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

Intraoperative radiation therapy (IORT) in soft-tissue sarcoma

Soft-tissue sarcoma (STS) represent a rare tumor entity, accounting for less than 1% of adult malignancies. The cornerstone of curative intent treatment is surgery with free margins, although the extent of the surgical approach has been subject to change in the last decades. Multimodal approaches usually including radiation therapy have replaced extensive surgical procedures in order to preserve functionality while maintaining adequate local control. However, the possibility to apply adequate radiation doses by external beam radiation therapy (EBRT) can be limited in some situation especially in case of directly adjacent organs at risk with low radiation tolerance. Application of at least a part of the total dose via intraoperative radiation therapy (IORT) with a single fraction during the surgical procedure may overcome those limitations, because radiosensitive structures can be moved out of the radiation field resulting in reduced toxicity while the enhanced biological effectivity of the high single dose improves local control. The current review summarizes rationale, techniques, oncological and functional outcomes including possible pitfalls and associated toxicities based on the published literature for IORT focusing on extremity and retroperitoneal STS. In extremity STS, combination of limb-sparing surgery, IORT and pre- or postoperative EBRT with moderate doses consistently achieved excellent local control rates at least comparable to approaches using EBRT alone but usually including patient cohorts with higher proportions of unfavourable prognostic factors. Further on, IORT containing approaches resulted in very high limb preservation rates and good functional outcome, probably related to the smaller high dose volume. In retroperitoneal STS, the combination of preoperative EBRT, surgery and IORT consistently achieved high local control rates which seem superior to surgery alone or surgery with EBRT at least with regard to local control and in some reports even to overall survival. Further on, preoperative EBRT in combination with IORT seems to be superior to the opposite combination with regard to local control and toxicity. No major differences in wound healing disturbances or postoperative complication rates can be observed with IORT compared to non-IORT containing approaches. Neuropathy of major nerves remains a dose limiting toxicity requiring dose restrictions or exclusion from target volume. Gastrointestinal structures and ureters should be excluded from the IORT area whenever possible and the IORT volume should be restricted to the available minimum. Nevertheless, IORT represents an ideal boosting method if combined with EBRT and properly executed by experiences users which should be further evaluated preferably in prospective randomized trials.

Long-term normal tissue effects of intraoperative electron radiation therapy (IOERT): late sequelae, tumor recurrence, and second malignancies

PURPOSE

To evaluate long-term survivors treated with intraoperative electron radiation therapy (IOERT) as a component, with particular emphasis on analyzing late normal tissue toxicity, second malignancies, and patterns of delayed tumor recurrence.

METHODS AND MATERIALS

From September 1984 to December 1991, 739 patients were treated with IOERT. One hundred ninety-five patients were alive at least 5 years after IOERT (26%). Patient information regarding late complications related symptoms, incidence of second tumors, and delayed relapses were analyzed. Normal tissue changes were categorized by a modified LENT/SOMA scale (Grade 0-1, Grade 2, and Grade 3-4). Risk of late toxicity was grouped by type and number of cancer treatment modalities employed in each patient: surgery + IOERT alone (17 patients, 9%); IOERT + external radiotherapy +/- chemosensibilization (90 patients, 46%); IOERT +/- external radiotherapy +/- neoadjuvant chemotherapy (+/- previous radiotherapy) (88 patients, 45%). Biologic effective doses (BED) were calculated for alpha/beta = 3.5 for late fibrosis.

RESULTS

With a mean follow-up time of the surviving patients of 94 months (range: 55-162 months), 99 patients (51%) had Grade 0-1 toxicity, 52 (27%) had Grade 2, and 44 patients (23%) presented Grade 3-4 late normal tissue complications. Risk groups by treatment intensity did correlate with severity of observed toxicity (p < 0.001). BED estimations did not correlate with late normal tissue damage. The tumor type with higher toxicity scores was bone sarcoma (28/46, 60%), in which the estimated BED = 100.5 Gy. Peripheral neuropathy was the dominant IOERT-specific toxicity present in 24 patients (12%). Second malignancies were identified in 8 patients (4%), none inside the IOERT field (3 questionable to be marginal to the external beam radiotherapy volume). In 36 patients (18%), recurrence of the originally treated tumor was detected, including 11 (7%) local relapses.

