodenum (median: 32.62GyE, p<0.05) when the target was located in the head of the pancreas compared to VMAT and three-field IMPT. The risks of gastric bleed (3.42%) and grade ≥ 3 GI toxicity (4.55%) were also decreased. However, for the target in the body of the pancreas, VMAT showed a lower maximum dose for the stomach (median 30.93GyE, p<0.05) and toxicity of gastric bleed (median: 8.67%, p<0.05) compared to two-field IMPT and three-field IMPT, while other maximum doses and NTCPs were similar. The RMSD volume histogram (RVH) analysis shows that three-field IMPT provided better robustness for targets but not for OARs. Instead, three-field IMPT increased the Dmean of organs such as the stomach, duodenum, and intestine.

Conclusion

The results indicated that the tumor locations could play a critical role in determining clinical benefits among different treatment modalities. Two-field IMPT could be a better option for LAPC patients whose tumors are located in the head of the pancreas. It provides lower severe toxicity for the stomach and duodenum. Nevertheless, VMAT is preferred for the body with better protection for the possibility of gastric bleed.

Korean clinical practice guideline for pancreatic cancer 2021: A summary of evidence-based, multi-disciplinary diagnostic and therapeutic approaches

Pancreatic cancer is the eighth most common cancer and the fifth most common cause of cancer-related death in Korea. To enable standardization of management and facilitate improvements in outcome, a total of 53 multi-disciplinary experts in gastroenterology, surgery, medical oncology, radiation oncology, radiology, nuclear medicine, and pathology in Korea developed new recommendations that integrate the most up-to-date, evidence-based research findings and expert opinions. Recommendations were made on imaging diagnosis, endoscopic management, surgery, radiotherapy, palliative chemotherapy, and specific management procedures, including neoadjuvant treatment or adjuvant treatment for patients with resectable, borderline resectable, and locally advanced unresectable pancreatic cancer. This is the English version of the Korean clinical practice guideline for pancreatic cancer 2021. This guideline includes 20 clinical questions and 32 statements. This guideline represents the most standard guideline for the diagnosis and treatment of patients with pancreatic ductal adenocarcinoma in adults at this time in Korea. The authors believe that this guideline will provide useful and informative advice.

The role of radiotherapy in locally advanced pancreatic cancer

At diagnosis, about 15% of patients with pancreatic cancer present with a resectable tumour, 50% have a metastatic tumour, and 35% a locally advanced tumour, non-metastatic but unresectable due to vascular invasion, or borderline resectable. Despite the technical progress made in the field of radiation therapy and the improvement of the efficacy of chemotherapy, the prognosis of these patients remains very poor. Recently, the role of radiation therapy in the management of pancreatic cancer has been much debated. This review aims to evaluate the role of radiation therapy for patients with locally advanced tumours.

Multimodal Treatment with GEMOX Plus Helical Tomotherapy in Unresectable Locally Advanced Pancreatic Cancer: A Pooled Analysis of Two Phase 2 Studies

In locally advanced pancreatic cancer (LAPC), the combination of chemotherapy and radiotherapy is a widely used treatment option. We performed a pooled analysis, including an exploratory analysis for prognostic and predictive factors, of two phase 2 trials including 73 patients with LAPC, treated with gemcitabine and oxaliplatin (GEMOX) and hypofractionated tomotherapy. With a median follow-up of 36 months (range 1–65), median progression-free (PFS) and overall survival (OS) were 10.2 (95% confidence interval [CI] 7.8–13.2) and 14.3 (95% CI 12.0–18.1) months, respectively. The overall resectability rate was 23.3% (95% CI 13.6–33.0), and the R0 resection rate was 13.7% (95% CI 5.8–21.6). In the multivariate analysis, ECOG performance status (PS) 0 and low levels of CA 19–9 were associated with improved OS and PFS. Concerning OS, log(CA19–9) resulted in a hazard ratio (HR) of 1.20 (95% CI 1.02–1.42), p = 0.027. For ECOG PS 0, HR was 1.00; for PS 1, HR was 2.69 (95% CI 1.46–4.96); for PS 2, HR was 4.18 (95% CI 0.90–19.46); p = 0.003. Low CA19–9 levels were also predictive for resection, with an odds ratio of 0.71 (95% CI 0.52–0.97), p = 0.034. In conclusion, GEMOX and hypofractionated radiotherapy is a treatment option in LAPC. Further studies are needed to identify differences in tumor biology, which may help to predict resectability and prognosis.

