Residual, unresectable, or recurrent colorectal cancer: external beam irradiation and intraoperative electron beam boost +/- resection

Peripheral nerve and ureteral tolerance to intraoperative radiation therapy: clinical and dose-response analysis

Between April 1981 and July 1984, 51 patients received intraoperative radiation therapy (IORT) as a component of therapy for the management of primary or recurrent pelvic malignancies which were initially unresectable for cure. For these patients, curative surgical alternatives did not exist, or would have involved extensive procedures such as pelvic exenteration, distal sacrectomy, hemipelvectomy, or hemicorporectomy. The primary disease was colorectal in 38 patients. Treatment consisted of external beam radiation (range 3000 to 6890 cGy, median 5040 cGy), surgical debulking when feasible, and an intraoperative electron beam boost to the gross or microscopic residual disease (dose range 1000 to 2500 cGy, median 1750 cGy) utilizing 9-18 MeV electrons. The most common IORT associated toxicities were peripheral neuropathy and ureteral obstruction. None were life-threatening or fatal in severity. Of the 50 patients evaluable for neurotoxicity analysis, 16 (32%) developed peripheral neuropathy consisting of pain in 16 patients, numbness and tingling in 11, and weakness in 8. The pain, numbness and tingling resolved in about 40% of patients, while weakness resolved in only 1 of 8. Sixteen ureters were initially unobstructed by tumor at the time of IORT. Of these, 10 (63%) subsequently showed evidence of obstruction and hydronephrosis. The development of neurotoxicity was more common at IORT doses of 1500 cGy or more versus 1000 cGy. Ureteral obstruction with hydronephrosis occurred more frequently at IORT doses of 1250 cGy or more compared to 1000 cGy. There was no relationship between the likelihood of developing complications and the total external beam dose. The observed dependence of human nerve toxicity primarily on the IORT dose is consistent with data generated from animal experiments.

Postoperative radiation therapy for incompletely resected colorectal carcinoma

The efficacy of high-dose post-operative radiation therapy was evaluated in 56 patients with pathologically proven or suspected residual disease after surgical resection of colon or rectal carcinoma. Patients had either microscopic or gross residual. They were treated with pelvic or abdominal irradiation to a dose of 4500 cGy followed by boost therapy to as much as 6000 to 7000 cGy if small bowel could be moved from the radiation field. Patients with microscopic residual had a local failure rate of 30% compared to 57% in those with gross residual disease. Five-year disease-free survival was 45% in patients with microscopic versus 10.6% for those with gross residual tumor. There was a trend toward a dose response curve for those with microscopic disease, but none was noted with gross residual. In view of the limited results obtained with current external beam techniques, it is recommended that newer avenues, such as high-dose preoperative therapy combined with intraoperative radiation, be investigated in this poor prognosis group.

Preoperative irradiation with and without chemotherapy (MFL) in the treatment of primarily non-resectable adenocarcinoma of the rectum. Results from two consecutive studies

Twenty-one consecutive patients with primarily non-resectable adenocarcinoma of the rectum were treated with preoperative split-course radiotherapy (40 Gy) and simultaneous sequential methotrexate + 5-fluorouracil + leucovorin (MFL). An initial infusion of methotrexate (250 mg/m2) was followed in the 2nd hour by 5-FU--first a bolus injection (10 mg/kg) and then continuous infusion (35 mg/kg/24 h) for 72 h. Leucovorin rescue (15 mg every 6 h) was initiated 24 h after the initial injection. Radiotherapy (10 Gy) was given with two 2.0 Gy fractions on days 1 and 2, and one fraction on day 3. The toxicity of the treatment was mostly mild to moderate. Compared with a previous consecutive series comprising 38 patients who received preoperative irradiation (greater than or equal to 40 Gy) only, with a resectability rate of 34%, the 71% resectability rate with this treatment seems to be superior.

