Survey of current practices from an international task force for gynecological stereotactic ablative radiotherapy.

BACKGROUND: Stereotactic Ablative Radiotherapy (SABR) is an effective treatment that improves local control for many tumours. However, the role of SABR in gynecological cancers (GYN) has not been well-established. We hypothesize that there exists considerable variation in GYN-SABR practice and technique. The goal of this study is to describe clinical and technical factors in utilization of GYN-SABR among 11 experienced radiation oncologists. MATERIALS AND METHODS: A 63 question survey on GYN-SABR was sent to 11 radiation oncologists (5 countries) who have published original research, conducted trials or have an established program at their institutions. Responses were combined and analyzed at a central institution. RESULTS: Most respondents indicated that salvage therapy (non-irradiated or re-irradiated field) for nodal (81%) and primary recurrent disease (91%) could be considered standard options for SABR in the setting of inability to administer brachytherapy. All other indications should be considered on clinical trials. Most would not offer SABR as a boost in primary treatment off-trial without absolute contraindications to brachytherapy. Multi-modality imaging is often (91%) used for planning including PET, CT contrast and MRI. There is a wide variation for OAR tolerances however small bowel is considered the dose-limiting structure for most experts (91%). Fractionation schedules range from 3 to 6 fractions for nodal/primary definitive and boost SABR. CONCLUSIONS: Although SABR has become increasingly standard in other oncology disease sites, there remains a wide variation in both clinical and technical factors when treating GYN cancers. Nodal and recurrent disease is considered a potential indication for SABR whereas other indications should be offered on clinical trials. This study summarizes SABR practices among GYN radiation oncologists while further studies are needed to establish consensus guidelines for GYN-SABR treatment.

Impact of improved irradiation technique, age, and lymph node sampling on the severe complication rate of surgically staged endometrial cancer patients: a multivariate analysis.

PURPOSE: Limited information is available regarding factors that predispose to complications following postoperative pelvic radiotherapy (RT) for endometrial cancer. To address this issue, patients with clinically staged I/II endometrial cancer who received postoperative RT following total abdominal hysterectomy and bilateral salpingo-oophorectomy (TAH/BSO) with or without lymph node sampling (LNS) were studied. PATIENTS AND METHODS: From 1960 through 1990, 235 patients with adenocarcinoma of the endometrium received postoperative RT after surgical staging. Multiple factors were evaluated to determine associations with severe complications. Pretreatment factors included age, stage, comorbidities. Treatment-related factors consisted of LNS, total RT dose, volume of RT fields, dose per fraction, total number of RT fields, number of RT fields treated per day, machine energy, and addition of vaginal implant. RESULTS: The 5-year actuarial risk of a severe complication was 5.5%. Factors associated with an increased risk of complications in univariate analysis included age more than 65 years (11% v 2%), use of only one portal per day (40% v 3%), use of anteroposterior/posteroanterior fields (23% v 4%), total dose > or = 50 Gy (8% v 2%), and LNS (11% v 3%). In a multivariate analysis, only older age, LNS, and the use of one field per day were significant. Increased risks associated with a total dose > or 50 Gy and the anteroposterior/posteroanterior technique were entirely attributable to the use of one field per day. A subanalysis among patients who had adequate RT techniques (eg, multiple fields treated per day) showed a significant increase in complications (7% v 1%) for those with and without LNS, respectively. CONCLUSIONS: Severe complications associated with adjuvant RT for endometrial cancer were increased among patients who were older or underwent LNS or received suboptimal RT technique. Pelvic RT using proper methods can be delivered with acceptable risks.

Pretreatment and treatment factors associated with improved outcome in squamous cell carcinoma of the uterine cervix: a final report of the 1973 and 1978 patterns of care studies.

