Quality of Life after Ablative 5-Fraction Radiation Therapy from the Phase 2 SMART Pancreas Trial

• Published in: International journal of radiation oncology, biology, physics Vol. 120; no. 2; pp. S174 - S175
• Main Authors: Chuong, M.D., Parikh, P.J., Low, D., Kim, J., Mittauer, K.E., Bassetti, M.F., Glide-Hurst, C., Raldow, A., Yang, Y., Portelance, L., Zaki, B., Kim, H., Mancias, J.D., Ng, J., Pfeffer, R.M., Mueller, A., Kelly, P., Boldrini, L., Fuss, M., Lee, P.
• Format: Journal Article
• Language: English
• Published: Elsevier Inc 01.10.2024
• ISSN: 0360-3016
• DOI: 10.1016/j.ijrobp.2024.07.2212

Prospective data demonstrate that non-ablative stereotactic body radiation therapy (SBRT) for pancreas cancer is well tolerated and results in stable patient-reported quality of life (QOL) although few studies have evaluated long-term QOL beyond ∼3 months after SBRT. Ablative SBRT (BED10 ∼100 Gy) is increasingly being adopted and its effects on QOL are unknown. We now present QOL outcomes from a phase 2 trial evaluating ablative 5-fraction stereotactic MR-guided on-table adaptive radiation therapy (SMART) for borderline resectable and locally advanced pancreas cancer. The multi-center single-arm phase 2 SMART trial enrolled 136 patients from January 2019 to January 2022 who received ≥3 months of induction chemotherapy without disease progression and were treated on a 0.35T MR-guided device with a prescribed dose of 50 Gy in 5 fractions (BED10 = 100 Gy). Intrafraction cine-MRI, soft tissue tracking, and automatic beam gating were mandatory. On-table adaptive replanning using an isotoxicity approach was performed prior to each fraction as needed. A secondary study endpoint was QOL using the NCCN-FACT FHSI-18 survey instrument at 3 times (T): prior to SMART (T1), 3 months after SMART (T2), and 12 months after SMART (T3). The total FHSI-18 score was calculated as a sum of the following subscale scores: disease related symptoms-physical, disease related symptoms-emotional, treatment side effects, and function/well-being. Surgery was performed in 44 patients (32.4%) after SMART. QOL assessment was completed at T1, T2, and T3 by 133 (97.8%) and 106 (77.9%), and 55 (40.4%) patients, respectively. Mean total score and subscale scores remained stable from T1-T2 or T1-T3. Mean individual question scores were stable from T1-T2 except for general pain (0.8 vs. 1.1; p=0.002) and localized stomach pain (1.0 vs. 1.3; p=0.013); a significant increase in pain scores was present among patients who had surgery after SMART while pain scores did not increase among those who did not have surgery. Mean individual scores were stable from T1-T3 except for increased stomach area pain (p<0.001) regardless of surgery and scores for feeling ill increased among patients who did not have surgery (p=0.004). This is the first prospective evaluation of QOL after ablative radiation therapy for pancreas cancer demonstrating that overall QOL remains stable at 3 and 12 months after SMART. Additional analysis is warranted to clarify factors significantly associated with QOL including disease progression and additional therapy after SMART.