The Impact of Heterogeneous Cell Density in Hypoxic Tumors Treated with Radiotherapy

© 2023. The Author(s), under exclusive license to Springer Nature Switzerland AG..

Hypoxia is frequently found in solid tumors and is known to increase the resistance to several kinds of treatment modalities including radiation therapy. Besides, the treatment response is also largely determined by the total number of clonogenic cells, i.e., cells with unlimited proliferative capacity. Depending on the duration of hypoxia, the rate of proliferation and hence also the clonogen density could be expected to differ in hypoxic compartments. The combination at the microscale between heterogeneous tumor oxygenation and clonogen density could therefore be crucial with respect to the outcome of a radiotherapy treatment. In this study it was investigated the impact of heterogeneous clonogen density on the outcome of stereotactic radiotherapy treatments of hypoxic tumors. A recently developed three-dimensional model for tissue vasculature and oxygenation was used to create realistic in silico tumors with heterogeneous oxygenation. Stereotactic radiotherapy treatments were simulated, and cell survival was calculated on a voxel-level accounting for the oxygenation. For a tumor with a diameter of 1 cm and a baseline clonogenic density of 107/cm3 for the normoxic subvolume, when the relative density for the hypoxic cells drops by a factor of 10 the tumor control probability (TCP) decreases by about 10% when relatively small hypoxic volumes and few fractions are considered; longer treatments tend to level out the results. With increasing size of the hypoxic subvolume, the TCP decreased overall as expected, and the difference in TCP between a homogeneous and a heterogeneous distribution of cells increased. The results demonstrate a delicate interplay between the heterogeneous distribution of tumor oxygenation and clonogenic cells that could significantly impact on the treatment outcome of radiotherapy.

Medienart:

E-Artikel

Erscheinungsjahr:

2023

Erschienen:

2023

Enthalten in:

Zur Gesamtaufnahme - volume:1438

Enthalten in:

Advances in experimental medicine and biology - 1438(2023) vom: 16., Seite 121-126

Sprache:

Englisch

Beteiligte Personen:

Schiavo, Filippo [VerfasserIn]
Toma-Dasu, Iuliana [VerfasserIn]
Kjellsson Lindblom, Emely [VerfasserIn]

Links:

Volltext

Themen:

Hypoxia
Journal Article
Radiotherapy
Tumors

Anmerkungen:

Date Completed 01.11.2023

Date Revised 01.11.2023

published: Print

Citation Status MEDLINE

doi:

10.1007/978-3-031-42003-0_20

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM363382127