The Patterns of Care Study (PCS) conducted two national surveys of patients treated in 1973 and 1978 for squamous cell cancer of the uterine cervix. In addition, a survey of patients treated in 1973 from selected large facilities was conducted to establish outcome with "optimal" radiotherapy. The large facility survey consistently reported improved outcome compared to both national average surveys when analyzed by stage and other significant pretreatment factors. That improved outcome was associated with the paracentral (PCS point A) dose and the use of intracavitary irradiation. In this study, we report the pretreatment and treatment factors associated with improved outcome in squamous cell carcinoma of the uterine cervix by analysis of the 1973 and 1978 PCS data. Pretreatment factors associated with improved pelvic control in multivariate analysis include higher Karnofsky Performance Status (KPS) (Stage I and II), older age (Stage I and II), unilateral parametrial involvement (Stage IIB), and unilateral sidewall involvement (Stage III). The only treatment factor associated with improved pelvic control in multivariate analysis is the use of intracavitary irradiation. However, a dose response for infield pelvic control was demonstrated only in Stage III cervix cancer with the highest rate of pelvic control with paracentral (PCS point A) dose greater than 8500 cGy. Multivariate analysis revealed that unilateral parametrial involvement for Stage IIB and unilateral sidewall involvement for Stage III are significant positive prognostic factors with respect to survival after treatment with radiotherapy. No FIGO substage significantly affected survival after radiotherapy. Although FIGO staging is the single most important pretreatment prognostic factor with respect to survival and infield pelvic failure, FIGO substaging deserves reappraisal and further refinement. Major complications were seen in only 9.5% of patients treated with radiotherapy and were stage but not survey related. There is a significant relationship between PCS point A dose and complications with the highest rate of complications for PCS point A dose greater than 8500 cGy. A significant relationship between lateral (external iliac lymph nodes or PCS point P) dose and major complications is also found, and doses greater than 5000 cGy are associated with a significant increase in complications. The PCS has established two sequential national benchmarks of treatment outcome for squamous cell carcinoma of the uterine cervix treated with radiotherapy with respect to survival, infield pelvic control, and complications.(ABSTRACT TRUNCATED AT 400 WORDS)

Tumor and treatment factors improving outcome in stage III-B cervix cancer.

This report reviews 271 patients with Stage III-B squamous cell cancer of the uterine cervix from three national surveys conducted by the Patterns of Care Study. A progressive increase in local control and survival is seen among the three surveys which parallels a progressive increase in paracentral (point A) dose and use of intracavitary treatment. Multivariate analysis reveals extent of pelvic disease (unilateral sidewall vs. bilateral sidewall vs. lower 1/3 vagina) and use of intracavitary treatment to be the only significant tumor and treatment factors associated with local control and survival. With aggressive radiotherapy, local control rates exceeding 65% and survival of 50% at 4 years can be anticipated at the expense of a small increase in complications.

Postoperative radiation therapy for surgically staged endometrial cancer: impact of time factors (overall treatment time and surgery-to-radiation interval) on outcome.

PURPOSE: To evaluate the impact of prolonged overall radiation treatment (RT) time and surgery-to-radiation interval on local control (LC) and disease-specific survival (DSS) of surgically staged endometrial cancer patients in relation to known prognostic factors. METHODS AND MATERIALS: Between 1971 and 1993, 195 endometrial cancer patients received postoperative RT at the Fox Chase Cancer Center. All patients underwent total abdominal hysterectomy (TAH), with 38% also having lymph node sampling. All patients received whole pelvic external beam RT to a median dose of 45 Gy (range 40 to 60 Gy). Sixty-nine percent received a vaginal cuff boost with either low dose rate or high dose rate brachytherapy. Tumor and treatment factors were analyzed for impact on LC and DSS. Median follow-up was 47 months (range: 6 to 187 months). RESULTS: The overall actuarial 5-year LC rate was 85%. In multivariate analysis, tumor grade, pathologic stage, external radiation dose, and surgical lymph node evaluation were independent prognostic variables for improved LC. Surgery-to-radiation interval of greater than 6 weeks was a marginally significant factor for decreased LC (p = 0.06). Overall RT time and external beam treatment time did not appear to impact LC rates. The overall actuarial 5-year DSS rate was 86%. In multivariate analysis, depth of myometrial invasion, tumor grade, and pathologic stage were independent prognostic variables for DSS. In addition, a surgery-to-radiation interval of greater than 6 weeks was significantly associated with decreased DSS (p < 0.005). CONCLUSIONS: Surgery-to-radiation interval of greater than 6 weeks is a significant independent prognostic variable for decreased DSS and a marginally significant variable for decreased LC in patients irradiated postoperatively for endometrial cancer. Other time factors (overall RT time and external beam treatment time) did not appear to impact outcome. Based on this analysis, postoperative radiation therapy for endometrial cancer should be initiated within 6 weeks following surgery.

The influence of treatment time on outcome for squamous cell cancer of the uterine cervix treated with radiation: a patterns-of-care study.

