An analysis of the serious late complications of post-operative radiation therapy for cancer of the rectum and rectosigmoid

249

Proceedings of the 34th Annual ASTRO Meeting

1013 AN ANALYSIS OF THE SERIOUS LATE COMPLICATIONS RECTUM AND RECT’OSiGMOID A.C. Mak. M.D., Department PURPOSE: late small

of

T.A. Rich. M.D., T.E. Schultheiss, Radiotherapy.

The

University

OF POST-OPERATIVE

Ph.D., B. Kavanagh.

of Texas

M.D.

Anderson

RADIATION THERAPY FOR CANCER OF THE

M.D., M.M. Romsdahl, Cancer

Center,

radiotherapeutic We retrospectively examined the surgical, medical, bowel (SMBO) and non-small bowel (non-SMBO) morbidity.

M.D., Ph.D

Houston, and

TX 77030

technical

MET HODS : The medical records were reviewed of 224 patients with cancer of the rectum resection (APR) or anterior resection and postoperative with abdomino-perineal mainly University of Texas M.D. Anderson Cancer Center from 1973 to 1990. The median dose was 54Gy to 2Gy per fraction using various techniques (23 had extended fields to Ll or L2; pelvic fields PA 85, 83 had PA & 2 laterals and 33 had 4 field “box”). 78 patients were irradiated prone on (OTD) with a PA and 2 lateral wedge filtered fields weighted 2:l:l; bladder distension was used concomitant 5-Fluorouracil. Small bowel series were performed in 122 patients to assess the inside the pelvis below the conjugate line.

factors

associated

with

and rectosigmoid treated radiotherapy (XRT) at (range 34 to 66Gy) at 1.8 were treated with - APan Open Table-top Device in 8. 47 patients received volume of small bowel

RESULTS: In 28 patients, the median time to the development of SMBO was 7 months (range 0 to 69 months); 18 patients required reoperations (64%). The SMBO rate was 30% in patients treated with extended field XRT, 21% in those with a sinale oelvic field and 9% with multiple Delvic fields treated each day. The analysis of the small bowel series showed a trend toward higher volume of smail bowel below the conjugate line in patients who developed SMBO. With the OTD, the SMBO rate was 3%. For the chemo-radiation patients treated on the OTD, the SMBO rate was 15% but they appeared to have more small bowel inside the pelvis than those without the complication. There was no correlation df diabetes, previous abdominal or pelvic surgeries, abdominal infections, delayed SMBO with a history of hypertension, wound healing, pathological stages, types of surgical procedures, age or sex. However, SMBO was positively correlated with post-surgical adhesions prior to XRT and absence of reperitonealization at the time of initial surgery. The median time to the development of non-SMBO was 8 months (range 0 10 85 months). and the complications included enteritis, rectal bleeding, proctitis, fistula formation, stricture, abscess, cystitis and neurogenic bladder. The non-SMBO was infections with post-operative and history of abdominal infections. Most of the genitourinary correlated only complications were also found to occur in patients who had APR.

serious latecomplications with post-operative XRT, a bowel exclusion technique such as CONCLUSION: To minimize the OTD with multiple fields each day is recommended. XRT with the OTD is reproducible, easy to perform, and does not depend on patient compliance as does bladder distension. Bladder distension can be used for selected patients during boost treatment with the OTD technique 10 exclude bowel further from the reducedtreatment volume. Patients with adhesions requiring treatment priorto XRT are highlyvulnerable to developing SMBO smallfields and/orhyperfractionation as means to decrease the riskof SMBO.

and we recommend XRT

with

1014 THE ROLE Y.

OF EXTERNAL

Shibamoto,

Departments

BEAM AND INTRAOPERATIVE

RADIOTHERAPY

IN

T. Manabe,* K. Sasai, G. Ohsio,* Y. Nishimura,

of Radiology

& *lst Surgery, Kyoto University

PANCREATIC

CANCER

M. Noguchi**

and M. Abe

& **Fukui Red Cross Hospital

To determine whether combined external beam radiotherapy (EBRT) and intraoperative radiotherapy (IORT) has improved the poor prognosis for resected and unresected pancreatic cancer, we analyzed the treatment results during the last 9 years.

Purpose:

& Methods: 159 patients were treated with EBRT (50-60 Gy with 1.7 or 1.8 Gy per day) and/or IORT (25-33 Gy). For comparison, historical controls of 174 patients treated without radiotherapy between 1968-1983 were also analyzed. Patients were grouped according to TNM stage (non-Stage IV or Stage IV) and resectability (macroscopic curative resection, non-curative resection, or no resection). Because of the limited IORT facilities available and due to our policy to treat Stage IV patients by either EBRT or IORT alone, 65 patients received EBRT alone and 21 IORT alone. The remaining 73 patients received EBRT plus IORT. Both single and multi-variate analyses of the surviGa1 data were carried out.

Materials

Results: In patients receiving curative resection, the median survival time (MST) was 14 months (M) for the EBRT group, 11M for the EBRT+IORT group, and 10.5M for the historical controls, the difference being not significant. In non-Stage IV patients receiving noncurative resection, the MST was 12M for the EBRT group, 15.5M for the EBRT+IORT group, and JM for the historical controls. The difference was significant between the radiotherapy group and the controls but not between the EBRT and EBRT+IORT groups. In non-Stage IV