ASTRO Publishes Its First Clinical Guideline on Radiation Therapy for Gastric Cancer
In this article
A Comprehensive, Evidence-Based Roadmap
The American Society for Radiation Oncology (ASTRO) has published its first guideline defining the changing role of radiotherapy in gastric cancer treatment. This report covers every scenario, from the FLOT era to immunotherapy and from palliation to oligometastases.
Gastric cancer is a challenging disease that ranks fifth among causes of cancer death worldwide and requires a multidisciplinary treatment approach. The rise of perioperative chemotherapy (the FLOT regimen) and immunotherapy in recent years has prompted questions about radiotherapy’s (RT) place in the treatment algorithm.
This first ASTRO guidelinereviews the literature from 2001-2024 and gives clear answers about “Who, When and How” to treat with radiotherapy. It is more than a treatment schedule: it is a modern reference that also emphasizes health inequalities and patient-centered care.
ALGORITHM 1: Local/Locally Advanced Disease Management
1. The Role of Radiotherapy in Curative Treatment
Although perioperative chemotherapy is the “gold standard” for gastric cancer, not every patient is suitable for this intensive treatment, and surgery may not always achieve the desired result (D2 dissection, negative margins). Radiotherapy closes these gaps.
| Clinical Situation | ASTRO Recommendation | Recommendation Strength |
|---|---|---|
| Standard Resectable Disease | Perioperative Chemotherapy (FLOT) should be preferred. | STRONG |
| Patients Unable to Tolerate Chemotherapy | If the patient cannot receive FLOT/ECF, Preoperative Chemoradiotherapy (with 5-FU/Capecitabine) is recommended. | STRONG |
| Borderline Resectable | If the risk of R1/R2 resection is high, preoperative CRT may be added to chemotherapy to achieve clear surgical margins. | CONDITIONAL |
| Postoperative (Inadequate Surgery) | If D2 lymph node dissection was not performed (< D2) or surgical margins are positive (R1/R2), postoperative CRT is recommended. | CONDITIONAL |
Citing the recently published MATTERHORN trial, the guideline “conditionally” recommends adding immunotherapy (Durvalumab) to perioperative chemotherapy in resectable gastric cancer, regardless of microsatellite-stable (MSS) or unstable (MSI-H) status. This may become a new standard in the treatment schedule.
2. Management of Inoperable and Palliative Disease
In patients with gastric cancer who cannot undergo surgery or have metastatic disease, radiotherapy plays a vital role in both tumor control and symptom management.
🛑 Definitive Chemoradiotherapy
What should be done if a patient cannot tolerate or declines surgery, but the disease has not yet metastasized (localized disease)?
ASTRO Recommendation (STRONG): Chemoradiotherapy at a curative dose (45-50.4 Gy) should be given rather than chemotherapy alone or supportive care. This approach may provide long-term survival.
🌍 Oligometastatic Disease
If a patient has a small number of metastases at diagnosis (usually 1-5; oligometastases), is systemic treatment alone sufficient?
ASTRO Recommendation (CONDITIONAL): In addition to systemic treatment, “Metastasis-Directed Therapy” (SBRT or surgery) targeting metastases is recommended. This may prolong survival.
🩸 Radiotherapy for Symptom Management (Palliation)
- Bleeding Control (Strong Recommendation): For bleeding caused by gastric tumors, radiotherapy stops bleeding in up to 80% of cases.
- Pain Control (Strong Recommendation): Radiotherapy provides effective and lasting analgesia for tumor-related pain.
- Blockage/Obstruction (Conditional Recommendation): It may be used with a stent or alone for swallowing difficulties or gastric outlet obstruction.
3. Technical Details: Dose, Planning and Targets
The guideline establishes modern, precise treatment standards for radiation oncologists. Older “wide-field” irradiation has been replaced by highly targeted treatments.
🎯 Curative Dose Schedule
- Standard: 4500 cGy (45 Gy) / 25 Fractions (1.8 Gy daily).
- Technique: IMRT or VMAT (Recommended). 3D-CRT is acceptable but carries a high risk of side effects.
- Planning: Patients should receive treatment on an empty stomach every day to minimize stomach filling.
🕊️ Palliative Dose Schedules
Selected according to the patient’s life expectancy:
- 30 Gy / 10 Fractions: A more lasting effect in patients with good performance status.
- 20 Gy / 5 Fractions: Standard palliation.
- 8 Gy / 1 Fraction: For patients with poor performance status or urgent bleeding control.
📍 Target Volumes (What Are We Irradiating?)
Preoperative: Entire stomach + Perigastric lymph nodes + Celiac, splenic, hepatoduodenal and pancreaticoduodenal nodes.
Postoperative: Tumor bed + Anastomotic sites + Resection margins + Regional lymph nodes. (The gastric remnant is not irradiated if the surgical margin is negative).
👨⚕️ Drozdoğan Commentary and Future Perspective
This ASTRO guideline is a critical document consolidating radiotherapy’s role in oncology practice. Earlier extremes of “everyone” or “no one” have given way to the principle of “the right patient, at the right time.”
- Message 1: RT saves lives in patients who cannot receive FLOT or whose surgery was inadequate (D1).
- Message 2: For bleeding and pain, RT is a highly effective and often overlooked palliative tool.
- Message 3: Combining immunotherapy with radiotherapy is a field for future research.
Was this article helpful?
Your feedback helps us improve our content.
Reader comments
Share your comment
Your name and comment are published only after administrator approval. Your email address is never shown to visitors.
Be the first to comment.