Consolidative mediastinal irradiation of malignant lymphoma using active scanning proton beams: clinical outcome and dosimetric comparison

Laila König; Nina Bougatf; Juliane Hörner-Rieber; Naved Chaudhri; Thomas Mielke; Sebastian Klüter; Matthias Felix Haefner; Stefan Rieken; Thomas Haberer; Jürgen Debus; Klaus Herfarth

doi:10.1007/s00066-019-01460-7

Consolidative mediastinal irradiation of malignant lymphoma using active scanning proton beams: clinical outcome and dosimetric comparison

Strahlenther Onkol. 2019 Jul;195(7):677-687. doi: 10.1007/s00066-019-01460-7. Epub 2019 Apr 10.

Authors

Laila König^{1

2

3}, Nina Bougatf^{4

5

6}, Juliane Hörner-Rieber^{4

5

6}, Naved Chaudhri^{5

6}, Thomas Mielke^{4

5

6}, Sebastian Klüter^{4

5}, Matthias Felix Haefner^{4

5

6}, Stefan Rieken^{4

5

6}, Thomas Haberer^{5

6}, Jürgen Debus^{4

5

6}, Klaus Herfarth^{4

5

6}

Affiliations

¹ Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. Laila.Koenig@med.uni-heidelberg.de.
² Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany. Laila.Koenig@med.uni-heidelberg.de.
³ Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany. Laila.Koenig@med.uni-heidelberg.de.
⁴ Department of Radiation Oncology, University Hospital Heidelberg, Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
⁵ Heidelberg Institute of Radiation Oncology (HIRO), National Center for Radiation Research in Oncology (NCRO), Im Neuenheimer Feld 400, 69120, Heidelberg, Germany.
⁶ Heidelberg Ion-Beam Therapy Center (HIT), Im Neuenheimer Feld 450, 69120, Heidelberg, Germany.

PMID: 30972453
DOI: 10.1007/s00066-019-01460-7

Abstract

Purpose: Current research approaches in lymphoma focus on reduction of therapy-associated long-term side effects. Especially in mediastinal lymphoma, proton beam radiotherapy (PT) may be a promising approach for reducing the dose to organs at risk (OAR).

Patients: In total, 20 patients were irradiated with active scanning PT at Heidelberg Ion Beam Therapy Center (HIT) between September 2014 and February 2017. For comparative analysis, additional photon irradiation plans with helical intensity-modulated radiotherapy (IMRT) were calculated and quantitative and qualitative dose evaluations were made for both treatment modalities. Toxicity and survival outcomes were evaluated.

Results: Clinical target volume coverage was comparable in both treatment modalities and did not significantly differ between IMRT and PT. Nevertheless, PT showed superiority regarding the homogeneity index (HI_PT = 1.041 vs. HI_IMRT = 1.075, p < 0.001). For all OAR, PT showed significantly higher dose reductions compared with IMRT. In particular, the dose to the heart was reduced in PT (absolute dose reduction of D_mean of 3.3 Gy [all patients] and 4.2 Gy [patients with pericardial involvement]). Likewise, the subgroup analysis of female patients, who were expected to receive higher doses to the breast, showed a higher dose reduction in D_mean of 1.2 Gy (right side) and 2.2 Gy (left side). After a median follow-up of 32 months (range 21-48 months), local and distant progression free survival (LPFS and DPFS) were 95.5% and 95.0%, respectively. Radiotherapy was tolerated well with only mild (grade 1-2) radiation-induced acute and chronic side effects.

Conclusion: A significant reduction in the dose to the surrounding OAR was achieved with PT compared with photon irradiation, without compromising target volume coverage. Dosimetric advantages may have the potential to translate into a reduction of long-term radiation-induced toxicity in young patients with malignant lymphoma of the mediastinum.

Keywords: Intensity modulated radiotherapy; Mediastinal lymphoma; Proton therapy; Radiotherapy; Secondary malignancies; Toxicity.

MeSH terms

Adolescent
Adult
Female
Follow-Up Studies
Hodgkin Disease / pathology
Hodgkin Disease / radiotherapy*
Humans
Lymphoma, Non-Hodgkin / pathology
Lymphoma, Non-Hodgkin / radiotherapy*
Male
Mediastinal Neoplasms / radiotherapy*
Middle Aged
Neoplasm Staging
Organs at Risk / radiation effects
Proton Therapy / methods*
Radiometry / methods*
Radiotherapy, Intensity-Modulated / methods*
Treatment Outcome
Young Adult