Reirradiation of recurrent breast cancer with proton beam therapy: A case report and literature review

Abstract

Background: Locoregional recurrence of breast cancer is challenging for clinicians, due to the various former treatments patients have undergone. However, treatment of the recurrence with systemic therapy and subsequent reirradiation of chest wall is accompanied by increased toxicities, particularly radiation-induced cardiovascular disease. Reirradiation by proton beam therapy (PBT) enables superior preservation of adjacent organs at risk as well as concurrent dose escalation for delivery to the gross tumor. This technology is expected to improve the overall outcome of recurrent breast cancer.

Case summary: A 47-year-old female presented with an extensive locoregional recurrence at 10 yr after primary treatment of a luminal A breast cancer. Because of tumor progression despite having undergone bilateral ovarectomy and systemic therapy, the patient was treated with PBT total dose of 64.40 Gy to each gross tumor and 56.00 Gy to the upper mediastinal and retrosternal lymphatics including the entire sternum in 28 fractions. Follow-up computed tomography showed a partial remission, without evidence of newly emerging metastasis. At 19 mo after the PBT, the patient developed a radiation-induced pericardial disease and pleural effusions with clinical burden of dyspnea, which were successfully treated by drainage and corticosteroid. Cytological analysis of the puncture fluid showed no malignancy, and the subsequent computed tomography scan indicated stable disease as well as significantly decreased pericardial and pleural effusions. The patient remains free of progression to date.

Conclusion: PBT was a safe and effective method of reirradiation for locoregionally recurrent breast cancer in our patient.

Keywords: Case report; Chest wall recurrence; Pericarditis; Proton beam therapy; Radiation-induced cardiovascular disease; Recurrent breast cancer; Reirradiation.

Figure 1

¹⁸F-FDG PET/CT performed immediately prior to proton beam therapy in October 2016. A: Overview of multilocular tumor recurrences with increased FDG uptake (marked with arrows); B: Sagittal plane; C-F: Axial plane. ¹⁸F-FDG PET/CT: 2-deoxy-2-[fluorine-18] fluoro-D-glucose positron emission tomography/computed tomography.

Figure 2

Pleural metastases with aspect of lymphangiosis carcinomatosa in the right upper lobe. A: Pleural metastasis; B: Lymphangiosis carcinomatosa (both marked with arrows).

Figure 3

Treatment plan of proton beam therapy with isodose distributions. A and B: Axial plane; C and D: Sagittal plane. Red line: Gross tumor volume; Green line: Clinical target volume; Blue line: Planning target volume of gross tumors; Lilac line: Planning target volume of gross tumors including adjacent regional lymphatics and sternum.

Figure 4

Incipient size reduction of right parasternal metastasis (with size measurement) and chest wall recurrence (marked with arrow) during the proton beam therapy. A: In planning computed tomography (CT) prior to proton beam therapy; B: In control CT at 26^th fraction of treatment.

Figure 5

Incipient size reduction of chest wall recurrence (with size measurement) during the proton beam therapy. A: In planning computed tomography (CT) prior to proton beam therapy; B: In control CT at 26^th fraction of treatment.

Figure 6

Incipient size reduction of right parasternal metastasis (with size measurement) as well as chest wall recurrence and pleural metastasis (both marked with arrows) during the proton beam therapy. A: In planning computed tomography (CT) prior to proton beam therapy; B: In control CT at 26^th fraction of treatment.

Figure 7

Continuous shrinkage of the chest wall recurrence, right pleural metastases and parasternal lymph node metastases, which are marked with arrows. A: Follow-up computed tomography (CT) at 3 mo after proton beam therapy; B: Follow-up CT at 9 mo after proton beam therapy; C: Follow-up CT at 13 mo after proton beam therapy.

Figure 8

Relevant pericardial and pleural effusions emerged at 19 mo after proton beam therapy. A: Pericardial effusion; B: Pleural effusion in the coronal plane.

Figure 9

A soft tissue augmentation occurred in the right parasternal area at 19 mo after proton beam therapy. A: Continuously reduced chest wall recurrence at 13 mo after proton beam therapy; B: Discreet augmentation of right parasternal soft tissue and significant pleural effusion on the right at 19 mo after proton beam therapy; C: Consistent size of right parasternal soft tissue and decrease of pleural effusion at 22 mo after proton beam therapy. The tumor is marked with arrows.

Figure 10

Follow-up computed tomography at 22 mo after proton beam therapy showed significantly improved findings of (A) pleural effusions and (B) pericardial effusions.

Figure 11

Dose-volume-histogram of the target volumes and organs at risk.