Proton therapy at Harvard.

Area of Science:

• Radiation Oncology
• Medical Physics
• Particle Therapy

Background:

• Fractionated high-dose proton radiotherapy has been utilized since 1973 at the Harvard Cyclotron Laboratory (HCL).
• Collaborative efforts involve Massachusetts General Hospital (MGH) and Massachusetts Eye and Ear Infirmary (MEEI).

Purpose of the Study:

• To discuss proton treatment principles and planning procedures.
• To present results from major patient categories treated with proton therapy.
• To evaluate the efficacy and safety of proton beam therapy.

Main Methods:

• Analysis of data from 846 patients treated with fractionated proton therapy at HCL.
• Application of a relative biological effectiveness (RBE) of 1.1 for proton beams.
• Comparison of proton therapy outcomes with conventional treatments.

Main Results:

• Proton beam therapy is the preferred treatment for uveal melanomas, chordomas, and chondrosarcomas.
• Enhanced dose delivery (10-20% higher) is possible for prostate carcinoma, head and neck, ano-rectal, and retroperitoneal tumors.
• Good local control rates were observed across various patient groups.

Conclusions:

• Fractionated proton therapy provides improved dose distribution and allows for higher therapeutic doses.
• Proton therapy demonstrates significant efficacy in treating challenging tumors like uveal melanomas and skull base malignancies.
• The established RBE of 1.1 is consistent with observed normal tissue and tumor responses.