Remote afterloading intraluminal brachytherapy in the treatment of rectal, rectosigmoid, and anal cancer: a feasibility study

From 1981 to 1986, 28 patients (27 evaluable) were treated with intraluminal brachytherapy (ILBT) using a remote afterloading technique for persistent or recurrent anal, rectal and rectosigmoid cancers. Eighty-nine percent underwent previous surgery for colorectal cancer. Seventy-seven percent of the patients received external beam irradiation (ERT) as a part of the present treatment. Intraluminal brachytherapy was given with a 2 cm diameter cylinder and the dose per fraction ranged from 440 cGy to 840 cGy at 0.5 cm from the surface of the cylinder. Follow-up ranged from 1 to 74 months with a median of 12 months. Patients were divided into two groups. Group I consisted of 15 patients receiving elective ILBT; Group II: 13 patients with recurrent disease. Seventy-one percent of the patients in Group I and 39% of the patients in Group II achieved local control. The majority of patients tolerated treatment well with only transient reactions. However, three patients (11%) developed grade 3 (G3) complications requiring surgical intervention. Eight patients developed moderate complications--grade 2 (G2)--requiring only conservative treatment. This study has identified several factors which appear to influence the risk of developing complications with this combined treatment, using remote afterloading apparatus, among which are technique of previous external beam irradiation, treatment length, anatomical location, intraluminal brachytherapy fractionation, and total cumulative dose (ERT + ILBT). This experience suggests that intraluminal brachytherapy appears to be an acceptable form of treatment, as a boost to external beam radiation therapy, in the management of rectal and colorectal cancers.

Extended resection of fixed rectal cancer

Between 1980 and 1987, we operated on 23 patients (16 men and 7 women) with fixed rectal cancer. Two patients had primary tumours. Twenty-one patients had recurrent disease (anterior resection, 8; abdominoperineal resection, 13). Eighteen patients had prior irradiation (40 Gy to 120 Gy). Resection was possible in 20 patients (16 for cure and 4 for palliation). Operations included extended proctectomy (n = 4), standard pelvic exenteration (n = 4), and sacropelvic exenteration (n = 12). One (5%) patient died postoperatively and five (25%) others had significant postoperative complications. With a follow-up time of 1 to 48+ months (median, 18 months), nine patients are dead of disease (operative death included), four are living with disease, two are dead free of disease, and eight (50% of those undergoing curative resection) are living free of disease. The results suggest that resection of fixed rectal cancer is feasible in many patients and of potential long-term benefit to approximately 50% of those in whom curative resection is possible.

Treatment of locally advanced rectal cancer with external beam radiation, surgical resection, and intraoperative radiation therapy

To try to improve the local control and survival of patients with locally advanced rectal cancer we have used a combination of high-dose pre-operative radiation therapy to 5,040 cGy followed by surgical resection and intraoperative electron beam radiation therapy (IORT) when there was visible or palpable residual disease, microscopically positive surgical margins, or persisting tumor adherence. A total of 75 patients were taken to surgery for resection +/- IORT who did not have distant metastases. Of the 49 patients with primary tumors, 11 did not have IORT as the tumor was thought to be completely resected. Of these 11, there were two local recurrences and a 3-year survival of 71%. Thirty-six patients with primary tumors had resection (20 complete, 16 partial) plus IORT, with a 3-year survival of 58% and three local failures. Twenty-six additional patients were treated for locally advanced recurrence of whom four could not receive IORT because of pelvic size or the extent of tumor. Of the 22 who received IORT, 7/9 with complete resection, 2/8 with partial resection, and 1/5 with no resection had local control with an overall 3-year actuarial survival of 32%. The local control and survival results in the primary tumors appear favorable compared to other series in the literature and suggest benefit to the use of IORT. For patients treated for local recurrence, local control and long-term survival can be obtained, but the results are not as encouraging as for the primary tumors.

Intraoperative radiotherapy for recurrent and/or residual colorectal cancer

Intraoperative radiotherapy (IORT) is an attractive boosting modality in the combined treatment of recurrent and/or residual colorectal cancer. Twenty seven patients treated with IORT are analysed. Residual disease following resection of the primary tumor was treated in 11 cases (group I). Localized recurrent disease without previous radiotherapy was treated in 11 cases (group II). IORT was used in five additional patients with local recurrences in previously irradiated areas (group III). The treatment program consisted of maximal tumor resection, IORT (10-30 Gy) to the area of residual disease and external beam radiotherapy (46-50 Gy). The median follow-up time for the entire series of patients is 11 months. Local tumor control rates are 90% in group I, 63% in group II and 60% in group III. Toxicity and complications related to IORT observed in this initial experience have been pelvic pain (29%) and lower extremity neuropathy (3%). These early clinical results suggest that the IORT combined with surgery and external beam radiotherapy is feasible in primary and recurrent disease. Local control rates obtained in patients not suitable for curative surgery are encouraging.

