Proton therapy for inflammatory breast cancer: research

Treatment of inflammatory breast cancer is a difficult problem for radiotherapists due to the lesion of cutaneous lymphatic vessels, which often requires the coverage of large volumes of targets and booster doses in the chest wall area. This feature of the disease makes the use of advanced planning methods especially attractive - because of the ability to reduce the impact of radiation doses on nearby organs.

An article published in April in the journal Radiotherapy and Oncology (publication of the European Community of Radiologists and Oncologists, ESTRO) describes the experience of using proton therapy with modulated intensity (intensity modulated proton therapy - IMPT) for the treatment of inflammatory breast cancer.

A group of specialists from the Mayo Clinic, USA, identified all patients with this disease who received adjuvant IMPT in this medical institution in the period from 2016 to 2020. In total, there were 19 patients with an average follow-up period of 24 months. Clinical target volume (CTV) included skin, chest wall, and regional lymph nodes. The average dose was 50 Gy for 25 fractions, while fifteen patients received booster doses to the chest wall area (an average of 56.25 Gy for 25 fractions). During treatment, 9 patients (47%) needed to re-optimize the plan.

Acute dermatitis of the 3rd degree occurred in 2 people (11%). Rib fractures occurred in 4 (21%). One patient with a pre-existing postoperative seroma developed a grade 3 fistula. The average radiation doses to the heart, left anterior descending artery and right coronary artery were 0.7 Gy, 2.3 Gy and 0.1 Gy, respectively. The average dose of V20 Gy for ipsilateral lung was 14.9%. No locoregional relapses were detected for 2 years, and OS and DMFS accounted for 89% and 82%, respectively.

IMPT in IBC is well tolerated due to excellent dosimetric indicators, low frequency of adverse events and favorable early control locoregional results. Long-term results are being monitored. Our results show that IMPT is an appropriate and attractive treatment method for patients with IBC that deserves further study.

The original article can be read here