PURPOSE: To analyze the effect of total treatment time on infield pelvic control and survival for squamous cell carcinoma of the uterine cervix using the combined 1973 and 1978 Patterns of Care (PCS) data base. METHODS AND MATERIALS: Eight hundred thirty-seven evaluable patients were analyzed for the effect of total treatment time on outcome. The Kaplan-Meier method was used to estimate time-to-outcome annual rates. Comparisons of time to failure were performed with the log rank test. Multivariate analysis was performed using the Cox regression analysis. RESULTS: A highly significant decrease in survival (p = .0001) and pelvic control (p = .0001) was demonstrated as the total treatment time was increased from < 6, 6 to 7.9, 8 to 9.9, and 10+ weeks. Stage III accounted for the majority of the adverse effect from the prolongation of total treatment time. Multivariate analysis of total treatment time in addition to previously reported significant pretreatment and treatment factors from the PCS data base revealed three independent factors for infield recurrence, namely Stage I versus II versus III (p = .0001), total treatment time < 6 versus 6 to 7.9 versus 8 to 9.9 versus 10+ weeks (p = .003), and age > 50 versus < or = 50 years (p = .01). When the analysis was performed by stage to evaluate the effect of overall treatment time with respect to the extent of pelvic disease as defined by PCS, total treatment time continued to be an independent prognosticator for infield pelvic control (p = .01) and survival (p = .02) for Stage III but not Stages I and II. CONCLUSION: This study demonstrates a significant adverse effect on survival and pelvic control with prolongation of the total radiation treatment time for Stage III squamous cell cancer of the uterine cervix in multivariate analysis. In the future design of clinical trials, limitations on total treatment time should be rigorously controlled, and the effect of variations in this important factor by altered fractionation schemes should be studied.

Improved outcome in patients treated with postoperative radiation therapy for pathologic stage I/II endometrial cancer.

PURPOSE: To evaluate prognostic factors and treatment outcome for high risk pathological Stage I and II endometrial cancer patients treated with consistent postoperative radiation therapy (RT) in a single institution and to compare these results to series where RT was variably applied. METHODS AND MATERIAL: Between 1986 and 1993, 98 pathologic Stage I and II endometrial cancer patients received postoperative RT at the Fox Chase Cancer Center. Papillary serous and clear cell histologies were excluded. Fifty-five patients underwent lymph node evaluation. In 17 patients, RT consisted of intracavitary brachytherapy alone to a median dose of 21 Gy, and in 81 patients, RT consisted of external beam RT to a median dose of 45 Gy followed by intracavitary brachytherapy to a median dose of 12 Gy. Intracavitary brachytherapy generally consisted of three high dose rate implants with the dose prescribed to a depth of 0.5 cm. Median follow up was 47 months. RESULTS: The 5-year overall survival (OS), disease free survival (DFS), and freedom from pelvic recurrence (FPR) rates were 83, 85, and 89%, respectively. Pelvic recurrence either as the sole pattern of failure or combined with distant metastases was seen in 2 and 7% of patients, respectively. Distant metastases alone occurred in 4% of the patients. Univariate analysis of prognostic factors including age, grade, capillary lymphatic space invasion, depth of myometrial invasion, type of lymph node evaluation, pathologic stage, the use of brachytherapy and the number of risk factors was performed for OS, DFS, FPR, and FDM. Capillary lymphatic space invasion was the only statistically significant predictor for reduced DFS. Absence of lymph node dissection as well as a higher number of risk factors showed a trend toward poorer DFS (p = 0.06 for both). Multivariate analysis revealed older age to be the only factor significant for reduced DFS, with the presence of capillary lymphatic space invasion and the absence of a lymph node dissection showing a trend toward poorer outcome (p = 0.07). CONCLUSIONS: The results of this study suggest a continued role for the use of postoperative RT in the treatment of patients with high risk endometrial cancer and will be compared to other series with similar high-risk factors.

Analysis of complications in patients with endometrial carcinoma receiving adjuvant irradiation.

