Colon and rectal cancer in pregnancy

Colorectal carcinoma presenting in pregnancy is an uncommon disease that is reported to be associated with an extremely poor prognosis. To better characterize this disease, we surveyed the membership of the American Society of Colon and Rectal Surgeons by mailed questionnaire and reviewed the literature. Forty-one new cases of women with large bowel cancer who presented during pregnancy or the immediate postpartum period were identified. The mean age at presentation was 31 years (range, 16–41 years). Tumor distribution was as follows: right colon-3, transverse colon-2, left colon-2, sigmoid colon-8, and rectum-26. Dukes stage at presentation was A=0, B=16, C=17, and D=6 (two patients were unstaged). Average follow-up was 41 months. Stage for stage, survival was found to be similar to patients with colorectal tumors in the general population. Large bowel cancer coexistent with pregnancy presents in a distal distribution (64 percent of tumors in the current series and 86 percent of those reported in the literature were located in the rectum) and presents at an advanced stage (60 percent were Stage C or more advanced at the time of diagnosis). While patient survival is poor, it is no different stage for stage from the general population with colorectal tumors.Read at the meeting of The American Society of Colon and Rectal Surgeons, Boston, Massachusetts, May 12 to 17, 1991.     

Role of carcinoembryonic antigen in predicting resectability of recurrent colorectal cancer

The reported low resectability rate for patients with recurrent colorectal cancer who have carcinoembryonic antigen (CEA) levels >11 has led us to perform this study. One hundred twenty-four patients who underwent Radioimmunoguided Surgery ^® (RIGS ^®)procedures for recurrent colorectal cancer from 1986 to the present were studied. In surgery, all patients underwent a traditional exploration followed by survey with a hand-held, gamma-detecting probe to detect preinjected radiolabeled monoclonal antibodies attached to cancer cells. Sites of metastases included: 72 liver (58.1 percent), 23 pelvis (18.5 percent), 15 distant lymph nodes (12.1 percent), 2 anastomotic (1.6 percent), and 12 other sites (9.7 percent). The resectability rate was 43.5 percent (54 patients). The mean preoperative CEA level for patients with resectable disease was significantly lower than for patients with unresectable disease (P=0.017): unresectable—mean, 87.1; SD, 141.0; minimum, 0.3; maximum, 501; resectable—mean, 36.6; SD, 59.3; minimum, 0.3; maximum, 329. The CEA level for patients with liver metastasis did not vary significantly from those patients without metastasis: 70 vs. 58.2 (P=0.58). Those patients with resectable liver tumors had lower mean CEA levels than those with unresectable liver, approaching significance: 41.6 vs. 91.9 (P=0.065). Other metastatic sites had a mean CEA level of: pelvic, 72.6; distant lymph nodes, 47.8; anastomotic, 2.7; and other sites, 53.8. These data suggest that there is a significant difference between the preoperative CEA level of the resectable and unresectable recurrent colorectal cancer patients, but the large standard deviation does not justify abandonment of exploration for any CEA level.Read at the meeting of The American Society of Colon and Rectal Surgeons, San Francisco, California, June 7 to 12, 1992.     

Aggressive surgical management of locally advanced primary and recurrent rectal cancer

Patients with locally advanced primary and recurrent rectal cancer without gross evidence of extrapelvic cancer represent a complex challenge to the surgeon. In selected patients, radical incontinuity resection or resection combined with radical radiation therapy offers a high likelihood of local tumor control and, to a lesser degree, the possibility of cure. This article defines current approaches to the aggressive management of such patients and investigative strategies for the future.     

Evaluation and biopsy of recurrent rectal cancer using three-dimensional endosonography

