Radiation Therapy for Rectal Cancer

Publication Date: November 25, 2024
Last Updated: November 26, 2024

Recommendations for neoadjuvant RT indications

For patients with rectal cancer, pelvic MRI with a rectal cancer protocol is recommended for preoperative clinical T and N staging. ( Moderate , Strong )
608
For patients with rectal cancer, testing the biopsy specimen for MMR/MSI is recommended. ( Moderate , Strong )
608
For patients with stage II-III rectal cancer, neoadjuvant RT is recommended. ( High , Strong )

Implementation remark: For patients at lower risk of locoregional recurrence, neoadjuvant RT may not always be appropriate.

608
For patients with stage II or III rectal cancer who wish to pursue nonoperative management, RT is recommended as part of a total neoadjuvant therapy regimen. ( Low , Conditional )
  • Lower risk is defined as a cT2 or cT3a/b tumor >5 cm from the anal verge, with radiographically <4 lymph nodes >1 cm in short axis and with mrCRM ≥2 mm and no mrEMVI.
  • Favorable response is defined as >20% decrease in the size of the primary tumor on imaging and endoscopic evaluation.
608
For patients with stage II or III rectal cancer at lower risk of locoregional recurrence, upfront surgery with omission of neoadjuvant RT is conditionally recommended. ( Moderate , Conditional )

Implementation remark: Lower risk is defined as a cT2 or cT3a/b tumor >5 cm from the anal verge, with radiographically <4 lymph nodes >1 cm in short axis and with mrCRM ≥2 mm and no mrEMVI.

608
For patients with stage II or III rectal cancer who wish to pursue nonoperative management, RT is recommended as part of a total neoadjuvant therapy regimen. ( Moderate , Strong )
608
For patients with cT1-2N0 rectal cancer who may need an abdominoperineal resection, neoadjuvant RT is conditionally recommended to improve the chance of sphincter preservation. ( Low , Conditional )

Expert Opinion

608
For patients with rectal cancer where radiation is indicated, RT should be performed preoperatively rather than postoperatively. (High-quality evidence, Strong recommendation)
608
For patients with MMRd/MSI-H rectal cancer, omission of neoadjuvant RT is recommended after a clinical complete response to upfront treatment with checkpoint inhibitors. ( Low , Strong )
608

Recommendations for neoadjuvant regimens

For patients with rectal cancer receiving neoadjuvant RT with conventional fractionation, 5000-5600 cGy in 25-31 fractions with concurrent capecitabine or continuous infusion 5-fluorouracil is recommended. (Moderate to high, Strong )
Implementation remark: A prescribed dose >5040 cGy is considered only for patients who may be candidates for future nonoperative management.
608
For patients with rectal cancer receiving neoadjuvant short-course RT, 2500 cGy in 5 fractions without concurrent chemotherapy is recommended. (High-quality evidence, Strong recommendation)
608
For patients with rectal cancer undergoing neoadjuvant chemoradiation, only concurrent 5-fluorouracil or capecitabine is recommended with RT for radiosensitization. (High-quality evidence, Strong recommendation)
608
For patients with cT3-4 or cN+ rectal cancer undergoing neoadjuvant therapy, a TNT approach is recommended. ( High , Strong )
Implementation remark: For patients at lower risk of recurrence, TNT may not always be appropriate.
608
For patients with rectal cancer undergoing neoadjuvant therapy without tumor factors that portend increased local recurrence risk, TNT with chemotherapy before or after long-course chemoradiation, or after short-course RT is recommended. ( High , Strong )

Implementation remarks:

  • Risk factors for increased local recurrence include cT3 tumors in the low rectum (<5 cm from anal verge); mrCRM <2 mm; cT4 tumor; presence of mrEMVI; or lateral pelvic lymph nodes.
  • For patients at lower risk of recurrence, TNT may not always be appropriate.
608
For patients with rectal cancer undergoing neoadjuvant therapy with tumor factors that portend increased local recurrence risk, TNT with chemotherapy before or after long-course chemoradiation is recommended. ( High , Strong )
Implementation remark: Risk factors for increased local recurrence include cT3 tumors in the low rectum (<5 cm from anal verge); mrCRM <2 mm; cT4 tumor; presence of mrEMVI; or lateral pelvic lymph nodes.
608
For patients with rectal cancer undergoing neoadjuvant therapy with tumor factors that portend increased local recurrence risk, TNT with short-course RT followed by chemotherapy is conditionally recommended. ( Moderate , Conditional )
Implementation remark: Risk factors for increased local recurrence include cT3 tumors in the low rectum (<5 cm from anal verge); mrCRM <2 mm; cT4 tumor; presence of mrEMVI; or lateral pelvic lymph nodes.
608
For patients with rectal cancer receiving neoadjuvant chemotherapy as a component of TNT, the following regimens are recommended:
  • •3-4 months of FOLFOX or CAPOX
  • (1) before or after chemoradiation OR
  • (2) after short-course RT
  • •3 months of induction mFOLFIRINOX before chemoradiation
(Moderate to high, Strong )

Implementation remark: Use mFOLFIRINOX with caution especially for patients who are elderly, have poor performance status, or have significant comorbidities.