Added Value of Radiotherapy Following Neoadjuvant FOLFIRINOX for Resectable and Borderline Resectable Pancreatic Cancer: A Systematic Review and Meta-Analysis

Background

The added value of radiotherapy following neoadjuvant FOLFIRINOX chemotherapy in patients with resectable or borderline resectable pancreatic cancer ((B)RPC) is unclear. The objective of this meta-analysis was to compare outcomes of patients who received neoadjuvant FOLFIRINOX alone or combined with radiotherapy.

Methods

A systematic literature search was performed in Embase, Medline (ovidSP), Web of Science, Scopus, Cochrane, and Google Scholar. The primary endpoint was pooled median overall survival (OS). Secondary endpoints included resection rate, R0 resection rate, and other pathologic outcomes.

Results

We included 512 patients with (B)RPC from 15 studies, of which 7 were prospective nonrandomized studies. In total, 351 patients (68.6%) were treated with FOLFIRINOX alone (8 studies) and 161 patients (31.4%) were treated with FOLFIRINOX and radiotherapy (7 studies). The pooled estimated median OS was 21.6 months (range 18.4–34.0 months) for FOLFIRINOX alone and 22.4 months (range 11.0–37.7 months) for FOLFIRINOX with radiotherapy. The pooled resection rate was similar (71.9% vs. 63.1%, p = 0.43) and the pooled R0 resection rate was higher for FOLFIRINOX with radiotherapy (88.0% vs. 97.6%, p = 0.045). Other pathological outcomes (ypN0, pathologic complete response, perineural invasion) were comparable.

Conclusions

In this meta-analysis, radiotherapy following neoadjuvant FOLFIRINOX was associated with an improved R0 resection rate as compared with neoadjuvant FOLFIRINOX alone, but a difference in survival could not be demonstrated. Randomized trials are needed to determine the added value of radiotherapy following neoadjuvant FOLFIRINOX in patients with (B)PRC.

Supplementary Information

The online version contains supplementary material available at 10.1245/s10434-021-10276-8.

Risk Adapted Ablative Radiotherapy After Intensive Chemotherapy for Locally Advanced Pancreatic Cancer

Background and Objective

To assess the efficacy of a Risk-Adapted Ablative Radiotherapy (RAdAR) approach, after intensive induction chemotherapy, in patients with locally advanced pancreatic cancer (LAPC).

Material and Methods

Patients with LAPC who received RAdAR following induction chemotherapy from January 2017 to December 2019 were included in this observational study. The RAdAR approach consisted of an anatomy- and simultaneous integrated boost (SIB)-based dose prescription strategy. RAdAR was delivered with stereotactic ablative radiation therapy (SAbR), administering 30 Gy in 5 fractions to the tumor volume (PTV_t) and 50 Gy SIB (BED₁₀ 100 Gy) to the vascular involvement, or with (hypo-)fractionated ablative radiotherapy (HART) prescribing 50.4 Gy in 28 fractions to the PTV_t, with a vascular SIB of 78.4 Gy (BED₁₀ 100 Gy). Primary end points were freedom from local progression (FFLP), overall survival (OS), and progression-free survival (PFS).

Results

Sixty-four LAPC patients were included. Induction chemotherapy consisted of gemcitabine/nab-paclitaxel in 60.9% and FOLFIRINOX in 39.1% of cases. SAbR was used in 52 (81.2%) patients, and HART in 12 (18.8%). After RAdAR, surgery was performed in 17 (26.6%) patients. Median follow-up was 16.1 months. Overall local control (LC) rate was 78.1%, with no difference between resected and non-resected patients (2-year FFLP 75.3% vs 56.4%; p = 0.112). Median OS and PFS were 29.7 months and 8.7 months, respectively, for the entire cohort. Resected patients had a better median OS (not reached versus 26.1 months; p = 0.0001) and PFS (19 versus 5.6 months; p < 0.0001) compared to non-resected patients. In non-resected patients, no significant difference was found between SAbR and HART for median FFLP (28.1 versus 18.5 months; p = 0.614), OS (27.4 versus 25.3 months; p = 0.624), and PFS (5.7 versus 4.3 months; p = 0.486). One patient (1.6%) experienced acute grade 4 gastro-intestinal bleeding. No other acute or late grade ≥ 3 toxicities were observed.