The combination of surgery and radiation in the treatment of cancer. A review

Although radiation and surgery have been combined for the treatment of cancer in humans and animals since the 1920s, little has been written about the methods of combining radiation and surgery and the efficacy of this combination for the treatment of animal tumors. This article reviews the rationale for combining radiation and surgery for the treatment of cancer and the ways in which these two modalities can be combined with emphasis placed on the advantages and disadvantages of preoperative and postoperative radiotherapy. The role of preoperative and postoperative irradiation for the treatment of various animal tumors is discussed. Directions for future clinical trials are pointed out. Finally, the importance of surgeons and radiation oncologists communicating with each other and participating in cooperative treatment methods is stressed.

Intraoperative and external beam irradiation for locally advanced colorectal cancer

In view of poor local control rates obtained with standard treatment, intraoperative radiation (IORT) using electrons was combined with external beam irradiation and surgical resection, with or without 5-fluorouracil (5FU), in 51 patients with locally advanced colorectal cancer (recurrent, 36 patients; primary, 15 patients). Patients received 4500-5500 cGy (rad) of fractionated, multiple field external beam irradiation and an IORT dose of 1000-2000 cGy. Thirty of 51 patients (59%) are alive and 22 patients (43%) are free of disease. In 44 patients at risk greater than or equal to 1 year, local progression within the IORT field has occurred in 1 of 44 (2%) and within the external beam field in 8 of 44 (18%). All local failures have occurred in patients with recurrence or with gross residual after partial resection, and the risk was less in patients who received 5FU during external irradiation (1 of 11, 9% vs. 6 of 31, 19%). The incidence of distant metastases is high in patients with recurrence, but subsequent peritoneal failures are infrequent. Acute and chronic tolerance have been acceptable, but peripheral nerve appears to be a dose-limiting structure. Randomized trials are needed to determine whether potential gains with IORT are real.

Intraoperative radiation therapy for advanced or recurrent head and neck cancer

Between 1982 and 1984, we treated 28 patients with advanced head and neck cancer with surgery, combined with intraoperative radiation. All patients had squamous cell carcinoma. One patient had two separate sites treated and a second patient was treated on two occasions, allowing 30 sites for analysis. The overall survival for all patients treated was 67% at 1 year. Local failure occurred in 13% of those with close surgical margins and 25% of those with microscopic residual disease. With gross residual disease 100% had local failure. Patients with gross residual disease had significantly higher local failure than microscopic residual disease (p less than 0.02) or close surgical margins (p less than 0.01). Carotid blowout was the major treatment complication. We believe intraoperative radiation is an effective treatment for advanced or recurrent head and neck cancer when all gross disease has been resected.

Initially unresectable rectal adenocarcinoma treated with preoperative irradiation and surgery

This is an analysis of 23 patients with clinically and/or surgically unresectable adenocarcinoma of the rectum on initial evaluation who were treated with preoperative irradiation and surgery between March 1970 and April 1981. All patients have had follow-up for at least 5 years. Five patients (22%) had exploratory laparotomy and diverting colostomy before irradiation. All patients were irradiated with megavoltage equipment to the pelvis at 180 rad/fraction, continuous-course technique. Total doses ranged from 3500 to 6000 rad with a mean of 4800 rad and a median of 5000 rad. All patients had surgery 2-11 weeks (mean: 4.9 weeks; median: 4 weeks) after radiation therapy. Twelve patients (52%) had lesions that were incompletely resected because of positive margins (7 patients), distant metastasis (1 patient), or both (4 patients). All of these patients died of cancer within 5 years of treatment. Eleven patients had an apparent complete excision of their rectal cancer; six patients (55%) subsequently had a local recurrence. The 5-year absolute survival rate for patients who had complete resection was 18% (2 of 11 patients). The 5-year absolute and determinate survival rates for the entire study were 9% (2 of 23 patients) and 9% (2 of 22 patients), respectively. One patient (in the incomplete resection group) died after operation secondary to sepsis and diffuse intravascular coagulation.

