Table 6.
Summary of studies comparing the use of IMRT with 3DCRT
| n | Stage | Median RT dose | Chemotherapy | Acute toxicity | Treatment break (%) | Late toxicity | Anus-preserving surgery | pCR rate (%) | Tumor control | |
|---|---|---|---|---|---|---|---|---|---|---|
| Parekh et al. [4] | IMRT: 20 | All Stage II or III, except 2 with Stage I; 6 with Stage IVa | IMRT: 50 Gy/25 Fr (SIB) | 5-FU (300 mg/m2): 67% Cap (825 mg/m2 twice daily): 33% |
IMRT: (Grade 2+) *GI 30%; Hema: 10%; skin 35%; GU 0% |
IMRT: 0 | IMRT: none | IMRT: 70% | IMRT: 21.4 | NR |
| 3DCRT: 28 | 3D-CRT: 50.4 Gy/28 Fr | 3DCRT: (Grade 2+) *GI 60.7%; Hema 28.6%; skin 39.3%; GU 7.4% | 3D-CRT: 7.1 | 3DCRT: Grade 3 small bowel obstruction 3.6% | 3DCRT: 64.3% | 3DCRT: 16.7 | NR | |||
| Yang et al. [17] 8% in adjuvant setting | IMRT: 98 | All Stage II or III except 14 with Stage I; 13 with Stage IV | IMRT: 50 Gy/25 Fr (SIB) | 5-FU (225 mg/m2): 93% Cap (875 mg/m2 twice daily): 7% |
IMRT (Grade 2+) *Diarrhea 10.8%; proctitis: 23%. |
NR | NR | NR | NR | NR |
| 3DCRT: 79 | 3DCRT: 50.4 Gy/28 Fr | 3DCRT (Grade 2+) *Diarrhea 32.3%; proctitis: 38% |
NR | NR | NR | NR | NR | |||
| Jabbour et al. [16] | IMRT: 30 | All Stage II or III except 7 with Stage IV | IMRT: 50.4 Gy/28 Fr | 5-FU (225 mg/m2) or Cap (825 mg/m2 twice daily): 83.7% Cap/oxaliplatin: 11.6% |
IMRT (Grade 3+): diarrhea 3%; GU 0% | IMRT: 0 | NR | NR | IMRT: 20 | cLRR: 6.7% |
| cDMR: 6.7% | ||||||||||
| 3DCRT: 56 | 3DCRT: 50.4 Gy/ 28 Fr | 3DCRT (Grade 3+): diarrhea 9%; GU 2% | 3DCRT: 20 | NR | NR | 3DCRT: 21 | cLRR: 7% | |||
| cDMR: 12.5% | ||||||||||
| Samuelian et al. [5] | IMRT: 31 | All Stage II or III, but 22 with recurrent disease 11 for postoperative RT | IMRT: 50 Gy/25 Fr (SIB) | 5-FU (250 mg/m2): 43.5% Cap (875 mg/m2 twice daily): 54.3% |
IMRT (Grade 3+): GI 3%; Hema: 3%; skin: 3.2%. (Grade 2+): *GI: 32%; Hema: 45%; GU 16%; skin 10% |
IMRT: 6.5% | aIMRT: 5.3% | IMRT: 82% | IMRT: 19 | NR |
| 3DCRT: 61 | 3DCRT: 50.4 Gy/28 Fr | 3DCRT (Grade 3+): GI 10%; Hema: 5%; skin: 1.6%. (Grade 2+): *GI: 62%; Hema 44%; GU 21%; skin 3% | 3DCRT: 16.4% | a3DCRT: 15% | 3DCRT: 84% | 3DCRT: 28 | NR | |||
| Droge et al. [18] | VMRT: 81 | Stage II or III | VMAT and 3DCRT: 50.4 Gy/28 Fr | 5-FU (1000 mg/m2 on Day 1–5 and 29–33 of the RT) | VMAT (Grade 3+): *proctitis 2%; Hema 3%; GU 1%; *skin 0% | NR | VMAT (Grade 3+): proctitis 3%; GU 3%; skin 0% | VMAT: 31%b | VMAT: 20 | NR |
| 3DCRT: 107 | 3DCRT (Grade 3+): *proctitis 12%; Hema 4%; GU 3%; *skin 7% | NR | 3DCRT (Grade 3+) proctitis 8%; GU 10%; skin 2% | 3DCRT: 23%b | 3DCRT: 13 | NR | ||||
| Present study | HT: 45 | Stage II or III | HT: 50 Gy/25 Fr (SIB) | 5-FU (350 mg/m2): 47.9% Cap (850 mg/m2 twice daily): 52.1% |
HT (Grade 3+): *GI 6.7%; GU 0%; Hema: 0%; skin: 2.2% | HT: 2.2% | HT (Grade 3+): GI 4.4%; GU 0% | HT: 84.4%b | HT: 17.8 | dLRR: 8.9% |
| dDMR: 26.7% | ||||||||||
| 3DCRT: 99 | 3DCRT: 50.4 Gy/28 Fr | 3DCRT (Grade 3+): *GI 15.1%; GU 3%; Hema: 2%; skin: 3% | 3DCRT: 8.1% | 3DCRT(Grade 3+): GI 10.1%; GU 3.1% | 3DCRT: 76.4%b | 3DCRT: 15.1 | dLRR: 19.2% | |||
| dDMR: 33.3% |
*Statistically significant difference between IMRT and 3DCRT.
aPostoperative complications.
bIn tumors located within 0–5 cm from anal verge.
cMedian follow-up time was 23 months in the 3DCRT group compared with 11 months in the IMRT group.
dMedian follow-up time was 53 months in the 3DCRT group and 43 months in the IG-IMRT group.
NR = not reported, IMRT = intensity-modulated radiotherapy, 3DCRT = 3D conformal radiotherapy, pCR = pathological complete response, RT = radiotherapy, GI = gastrointestinal, Hema = hematological, GU = genitourinary, Cap = capecitabine, Fr = fraction, SIB = simultaneous integral boost, VMAT = volumetric-modulated arc therapy, HT = helical tomotherapy, LRR = local recurrence rate, DMR = distant metastasis rate.