Lattice Radiation Therapy Versus Conventional Radiation Therapy for the Palliation of Large Tumors

The goal of this randomized, phase III trial is to to determine if Spatially Fractionated Lattice Radiotherapy (SFRT) known as LATTICE therapy, leads to a greater reduction in pain or discomfort compared with conventional Radiation Therapy (RT) in patients with large tumours. This is evaluated by assessing if a greater proportion of patients who receive RT with SFRT will have an improvement in pain/discomfort at 30 days defined using the International Consensus Pain Response (ICPR) compared with those treated with conventional RT.

This study aims to compare the pain scores of patients receiving conventional radiotherapy and spatially fractionated lattice radiotherapy (SFRT). About half of all cancer patients will undergo palliative radiotherapy (RT) during their illness to manage distressing symptoms such as pain and bleeding. Great and more durable pain responses have been observed with higher dose RT, including stereotactic body radiation therapy (SBRT). Unfortunately, it is not possible to treat large tumors with SBRT for several reasons. SFRT is an innovative RT technique that addresses some of the limitations of SBRT. SFRT uses very high doses of radiation on specific spots inside the tumour, creating a lattice-like pattern. The outer edges of the tumor get a much lower dose, which helps protect nearby healthy organs from radiation. Early phase studies have shown excellent response rates in terms of pain as well as dramatic and rapid resolution of large tumours. Similar results with high responses and low toxicity have been reported in the setting of locally advanced and bulky lung cancer, head and neck cancer, and cervical cancer. This study determines if SFRT leads to a greater reduction in pain or discomfort compared with conventional radiation therapy (RT), defined using the International Consensus for Pain Response (ICPR) which includes the short form Brief Pain inventory questionnaire and self-reporting of opioid and/or co-analgesic use, measured at 30 +/- 7 days following treatment. Pain is defined by a worst pain score of 2 or greater at the target site on the short form Brief pain inventory, within 7 days prior to randomization. The primary endpoint of this study is improvement in pain response with secondary endpoints including treatment-related toxicity above grade 2, objective tumor response, survival, and health-economics endpoints.