Irradiation of ovarian carcinomas: a prospective comparison of the open-field and moving-strip techniques

Radiation Treatment in Women with Ovarian Cancer: Past, Present, and Future

Ovarian cancer is the most lethal of the gynecologic cancers, with 5-year survival rates less than 50%. Most women present with advanced stage disease as the pattern of spread is typically with dissemination of malignancy throughout the peritoneal cavity prior to development of any symptoms. Prior to the advent of platinum-based chemotherapy, radiotherapy was used as adjuvant therapy to sterilize micrometastatic disease. The evolution of radiotherapy is detailed in this review, which establishes radiotherapy as an effective therapy for women with micrometastatic disease in the peritoneal cavity after surgery, ovarian clear cell carcinoma, focal metastatic disease, and for palliation of advanced disease. However, with older techniques, the toxicity of whole abdominal radiotherapy and the advancement of systemic therapies have limited the use of radiotherapy in this disease. With newer radiotherapy techniques, including intensity-modulated radiotherapy (IMRT), stereotactic body radiotherapy (SBRT), and low-dose hyperfractionation in combination with targeted agents, radiotherapy could be reconsidered as part of the standard management for this deadly disease.

Whole abdomen radiotherapy for patients with peritoneal dissemination of endometrial adenocarcinoma

PURPOSE

No standard, universally accepted therapy exists for patients with adenocarcinoma of the endometrium with peritoneal dissemination. We report mature outcomes of selected patients with this uncommon pattern of spread treated with whole abdomen radiotherapy (RT).

METHODS AND MATERIALS

A retrospective review was undertaken of all patients with a diagnosis of endometrial cancer referred to the Radiologic Associates of Sacramento Medical Group between January 1, 1988 and October 1, 1999. Eleven patients were identified who had surgically proven peritoneal dissemination (peritoneal seeding) treated with whole abdomen RT as the sole cytotoxic therapy after operative cytoreduction. Ten patients had International Federation of Obstetrics and Gynecology (1988) Stage IV disease at diagnosis, and one had peritoneal dissemination at the time of initial recurrence after hysterectomy for Stage I disease. RT was administered to the whole abdomen using 10-MV photons in fractions of 1.0 or 1.5 Gy. A cumulative dose of 30 Gy was given in all patients, with shielding used to reduce the dose to the liver and kidneys. Partial abdominal volumes (pelvis plus paraaortic nodes) received supplementary dose at 1.5-1.8 Gy/fraction to bring the cumulative dose within the limited volumes to 46.2-54 Gy.

RESULTS

Four patients developed progressive cancer within 13 months of completion of whole abdomen RT. One additional patient died of hepatic venoocclusive disease (radiation hepatitis) 15 months after RT without evidence of cancer recurrence. Five patients were alive and clinically cancer free 55, 129, 131, 134, and 178 months after RT completion. One patient died of unrelated causes 79 months after treatment completion.

CONCLUSION

Abdominal RT, in doses compatible with the acute and late tolerance of normal tissues, can eradicate small deposits of disseminated, intraperitoneal endometrial cancer. Currently, our patient selection criteria include limited peritoneal dissemination at diagnosis permitting complete surgical clearance (<1 mm residual) of visible and palpable disease, Grade 1 or 2 histologic features, lack of demonstrable extraabdominal metastasis, and absence of major medical contraindications.

WART revisited: the treatment of epithelial ovarian cancer by whole abdominal radiotherapy

The present study investigated outcomes for 78 women with epithelial ovarian carcinoma treated by whole abdominal radiotherapy (WART) after cyto-reductive surgery at Westmead Hospital between 1980 and 1993. These patients had 5-year relapse-free and overall survival rates of 52 and 55%, respectively. The median follow-up was 7.5 years. Fifty-eight of the 78 women fulfilled the criteria as defined by the Princess Margaret Hospital's intermediate risk' category. These patients had both a relapse-free and overall survival rate of 62% at 5 years (P = 0.001 as compared with the remaining 20 women). Mild gastrointestinal upset was common during radiotherapy. Five women did not complete treatment. Late toxicity (grade 3 or more, using the Radiotherapy Oncology Group (RTOG) system) occurred in eight women, and five women required surgery for intestinal complications (6.4%). There were no deaths due to late side effects. In conclusion the results are consistent with those of other series in the treatment of epithelial ovarian cancer by adjuvant WART. When compared to a similar-stage disease treated with cisplatin-based chemotherapy, there is no evidence to support the exclusive use of chemotherapy.