Conclusions

The RAdAR approach, following intensive induction chemotherapy, is an effective radiation treatment strategy for selected LAPC patients, representing a promising therapeutic option in a multimodality treatment regimen.

Radiotherapy for Resectable and Borderline Resectable Pancreas Cancer: When and Why?

The role of (chemo) radiation in the perioperative management of patients with resectable and borderline resectable pancreatic ductal adenocarcinoma is controversial. Herein, we review and interpret existing data relating to the ability of (chemo) radiation to "downstage" pancreatic tumors, delay recurrence, and prolong patients' survival. In sum, the evidence suggests that while neoadjuvant (chemo) radiation may impact pathologic metrics favorably, it rarely converts anatomically unresectable tumors to resectable ones. And while data do support the ability of (chemo)radiation to delay cancer progression, its ability to prolong longevity has not been confirmed. It is possible that (chemo)radiation is effective in prolonging the survival of select patients, but to date, this cohort remains undefined due to heterogeneity in both the populations studied and the regimens used to treat them. Based on our interpretation of existing data, we currently administer neoadjuvant and adjuvant (chemo)radiation selectively to patients with localized pancreatic cancer who we consider at highest risk for local progression. We may also use it as an alternative to pancreatectomy in patients who are poor candidates for surgery. Ultimately, the role of (chemo)radiation in these settings is evolving. Better studies of patients most likely to benefit from its local effects are necessary to clearly define its place within the perioperative treatment algorithms used for patients with localized pancreatic cancer.

[Stereotactic body radiotherapy for locally advanced pancreatic cancer: A systemic review]

Stereotactic body radiation therapy (SBRT) for locally advanced pancreatic cancer (LAPC) is an emerging treatment option. Most studies showed local control of approximately 75% with no evidence of improved overall survival. Gastrointestinal toxicities could be significant, ranging up to 22% for acute toxicities≥grade 3+ and 44% for late toxicities≥grade 3+. Currently, no standardized guidelines for treatment and management scheme. We conducted a systemic review of published prospective and retrospective trials to evaluate the efficacy, safety, technical data, and discuss future directions.

Dosimetric Feasibility Study of Dose Escalated Stereotactic Body Radiation Therapy (SBRT) in Locally Advanced Pancreatic Cancer (LAPC) Patients: It Is Time to Raise the Bar

Background and Objective

To assess the dosimetric feasibility of a stereotactic body radiotherapy (SBRT) dose escalated protocol, with a simultaneous integrated boost (SIB) and a simultaneous integrated protection (SIP) approach, in patients with locally advanced pancreatic cancer (LAPC).

Material and Methods

Twenty LAPC lesions, previously treated with SBRT at our Institution, were re-planned. The original prescribed and administered dose was 50/30/25 Gy in five fractions to PTV_sib (tumor-vessel interface [TVI])/PTV_t (tumor volume)/PTV_sip (overlap area between PTV_t and planning organs at risk volume [PRV_oars]), respectively. At re-planning, the prescribed dose was escalated up to 60/40/33 Gy in five fractions to PTV_sib/PTV_t/PTV_sip, respectively. All plans were performed using an inspiration breath hold (IBH) technique and generated with volumetric modulated arc therapy (VMAT). Well-established and accepted OAR dose constraints were used (D_0.5cc < 33 Gy for luminal OARs and D_0.5cc < 38 Gy for corresponding PRV_oars). The primary end-point was to achieve a median dose equal to the prescription dose for the PTV_sib with D₉₈≥ 95% (95% of prescription dose is the minimum dose), and a coverage for PTV_t and PTV_sip of D₉₅≥95%, with minor deviations in OAR dose constraints in < 10% of the plans.