We analyzed the complications in 310 patients with pathologically documented endometrial carcinoma who received adjuvant radiation therapy (RT) at Fox Chase Cancer Center between 1970 and 1986. Variables included timing of treatment, technique, total dose, age, diabetes, previous abdominal surgery, hypertension, prior bowel pathology, and lymphadenectomy. According to the FIGO (1985) system, 258 patients had Stage I disease, 48 had Stage II, and one had Stage III. One hundred seventy patients received preoperative (preop) RT, 138 received postoperative (postop) RT, and 2 received preop and postop RT. A 4-field technique was used for 212 of 235 patients receiving external-beam (EX) RT, and 75 patients were treated with intracavitary (IC) RT only. Median follow-up was 5.5 years. Actuarial survival of all 310 patients was 78% at 5 years. Thirty-two complications occurred, involving the rectum, small bowel, femur, or lower extremity. Complications were graded according to the ECOG scoring system as grade 2 (mild) and grades 3, 4, or 5 (serious). One of 75 patients treated with IC RT only experienced a grade-2 complication (proctitis). Of 71 patients receiving 4-field EX RT only, 25 preop (16%) and 14 postop (14%) patients had complications. Of 139 patients treated with both EX and IC RT, grade-2 complications were seen in 5% of 87 preop patients and 12% of 52 postop patients (p = 0.17), whereas serious complications were observed in 4% of each group. Univariate analysis of the variables of interest revealed that the incidence of complications was associated with a lymphadenectomy (p = .03), use of external RT (p less than .01), and decreasing age (p = .04). Multivariate analysis confirmed that use of external RT was the most significant predictor for complications. In conclusion, similar complication rates were found in patients treated with either preop or postop 4-field EX RT. While pelvic RT clearly decreases pelvic relapse in patient with endometrial carcinoma, the risk benefit ratio for treatment of these patients should be carefully considered when recommending adjuvant RT for pelvic control.

Efficacy of a belly board device with CT-simulation in reducing small bowel volume within pelvic irradiation fields.

PURPOSE/OBJECTIVE: Acute and chronic small bowel toxicity associated with pelvic irradiation limits dose escalation for both chemotherapy and radiotherapy for rectal cancer. Various surgical and technical maneuvers including compression and belly board devices (BBD) have been used to reduce small bowel volume in treatment fields. However, quantitative dose volume advantages of such methods have not been reported. In this study, the efficacy of BBD with CT-simulation is presented with dose-volume histogram (DVH) analyses for rectal cancer. METHODS AND MATERIALS: Twelve consecutive patients referred to our department with rectal cancer were included in this study. Patients were given oral contrast 1.5 h prior to scanning and instructed not to empty their bladder during the procedure. The initial CT scan without BBD was taken in the prone position with an immobilization cast. A second CT study was performed with a commercially available BBD consisting of an 18-cm thick hard sponge with an adjustable opening (maximum 42 x 42 cm2). All patients were positioned prone over the BBD so that the opening was above the treatment volume and usually extended from the diaphragm to the bottom of the fourth lumbar spine. Image fusion between both sets of CT scans (with and without BBD) was performed using common bony landmarks to maintain the same target volume. The critical structures including small bowel and bladder were delineated on each slice for DVH analysis. On each study, a three-field optimized plan with conformal blocks in beams-eye-view was generated for volumetric analysis. The DVHs with and without BBD were evaluated for each patient. RESULTS: The median age and body weight of 12 patients (4 females and 8 males) were 57.5 years and 82.7 kg, respectively. The changes in posterior-anterior (PA) and lateral separation with and without BBD at central axis slices were analyzed. The changes in lateral separation were minimal (<0.8 cm); however, the PA separation was reduced by 11.3 +/- 3.3% when BBD was used. The reduction in PA separation was directly related to the reduction in small bowel volume. The small bowel volume was significantly reduced with a median reduction of 70% (range 10-100%) compared to the small bowel volume without BBD. The small bowel volume reduction did not correlate either with body weight, age, gender, or sequence of radiation treatment with surgery (pre-op vs. post-op). The DVH analysis of small bowel with BBD showed significant volume reduction at each dose level. For 50% patients, the DVH analysis demonstrated an increase in bladder volume with BBD. All patients treated with the BBD completed their treatment without any break and without significant acute gastrointestinal or genitourinary toxicity. CONCLUSIONS: For rectal cancers, small bowel is the dose-limiting structure for acute and chronic toxicity. The use of the BBD should improve the tolerance of aggressive combined modality treatment by reducing the small bowel volume within the pelvis compared to the prone position alone. The BBD provides an easy, economical, comfortable, and noninvasive technique to displace small bowel from pelvic treatment fields. The small bowel volume is dramatically reduced at each dose level. The volume reduction does not correlate with gender, age, weight, pelvic separation, and sequence of radiation treatment vs. surgery.