CONCLUSIONS

The incidence of late normal tissue complications (50%) and severity (23%) is significant in a cohort of patients surviving more the 5 years after IOERT. The understanding of the contribution of IOERT to late tissue damage requires specific analysis. Peripheral neuropathy is a characteristic finding in IOERT trials. Second malignancies inside the IOERT field were not identified during the study period. The risk of recurrences, including local failures, requires an intensive follow-up of long-term survivors from IOERT trials.

Brachytherapy in the treatment of colorectal malignancies

By precisely delivering a single, high dose fraction of intraoperative radiation under direct visualization while excluding surrounding normal dose-limiting tissues, IORT has improved the therapeutic ratio of tumor control to morbidity. Both IOERT and HDR-IORT represent effective means of delivering this therapy, and either may be chosen with equal confidence, depending upon the facilities available, physician preference, and the clinical situation. The extraordinary efforts often required in the management of these highly selected patients is justified by the improvement achieved in the enhanced local control rates and increased cure rates. Preoperative chemoradiation therapy followed by gross total resection and IORT affords the patient the highest likelihood of local control and survival. The importance of aggressive surgery in achieving gross total resection with pathologically negative margins is reflected by the dramatic correlation reported between margin status and local control. The high complication rate associated with this multidisciplinary therapy is, no doubt, multifactorial and may be attributed to the advanced disease state at presentation and the intensive multidisciplinary treatments administered. In an effort to eradicate disease and prolong survival, many consider these elevated complication rates acceptable, particularly in light of the complexity of these cases, as well as the morbidity and mortality associated with persistent disease in the pelvis.

Intraoperative electron and external beam irradiation with or without 5-fluorouracil and maximum surgical resection for previously unirradiated, locally recurrent colorectal cancer

PURPOSE/OBJECTIVE

1) Disease control and survival will be evaluated for treatment regimens containing intraoperative electron irradiation (IOERT) for locally recurrent, previously unirradiated colorectal cancers. 2) Various prognostic factors will be evaluated to determine whether they have an impact on disease control or survival.

MATERIALS AND METHODS

From April 1981 through August 1995, 123 patients with previously unirradiated locally recurrent colorectal cancers received IOERT at our institution, usually as a supplement to external beam irradiation (EBRT) and maximum resection. All received EBRT with or without concomitant 5-fluorouracil-based chemotherapy. Forty-five Gy in 25 fractions was given to the tumor or tumor bed plus 3-cm to 5-cm margins in 121 of 123 patients and a boost of 5.4 to 9 Gy in 3 to 5 fractions to the tumor plus 2-cm margins. Maximum resection was performed before or after EBRT. IOERT doses ranged from 10 to 20 Gy in 119 of 123 patients, with dose dependent on resection margins (130 fields in 123 patients). Maintenance chemotherapy was given to only two patients.

RESULTS

Disease relapse and survival were evaluated. Central failure (within the IOERT field) was documented in 13 of 123 patients (11 percent) with a five-year actuarial rate of 26 percent. Local relapse (in EBRT field) occurred in 24 patients (20 percent); five-year rate was 37 percent. Distant metastases occurred in 66 patients (54 percent); five-year rate was 72 percent. Median survival was 28 months, with overall survival at two, three, and five years of 62, 39, and 20 percent, respectively. Tolerance data suggest a relationship between IOERT dose and incidence of Grade 2 or 3 neuropathy (< or = 12.5 Gy, 2 of 29 or 7 percent; > or = 15 Gy, 19 of 101 or 19 percent; P = 0.12). Survival and disease control were analyzed as a function of potential prognostic factors. None of the prognostic factors had a significant impact on disease control or survival. Although there was a trend for reduction in local relapse rates with gross total vs. partial resection, this neither achieved statistical significance nor translated into improved survival. Patients with gross residual disease after maximum resection had three-year and five-year survival rates of 36 and 18 percent, respectively, which paralleled results for patients with gross total resection at 41 and 24 percent, respectively.