Quality of evidence is high for FOLFOX/CAPOX

Quality of evidence is moderate for mFOLFIRINOX

608

Recommendations for nonoperative or LE approaches

Organ preservation through TNT followed by NOM is conditionally recommended after multidisciplinary discussion if a complete clinical response is achieved in patients with cT3-4 or cN+ rectal cancer who:•prefer an organ preservation approach, AND•will undergo close follow-up by a multidisciplinary team. ( Moderate , Conditional )
608
Organ preservation through neoadjuvant chemoradiation and local excision is conditionally recommended after multidisciplinary discussion if a near-complete response is achieved in patients with cT2-3N0 rectal cancer who:
  • have tumors in the low-to-mid rectum, maximum size 4 cm, AND
  • prefer an organ preservation approach, AND
  • will undergo close follow-up by a multidisciplinary team.
( Moderate , Conditional )
608
For patients with rectal cancer considering NOM after RT, conventional fractionation of 5000-5600 cGy in 25-31 fractions with concurrent chemotherapy is recommended. ( Moderate , Strong )
608
For patients with rectal cancer considering local excision after RT, conventional fractionation of 5000-5040 cGy in 25-28 fractions with concurrent chemotherapy is recommended. ( Moderate , Strong )
608
For patients with rectal cancer for whom NOM is a priority, concurrent chemoradiation followed by consolidation chemotherapy is recommended. ( Moderate , Strong )
608
For patients with rectal cancer considering NOM, assessment for response is recommended with rectal protocol MRI, CT abdomen/pelvis, and proctoscopy/sigmoidoscopy with DRE 2-3 months after completion of treatment. ( Moderate , Strong )
608
For patients with rectal cancer undergoing NOM or LE, surveillance is recommended with:
• proctoscopy/sigmoidoscopy with DRE every 3 months for the first 2 years, then every 6-12 months thereafter,
• rectal protocol MRI every 3-6 months for the first 2 years, then every 6-12 months thereafter, and
• cross-sectional imaging of the chest, abdomen and pelvis every 6-12 months for the first 2 years, then every 12 months thereafter.
( Moderate , Strong )

Implementation remark: Follow-up should continue for a minimum of 5 years.

608

Recommendations for appropriate treatment volumes and techniques

For patients with cT3-4 and/or cN + rectal cancers, inclusion of the rectum, mesorectal nodes, presacral nodes, internal iliac nodes, and obturator nodes in the CTV is recommended. (High-quality evidence, Strong recommendation)
608
For patients with rectal tumors invading an anterior organ or structure (eg, prostate, seminal vesicles, cervix, vagina, and/or bladder), inclusion of the external iliac nodes in the CTV is conditionally recommended in addition to the rectum, mesorectal nodes, presacral nodes, internal iliac nodes, and obturator nodes. (Low-quality evidence, Conditional recommendation)
608
For patients with rectal cancer involving the anal canal, inclusion of inguinal and external iliac nodes in the CTV is conditionally recommended in addition to the rectum, mesorectal nodes, presacral nodes, internal iliac nodes, and obturator nodes. (, Conditional recommendation)
Expert Opinion
608
For patients with rectal cancer treated with RT, an IMRT/VMAT technique is conditionally recommended. (Low-quality evidence, Conditional recommendation)
Implementation remark: IMRT/VMAT may be beneficial when the external iliac nodes and/or the inguinal nodes require treatment or when 3-D conformal techniques may confer a higher risk for toxicity.
608
For patients with rectal cancer receiving IMRT/VMAT, daily image guidance to verify localization is conditionally recommended. (, Conditional recommendation)
Expert opinion
608
For patients with rectal cancer in whom the CTV does not include the inguinal nodes, simulation prone with a belly board is conditionally recommended. (Low-quality evidence, Conditional recommendation)
608

Recommendation Grading

Overview

Title

Radiation Therapy for Rectal Cancer

Authoring Organization

American Society for Radiation Oncology

Publication Month/Year

November 25, 2024

Last Updated Month/Year

November 26, 2024

Supplemental Implementation Tools

Document Type

Guideline

External Publication Status

Published

Country of Publication

US

Document Objectives

With the results of several recently published clinical trials, this guideline focused update provides evidence-based recommendations for the indications and dose-fractionation regimens for neoadjuvant radiation therapy (RT), optimal sequencing of RT and systemic therapy in the context of total neoadjuvant therapy (TNT), and considerations for selective omission of RT and surgery for rectal cancer.

PICO Questions

  1. What are the indications for neoadjuvant RT for operable rectal cancer?

  2. What neoadjuvant regimens are appropriate for patients with operable rectal cancer?

  3. What are the appropriate indications and considerations of a nonoperative (active surveillance) or local excision approach after definitive/preoperative chemoRT?

  4. What are the appropriate treatment volumes, dose constraints, and techniques for patients treated with RT

Inclusion Criteria

Male, Female, Adult, Older adult

Health Care Settings

Ambulatory, Hospital, Outpatient, Radiology services

Intended Users

Nurse, nurse practitioner, physician, physician assistant, social worker

Scope

Treatment, Management

Diseases/Conditions (MeSH)

D011827 - Radiation, D012004 - Rectal Neoplasms

Keywords

rectal cancer, radiation therapy (RT), rectal adenocarcinomas, neoadjuvant therapy

Source Citation

Radiation Therapy for Rectal Cancer: An ASTRO Clinical Practice Guideline Focused Update, Wo, Jennifer Y., Ashman, Jonathan B., Bhadkamkar, Nishin A., Bradfield, Lisa, Chang, Daniel T., Hanna, Nader, Hawkins, Maria, Holtz, Michael, Kim, Edward, Kelly, Patrick, Ling, Diane C., Olsen, Jeffrey R., Palta, Manisha, Raldow, Ann C., Ruiz-Garcia, Erika, Sheybani, Arshin, Stitzenberg, Karyn B., Das, Prajnan, Practical Radiation Oncology, 1879-8500, doi: 10.1016/j.prro.2024.11.003

Supplemental Methodology Resources

Data Supplement, Data Supplement