Leslie K Ballas1, Chunqiao Luo2, Eugene Chung3, Amar U Kishan4, Igor Shuryak5, David I Quinn6, Tanya Dorff7, Shamim Jhimlee8, Raymond Chiu8, Andre Abreu9, Richard Jennelle8, Monish Aron9, Susan Groshen2. 1. Department of Radiation Oncology, University of Southern California Keck School of Medicine, Los Angeles, California. Electronic address: lballas@med.usc.edu. 2. Department of Preventative Medicine, University of Southern California Keck School of Medicine, Los Angeles, California. 3. Rose Medical Center, Denver, Colorado. 4. Department of Radiation Oncology, University of California Los Angeles, Los Angeles, California. 5. Center for Radiological Research, New York, New York. 6. Department of Medical Oncology, University of Southern California Keck School of Medicine, Los Angeles, California. 7. Department of Medical Oncology and Therapeutics Research, City of Hope, Duarte, California. 8. Department of Radiation Oncology, University of Southern California Keck School of Medicine, Los Angeles, California. 9. Department of Urology, University of Southern California Keck School of Medicine, Los Angeles, California.
Abstract
PURPOSE: The primary objective was to evaluate the maximum tolerated dose (within 10 weeks after treatment) associated with increasing hypofractionation to the prostate fossa (PF). We hypothesized that escalating the dose per fraction (fx) to the PF would have acceptable toxicity. MATERIALS AND METHODS: Tested dose levels (DLs) were 3.6 Gy × 15 fx (DL1); 4.7 Gy × 10 fx (DL2); and 7.1 Gy × 5 fx (DL3). Escalation followed a 6 + 6 rules-based design with 12 patients required at the maximum tolerated dose. Dose-limiting toxicity was defined as grade (G) ≥3, gastrointestinal (GI) or genitourinary (GU) toxicity by National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.03). Patients completed quality-of-life questionnaires. RESULTS: Twenty-four patients with indications for adjuvant or salvage radiation therapy (RT) enrolled (6 at DL1 and 2; 12 at DL3). All patients had at least 6 months of follow-up (median follow-up, 14.1 months). Four patients received concurrent androgen deprivation therapy. No G ≥ 3 GI or GU toxicity was seen at any DL; 2 of 6 patients in the DL1 group, 3 of 6 in DL2, and 7 of 12 in DL3 experienced G2 GI toxicity during RT. Except in 1 patient, all acute G2 GI toxicity resolved by 10 weeks. Three of 12 patients reported an increase to G1 and G2 GU toxicity in the 2 weeks after RT in groups DL1 and DL2 and 1 of 12 patients in DL3. At week 2 after RT, decline in the 26-item Expanded Prostate Cancer Index Composite bowel domain met criteria for a minimally important difference in 71% of patients. At week 10, 1 of 6, 2 of 6, and 7 of 11 patients at DLs 1, 2, and 3, respectively, still met minimally important difference criteria. International Prostate Symptom Scores worsened 2 weeks after treatment but improved by 6 to 10 weeks. CONCLUSIONS: Dose escalation up to 7.1 Gy × 5 fx to the PF was completed without acute G ≥ 3 toxicity. There was transient G2 rectal toxicity at all DLs during and immediately after RT. We must perform long-term follow-up and assessment of late toxicity of SBRT to the PF.
PURPOSE: The primary objective was to evaluate the maximum tolerated dose (within 10 weeks after treatment) associated with increasing hypofractionation to the prostate fossa (PF). We hypothesized that escalating the dose per fraction (fx) to the PF would have acceptable toxicity. MATERIALS AND METHODS: Tested dose levels (DLs) were 3.6 Gy × 15 fx (DL1); 4.7 Gy × 10 fx (DL2); and 7.1 Gy × 5 fx (DL3). Escalation followed a 6 + 6 rules-based design with 12 patients required at the maximum tolerated dose. Dose-limiting toxicity was defined as grade (G) ≥3, gastrointestinal (GI) or genitourinary (GU) toxicity by National Cancer Institute Common Terminology Criteria for Adverse Events (version 4.03). Patients completed quality-of-life questionnaires. RESULTS: Twenty-four patients with indications for adjuvant or salvage radiation therapy (RT) enrolled (6 at DL1 and 2; 12 at DL3). All patients had at least 6 months of follow-up (median follow-up, 14.1 months). Four patients received concurrent androgen deprivation therapy. No G ≥ 3 GI or GU toxicity was seen at any DL; 2 of 6 patients in the DL1 group, 3 of 6 in DL2, and 7 of 12 in DL3 experienced G2 GI toxicity during RT. Except in 1 patient, all acute G2 GI toxicity resolved by 10 weeks. Three of 12 patients reported an increase to G1 and G2 GUtoxicity in the 2 weeks after RT in groups DL1 and DL2 and 1 of 12 patients in DL3. At week 2 after RT, decline in the 26-item Expanded Prostate Cancer Index Composite bowel domain met criteria for a minimally important difference in 71% of patients. At week 10, 1 of 6, 2 of 6, and 7 of 11 patients at DLs 1, 2, and 3, respectively, still met minimally important difference criteria. International Prostate Symptom Scores worsened 2 weeks after treatment but improved by 6 to 10 weeks. CONCLUSIONS: Dose escalation up to 7.1 Gy × 5 fx to the PF was completed without acute G ≥ 3 toxicity. There was transient G2 rectal toxicity at all DLs during and immediately after RT. We must perform long-term follow-up and assessment of late toxicity of SBRT to the PF.
Authors: Christina Schröder; Hongjian Tang; Paul Windisch; Daniel Rudolf Zwahlen; André Buchali; Erwin Vu; Tilman Bostel; Tanja Sprave; Thomas Zilli; Vedang Murthy; Robert Förster Journal: Cancers (Basel) Date: 2022-01-29 Impact factor: 6.639
Authors: Neil R Parikh; Amar U Kishan; Nathanael Kane; Silvia Diaz-Perez; Ekambaram Ganapathy; Ramin Nazarian; Carol Felix; Colleen Mathis; Margaret Bradley; Ankush Sachdeva; Bashir Wyatt; Vince Basehart; Nazy Zomorodian; Lin Lin; Christopher R King; Patrick A Kupelian; Matthew B Rettig; Michael L Steinberg; Minsong Cao; Beatrice S Knudsen; David Elashoff; Dorthe Schaue; Robert E Reiter; Nicholas G Nickols Journal: Int J Radiat Oncol Biol Phys Date: 2020-06-17 Impact factor: 7.038