Comparing morbidity and cancer control after 3D-conformal (70/74 Gy) and intensity modulated radiotherapy (78/82 Gy) for prostate cancer

• Published in: Strahlentherapie und Onkologie Vol. 191; no. 4; pp. 338 - 346
• Main Authors: Dolezel, Martin, Odrazka, Karel, Zouhar, Milan, Vaculikova, Miloslava, Sefrova, Jana, Jansa, Jan, Paluska, Petr, Kohlova, Tereza, Vanasek, Jaroslav, Kovarik, Josef
• Format: Journal Article
• Language: English
• Published: Berlin/Heidelberg Springer Berlin Heidelberg 01-04-2015; Springer Nature B.V
• Subjects: Aged; Aged, 80 and over; Causality; Comorbidity; Czech Republic - epidemiology; Disease-Free Survival; Gastrointestinal Diseases - diagnosis; Gastrointestinal Diseases - mortality; Humans; Incidence; Male; Male Urogenital Diseases - diagnosis; Male Urogenital Diseases - metabolism; Medicine; Medicine & Public Health; Middle Aged; Neoplasm Recurrence, Local - diagnosis; Neoplasm Recurrence, Local - mortality; Neoplasm Recurrence, Local - prevention & control; Oncology; Original Article; Prostatic Neoplasms - diagnosis; Prostatic Neoplasms - mortality; Prostatic Neoplasms - radiotherapy; Radiation Injuries - mortality; Radiotherapy; Radiotherapy Dosage; Radiotherapy, Intensity-Modulated - methods; Radiotherapy, Intensity-Modulated - mortality; Risk Assessment; Czech Republic; Toxizität; 3D-konformaler Strahlentherapie; Toxicity; Intensitätsmodulierter Strahlentherapie; Prostatakarzinom; Intensity-modulated radiotherapy; Cancer control; 3D-conformal radiotherapy; Prostate cancer; Tumorkontrolle
• ISSN: 0179-7158; 1439-099X
• DOI: 10.1007/s00066-014-0806-y

Purpose
The purpose of this work was to compare toxicity and cancer control between patients with prostate cancer treated using three-dimensional conformal radiotherapy (3D-CRT) and those treated using intensity-modulated radiation therapy (IMRT).
Methods and materials
A total of 553 patients with prostate cancer were treated with 3D-CRT 70–74 Gy (3D-CRT 70, 3D-CRT 74) or IMRT 78–82 Gy (IMRT 78, IMRT/SIB 82). Late toxicity was scored according to FC-RTOG/LENT criteria. Biochemical failure was defined using the Phoenix and ASTRO definitions.
Results
The 5-year risk of grade 2–4 genitourinary toxicity was 26.3 % (3D-CRT 70), 27.2 % (3D-CRT 74), 17.3 % (IMRT 78), and 25.1 % (IMRT/SIB 82) without statistical differences. The 5-year risk of grade 2–4 gastrointestinal toxicity was 19.4 % (3D-CRT 70), 42.1 % (3D-CRT 74), 20.5 % (IMRT 78), and 26.6 % (IMRT/SIB 82). The differences between 3D-CRT 74 and 3D-CRT 70 and between 3D-CRT 74 and IMRT 78 were statistically significant (log rank
p
 = 0.03). The 5-year Phoenix PSA relapse-free survival (PSA-RFS) in low-risk, intermediate-risk, and high-risk patients treated using 3D-CRT were 89.4, 65.5, and 57.8 %, respectively. Patients treated with IMRT achieved the following results: 90.9, 89.4, and 83.9 %. Clinical relapse-free survival (C-RFS) in patients treated using 3D-CRT vs. IMRT for the aforementioned groups were 94.7 vs. 100 %, 86.8 vs. 98.6 %, and 84.4 vs. 94.5 %. Disease-free survival (DFS) for patients treated using 3D-CRT were 83.1, 70.9, and 71.5 %. The IMRT group reached 95.8, 89.1, and 87.6 %. The PSA-RFS for intermediate- and high-risk patients were statistically significant, while C-RFS and DFS were marginally better.
Conclusion
Dose escalation with IMRT was associated with improved cancer control in intermediate- and high-risk patients in comparison with 3D-CRT, without compromising toxicity.