Which prognostic factors influence the outcome of patients with surgically staged endometrial cancer treated with adjuvant radiation?

PURPOSE: Despite the fact that retrospective reviews have documented pelvic failure rates ranging from 15-20% in patients with high-risk uterine-confined endometrial cancer who have received no or "inadequate" RT, the role of RT has been questioned. We sought to analyze pelvic control and disease-free survival for a large data base of women with corpus cancers managed with initial surgery followed by adjuvant irradiation. METHODS AND MATERIALS: Between 1983 and 1993, 294 patients received adjuvant postoperative RT from one of three academic radiation practices. RT consisted of vaginal brachytherapy alone in 28 patients, pelvic RT in 173 patients, pelvic RT with vaginal brachytherapy in 97 patients, and whole abdominal RT in 2 patients. Lymph nodes were evaluated in 49%. The median number of pelvic and periaortic LN in the pathology specimen were 6 and 4, respectively. Median follow up was 63 months. RESULTS: 5-year disease-free survival (DFS) rate and pelvic control rates were 86 and 95%, respectively. Patient-related, treatment-related, and tumor-related characteristics were assessed for the effect on time to relapse. Unfavorable histology, older age, and capillary space invasion were univariately associated with decreased DFS and pelvic control. Pathologic Stage II patients had significantly worse DFS than Stage I patients. Multivariate analysis revealed that age, capillary space invasion, and histology were jointly predictive of disease free survival. CONCLUSION: The excellent pelvic control and disease-free survival of patients with uterine-confined disease in this series suggest that adjuvant RT should continue for patients with high risk disease. This analysis of a large group of postoperatively treated patients will provide a basis for determining alternative treatment strategies for patients who have an increased risk of disease recurrence despite RT.

Is there a role for a brachytherapy vaginal cuff boost in the adjuvant management of patients with uterine-confined endometrial cancer?

PURPOSE/OBJECTIVE: Many patients who have uterine-confined endometrial cancer with prognostic factors predictive of recurrence are treated with adjuvant pelvic radiation. The addition of a brachytherapy vaginal cuff boost is controversial. MATERIALS AND METHODS: Between 1983 and 1993, 270 patients received adjuvant postoperative pelvic irradiation following hysterectomy for Stage I or II endometrial cancer. Group A includes 173 patients who received external beam irradiation alone (EBRT), while group B includes 97 patients who received EBRT with a vaginal brachytherapy application. The median dose of EBRT was 45 Gy. Vaginal brachytherapy consisted of a low dose rate ovoid or cylinder in 41 patients, a high dose rate cylinder in 54 patients, and a radioactive gold seed implant in two patients. The median follow-up time was 64 months. The two groups were compared in terms of age, histologic grade, favorable versus unfavorable histology, capillary space invasion, depth of myometrial invasion, and pathologic stage. RESULTS: Chi-square analysis revealed that the only difference between the two groups was the presence of more Stage II patients in group B (38% versus 14%). No difference was detected for 5 year pelvic control and disease-free survival rates between groups A and B. CONCLUSION: There is no suggestion that the addition of a vaginal cuff brachytherapy boost to pelvic radiation is beneficial for pelvic control or disease-free survival for patients with Stage I or II endometrial cancer. Prospective randomized trials designed to study external irradiation alone versus external beam treatment plus vaginal brachytherapy are unlikely to show a positive result. Because EBRT provides excellent pelvic control, protocol development for uterine-confined corpus cancer should focus on identifying patients at risk for recurrence as well as other means of augmenting EBRT (e.g. addition of chemotherapy) in order to improve disease free survival in those subgroups.

Endometrial cancer with para-aortic adenopathy: patterns of failure and opportunities for cure.