PURPOSE: The value of endorectal ultrasonography for postoperative follow-up of rectal cancer is limited by the inability to distinguish recurrent malignancy from benign lesions,e.g., fibrotic tissue. This study was conducted to investigate the role of three-dimensional (3D) endosonography for evaluation and biopsy of recurrent rectal cancer. METHODS: Endorectal ultrasonography was performed in routine follow-up program after resection of rectal cancer. 3D volume scans were recorded using a bifocal multiplane 3D transducer (7.5/10 MHz) with a 100 longitudinal and a 360 transversal scan angle. For transrectal ultrasound-guided biopsy of pararectal lesions, a specially designed targeting device was attached to the endoprobe. RESULTS: Overall pararectal lesions were detected in 28 of 163 patients (17 percent) who were undergoing endorectal ultrasonography for follow-up after resection of rectal cancer. 3D image analysis facilitated assessment of suspicious pararectal lesions by contemporary display of three perpendicular scan planes or volume reconstructions of the scanned area. Ultrasound-guided biopsy was performed in all 28 patients with pararectal lesions identified by endorectal ultrasonography. Biopsy revealed recurrent disease or lymph node metastases in seven and two patients, respectively. Benign lesions explained the endosonographic findings in 17 patients. All patients with benign histology still have no evidence of recurrent disease after a median follow-up of seven months. Nonrepresentative material was obtained in only 2 of 28 patients (accuracy, 93 percent). Histology changed the endosonographic diagnosis in 28 percent of cases. CONCLUSIONS: 3D endosonography with ultrasound-guided biopsy improves the diagnosis of extramural recurrence after curative resection of rectal cancer. 3D image display allows precise control of the position of the biopsy needle within the target.     

Impact of computed tomographyvs. intrarectal ultrasound on the diagnosis,resectability, and prognosis of locally recurrent rectal cancer

The use of modern techniques of imaging in the postoperative follow-up is reported to allow an earlier diagnosis of local recurrence in patients operated on with anterior resection for rectal cancer and, consequently, to allow a higher percentage of local recurrence resection to be performed. Although intrarectal ultrasound (IU) has proved highly reliable in preoperative staging, its value in relapse detection has been investigated only in retrospective studies and rarely compared with that of computed tomography (CT). The present prospective study aims at evaluating the role of IUvs. CT in the diagnosis of local recurrence and at verifying whether an earlier diagnosis and a higher resectability rate of recurrence result in an acceptable long-term survival. Thirty-seven patients who had undergone low and ultralow anterior resection for rectal cancer (anastomosis within 10 cm of the anal verge) were investigated prospectively. All the patients have been followed up by IU and CT at predetermined intervals. Six local recurrences were detected. CT correctly identified all the local recurrences (sensitivity = 100 percent, specificity = 93 percent, and accuracy = 94.5 percent); IU correctly identified only four of six local recurrences (sensitivity = 66.6 percent, specificity = 93 percent, and accuracy = 89 percent). Four patients with local recurrence underwent surgical treatment (resectability rate = 66.6 percent). Abdominoperineal resection in three patients and Hartmann's procedure in one patient were performed. In the other two patients, extensive metastatic liver involvements contraindicated surgery. All the resected patients were alive after one year; two of them are disease free, and the other two experienced recurrent disease. In conclusion, CT seems to have a higher sensitivity and accuracy in relapse detection. The increase in the local recurrence resectability rate does not result in a significant improvement in longterm survival. However, the good quality of life justifies the high cost of an intensive follow-up and a more aggressive surgical approach.     

Surgical treatment of locally recurrent rectal carcinoma

PURPOSE: This study was performed to analyze the outcomes of patients with local (pelvic) recurrence (following radical surgery for rectal cancer) who subsequently underwent a new operation. METHODS: Forty-five patients (19 percent of 213 local recurrences) were explored surgically because the disease was deemed to be confined to the pelvis with a limited extension and, therefore, amenable to surgical cure. RESULTS: Only 21 of the 45 patients who underwent surgical exploration had an oncologically radical operation (RO). In the remaining 24 patients, either a simple exploration or palliation or a nonradical procedure (R1-R2) was performed. In the RO group, there was a 19 percent five-year survival rate vs. a 0 percent rate in the R1-R2 group (median survival, 4 months). Site of recurrence (anastomosis vs. other sites) was statistically associated with a higher chance of long-term survival for those who underwent an RO operation. CONCLUSIONS: The prognosis of locally recurrent rectal cancer is dismal; less than 10 percent of all patients who underwent surgical treatment benefit from reoperation with an overall survival for five years. On the basis of these results, we no longer consider the surgical approach as the primary option for treating locally recurrent rectal cancer.Supported by a grant from the Italian Association for Cancer Research (AIRC) and by the CNR.     