CONCLUSION

Encouraging trends for improved local control with or without survival exist in separate locally recurrent colorectal IOERT analyses from our institution and other institutions. Therefore, continued evaluation of IOERT approaches seems warranted. Disease control within the IOERT and external fields is decreased when the surgeon is unable to accomplish a gross total resection. Therefore, it is reasonable to consistently add 5-fluorouracil or other dose modifiers during EBRT and to evaluate the use of dose modifiers in conjunction with IOERT (sensitizers and hyperthermia). In view of high systemic failure rates of > 50 percent in patients with locally recurrent disease, more routine use of systemic therapy is indicated as a component of IOERT-containing treatment regimens (use existent chemotherapy and/or develop effective immunotherapy and gene transfer therapy). Even with locally recurrent lesions, the aggressive multimodality approaches including IOERT have resulted in improved local control and long-term survival rates of 20 percent vs. an expected 5 percent with conventional techniques.

Intraoperative radiation therapy in advanced thyroid cancer

An intraoperative radiation therapy (IORT)-protocol was designed for poorly differentiated non-anaplastic thyroid carcinoma. Out of 155 cases of differentiated thyroid tumours, 12 showed marked vascular/capsular invasion. Five entered the study (three primarily local invasive tumours, two local recurring). IORT was administered after tumour surgery (4-10 GY) and combined with post-operative percutaneous irradiation. The tumour control rate in the thyroid bed was achieved in all five patients, 1/5 developed mediastinal nodes and 1/5 with primary mediastinal tumour extension showed tumour progression. No specific complications occurred.

Intraoperative irradiation after palliative surgery for locally recurrent rectal cancer

BACKGROUND

In patients with locally recurrent rectal cancer, long-term disease control and survival is uncommon with single-modality therapy. This report evaluates results achieved at the Mayo Clinic (Rochester, MN) with single- or combined-modality treatment, including intraoperative irradiation.

METHODS

From 1981 to 1988, 106 patients underwent palliative surgical resections at the Mayo Clinic for locally recurrent rectal cancer. None had evidence of extrapelvic disease, and 42 received intraoperative electron beam irradiation (IORT) as a component of treatment. Gross residual disease remained after maximal surgical resection in 34 of the 42 patients and 61 of the patients who did not receive IORT. The IORT dose was 15-20 Gy in 39 patients and 10, 25, and 30 Gy in the other 3. External beam irradiation (EBRT) was administered to 41 of the 42 patients (doses > or = 45 Gy to 38 patients).

RESULTS

Kaplan-Meier survival estimates at 3 and 5 years were analyzed for the 106 patients. Palliative surgical resection alone (12 patients) resulted in a 3-year survival of 8% and a 5-year survival of 0%. Statistically significant factors relative to survival based on the univariate analysis of all patients included amount of residual tumor (microscopic vs. gross, P = 0.032) treatment method (P = 0.005), IORT versus no IORT (P = 0.0006), type of symptoms (P = 0.0075), type of fixation (P < 0.0001), and preoperative Eastern Cooperative Oncology Group status (P = 0.03). For patients who received IORT, 3-year survival with gross residual tumor or presentation with pain was 44% and 43%, respectively. Factors not associated with survival (univariate) included extended versus conventional surgical resection, grade, age, and sex. The 3-year cumulative probability of distant metastasis was 60% in the patients who received IORT and 54% in those who did not. The 3-year local relapse rates were 40% versus 93% in patients who received IORT versus those who did not.

