External Radiation Therapy

External Radiation Therapy: Applications and Advances

External Beam Radiation Therapy (EBRT) for Liver Cancers

Indications and Techniques for Hepatocellular Carcinoma (HCC) and Intrahepatic Cholangiocarcinoma (IHC)

External Beam Radiation Therapy (EBRT) is increasingly recognized as a valuable treatment option for primary liver cancers, including hepatocellular carcinoma (HCC) and intrahepatic cholangiocarcinoma (IHC). EBRT is recommended as a first-line treatment for patients with liver-confined HCC who are not candidates for curative therapies. It is also used as consolidative therapy after incomplete responses to liver-directed treatments and as a salvage option for local recurrences. For unresectable IHC, consolidative EBRT with or without chemotherapy is advised, typically following systemic therapy.

Palliative and Preoperative Uses

EBRT is conditionally recommended for palliative care in symptomatic primary HCC and macrovascular tumor thrombi. It can also serve as a bridge to liver transplantation or prior to surgery in carefully selected patients. The selection of dose-fractionation regimens and techniques should be tailored based on disease extent, location, underlying liver function, and available technologies.

EBRT in Cervical Cancer

Boost Techniques and Clinical Outcomes

In the treatment of locally advanced cervical cancer, EBRT is often combined with brachytherapy. However, high-tech EBRT has not shown superiority over image-guided brachytherapy for delivering a boost. Advances in EBRT, such as intensity-modulated radiation therapy (IMRT), have improved the ability to target tumors while sparing nearby critical structures, thereby reducing toxicity. The EMBRACE-II study highlights the importance of detailed protocols and comprehensive accreditation to enhance treatment conformality and reduce treated volumes.

EBRT for Prostate Cancer

Comparative Efficacy of EBRT and Combined Modalities

For locally advanced prostate cancer, combining EBRT with an iridium implant (IM) has shown superior outcomes in terms of biochemical or clinical failure compared to EBRT alone. This combination also resulted in lower post-radiation biopsy positivity rates. Additionally, the PACE-B trial demonstrated that stereotactic body radiotherapy (SBRT) has similar acute toxicity rates compared to conventionally fractionated or moderately hypofractionated EBRT, despite a more compressed treatment schedule.

EBRT for Brain Tumors

Efficacy in Malignant Gliomas

A randomized trial comparing surgery, EBRT, and carmustine (BCNU) with and without an interstitial radiotherapy boost using 125I seeds found no significant long-term survival advantage for the additional radiation dose. Age, Karnofsky score, and pathology were significant predictors of mortality.

EBRT for Orthopaedic Pathologies

Applications in Musculoskeletal Conditions

EBRT is essential in managing various musculoskeletal conditions, including bony and soft-tissue sarcomas, metastatic tumors, pigmented villonodular synovitis, and heterotopic ossification. It is often used in combination with surgery to reduce functional loss from cancer resections. Different energy types, such as protons, photons, electrons, and neutrons, each have unique roles and limitations in treating these pathologies.

Conclusion

External Beam Radiation Therapy (EBRT) continues to evolve, offering significant benefits across a range of cancers and other conditions. Advances in technology and technique have improved the precision and efficacy of EBRT, making it a cornerstone in modern oncology. Future research should focus on refining these techniques and exploring new applications to further enhance patient outcomes.

Summary

Not a yes or no question