Serum sialic acid and carcinoembryonic levels in the detection and monitoring of colorectal cancer

Total sialic acid (TSA), total protein (TP), TSA normalized to total TP (TSA/TP), and carcinoembryonic antigen levels were determined in 146 consecutive colorectal patients. These results were compared with results from 73 people with nonmalignant gastrointestinal disease, and with results from 96 normal controls. All malignancies were staged according to the Astler-Coller modification of Dukes' classification for colorectal cancer. All blood samples were drawn before surgical therapy. The TSA/TP ratio for colorectal cancer was 13.4 (mg/gm) in contrast to 12.1 (mg/gm) for pathologic controls, and 9.7 (mg/gm) for normal controls. Student's t test showed a P value less than 0.001 for normal controls and a P value less than 0.001 for pathologic controls. The TSA/TP also showed statistical significance in Dukes A, B2, C, and D subgroups when compared with normal controls. There were only four patients with stage Cl carcinoma, thus statistical analysis would be questionable. In contrast, carcinoembryonic antigen levels showed no significant elevations until Dukes C2 tumors were encountered. These preliminary findings suggest that TSA/TP ratio may detect colorectal cancer patients with less tumor burden and be more beneficial as a tumor marker than CEA for monitoring patients with colorectal cancer.Read at XIIth Biennial Congress of the International Society of University Colon and Rectal Surgeons, Glasgow, Scotland, July 10 to 14, 1988.     

New perspective in the treatment of low rectal cancer: Total rectal resection and coloendoanal anastomosis

PURPOSE: Presently abdominoperineal resection still remains the most diffuse modality of treatment of low rectal cancer. However, a new surgical approach is now available to avoid such a demolitive surgery and a definitive colostomy. METHODS: From March 1990 to March 1993, 58 total rectal resections were performed in 55 patients affected with primary or recurring cancers of the low rectum. As a restorative procedure, a colic J-shaped pouch and a handsewn pouch-endoanal anastomosis was adopted. All of the primary lesions were within 7 cm of the anal verge; in 74 percent the distal tumor margin was located less than 6 cm from the cutaneous edge. RESULTS: Histologic clearance of the rectum cut edge was documented in all cases. Seven patients relapsed locally from 7 to 14 months after surgery and in 3 more cases distant metastases were documented. Postoperative morbidity is low. After colostomy closure in 78 percent of patients, perfect continence was achieved and in 74 percent less than two bowel movements a day were recorded. Fifty patients are presently alive, 46 without evidence of disease. The follow-up ranged from 2 to 37 (median, 13) months. CONCLUSION: This experience, along with data obtained from last year's literature, indicates that a conservative surgical procedure, such as total rectal resection and coloendoanal anastomosis, can be considered a feasible and radical option for treatment of low rectal cancer.     

The role of CEA,TPA and CA 19-9 in the early detection of recurrent colorectal cancer

Eighty-eight consecutive patients who underwent curative resection for colorectal cancer between 1983 and 1985 were studied prospectively to evaluate the roles of sequential CEA, TPA and CA 19-9 determinations and independent clinical examination in the early diagnosis of resectable recurrences. Twenty nine recurrences were detected between 8 and 38 months after primary surgery. CEA, TPA and CA 19-9 showed a sensitivity of 72%, 62% and 38%, and a specificity of 78%, 86% and 97%, respectively. Of eight recurrences in which CEA was not raised, five induced a rise in TPA and two a rise in CA 19-9. The rise in the serum concentration of one of the three markers was the first sign of relapse in 23 (79%) patients. Two second-look laparotomies based solely on a rise in serum markers were performed. In one case diffuse recurrent disease was found, and in the other a resectable solitary hepatic metastasis was found.     

Progress in the assessment of lymphatic spread in rectal cancer Rectal endoscopic lymphoscintigraphy

Rectal endoscopic lymphoscintigraphy was performed in 10 control subjects and in a series of 85 patients with adenocarcinoma of the rectum as a prospective study to evaluate lymphatic drainage of the rectum and lymphatic spread in rectal cancer. Complete cranial drainage was demonstrated in all control subjects, and internal iliac nodes were also visible in 50 percent of cases. Results were correlated with histologic node examination in all patients operated upon for rectal cancer. Rectal endoscopic lymphoscintigraphy was assessed for sensitivity (85 percent), specificity (68 percent), overall accuracy (76 percent), positive predictive value (71 percent), and negative predictive value (83 percent). False-negative and false-positive results are discussed. Rectal endoscopic lymphoscintigraphy represents the only method currently available for evaluation of lymphatic spread in rectal cancer.     