CONCLUSIONS

Although the addition of IORT to external irradiation and maximal surgical resection appears to improve local tumor control and survival in patients who undergo palliative surgical resection for locally recurrent rectal cancer, further gains in treatment are necessary. Considering the high rates of distant metastasis, more routine systemic therapy with 5-fluorouracil (5-FU) leucovorin, 5-FU levamisole, or all three needs to be incorporated into aggressive treatment approaches. In patients with gross residual tumor after maximum surgical resection, local tumor control is inadequate despite treatment combinations including IORT. The evaluation of radiation sensitizers or biologic modifiers during external irradiation and IORT is indicated.

Radiation therapy for advanced colorectal cancer

Locally advanced, inoperable, and recurrent colorectal cancer requires multitechnique therapy to achieve optimal control and palliation. The role of radiation therapy as an adjuvant in resectable rectal cancer has been studied extensively in clinical trials, but its role in more advanced disease has not been explored to the same extent. The use of radiation in colonic rather than rectal cancer is more problematic because of natural tissue tolerance constraints in the abdomen versus the pelvis. The current and past role of radiation in advanced colorectal cancer will be reviewed, and avenues of ongoing and future investigation will be outlined. The role of radiation for palliation also will be discussed.

The role of intra-operative irradiation in locally advanced primary and recurrent rectal adenocarcinoma

Useful palliation can often be achieved when standard treatment approaches of external beam irradiation and chemotherapy with or without resection are used for locally advanced primary rectal malignancies. Local control and long-term survival are achieved in only 10% to 50% of patients, however, due to the limited irradiation tolerance of surrounding organs and tissues. Encouraging trends exist in separate intra-operative irradiation analyses from Massachusetts General Hospital and Mayo Clinic with regard to improvement in local control and possibly survival of locally advanced rectal lesions, warranting continued evaluation of such approaches. Disease control within the intra-operative and external irradiation field is decreased, however, when the surgeon is unable to accomplish gross total resection. Therefore it seems reasonable to consistently add 5-Fluorouracil with or without Leucovorin during external irradiation and to evaluate the use of dose modifiers, such as sensitizers or hyperthermia, in conjunction with intra-operative irradiation. Since high systemic failure rates exist with both locally advanced primary and recurrent lesions, more effective chemotherapy needs to be evaluated during external irradiation as well as after completion of such. In view of survival advantages with 5-Fluorouracil plus Leucovorin versus 5-Fluorouracil alone for metastatic disease, this regimen is currently being employed. Even with locally recurrent lesions, the aggressive multimodality approaches including intra-operative irradiation have resulted in improved local control, and long-term survival rates of 20% to 25% versus an expected 5% with conventional techniques in historical series.

Management of primary and recurrent soft-tissue sarcoma of the retroperitoneum

From 1982 to 1987, 114 patients underwent operation at Memorial Sloan-Kettering Cancer Center for soft-tissue sarcoma of the retroperitoneum. A retrospective analysis of these patients defines the biologic behavior, surgical management of primary and recurrent disease, predictive factors for outcome, and impact of multimodality therapy. Complete resection was possible in 65% of primary retroperitoneal sarcomas and strongly predicts outcome (p less than 0.001). The rate of complete resection was not altered by histologic type, size, or grade of tumor. These patients had a median survival of 60 months compared to 24 months for those undergoing partial resection and 12 months for those with unresectable tumors. Forty-nine per cent of completely resected patients have had local recurrence. This is the site of first recurrence in 75% of patients. These patients undergo reoperation when feasible. Complete resection of recurrent disease was performed in 39 of 88 (44%) operations, with a 41-month median survival time after reoperation. Tumor grade was a significant predictor of outcome (p less than 0.001). High-grade tumors (n = 65) were associated with a 20-month median survival time compared to 80 months for low-grade tumors (n = 49). Gender, histologic type, size, previous biopsy, and partial resection versus unresectable tumors did not predict outcome by univariate analysis. Adjuvant radiation therapy and chemotherapy could not be shown to have significant impact on survival. Concerted attempt at complete resection of both primary and recurrent retroperitoneal soft-tissue sarcoma is indicated.