Accelerated hyperfractionated hepatic irradiation in the management of patients with liver metastases: results of the RTOG dose escalating protocol

PURPOSE

This study was prepared to address two objectives: (a) to determine whether progressively higher total doses of hepatic irradiation can prolong survival in a selected population of patients with liver metastases; (b) to refine existing concepts of liver tolerance for fractionated external radiation employing a fraction size which might be appropriate in clinical protocols evaluating elective or adjuvant radiation of the liver.

METHODS AND MATERIALS

One hundred seventy-three analyzable patients with computed tomography measurable liver metastases from primary cancers of the gastrointestinal tract were entered on a dose escalating protocol of twice daily hepatic irradiation employing fractions of 1.5 Gy separated by 4 hr or longer. Sequential groups of patients received 27 Gy, 30 Gy, and 33 Gy to the entire liver and were monitored for acute and late toxicities, survival, and cause of death. Dose escalation was implemented following survival of 10 patients at each dose level for a period of 6 months or longer without clinical or biochemical evidence of radiation hepatitis.

RESULTS

The use of progressively larger total doses of radiation did not prolong median survival or decrease the frequency with which liver metastases were the cause of death. None of 122 patients entered at the 27 Gy and 30 Gy dose levels revealed clinical or biochemical evidence of radiation induced liver injury. Five of 51 patients entered at the 33 Gy level revealed clinical or biochemical evidence of late liver injury with an actuarial risk of severe (Grade 3) radiation hepatitis of 10.0% (+/- 7.3% S.E.) at 6 months, resulting in closure of the study to patient entry.

CONCLUSION

The study design could not credibly establish a safe dose for hepatic irradiation, however, it did succeed in determining that 33 Gy in fractions of 1.5 Gy is unsafe, carrying a substantial risk of delayed radiation injury. The absence of apparent late liver injury at the 27 Gy and 30 Gy dose levels suggests that a prior clinical trial of adjuvant hepatic irradiation in patients with resected colon cancer may have employed an insufficient radiation dose (21 Gy) to fully test the question.

Integrating radiation therapy into the management of ovarian cancer

Several studies during the last 15 years have elucidated the role of postoperative external beam radiation therapy as curative management of some subsets of patients with ovarian cancer. Despite this, the use of radiation therapy in patients with ovarian cancer has remained a controversial subject. Substantially improved cure rates have not been realized during the past decade despite the early promise of high response rates to cisplatin chemotherapy. Thus, it is important that all currently effective therapies be used for maximum therapeutic gain. This article will review the evidence that radiation therapy is curative in ovarian cancer and highlight the criteria, including stage and grade of disease and tumor residuum, by which patients suitable for such therapy are selected. The rationale for the use of whole abdominopelvic irradiation rather than pelvic or lower abdominal treatment will be discussed, as will the optimal radiation technique and its attendant morbidity. Limited data pertinent to the controversy over the use of radiation therapy versus chemotherapy in early disease, will be reviewed. The possible benefits of consolidation abdominopelvic radiation therapy after chemotherapy in highly selected patients with well-differentiated microscopic residual disease at second-look laparotomy or with no residual disease but high a risk for relapse will be considered.

Epithelial ovarian cancer: the role of radiotherapy

Although several studies during the last 10-15 years have served to clarify the role of postoperative external beam radiotherapy in patients with ovarian cancer, the subject remains controversial. This paper will review the following topics: 1. Stage I Ovarian Cancer. 2. The rationale for selecting whole abdominopelvic radiotherapy over other forms of radiotherapy, such as pelvic or lower abdominal radiotherapy. 3. The choice of radiation technique. 4. The evidence that radiotherapy is curative in ovarian cancer. 5. The toxicity of abdominopelvic radiotherapy. 6. The criteria by which patients are selected for abdominopelvic radiotherapy. 7. Radiotherapy versus chemotherapy in early disease. 8. Consolidation radiotherapy after chemotherapy in advanced disease.

Delayed split whole abdominal irradiation in the combined modality treatment of ovarian cancer