Prognostic value of positive lymph nodes in rectal cancer

Abdominal curative resections for rectal cancer in 109 patients with positive lymph nodes were prospectively studied. The best subdivision of patients for predicting outcome was into 1–3 and >3 positive lymph node groups. Comparison with patients with >3 positive lymph nodes demonstrated that patients with 1–3 positive nodes had less local (35.0 percent vs. 13.0 percent;P =0.007) and less distant recurrences (45.0 percent vs.26.0 percent;P =0.04) and had much better crude five-year survival (58.2 percent vs.17.0 percent; P < 0.0001). For predicting postsurgical outcome in patients with positive lymph nodes, the results justify subdividing patients into the following two prognostic subgroups: 1) those with 1–3 involved lymph nodes and 2) those with metastatic tumor in four or more lymph nodes.     

Proctectomy and coloanal reconstruction for rectal cancer

There is increasing interest in the use of coloanal reconstruction following proctectomy for low rectal cancer. The authors review the surgical options for such sphincter-saving approaches, and report their pilot experience with eight patients receiving high-dose preoperative radiation with subsequent proctectomy and endoanal anastomosis. There were no anastomotic leaks.     

Predicting lymph node metastases in rectal cancer

For properly selected rectal cancers, local excision is a sphincter-saving alternative to abdominoperineal resection. If histologic assessment of a locally excised tumor reveals ominous features, further treatment with radical resection or irradiation may be necessary to treat potential lymph node metastases. PURPOSE: We wished to determine which features, if any, were predictors of nodal metastases. METHODS: Nine histologic and morphologic features of 62 radically excised rectal cancers were reviewed to determine which factors, if any, were associated with nodal disease. RESULTS: Using a chi-squared analysis, we found worsening differentiation (P=0.0001), increasing depth of penetration (P=0.026), a microtubular configuration of 20 percent or more (P=0.023), and the presence of venous (P=0.001) or perineural invasion (P=0.002) to significantly influence nodal disease. Lymphatic invasion was witnessed too infrequently to determine significance but, when present, was associated with nodal metastases in every case. Exophytic tumor morphology, mitotic count, and tumor size were not significant predictors. An analysis of variables determined that, of all factors or combination of factors examined, Broder's classification was the strongest predictor of nodal disease. CONCLUSIONS: If a rectal cancer is accessible and of small size to facilitate local excision, an in-depth histologic assessment is needed to determine if nodal metastases are likely on a statistical basis.This work was supported by the Bowman Research Fund.     

Differences in serum tumor markers between colon and rectal cancer

PURPOSE: We investigated whether there are differences in serum levels of CA 242 and carcinoembryonic antigen (CEA) between patients with colon and rectal cancer. METHODS: Preoperative serum levels of CA 242 and CEA were determined in 153 patients with colon cancer and in 107 patients with rectal cancer. RESULTS: At the recommended cut-off levels for CA 242 and CEA, the overall sensitivity of CA 242 was 39 percent for both colon and recta! cancer, whereas the sensitivity of CEA was 40 percent for colon and 47 percent for rectal cancer. A combination of CA 242 and CEA increased overall sensitivity to 57 percent in colon cancer and to 62 percent in rectal cancer, whereas specificity decreased by 10 percent, compared with CEA alone. In colon cancer either or both markers were elevated in 38, 46, 56, and 84 percent of patients with Dukes Stages A, B, C, and D, respectively. Corresponding figures for rectal cancer were 52, 46, 71, and 87 percent, respectively. CONCLUSIONS: CA 242 showed equal sensitivity for colon and rectal cancer. In Stages A, C, and D, sensitivity of CEA and of a combination of CEA and CA 242 was higher in rectal than in colon cancer, but the difference was not significant. Concomitant use of markers increased sensitivity sharply compared with use of a single marker both in colon and rectal cancer.Supported by grants from Finska Läkaresällskapet and Stiftelsen Dorothea Olivia, Karl Walter and Jarl Walter Perkle'ns minne and Medicinska Understödsföreningen Liv och Hälsa. CA 242 test kits were supplied by Wallac Oy.     