Quality control parameters of intraoperative radiation therapy

We have tried to outline many of the factors which must be considered in the technical delivery of IORT and in subsequent evaluation of these patients. Unless careful attention is given to details of patient selection, surgery, pathology, radiation therapy and follow-up, it is likely that a vast morass of data will be obtained which will be very difficult to interpret. It is the hope of the IORT Working Group that other institutions using IORT will employ our recommendations with regard to dosimetry, follow-up, and the general technical approach. This will likely lead to an earlier understanding of the exact role of this modality in cancer therapy today.

Carcinoma of the rectum: current management

In recent years, various approaches have been used to improve survival and the quality of life in patients after surgical treatment of rectal carcinoma. These approaches include earlier detection, sphincter-saving procedures, and adjuvant therapy, intraoperative therapy for locally advanced tumors, and a more aggressive approach for locally recurrent or distal but isolated spread of the disease.

Intraoperative radiotherapy

The potential benefit of intraoperative radiotherapy (IORT) was originally recognized years ago and has recently attracted renewed interest. Modern radiotherapeutic approaches may be more successful as a result of technical innovation, particularly in the use of electron beam accelerators. Preliminary studies, mainly uncontrolled and nonrandomized, have assessed the role of IORT for treatment of a variety of deep seated abdominal, retroperitoneal, and pelvic cancers. The results of some studies show much promise, but prospective trials are needed to scientifically validate these favorable initial observations.

Local control and survival in locally advanced gastrointestinal cancer

When conventional modalities (external beam irradiation and chemotherapy +/- resection) are used in the treatment of locally advanced gastrointestinal malignancies, although useful palliation can be achieved in many patients, local control and long-term survival are infrequent. In recent trials, investigators have used fractionated external beam doses of 4500-5000 rad in 180 rad fractions in combination with irradiation boost techniques of intraoperative electrons, or intraoperative or transcatheter brachytherapy (+/- chemotherapy and resection). With colorectal and biliary cancer, both local control and long-term survival appear to be improved, compared to results achieved with conventional treatment. With pancreatic cancer, an apparent improvement has been noted with local control and median survival, but long-term survival has not been altered. For partially resected gastric cancer, the use of intraoperative irradiation has yielded five year survival rates of approximately 20%. With unresectable or residual gastric cancer, accelerated fractionation alone or in combination with chemotherapy has yielded excellent local control, but patients have died as a result of abdominal failure or lung metastases. Prevention of abdominal failures will be necessary to improve long-term survival with pancreatic and gastric cancer. Randomized trials by site are needed to determine if the observed differences seen in prospective nonrandomized trials are real or due to differences in case selection.

Photodynamic therapy in patients with colorectal cancer

A pilot study was conducted, in which photodynamic therapy (PDT), a technique in which malignant cells are destroyed by light after being previously photosensitized by a chemical compound, was tried in a group of 14 patients with recurrent or residual colorectal cancer in the pelvis. Three of the six patients with unresectable pelvic recurrences experienced a significant relief of pain after PDT. In two of the five patients who had an incomplete resection of their pelvic recurrences, there was also a substantial relief of pelvic pain after surgery and PDT. In one of these patients subsequent biopsies proved the disappearance of the residual pelvic microscopic disease after several sessions of PDT. Three patients had a recurrence from a squamous cell carcinoma primary of the anal canal. All recurrences were amenable to surgical resection. In one of the patients, PDT was used in an attempt to sterilize an area of residual tumor that was located over the left ischial tuberosity. The patient experienced good relief of pain, but died of her disease 7 months after PDT. In the other two patients, PDT was used as an "adjunct" after resection of their recurrences. One of these patients was free of disease and died of an unrelated cause 12 months after PDT. The other is alive and well. This study demonstrated that PDT can be safe and tolerable in patients with pelvic malignancies. PDT is capable of tumor destruction, can be used repeatedly in areas previously exposed to ionizing radiation, and may have a role in the prevention and management of pelvic-perineal recurrences from colorectal cancer.