Pediatric urological complications with intraoperative radiation therapy

Intraoperative radiotherapy with variable energy electrons has been used as a supplemental boost to treat 6 children with locally advanced retroperitoneal malignancies. Of the patients 4 had treatment-related injuries to portions of the urinary tract within the intraoperative and external radiation fields. Three patients had significant renal impairment requiring surgical correction. The pathogenesis and management of treatment-induced injury to the urinary tract are discussed.

Intraoperative radiotherapy for patients with carcinoma of the pancreas. The Howard University Hospital experience, 1978-1986

During the period from 1978 to 1986, 106 patients were diagnosed with carcinoma of the pancreas; 30 of these patients were excluded from this study. Of the remaining 76 patients, 40 did not receive intraoperative radiotherapy (IORT) and were used as the nonrandomized control group for the 36 patients who did receive IORT after histologic confirmation of carcinoma of the pancreas. The records of 35 patients were available for review. The group receiving IORT ranged in ages from 43 to 89 years (20 males and 15 females). Seventeen patients had distant metastatic disease. The primary was located in the head of the pancreas in 32 and the body in three. No patient in this group had a curative resection. All patients were treated by a combination of biliary and gastric bypass prior to or concurrent with IORT. IORT was begun only after obtaining a histologic diagnosis and prior to the completion of any anastomosis. Necrotizing pancreatitis occurred in the treated group. There was no statistically significant difference in the survival of the nonrandomized control and treated groups.

External beam versus intraoperative and external beam irradiation for locally advanced pancreatic cancer

One hundred fifty-nine patients with unresectable but localized pancreatic cancer, as defined at exploratory laparotomy, were treated at the Mayo Clinic between February 1974 to April 1985. Postoperative therapy consisted of 4000 to 6000 cGy external beam irradiation (XRT) alone in 122 patients or 4500 to 5500 cGy XRT in combination with an intraoperative electron boost in 37. In addition, 132 (both groups) received 5-fluorouracil (5-FU) chemotherapy. Local control (LC) at 1 year was 82% with XRT + intraoperative radiation therapy (IORT) versus 48% with XRT and 66% versus 20% at 2 years respectively (P less than 0.0005). Due to the high incidence of hematogenous and/or peritoneal spread in both groups (abdominal failure in 54 and 56% of patients at risk), the decreased frequency of local progression did not translate into an improved survival. Neither median nor long-term survival of the two treatment groups (XRT versus XRT + IORT) was statistically different (median 12.6 months versus 13.4 months, P = 0.25). With tumor arising in the head of the pancreas, survival at 2 years was 18% as opposed to 0% for other locations (P less than 0.01). On the basis of a Cox multivariate analysis, no other treatment or prognostic factor significantly altered survival. Until the problem with systemic failure (usually abdominal) can be resolved, the median and long-term survival of patients with pancreatic carcinoma is likely to remain unchanged. Since IORT appears to improve local control, we will continue to utilize IORT in phase 1, 2 studies which also attempt to decrease the incidence of abdominal failures. Even with IORT + XRT combinations, the incidence of local progression is excessive and radiation dose modifiers need to be evaluated.

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.

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.

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.

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.

The intraoperative intraperitoneal administration of cisplatin: a case report

A 63-year-old female with endometrial carcinoma who had received prior extensive systemic chemotherapy and pelvic radiotherapy was administered intraoperative cisplatin (100 mg/m2) by the i.p. route. The method and timing of chemotherapy administration were chosen to optimize delivery of the antineoplastic agent to tumor remaining following debulking surgery. There was no evidence of excessive or unexpected local or systemic toxicity. The intraoperative i.p. instillation of chemotherapeutic agents has the theoretical potential of improving to a limited degree the problem of insuring adequate drug distribution over i.p. chemotherapy.