Tumor angiogenesis and rectal carcinoma

PURPOSE: This study was designed to determine whether those rectal cancers that demonstrated increased vessel ingrowth or angiogenesis behave in a different fashion. METHODS: The paraffin blocks of 48 rectal cancers removed by low anterior or abdominoperineal resection were recalled and immunostained with a monoclonal antibody specific for endothelial cell Factor VIII. The intense reddish brown color imparted to blood vessels facilitated their quantification which was undertaken at ×100 and ×200 magnification. Vessel counts within three microscopic fields were averaged and the relationships between angiogenesis score and tumor size, depth of invasion, incidence of lymph node or distant metastases, and survival were assessed. RESULTS: Significantly higher angiogenesis scores were seen in tumors with transmural penetration (at ×100,P=0.002; at ×200,P =0.002) and in patients dying before five years (at ×100,P =0.013; at ×200,P =0.034). Although higher angiogenesis scores were seen in patients with larger tumors and metastases, these trends were not statistically significant. CONCLUSIONS: Our results suggest that the growth of rectal cancer is dependent on the ingrowth of new blood vessels, and that increased vascularity promotes dissemination and adversely affects survival.Supported in part by the Bowman Research Fund. Read at the meeting of The American Society of Colon and Rectal Surgeons, Chicago, Illinois, May 2 to 7, 1993. Winner of the Northwest Society of Colon and Rectal Surgeons Award.     

Endorectal ultrasonic detection of malignancy within rectal villous lesions

PURPOSE: The ability of endorectal ultrasonography (EU) to detect the presence of a malignant focus within rectal villous adenomas was studied. METHODS: Clinical charts were reviewed of 62 consecutive patients undergoing EU of rectal villous adenomas, in whom Histologic confirmation was available. RESULTS: Twelve lesions were found to contain cancer, of which only two demonstrated clinical signs of induration. Positive predictive value of EU for detecting a malignant focus was 66.7 percent, negative predictive value was 88.7 percent, sensitivity was 50 percent, and specificity was 94 percent. There was moderate overall agreement between pathologic and ultrasound staging (kappa statistic, 0.48). When an optimal image was obtained, all cancers that penetrated the submucosa were detected. Sensitivity of the technique was compromised in some large exophytic lesions and those at the level of the anal sphincter because of artefacts produced in the ultrasonographic image. CONCLUSION: A clear EU image can detect a malignant focus within a villous adenoma and direct the surgeon to the appropriate plane of surgical resection. In lesions with an ambiguous image, a malignancy cannot be excluded.All work was performed at the Division of Colon and Rectal Surgery, University of Minnesota, Minneapolis, Minnesota.     

Locally advanced rectal cancer: Resection and intraoperative radiotherapy using the flab method combined with preoperative or postoperative radiochemotherapy

PURPOSE: Surgery often fails to achieve local control in advanced rectal cancer. Additional measures are necessary to prevent local recurrence. The aim of this study was to evaluate intraoperative radiation therapy (IORT) (flab technique) combined with preoperative or postoperative radiochemotherapy. PATIENTS/METHODS: IORT is performed using a flexible flab containing hollow plastic tubes that are connected to a multichannel afterloading device with a 370 Gbq-192-Ir source. Patients receive an intraoperative dose of 15 Gy. Target volumes were measured in a cadaver experiment. From 1989 to 1993, 38 patients were included in this study. Nineteen patients were staged as T3 tumors by preoperative endosonography (Group I) and 19 as T4 tumors (Group II). Patients in Group I underwent resection (abdominoperineal resection (APR), 16; anterior resection, 3) and IORT, followed by postoperative radiochemotherapy (50 Gy/5-fluorouracil), whereas patients in Group II received preoperative radiochemotherapy (40 Gy/5-fluorouracil) followed by resection (APR, 18; anterior resection, 1) and IORT. Mean follow-up was 25.5 months. RESULTS: Operative radicality in Group I was R0 (13), R1 (3), and R2 (3), and in Group II it was R0 (14), R1 (3), R2 (2). R2 resections were attributable to preoperative undetected distant metastases. Perioperative mortality was 0 percent in Group I and 10.5 percent (n=2) in Group II. Postoperative morbidity was 53 percent (n=10) in Group I and 84 percent (n=16) in Group II with delayed sacral wound healing being the predominant problem. Stenosis of the ureter occurred in two patients (Group II). Late or persistent therapy-related complications were seen in two patients in Group I and in six patients in Group II. Local recurrence developed in three patients in Group I (15.8 percent) and in two patients in Group II (10.5 percent). Survival data do not reach statistical significance between the two groups because of small numbers but show a favorable trend for the preoperative radiochemotherapy group. When compared with a matched historical control group of patients receiving resection only, adjuvant/neoadjuvant radiotherapy with resection/IORT improves survival significantly. CONCLUSION: The flab method is a simple but especially practical technique for IORT in the pelvis. Adjuvant/neoadjuvant therapy combined with resection/IORT is associated with high morbidity but acceptable mortality. Preliminary survival data are encouraging and call for a controlled prospective randomized trial.Read at the meeting of The American Society of Colon and Rectal Surgeons, Montreal, Quebec, Canada, May 7 to 12, 1995.     