PURPOSE: To examine the outcome of patients with advanced endometrial cancer whose para-aortic involvement was diagnosed pathologically or lymphographically. METHODS AND MATERIALS: Fifty patients from four institutions were treated between 1959 and 1990 with preoperative, post-operative, and primary radiotherapy. Para-aortic disease was diagnosed pathologically in 26 patients and lymphographically in the remaining 24 patients. Pathologically diagnosed patients underwent debulking of grossly involved nodes. All patients received external beam treatment through pelvic and para-aortic portals. Median prescribed dose to the pelvic and para-aortic fields was 50 and 47 Gy, respectively. Those treated with primary or pre-operative irradiation also received intrauterine brachytherapy. RESULTS: The actuarial 5-year disease-free survival was 46% for all patients. Para-aortic failure was significantly decreased among patients undergoing lymph node resection (13% versus 39%, respectively). Relapse-free survival and pelvic control tended to improve among patients receiving surgery plus irradiation in comparison to those treated by irradiation alone. Distant metastases were most common among patients with high grade lesions. CONCLUSIONS: Long-term disease-free survival is achievable in endometrial cancer patients with para-aortic lymphadenopathy who are treated with extended-field radiotherapy. Cure is mot attainable among patients with well differentiated, early clinical stage disease who receive combined modality treatment. Survival and local failure are similar for radiologically and pathologically diagnosed patients; however, para-aortic failure as a component of local failure was increased in patients who did not undergo surgical debulking of the adenopathy.

Bony landmarks are not an adequate substitute for lymphangiography in defining pelvic lymph node location for the treatment of cervical cancer with radiotherapy.

PURPOSE: Curative radiotherapy (RT) for carcinoma of the cervix requires adequate irradiation of regional lymph node groups. The best nonsurgical method of defining lymph node anatomy in the pelvis remains the lymphangiogram (LAG). This study was designed to determine if bony landmarks could accurately substitute for LAG as a means of determining lymph node position for the purpose of pelvic RT treatment planning. METHODS AND MATERIALS: The post-LAG simulation films of 22 patients treated at the Fox Chase Cancer Center for cervical cancer were examined. On anterior/posterior (A/P) simulation films, the distance of lymph nodes was determined from the top, middle, and bottom of the sacroiliac joint, and at the pelvic rim, 1 and 2 cm above the acetabulum. On lateral (LAT) simulation films, lymph node position was measured at points 0, 4, and 8 cm along a line from the bottom of L5 to the anterior aspect of the pubic symphysis. Positive values represent lateral and anterior distances relative to the reference point on A/P and LAT films, respectively. Negative values represent distances in the opposite direction. The adequacy of standard pelvic fields as defined by the Gynecologic Oncology Group (GOG) (A/P: 1.5 cm margin on the pelvic rim; LAT field edge is a vertical line anterior to the pubic symphysis) was also examined. Data are expressed as the mean +/- two standard deviations, (i.e. 95% confidence level). RESULTS: On A/P simulation films, the distance of visualized lymph nodes had mean values of -1.6 +/- 1.7 cm (range -4.1 to -0.4 cm), -1.3 +/- 1.5 cm (range -3.4 to 0.0 cm), and 1.2 +/- 1.8 cm (range -1.0 to 2.6 cm) from the sacro-iliac (SI) joint at the superior, middle, and inferior points, respectively. The mean distance of the nodes from the pelvic rim at points 1 and 2 cm above the acetabulum was 0.3 +/- 1.2 cm (range -0.6 to 1.8 cm) and 0.2 +/- 1.8 cm (range -1.6 to 2.1 cm), respectively. On LAT simulation films, the distance of lymph nodes from points 0, 4, and 8 cm from the previously described reference line had mean values of 2.0 +/- 1.0 cm (range 1.3 to 3.0 cm), 0.9 +/- 3.9 cm (range -1.9 to 5.1 cm), and 1.8 +/- 2.1 cm (range -0.8 to 3.5 cm), respectively. Ten of 22 (45%) patients would have had inadequate nodal irradiation if their fields had been designed according to standard GOG parameters. In all cases, these incompletely irradiated lymph nodes were from the lowest of the lateral external iliac group. CONCLUSION: Great variability in pelvic lymph node location is demonstrated when LAG is used to directly visualize their location. Bony structures are inaccurate landmarks for pelvic lymph node position. The GOG standard pelvic fields are not consistently adequate to cover all lateral external iliac lymph nodes, although the clinical significance of this subgroup of lymph nodes is not known. At this time, LAG remains the ideal radiographic modality to define anatomic location of regional lymph nodes for pelvic RT treatment planning. The clinical importance of the most lateral group of external iliac lymph nodes in various stages of cervical cancer represents a potential area of future research.

Decreasing gastrointestinal morbidity with the use of small bowel contrast during treatment planning for pelvic irradiation.