Results

PTV_sib median (± SD) dose/D₉₅/conformity index (CI) were 60.54 (± 0.85) Gy/58.96 (± 0.86) Gy/0.99 (± 0.01), respectively; whilst PTV_t median (± SD) dose/D₉₅ were 44.51 (± 2.69) Gy/38.44 (± 0.82) Gy, and PTV_sip median (± SD) dose/D₉₅ were 35.18 (± 1.42) Gy/33.01 (± 0.84) Gy, respectively. With regard to OARs, median (± SD) maximum dose (D_0.5cc) to duodenum/stomach/bowel was 29.31 (± 5.72) Gy/25.29 (± 6.90) Gy/27.03 (± 5.67) Gy, respectively. A minor acceptable deviation was found for a single plan (bowel and duodenum D_0.5cc=34.8 Gy). V38 < 0.5 cc was achieved for all PRV luminal OARs.

Conclusions

In LAPC patients SBRT, with a SIB/SIP dose escalation approach up to 60/40/33 Gy in five fractions to PTV_sib/PTV_t/PTV_sip, respectively, is dosimetrically feasible with adequate PTVs coverage and respect for OAR dose constraints.

Making radiation therapy more effective in the era of precision medicine

Cancer has become a leading cause of death and constitutes an enormous burden worldwide. Radiation is a principle treatment modality used alone or in combination with other forms of therapy, with 50%–70% of cancer patients receiving radiotherapy at some point during their illness. It has been suggested that traditional radiotherapy (daily fractions of approximately 1.8–2 Gy over several weeks) might select for radioresistant tumor cell sub-populations, which, if not sterilized, give rise to local treatment failure and distant metastases. Thus, the challenge is to develop treatment strategies and schedules to eradicate the resistant subpopulation of tumorigenic cells rather than the predominant sensitive tumor cell population. With continued technological advances including enhanced conformal treatment technology, radiation oncologists can increasingly maximize the dose to tumors while sparing adjacent normal tissues, to limit toxicity and damage to the latter. Increased dose conformality also facilitates changes in treatment schedules, such as changes in dose per treatment fraction and number of treatment fractions, to enhance the therapeutic ratio. For example, the recently developed large dose per fraction treatment schedules (hypofractionation) have shown clinical advantage over conventional treatment schedules in some tumor types. Experimental studies suggest that following large acute doses of radiation, recurrent tumors, presumably sustained by the most resistant tumor cell populations, may in fact be equally or more radiation sensitive than the primary tumor. In this review, we summarize the related advances in radiotherapy, including the increasing understanding of the molecular mechanisms of radioresistance, and the targeting of these mechanisms with potent small molecule inhibitors, which may selectively sensitize tumor cells to radiation.

Outcomes of Neoadjuvant Chemotherapy Versus Chemoradiation in Localized Pancreatic Cancer: A Case-Control Matched Analysis

BACKGROUND

Neoadjuvant therapy is increasingly used for patients with pancreatic ductal adenocarcinoma (PDAC). It is unknown whether neoadjuvant chemoradiotherapy is more effective than chemotherapy (NCRT vs. NAC). We aim to compare pathological and survival outcomes of NCRT and NAC in patients with PDAC.

PATIENTS AND METHODS

Single-center analysis of PDAC patients treated with NCRT or NAC followed by resection between December 2008 and December 2018 was performed. Average treatment effect (ATE) was estimated after case-control matching using Mahalanobis distance nearest-neighbor matching. Inverse probability weighted estimates (IPWE)-based ATE was estimated for disease-free survival (DFS) and overall survival (OS).

RESULTS

Among the 418 patients (mean age 66.8 years, 51% female) included in the study, 327 received NAC and 91 received NCRT. NCRT patients had higher rates of locally advanced disease, number of neoadjuvant chemotherapy cycles, more chemotherapy regimen crossover (gemcitabine and 5-FU based), and were more likely to undergo open surgical procedures and/or vascular resection (all p < 0.05). After matched analysis, NCRT was associated with a significant reduction in lymph node positive disease [ATE = (-)0.24, p = 0.007] and lymphovascular invasion [ATE = (-)0.20, p = 0.02]. While NCRT was associated with significantly improved DFS by 9.5 months (p = 0.006), it did not affect OS by IPWE-based ATE after adjusting for adjuvant therapy (ATE = 5.5 months; p = 0.32).