Fifty-eight patients with ovarian malignancies have been treated using a delayed split whole abdominal irradiation technique (DSA) allowing the entire tumor volume to be irradiated with tumoricidal fractional doses without undue toxicity. The lower hemiabdomen was irradiated with 2 Gy per fraction to a total dose of 40 Gy. A 2-6 hour delay was used between the irradiation of each half of the abdomen to avoid excessive acute gastrointestinal toxicity. The upper hemiabdomen was irradiated with 1.5 Gy per fraction to a total dose of 30 Gy. The acute toxicity was acceptable, with 53 of 58 patients able to complete the prescribed course of treatment. Three patients (5%) experienced grade 3 or greater acute gastrointestinal toxicity. Fourteen of 60 patients (24%) required treatment breaks because of thrombocytopenia. Nadir platelet counts were lower in patients who had received previous chemotherapy than in previously untreated patients (80,000 vs 118,000; p = .02). However, only 4 out of 60 patients were unable to complete DSA because of prolonged thrombocytopenia. In addition to DSA, patients were also treated with intraperitoneal 32P (52 patients), intraperitoneal human ovarian antitumor serum (14 patients), and prior (14 patients) or subsequent (32 patients) chemotherapy. Granulocytopenia was more severe among patients who had received prior chemotherapy (mean nadir 900 vs 2200). Seven patients (11.5%) developed delayed bowel obstruction in the absence of recurrence. There was one death caused by hepatitis, presumably related to colloidal 32P and DSA. Twenty-five percent of Stage III optimally cytoreduced patients were disease-free at 5 years; these patients had a median survival of 45 months. DSA irradiation is an acceptable technique for delivering a high fractional dose of radiation to the entire peritoneal cavity. Shielding of the iliac crests spares bone marrow allowing DSA irradiation to be integrated into an aggressive combined modality treatment plan.

Toxicity of open-field whole abdominal irradiation as primary postoperative treatment in gynecologic malignancy

Between June 1979 and March 1985, 77 patients received whole abdominal radiation as the sole postoperative treatment for gynecologic malignancy. With an open-field technique of irradiation, a median of 3,000 cGy was delivered to the entire abdominal contents with partial liver and kidney shielding; the total dose to the pelvis after boosts was 5,100 cGy, and that to the sub-diaphragmatic and para-aortic nodal regions was 4,200 cGy. The primary sites of malignancy were the endometrium in 41 patients, ovary in 25, uterus in 5, fallopian tube in 4, and cervix in 2. Seven patients (9%), all older than 60 years, experienced acute gastrointestinal toxicity that interrupted treatment, only one of whom failed to complete the prescribed course as a result. Hematologic toxicity was sufficient to interrupt therapy in 21 patients (27%), 1 of whom failed to complete therapy as a result. Hematologic toxicity was not increased in elderly patients. All patients were followed up for a minimum of 30 months (median, 43 months) or until death. Six patients experienced a treatment-related bowel obstruction (two of whom had concomitant progressive intra-abdominal disease); the 3-year actuarial risk for a treatment-related bowel obstruction was 9%. This risk was significantly increased by high-dose boosting for residual disease. Only one instance of clinical radiation pneumonitis occurred, and no cases of clinical hepatitis were noted; however, subclinical evidence of pulmonary and hepatic radiation effect was frequent. Whole abdominal irradiation as described has modest toxicity for patients with gynecologic cancer who are at high risk for intra-abdominal failure.

Determinants of survival of patients with epithelial ovarian carcinoma following whole abdomen irradiation (WAR)

In an attempt to identify those parameters which represent predictors of clinical outcome, a retrospective review of patients with epithelial ovarian carcinoma who were primarily treated with whole abdominal irradiation (WAR) following staging laparotomy was performed. Complete records with extensive long-term follow-up were available on 102 patients treated from 1962 through 1974. Histopathologic review excluded 18 patients with lesions of low malignant potential. Of the remaining 84 cases there were 12 Stage I (14%), 23 Stage II (27%), 45 Stage III (54%), and 4 Stage IV (5%). Measure of completeness of surgical resection was expressed as the largest diameter of residual gross tumor. Following primary surgical debulking Stages II and III patients, 24 patients had no gross residual disease, 24 patients had less than 2 cm of residual disease, and 20 patients had greater than 2 cm of residual disease. For Stages II and III patients together, 5- and 10-year actuarial survivals were: No gross residual, 69% and 59%; less than 2 cm, 48% and 42%; and greater than 2 cm, 15% and 10%. The technique of administration of WAR did not appear to influence survival. The results of this review support the concept that in selecting WAR for primary treatment of ovarian carcinoma, completeness of cytoreductive surgery should be considered. These data justify a prospective randomized study in patients with minimal residual disease following staging laparotomy comparing WAR with current first-line combination chemotherapy.

Radiation therapy of ovarian carcinoma: presentation of a six-field technique

A new technique for radiotherapy in ovarian carcinoma is presented. The aim was to deliver a homogeneous radiation dose to the entire abdominal cavity. The whole abdomen, except for 20% of the upper compartment, received a homogeneous dose of 40 Gy, while 2/3 of the kidneys and the posterior part of the liver received a dose ranging from 40 to 20 Gy. No clinically significant impairment of liver function was seen during follow-up.