Current issues in the treatment of colorectal cancer

For colorectal cancers that are confined to the bowel wall with uninvolved nodes, surgery alone is curative in most patients, and adjuvant treatment is usually not indicated. A combined modality approach for the initial treatment of many rectal and selected colonic carcinomas is based on data that "radical" operations do not necessarily prevent either local regrowth or distant failures and acceptance of a significant palliative but infrequent curative role for irradiation and chemotherapy when such failures occur. Published data for rectal cancer indicates that local recurrence can be markedly reduced by moderate to high dose pre- and post-operative irradiation +/- chemotherapy. For colon cancer, data from pilot trials suggest that post-operative irradiation may reduce local recurrence by stage when compared with surgery alone analyses, but randomized trials are needed. With locally advanced disease, aggressive treatment combinations appear to increase both local control and survival, but much interaction is required between involved physicians.

Therapeutic advantage in preoperative single-dose radiation combined with conservative and radical surgery in different-size murine fibrosarcomas

The efficacy of surgery alone or combined with preoperative radiation was examined using isotransplants of the spontaneous fibrosarcoma (FSaII) growing in the right leg of syngeneic C3Hf/Sed mice and employing as end-points both local tumor control probability and normal tissue damage. Complete assays have been performed on small (4-5 mm) and large (8 mm) tumors. The TCD50s (the dose required to control half the irradiated tumors) for radiation alone were 63.2 and 82.7 Gy for small and large tumors, respectively. Surgery was performed 4 days after the radiation treatment. Surgical resections were performed under an 8 X dissecting microscope. In small tumors, radical (enbloc resection) and conservative (local resection) surgery alone achieved 69.8% (30/43) and 21.9% (7/32) tumor control. The corresponding figures for large tumor were 25% (8/32) and 6.1% (2/33), respectively. The combination of radiation and surgery increased tumor control frequency up to 100% with doses lower than TCD50 for radiation alone. The TGF is expressed as therapeutic gain factor for conservative and for radical surgery for 4-5-mm and for 8-mm tumors from analyses of dose response curves for tumor control and leg shortening. In small tumors, the TGFs at the 80% tumor control (TCD80) and leg shortening of 5 mm were 1.4 and 1.8 for radical and conservative resection, respectively. The TGFs at the TCD50 level for large tumors were 1.4 and 1.7 in respective resections. In this particular experimental system, conservative surgery yielded higher TGFs than radical surgery for both tumor sizes. No effect of preoperative treatment on the frequency of distant metastasis was observed.

Treatment planning for colorectal cancer: radiation and surgical techniques and value of small-bowel films

For colorectal cancer, the adjuvant radiation dose levels required to achieve a high incidence of local control closely parallel the radiation tolerance of small bowel (4500-5000 rad), and for patients with partially resected or unresected disease, the dose levels exceed tolerance (6000-7000 rad). Therefore, both the surgeon and the radiation oncologist should use techniques that localize tumor volumes and decrease the amount of small intestine within the irradiation field. Surgical options include pelvic reconstruction (reperitonealization, omental flaps, retroversion of uterus, etc.) and clip placement. Radiation options include the use of radiographs to define small bowel location and mobility combined with treatment techniques using multiple fields, bladder distention, shrinking or boost fields, and/or patient position changes (prone, decubitus, etc.). When both specialties interact in optimum fashion, local control can be increased with minimal risks to achieve a suitable therapeutic ratio.

Residual, recurrent, or unresectable gastrointestinal cancer. Role of radiation in single or combined modality treatment

When conventional modalities of external beam irradiation and chemotherapy +/- resection are used in the treatment of locally advanced gastrointestinal malignancies, although useful palliation can be achieved in many patients, cure and long-term survival is infrequent. Aggressive combined modality approaches have recently encorporated irradiation boost techniques with intraoperative electrons or intraoperative or transcatheter brachytherapy. Both local control and long-term survival appear to be improved when compared with results achieved with conventional treatment. Randomized trials are needed to determine if the observed differences are real or due to differences in case selection.