CONCLUSION

Compared with NAC alone, NCRT is associated with improved pathologic surrogates and disease-free survival, but not overall survival in patients with PDAC.

A phase II study of stereotactic radiotherapy after FOLFIRINOX for locally advanced pancreatic cancer (LAPC-1 trial): Long-term outcome

PURPOSE

To report the long-term outcome of a multicenter phase II study with FOLFIRINOX followed by stereotactic body radiotherapy (LAPC-1 trial) in patients with locally advanced pancreatic cancer (LAPC).

MATERIALS AND METHODS

Patients with histological confirmation of LAPC inoperable at diagnosis were enrolled. Induction therapy with 8 cycles of FOLFIRINOX was administered. If no disease progression was found after chemotherapy, patients received stereotactic body radiotherapy (SBRT) at a total dose of 40 Gy in 5 fractions.

RESULTS

In LAPC-1 trial, 50 patients were included, but due to disease progression in 11 patients under chemotherapy, 39 patients received stereotactic SBRT after FOLFIRINOX treatment. In whole population, the 1- and 3-year overall survival (OS) were 62% and 10%, respectively. Median follow-up was 13 months. The SBRT group had median OS of 18 months (95% CI 13.2-21.5) versus 5 months (95% CI 4.1-6.7) in non-SBRT group (p<0.001). After chemoradiotherapy, seven patients underwent surgery achieving a radical resection. Patients who underwent surgery had a 3-years OS of 43% compared to 6.5% in the unresected group (p=0.03). Four patients developed grade ≥ 3 adverse events during SBRT.

CONCLUSIONS

Long-term survival has been found in patients with LAPC underwent FOLFIRINOX followed by SBRT. This approach increased the probability of a radical surgery. The resected patients achieved a significant better survival compared to unresected group.

Immunomodulatory Effects of Radiotherapy

Radiation therapy (RT), an integral component of curative treatment for many malignancies, can be administered via an increasing array of techniques. In this review, we summarize the properties and application of different types of RT, specifically, conventional therapy with x-rays, stereotactic body RT, and proton and carbon particle therapies. We highlight how low-linear energy transfer (LET) radiation induces simple DNA lesions that are efficiently repaired by cells, whereas high-LET radiation causes complex DNA lesions that are difficult to repair and that ultimately enhance cancer cell killing. Additionally, we discuss the immunogenicity of radiation-induced tumor death, elucidate the molecular mechanisms by which radiation mounts innate and adaptive immune responses and explore strategies by which we can increase the efficacy of these mechanisms. Understanding the mechanisms by which RT modulates immune signaling and the key players involved in modulating the RT-mediated immune response will help to improve therapeutic efficacy and to identify novel immunomodulatory drugs that will benefit cancer patients undergoing targeted RT.

Stereotactic body radiotherapy vs conventionally fractionated chemoradiation in locally advanced pancreatic cancer: A multicenter case-control study (PAULA-1)

Conventionally fractionated chemoradiation (CRT) or chemotherapy (CHT) are considered as standard options in locally advanced pancreatic cancer (LAPC) while stereotactic body radiotherapy (SBRT) is an emerging treatment in this setting. The aim of this study was to compare two cohorts of LAPC patients treated with SBRT ± CHT vs CRT ± CHT in terms of local control (LC), distant metastases-free survival (DMFS), progression-free survival (PFS), overall survival (OS), and toxicity. Eighty patients were included. Patients in the two cohorts were matched according to: age ≤/>65 years, tumor diameter (two cut-offs: </≥3.0 and </≥3.9 cm), clinical tumor stage and clinical nodal stage, neoadjuvant CHT, and adjuvant CHT. Median prescribed total dose was 30.0 Gy (range: 18.0-37.5) and 54.0 Gy (18.0-63.0) in SBRT and CRT cohorts, respectively. Toxicity was evaluated by CTCAE v4.0 scale. Survival curves were calculated by Kaplan-Meier method. For hypothesis testing an equivalence and a non-inferiority test was calculated. No statistically significant differences in terms of acute and late toxicity, DMFS, PFS, and OS were recorded among the two cohorts. Median, 1-, and 2-year LC was: 16.0 months, 53.1%, and 40.5% in the CRT cohort and 22.0 months, 80.4%, and 49.8% in the SBRT cohort, respectively (P: .017). A statistically non-inferiority significance was recorded in terms of OS between CRT and SBRT (P = .031). Patients treated with SBRT showed higher LC rate and similar OS compared to CRT. Therefore, the design of confirmatory randomized studies comparing SBRT and CRT seems justified.

