Short-course intensity-modulated radiotherapy (70 GY at 2.5 GY per fraction) for localized prostate cancer: Preliminary results on late toxicity and quality of life

Purpose: To present our preliminary observations on the late toxicity and q uality of life (QOL) of patients treated with short-course intensity-modula ted radiotherapy (SCIM-RT). Methods and Materials: Fifty-one patients were treated with SCIM-RT at the Cleveland Clinic Foundation between October 1998 and May 1999. The techniqu e consisted of intensity-modulated radiotherapy using 5 static fields (ante rior, 2 laterals, and 2 anterior obliques). Inverse plans were generated by the Corvus treatment-planning system. The treatment delivery was performed with a dynamic multileaf collimator. A total of 70.0 Gy was prescribed in all cases at 2.5 Gy per fraction to be delivered in 28 fractions over 5 and a half weeks. The location of the prostate gland was verified and adjusted daily with the BAT transabdominal ultrasound system. The median follow-up was 18 months (range: 11 to 26 months). The Radiation Therapy Oncology Grou p (RTOG) scales were used to evaluate late toxicity. The Expanded Prostate Cancer Index Composite (EPIC) was used to evaluate QOL. A total of 24 patie nts completed the EPIC questionnaire at approximately 2 years after therapy (median time from treatment to questionnaire administration: 24 months; ra nge: 21 to 26 months). The results from the EPIC questionnaires were compar ed to scores from 46 patients treated during the same time period with conf ormal radiotherapy (CRT) to 78 Gy at 2 Gy per fraction. Results: The dose was prescribed to an isodose line ranging from 82.0% to 9 0.0% (mean: 87.2%). The range of the individual prostate mean doses was 73. 5 to 78.5 Gy (average: 75.3 Gy). To date, only I patient had Grade I late u rinary toxicity. To date, only 4 patients had Grade I late rectal toxicity. No Grade 2 or 3 late urinary or rectal complications have occurred. The ac tuarial rectal bleeding rate observed at 18 months was 7%. There were no di fferences in scores from the urinary, bowel, hormonal, and overall QOL doma ins between SCIM-RT patients and patients treated with CRT. The overall phy sical and mental QOL scores were also nearly identical to scores reported f or the general U.S. population. Conclusion: Preliminary late toxicity results up to 2 years after SCIM-RT a re encouraging, with a median follow-up of 18 months (range 11 to 26 months ). Late toxicity assessed by the physicians using RTOG late toxicity scores has been excellent. QOL reported by the patients using the EPIC questionna ire reveals no difference between patients treated with high-dose CRT at st andard fractionation and patients treated with SCIM-RT. SCIM-RT is an alter native method of dose escalation in the treatment of localized prostate can cer. The proposed schedule significantly increases convenience to patients due to the decrease in overall treatment time. (C) 2001 Elsevier Science In c.