Rationale for combining surgery and radiation therapy

The combination of radiation and surgery is being employed increasingly in preference to radical surgery alone or high radiation dose alone in the treatment of malignant epithelial and mesenchymal neoplasms. The basis for this interest is that the scope of the surgery and/or the radiation dose level are less than if either were employed alone. A reduction in treatment related morbidity, improved cosmetic and functional status, and in some instances a lower local failure rate may be achieved by this approach. The rationale for combining radiation and surgery is that radiation at moderate dose levels is effective in the eradication of microscopic extensions of tumor beyond the clearly obvious mass while the surgery (usually more conservative) removes the principal mass.

Adjuvant postoperative radiotherapy in carcinoma of the rectum and rectosigmoid

Local recurrence occurs in 30% to 50% of rectal cancer patients treated with surgery alone if there is tumor extension beyond the bowel wall alone or in conjunction with nodal involvement. This analysis is of 97 such patients who received postoperative irradiation (XRT) in prospective and standardized fashion at Massachusetts General Hospital (MGH) (4500 rad in 25 fractions to large fields and minimum dose of 5040 rad in 28 fractions within a boost field). Results were compared with a group of 103 previously analyzed patients treated with surgery alone at MGH. A statistically significant decrease in local recurrence was seen in four of the six irradiated subgroups (modified Astler-Coller Stages B2g, B3, C1 + C2m, and C2g) at an interval 3 years from resection. This improvement was achieved with no increase in small bowel complications (4% with XRT versus 5% with surgery alone) in view of efforts at surgical reconstruction and use of multiple-field XRT techniques, bladder distension, etc.

Complications of intraoperative radiation therapy

The ability to demonstrate an improvement in therapeutic ratio is critical in assessing new treatment modalities; an evaluation of treatment complications is essential for this purpose. We have studied the severe complications occurring after treatment with intraoperative radiation therapy (IORT) in patients with locally advanced carcinoma of the rectum. Four groups of patients were compared: Group 1 (80 patients) had treatment with surgery alone for mobile and resectable tumors; Group 2 (23 patients) had treatment with high dose preoperative irradiation followed by surgical resection for tumors which were fixed to adjacent structures and initially unresectable for cure; Group 3 (24 patients, primary disease) and Group 4 (17 patients, locally recurrent disease) had locally advanced tumors as in Group 2 but were treated with IORT after preoperative irradiation and attempted surgical resection. All but 3 complications occurred within one year of therapy. Severe complications were seen in 16% of patients in Group 1, 35% in Group 2, 21% in Group 3 and 47% in Group 4 (32% in Groups 3 and 4 combined). There was a statistically insignificant increase (p = .10) in the complication rate in all irradiated patients (locally advanced tumors) compared to surgery alone (clinically mobile tumors). These data indicate no increase in severe complications with the use of IORT. If the ongoing studies continue to show improved local control with the use of IORT, expanded use of this modality may be warranted.

Intraoperative and external beam irradiation with or without resection: Mayo pilot experience

At our institution, intraoperative radiation therapy (IORT) with an electron beam has been administered as a single boost dose of 1,000 to 2,000 cGy (rad) in combination with 4,500 to 5,000 cGy (rad) of fractionated external beam irradiation. From April 1981 to July 1983, 50 patients received such treatment, and results are analyzed in detail in this article. All patients had locally advanced disease (initially unresectable for cure, residual after resection, or recurrent), and the main disease sites were gastrointestinal (pancreatic, colorectal, and biliary tumors) and soft tissue (sarcomas). Disease-free survival to date has been excellent in our colorectal and biliary subsets of patients. Although local progression has not been a major problem in patients with unresectable pancreatic lesions, failures in the liver and peritoneal cavity have been excessive, and treatment strategies have been altered in an attempt to decrease the frequency of such failures. Although both short-term and long-term morbidity are acceptable, pilot trials with use of radiation-dose modifiers are planned to determine whether the therapeutic ratio of local control to associated complications can be improved even further.