Considerations for the treatment of pancreatic cancer during the COVID-19 pandemic: the UK consensus position

The coronavirus disease 2019 (COVID-19) pandemic epicentre has moved to the USA and Europe, where it is placing unprecedented demands on healthcare resources and staff availability. These service constraints, coupled with concerns relating to an increased incidence and severity of COVID-19 among patients with cancer, should lead to re-consideration of the risk-benefit balance for standard treatment pathways. This is of particular importance to pancreatic cancer, given that standard diagnostic modalities such as endoscopy may be restricted, and that disease biology precludes significant delays in treatment. In light of this, we sought consensus from UK clinicians with an interest in pancreatic cancer for management approaches that would minimise patient risk and accommodate for healthcare service restrictions. The outcomes are described here and include recommendations for treatment prioritisation, strategies to bridge to later surgical resection in resectable disease and factors that modify the risk-benefit balance for treatment in the resectable through to the metastatic settings. Priority is given to strategies that limit hospital visits, including through the use of hypofractionated precision radiotherapy and chemoradiotherapy treatment approaches.

Novel strategies using modern radiotherapy to improve pancreatic cancer outcomes: toward a new standard?

Pancreatic ductal adenocarcinoma (PDAC) remains one of the most aggressive solid tumours with an estimated 5-year overall survival rate of 7% for all stages combined. In this highly resistant disease that is located in the vicinity of many radiosensitive organs, the role of radiotherapy (RT) and indications for its use in this setting have been debated for a long time and are still under investigation. Although a survival benefit has yet to be clearly demonstrated for RT, it is the only technique, other than surgery, that has been demonstrated to lead to local control improvement. The adjuvant approach is now strongly challenged by neoadjuvant treatments that could spare patients with rapidly progressive systemic disease from unnecessary surgery and may increase free margin (R0) resection rates for those eligible for surgery. Recently developed dose-escalated RT treatments, designed either to maintain full-dose chemotherapy or to deliver a high biologically effective dose, particularly to areas of contact between the tumour and blood vessels, such as hypofractionated ablative RT (HFA-RT) or stereotactic body RT (SBRT), are progressively changing the treatment landscape. These modern strategies are currently being tested in prospective clinical trials with encouraging preliminary results, paving the way for more effective treatment combinations using novel targeted therapies. This review summarizes the current literature regarding the use of RT for the treatment of primary PDAC, describes the limitations of conventional RT, and discusses the emerging role of dose-escalated RT and heavy-particle RT.

Recommendations for the use of radiation therapy in managing patients with gastrointestinal malignancies in the era of COVID-19

As of April 6, 2020, there are over 1,200,000 reported cases and 70,000 deaths worldwide due to COVID-19, the disease caused by the SARS-CoV-2 virus, and these numbers rise exponentially by the day [1]. According to the Centers for Disease Control (CDC), the most effective means of minimizing the spread of the virus is through reducing interactions between individuals [2]. We performed a review of the literature, as well as national and international treatment guidelines, seeking data in support of the RADS principle (Remote visits, Avoid radiation, Defer radiation, Shorten radiation) [3] as it applies to gastrointestinal cancers. The purpose of the present work is to guide radiation oncologists managing patients with gastrointestinal cancers during the COVID-19 crisis in order to maintain the safety of our patients, while minimizing the impact of the pandemic on cancer outcomes.