High-dose preoperative radiation for cancer of the rectum: Impact of radiation dose on patterns of failure and survival

Journal Article · Mon Nov 15 04:00:00 EST 1993 · International Journal of Radiation Oncology, Biology and Physics; (United States)

DOI:https://doi.org/10.1016/0360-3016(93)90448-5· OSTI ID:7066138

Ahmad, N R; Mohiuddin, M; Marks, G ^[1]

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1. Thomas Jefferson Univ. Hospital, Philadelphia, PA (United States)

A variety of dose-time schedules are currently used for preoperative radiation therapy of rectal cancer. An analysis of patients treated with high-dose preoperative radiation therapy was undertaken to determine the influence of radiation dose on the patterns of failure, survival, and complications. Two hundred seventy-five patients with localized rectal cancer were treated with high-dose preoperative radiation therapy. One hundred fifty-six patients received 45 Gy (low-dose group). Since 1985, 119 patients with clinically unfavorable cancers were given a higher dose, 55 Gy using a shrinking field technique (high-dose group). All patients underwent curative resection. Median follow-up was 66 months in the low-dose group and 28 months in the high-dose group. Patterns of failure, survival, and complications were analyzed as a function of radiation dose. Fourteen percent of the total group developed a local recurrence; 20% in the low-dose group as compared with 6% in the high-dose group. The actuarial local recurrence rate at 5 years was 20% for the low-dose group and 8% for the high-dose group, and approached statistical significance with p = .057. For tethered/fixed tumors the actuarial local recurrence rates at 5 years were 28% and 9%, respectively, with p = .05. Similarly, for low-lying tumors (less than 6 cm from the anorectal junction) the rates were 24% and 9%, respectively, with p = .04. The actuarial rate of distant metastasis was 28% in the low-dose group and 20% in the high-dose group and was not significantly different. Overall actuarial 5-year survival for the total group of patients was 66%. No significant difference in survival was observed between the two groups, despite the higher proportion of unfavorable cancers in the high-dose group. The incidence of complications was 2%, equally distributed between the two groups. High-dose preoperative radiation therapy for rectal cancer results in excellent local control rates. 27 refs., 2 figs., 8 tabs.

• OSTI ID: 7066138
• Journal Information: International Journal of Radiation Oncology, Biology and Physics; (United States), Journal Name: International Journal of Radiation Oncology, Biology and Physics; (United States) Vol. 27:4; ISSN IOBPD3; ISSN 0360-3016
• Country of Publication: United States
• Language: English

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62 RADIOLOGY AND NUCLEAR MEDICINE
63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
BODY
DIGESTIVE SYSTEM
DISEASES
DOSE-RESPONSE RELATIONSHIPS
GASTROINTESTINAL TRACT
INTESTINES
LARGE INTESTINE
MEDICINE
NEOPLASMS
NUCLEAR MEDICINE
ORGANS
RADIOLOGY
RADIOTHERAPY
RECTUM
SIDE EFFECTS
SURVIVAL TIME
THERAPY