The use of intravenous phenylalanine mustard followed by supervoltage irradiation in the treatment of carcinoma of the ovary

Between 1970 and 1980, 50 patients with carcinoma of the ovary were treated sequentially with six courses of IV phenylalanine mustard (L-PAM), second look surgery, and radiotherapy using the strip technique. Seven patients had advanced Stage I disease and six patients had Stage II disease; all of these patients are alive and well with no evidence of disease (NED) with a mean survival of five years. Thirty-seven patients had Stage III disease: ten of these patients did not respond to L-PAM (26%); 17 patients had a partial response (48%), and four of these (22%) are alive with NED and a mean survival of five years; ten patients (26%) had a complete response to L-PAM and all are alive and well with a mean survival of five years. The presence of a minimal tumor burden after the initial surgery, a mixed histology, a low-grade differentiation, suppression of leukocyte count to below 2000/mm3 after the first course of chemotherapy, and a complete response to L-PAM, were all factors that contributed to the probability of a long-term survival. Tumors responding to L-PAM and then recurring also responded to a combination of cisplatin and adriamycin, and hexamethylmelamine.

Lower abdominal radiotherapy for stages I, II, and selected III epithelial ovarian cancer: 20 years experience

Between 1956 and 1975, lower abdominal radiotherapy was administered as primary postoperative treatment to 82 patients with stages I, II, and selected III epithelial ovarian carcinoma and with varying amounts of postoperative residual disease. The median follow-up was 7.5 years, and the overall freedom from relapse (FFR) at 10 years for the entire group was 57%. The FFR at 10 years for stages I, II, and III was 78, 60, and 24% respectively, and these results are better than published series of similarly staged patients treated with surgery alone. Ten-year FFR was 79% for patients with no residual disease (NRD), 49% for patients with minimal residual disease (MRD) of less than 2 cm, and 24% for patients with gross residual disease (GRD) of greater than 2 cm. Control within the irradiated lower abdomen was achieved in 97% of patients with NRD, 84% of patients with MRD, and in 55% of those with GRD. Of all relapses, 33% occurred in the pelvis (almost all in patients with GRD), 37% in the untreated upper abdomen, 21% in distant sites, and 9% had an undetermined intraabdominal site of relapse. Among those patients with stage I and II disease or favorable residual tumor (NRD and MRD), approximately 50% of relapses occurred in the untreated upper abdomen alone.

Advances in the staging and treatment of ovarian cancer

The age adjusted death rate for ovarian cancer has remained unchanged for the past 20 years. Recent data obtained by staging ovarian cancer patients with lymphangiography and peritoneoscopy demonstrated that many patients with apparently localized disease actually have occult dissemination within the abdomen. These new staging techniques plus the determination of the histologic grade of anaplasia may permit a more precise determination of a patient's prognosis and therefore better design of therapeutic stategy. Radiotherapeutic techniques are being adapted to attempt to treat some areas of occult disease. Numerous single chemotherapeutic agents are capable of producing objective tumor responses. Preliminary data suggest that combination chemotherapy can increase the objective response rate above that seen with single agents. Longer follow-up is necessary to determine whether combination chemotherapy can prolong survival.

Future prospects of radiotherapy in gynecologic oncology

Major areas of progress in radiotherapy over the past decade have included important refinements in equipment and treatment techniques, as well as improved and expanded training programs for radiation oncologists. In 1975, approximately 14% of all new cancers were gynecologic, representing almost 68,000 new cases. Although end results in treatment of early cervix and corpus uteri lesions are quite good, results in treatment of early cervix and corpus uteri lesions are quite good, results in treatment of the later stage lesions, as well as ovarian and vulvo-vaginal tumors, are discouraging. Progress in the future will center around five primary areas: 1) greater understanding and utilization of radiation sensitizing agents such as hyperbaric oxygen, metronidazol, and other electroaffinic agents, purine and pyrimadine analogs, and antibiotics such as Actinomycin D and Adriamycin; 2) introduction into clinical use of high LET particle beams, such as fast neutrons, pi mesons, low atomic number nuclei, and heavy accelerated nuclei; 3) combined modality therapy utilizing radiation and chemotherapy or radiation and immunotherapy for management of subclinical disease; 4) radiobiologic and clinical advances in the utilization of radiation and hyperthermia; and 5) improved understanding of the pathophysiology and natural history of the gynecologic malignancies with increasing use of staging laparotomies, lymphangiography and peritoneoscopy.