NRI PULSE STAFF REPORT
Los Angeles, CA, October 7, 2025: A 20-year-old biomedical engineering student at the University of Southern California (USC) has developed a software tool that is improving the speed and accuracy of cancer treatment planning at Children’s Hospital Los Angeles (CHLA).
Arjun Karnwal, a biomedical engineering major at USC’s Alfred E. Mann Department of Biomedical Engineering, created an algorithm-based software called ShotCaller to assist radiation oncologists in designing complex treatment plans for pediatric cancer patients.
Traditionally, doctors using spatially fractionated radiation therapy (SFRT)—a technique that delivers high radiation doses to targeted “hot spots” within a tumor while sparing nearby healthy tissue—spend several hours manually determining the optimal layout of those regions. Karnwal’s software computes the same calculations in minutes, automating a process that previously took up to two hours.
According to USC’s Viterbi School of Engineering, ShotCaller uses randomized simulations and optimization algorithms to identify the most effective arrangement of radiation “hot spots,” ensuring precise targeting and compliance with safety constraints. The program is now being used not only at CHLA but also at USC’s Norris Comprehensive Cancer Center.
By significantly reducing planning time, the software enables clinicians to prepare treatment plans on the same day, a step forward for hospitals where rapid decision-making is critical to patient care. CHLA oncologists say the tool could streamline workflows and potentially improve treatment outcomes for young cancer patients.
Karnwal’s work has been presented at medical and engineering conferences, including the Radiosurgery Society’s annual meeting. Experts describe it as a promising example of how computational modeling can enhance clinical efficiency in oncology.
However, medical specialists emphasize that while early results are encouraging, further testing and validation are needed before ShotCaller or similar algorithms can be widely adopted across hospitals. Integrating such tools into clinical systems also requires regulatory review and extensive real-world evaluation.
“It’s incredibly rewarding to see that something I developed is helping doctors save time and help patients,” Karnwal said in a statement released by USC.
Cover photo: Arjun Karnwal/LinkedIn.
