The calculated distance (air line) between Spiesen-Elversberg and Dortmund is approximately 153 miles respectively 246 kilometers.
By car or train, the actual journey to Dortmund is certainly longer, as only the direct route (as the crow flies) between Spiesen-Elversberg and Dortmund has been calculated here.
Air line (approximately)
246 kilometers
133 nautical miles