Surgical adjuvant therapy for rectal cancer: Present options

Recent advances have been made with the publication of the results of GITSG and NCCTG trials, which demonstrated the significant improvement of survival by combined postoperative radiochemotherapy protocols for Stage II and III rectal cancer. These data show that systemic chemotherapy has a decisive role to play in this policy. Some of the advantages of preoperative irradiation compared with postoperative radiation therapy consist of the improvement of resectability of T4 tumors and the anal preservation for low-lying cancers. These data suggest that preoperative chemoradiotherapy should be applied not only to T4 tumors but also to all T3 tumors even when the transrectal extension is limited. The most usual protocol combines 5-fluorouracil (300–350 mg/m²/day) and leucovorin (20 mg/m₂/day) for 5 days, followed by radiation therapy (30–35 Gy in 10 fractions within 12–15 days), with surgery taking place 4 to 8 weeks later, after the tumor has been restaged. Systemic therapy is continued for four more months. T2 cancers should not be excluded from the benefit of preoperative irradiation.     

Correlation of nuclear morphometry and DNA ploidy in rectal cancer

Several investigators have used morphometric measurements to determine differences in the nuclear size and shape of normal and neoplastic colorectal tissue. Changes in nuclear morphometric parameters have also been shown to correlate with prognosis in a variety of noncolorectal cancers. The association of nuclear morphometry with prognostic indicators in rectal cancer has not been well studied. Measurements of the nuclear area, perimeter, longest cord, and circularity factor from 39 primary rectal adenocarcinomas were compared with DNA content, degree of tumor differentiation, Dukes' class, and patient survival. Nuclear circularity was found to correlate with DNA ploidy. Nondiploid tumors with a DNA index greater than 1.3 had significantly more circular nuclei than tumors with diploid or near-diploid DNA content. There was no correlation between nuclear morphometry and Dukes' class or patient survival. Significant increases in DNA content of rectal cancers appear to be reflected by measurable changes in nuclear shape. Nuclear morphometric measurements may provide useful information in the study of the progression of neoplastic changes in colorectal cancer.     

Preliminary results of preoperative 5-fluorouracil, low-dose leucovorin, and concurrent radiation therapy for clinically resectable T3 rectal cancer

PURPOSE: We report the downstaging, sphincter preservation, acute toxicity, and preliminary local control and survival results of preoperative 5-fiuorouracil (5-FU), low-dose leucovorin (LV), and concurrent radiation therapy followed by postoperative LV/5-FU for treatment of patients with clinically resectable T3 rectal cancer. MATERIALS AND METHODS: A total of 32 patients received two monthly cycles of preoperative LV/5-FU (bolus daily×5). Radiation therapy (5,040 cGy) began concurrently on day 1. Postoperatively, patients received a median of two monthly cycles of LV/5-FU (range, 0–10). RESULTS: The complete response rate was 9 percent pathologic and 13 percent clinical, for a total of 22 percent. Total Grade 3+ acute toxicity during the preoperative combined modality segment was 25 percent (8/32). Of the 20 patients who were thought to initially require an abdominoperineal resection and for whom the intent of treatment was sphincter preservation, 17 (85 percent) were able to undergo sphincter-preserving surgery. With a median follow-up of 22 (3–59) months, none have developed local failure, and the three-year actuarial diseasefree survival rate was 60 percent. CONCLUSION: Our data reveal encouraging downstaging, sphincter preservation, and acute toxicity with this regimen. Additional follow-up is needed to assess the long-term local control and survival rates.Presented at the meeting of the American Society of Therapeutic Radiology and Oncology, Los Angeles, California, October 25 to 29, 1996.