Five-year outcomes of a phase 1 dose-escalation study using stereotactic body radiosurgery for patients with low-risk and intermediate-risk prostate cancer Journal Article

   


Authors: Zelefsky, M. J.; Kollmeier, M.; McBride, S.; Varghese, M.; Mychalczak, B.; Gewanter, R.; Garg, M. K.; Happersett, L.; Goldman, D. A.; Pei, I.; Lin, M.; Zhang, Z.; Cox, B. W.
Article Title: Five-year outcomes of a phase 1 dose-escalation study using stereotactic body radiosurgery for patients with low-risk and intermediate-risk prostate cancer
Abstract: Purpose: To report toxicity outcomes, prostate-specific antigen (PSA) relapse, and cumulative incidence posttreatment biopsy results among patients treated on a prospective dose escalation study using ultra-hypofractionated stereotactic body radiation therapy (SBRT) for patients with low- and intermediate-risk prostate cancer. Methods and Materials: A total of 136 patients were enrolled in a phase 1 dose-escalation study to determine the tolerance of escalating radiation dose levels of SBRT for the treatment of localized prostate cancer. The initial dose level was 32.5 Gy in 5 fractions, and doses were then sequentially escalated to 35 Gy, 37.5 Gy, and 40 Gy. Eligibility criteria included only patients with low and intermediate risk, and the maximum prostate volume was 60 cm 3 . Patients treated with neoadjuvant androgen deprivation were excluded. The median follow-up in survivors for the 4 dose levels was 5.9, 5.4, 4.1, and 3.5 years, respectively. Results: The incidence of acute grade 2 rectal toxicities for dose levels 1 to 4 were 0%, 2.9%, 2.8%, and 11.4% respectively. No grade 3 or 4 acute rectal toxicities were observed. The incidence of acute grade 2 urinary toxicities for dose levels 1 to 4 were 16.7%, 22.9%, 8.3%, and 17.1%, respectively. No grade 3 or 4 acute urinary toxicities were observed. No grade 2 or higher rectal toxicities were observed. The incidence of late grade 2 urinary toxicities for dose levels 1 to 4 was 23.3%, 25.7%, 27.8%, and 31.4%, respectively. Only 1 late grade 3 urinary toxicity (urethral stricture) developed in the 40-Gy dose arm; the stricture was corrected with transurethral resection. No grade 4 late urinary toxicity was observed. The 5-year cumulative incidence of prostate-specific antigen failure for dose levels 1 to 4 was 15%, 6%, 0%, and 0%. The incidence of a 2-year positive posttreatment biopsy was 47.6%, 19.2%, 16.7%, and 7.7%, respectively for the 4 dose arms (P =.013). Conclusions: SBRT doses ranging from 32.5 to 40 Gy in 5 fractions were well tolerated without severe urinary or rectal toxicities. Biopsy outcomes suggest improved rates of tumor clearance observed with higher doses. © 2019 Elsevier Inc.
Keywords: adult; aged; major clinical study; cancer recurrence; treatment planning; cancer patient; cancer radiotherapy; follow up; prospective study; prostate specific antigen; radiotherapy; patient monitoring; radiation injury; biopsy; cancer survivor; prostate cancer; gastrointestinal toxicity; sexual dysfunction; antigens; radiation dose fractionation; prostate biopsy; urology; phase 1 clinical trial; cancer control; toxicity; transurethral resection; stereotactic body radiation therapy; biochemical recurrence; diseases; localized prostate cancer; clinical target volume; international index of erectile function; intermediate risk patient; clinical outcome; dose-escalation study; prostate volume; rectum disease; low risk patient; planning target volume; international prostate symptom score; hypofractionated radiotherapy; methods and materials; radiation dose escalation; human; male; priority journal; article; transurethral resections; urethra stenosis; eligibility criterion; radiation dose levels
Journal Title: International Journal of Radiation Oncology, Biology, Physics
Volume: 104
Issue: 1
ISSN: 0360-3016
Publisher: Elsevier Inc.  
Date Published: 2019-05-01
Start Page: 42
End Page: 49
Language: English
DOI: 10.1016/j.ijrobp.2018.12.045
PUBMED: 30611838
PROVIDER: scopus
PMCID: PMC7525798
DOI/URL:

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063917980&doi=10.1016%2fj.ijrobp.2018.12.045&partnerID=40&md5=4faecfdc6cf9e19cbadc5928cd31e838
Notes: Article -- Export Date: 1 May 2019 -- Source: Scopus
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MSK Authors
  1. Richard Gewanter
    35 Gewanter
  2. Zhigang Zhang
    427 Zhang
  3. Borys Mychalczak
    97 Mychalczak
  4. Michael J Zelefsky
    754 Zelefsky
  5. Laura Happersett
    89 Happersett
  6. Marisa A Kollmeier
    227 Kollmeier
  7. Debra Alyssa Goldman
    158 Goldman
  8. Sean Matthew McBride
    293 McBride
  9. Mary Lin
    6 Lin
  10. Melissa Shaji Varghese
    14 Varghese
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