Palliative Radiotherapy for Bleeding from Unresectable Gastric Cancer Using Three-Dimensional Conformal Technique

Reconsidering the Role of Radiotherapy for Inoperable Gastric Cancer: A Systematic Review of Gastric Radiotherapy Given With Definitive and Palliative Intent

AIMS

The role of radiotherapy (RT) for inoperable gastric cancer (IGC) is commonly low-dose, given reactively for symptoms (e.g. bleeding), in contrast to the oesophagus, where high quality evidence exists for higher doses of RT. This systematic review aims to evaluate the use of, and evidence for, definitive and high-dose palliative RT for IGC and whether a change in practice is warranted.

MATERIALS AND METHODS

Following registration with PROSPERO (CRD42022297080), MEDLINE, EMBASE and The Cochrane Library were searched in accordance with PRISMA standards for studies evaluating definitive (non-metastatic disease, BED10 >45Gy) or high-dose palliative RT (for symptom/local control, minimum BED10 >30Gy). A manual search of meeting proceedings and clinical trial registries was also performed.

RESULTS

31 studies were selected for analysis. 10 definitive studies totalling n = 354 patients receiving RT with 45-50.4Gy/25-28#, showed median overall survival ranging between 11 and 26.4 months, clinical complete response range 12%-45%, G3 gastrointestinal toxicity 0-31% (range) and RT completion rates ranging from 81% to 100%. 21 high-dose palliative studies (n = 955) mostly evaluated haemostatic control and reported 38 different RT regimens (most commonly 30Gy/10#). Bleeding response rate (RR) was 59.6%-90%, pain RR 45.5-100%, obstruction RR 52.9%-100%, G3 gastrointestinal toxicity <5% and RT completion 68%-100%. An additional American National Cancer Database review >4700 non metastatic IGC patients which combined both definitive and palliative doses found significant benefit to RT in addition to chemotherapy. Evidence regarding a dose-response relationship is conflicting, limited by retrospective data. Two studies report high quality -of-life (QOL) scores following gastric RT.

CONCLUSION

There is a body of mainly non-randomised, observational evidence showing high-dose RT is efficacious, safe and may maintain QOL for patients with IGC. A change in practice will require a prospective randomised controlled trial, which should explore the role of prophylactic, high-BED RT combined with optimal systemic therapy using modern IMRT techniques and RT quality assurance.

Hemostatic palliative radiotherapy for gastric cancer: A literature review

Background

Gastric cancer has a high prevalence in Asia and may only be diagnosed in advanced stages. Therefore, patients with gastric cancer may experience fatal symptoms, such as bleeding or stenosis at the time of consultation. In this review, we aimed to describe the effectiveness and toxicity of hemostatic radiotherapy (RT).

Methods

A total of 17 retrospective and 3 prospective studies were analyzed. The prescription dose, biologically effective dose, equivalent dose in 2 Gy fractions, response rate, survival prognosis, and toxicities were also reported.

Results

Using 20 studies, the following observations were made the hemostatic effect was ∼ 80 %, the mean survival time after irradiation was about 3 months, and prescribed doses of 30 Gy/10 fractions and 20 Gy/5 fractions were considered suitable.

Conclusion

In this review, studies on hemostatic irradiation have been summarized, and the most optimal treatment method has been proposed. 30 Gy/10 fractions and 20 Gy/5 fractions were ideal. However, because palliative RT is preferably completed within a short period of time, a randomized trial is needed to determine whether the 8 Gy/single fraction treatment is equivalent to fractionated RT. Therefore, more prospective studies are warranted to establish a standard of care for palliative RT in gastric cancer.

A Comprehensive Primer on Radiation Oncology for Non-Radiation Oncologists

Background: Multidisciplinary management is crucial in cancer diagnosis and treatment. Multidisciplinary teams include specialists in surgery, medical therapies, and radiation therapy (RT), each playing unique roles in oncology care. One significant aspect is RT, guided by radiation oncologists (ROs). This paper serves as a detailed primer for non-oncologists, medical students, or non-clinical investigators, educating them on contemporary RT practices. Methods: This report follows the process of RT planning and execution. Starting from the decision-making in multidisciplinary teams to the completion of RT and subsequent patient follow-up, it aims to offer non-oncologists an understanding of the RO's work in a comprehensive manner. Results: The first step in RT is a planning session that includes obtaining a CT scan of the area to be treated, known as the CT simulation. The patients are imaged in the exact position in which they will receive treatment. The second step, which is the primary source of uncertainty, involves the delineation of treatment targets and organs at risk (OAR). The objective is to ensure precise irradiation of the target volume while sparing the OARs as much as possible. Various radiation modalities, such as external beam therapy with electrons, photons, or particles (including protons and carbon ions), as well as brachytherapy, are utilized. Within these modalities, several techniques, such as three-dimensional conformal RT, intensity-modulated RT, volumetric modulated arc therapy, scattering beam proton therapy, and intensity-modulated proton therapy, are employed to achieve optimal treatment outcomes. The RT plan development is an iterative process involving medical physicists, dosimetrists, and ROs. The complexity and time required vary, ranging from an hour to a week. Once approved, RT begins, with image-guided RT being standard practice for patient alignment. The RO manages acute toxicities during treatment and prepares a summary upon completion. There is a considerable variance in practices, with some ROs offering lifelong follow-up and managing potential late effects of treatment. Conclusions: Comprehension of RT clinical effects by non-oncologists providers significantly elevates long-term patient care quality. Hence, educating non-oncologists enhances care for RT patients, underlining this report's importance.

The Impact of Palliative Radiation Therapy on Patients With Advanced Gastric Cancer: Results of a Retrospective Cohort Study

Aim In advanced gastric cancer, symptoms such as loss of appetite, stomach tightness, occasional pain, vomiting blood, and melena may occur. Palliative radiation therapy may be indicated in such cases. This study aimed to investigate the clinical outcomes of palliative radiotherapy in patients with advanced-stage gastric carcinoma. Methods From April 2018 to October 2022, consecutive patients with non-resected advanced gastric cancer who received radiation therapy for palliation of symptoms were included. Results A total of 23 patients with advanced-stage gastric carcinoma were analyzed in this study. Twelve male and 11 female patients were included. The median overall survival period was 3.9 months (95% confidence interval: 1.0-8.7 months). Sixteen patients required erythrocyte transfusion before radiotherapy; for 13 patients (83%), the required units of erythrocyte transfusion decreased after palliative radiotherapy. The mean erythrocyte transfusion units significantly decreased from 4.2 (standard deviation [SD]: 4.3) to 1.7 (SD: 3.6) (p = 0.02). No adverse events of grade ≥3 were observed in this study population. Conclusion Palliative radiation therapy for advanced gastric cancer yielded a good response rate and can be a useful treatment option.