Small bowel tolerance is a major dose-limiting factor in treating the pelvis with radiation therapy (RT). The use of small bowel contrast during RT simulation is one technique used to localize the bowel and identify the treatment plan that would exclude the greatest volume. To determine the influence of treatment planning with oral contrast on gastrointestinal injury, acute and chronic small bowel morbidity was analyzed in 115 patients with endometrial and rectal carcinoma who received postoperative radiation therapy at the Fox Chase Cancer Center. Mean and median time of follow-up were 31 and 27 months, respectively. Acute diarrhea was seen in 82% of the patient population. Ten percent of patients experienced major complications requiring hospitalization. Ninety-three percent of patients simulated without contrast experienced side effects compared to 77% of patients simulated with contrast (p = .026). There was an increased incidence of chronic complications in patients who were not simulated with contrast dye (50% vs 23%, p = .014). Median duration of minor side effects was 4 months for patients planned without oral contrast and 1 month for patients who had contrast at the time of simulation (p = .036). The superior aspect of the treatment field was determined to be at a more inferior location in patients simulated with contrast, thereby excluding small bowel from treatment. Seventy-four percent of patients simulated without contrast had the upper border of the field placed at the superior aspect of the sacroiliac joint or above, compared to only 40% of patients planned with oral contrast (p = .002). This study has demonstrated decreased complications (both overall and chronic) as well as a change in the location of the treatment field with the use of small bowel contrast. Multivariate analysis revealed that both the use of oral contrast (p = .026) and a lower superior border of the treatment field (p = .007) were predictive for fewer sequelae to RT, indicating that planning with contrast leads to changes in the technical delivery of RT other than field placement (e.g., block placement). The reduced incidence and duration of small bowel morbidity may be in part caused by alterations of the treatment plan made when the small bowel is visualized at the time of simulation. It is therefore recommended that oral small bowel contrast be used during treatment planning for pelvic irradiation.

Comparison of 1 vs 2 or more intracavitary brachytherapy applications in the management of carcinoma of the cervix, with irradiation alone.

Four hundred ninety-eight patients treated in the USA in 1978 for cancer of the cervix by external beam and intracavitary irradiation have been studied to determine the effect of using a single intracavitary (IC) application versus more than one. Most of the patients (46%) underwent intracavitary (IC) treatment after external radiation therapy (RT), 40% during external RT, and 14% prior to external RT. Five-year actuarial survival for all stages was 66% for greater than or equal to 2 applications versus 59% for 1 application, p less than .01. When survival was analyzed by stage, there was a trend toward improved survival with greater than or equal to 2 applications in Stage II (p .10). The rate of infield recurrence for all stages was higher in the 1 IC group (30% vs 17%, p less than .01). These were more frequent in the 1 IC group (53% vs 34%, p less than .05), in Stage III patients, but no significant difference was noted in the other stages. Distant metastases were more frequent in the 1 IC group (19% vs 11%, p .01). The incidence of major complications was the same in both groups. An analysis of patient characteristics and other variables that would explain the difference in results revealed that older patients (p .03), worse Karnofsky (p .056), and more parametrial involvement (p less than .01) accrued more in the 1 IC group. Higher paracentral point doses were administered when greater than or equal to 2 IC applications were used (p less than 0.01); this group also received higher bladder and rectal doses and lower whole pelvic doses. The use of two or more intracavitary insertions affords an opportunity to administer higher paracentral point doses, which appear to be related to higher pelvic tumor control, lower rate of distant metastasis, and better survival.

Polarographic needle electrode measurements of oxygen in rat prostate carcinomas: accuracy and reproducibility.

PURPOSE: The oxygenation status of tumors may be important for predicting tumor response to therapy. Previous studies with the anaplastic (R3327-AT) and well-differentiated (R3327-H) Dunning rat prostate tumors using indirect assays of tumor oxygenation indicated the relative hypoxic and radioresistant nature of the anaplastic tumor. We now report direct measurements of oxygen in these tumors made with the pO2 histograph to determine: (a) whether a significant difference in oxygenation status could be detected between them: (b) whether sequential measurements on the same tumor gave similar values; and (c) whether tumor oxygenation correlated with tumor volume. METHODS AND MATERIALS: R3327-AT and R3327-H tumors were grown in Fischer X Copenhagen rat to volumes of 1.0-7.0 cm3. Electrode measurements (100-200) were made in tumors in anesthetized animals along two parallel tracks. Repeat measurements were made at 1-5 days along different parallel tracks. Oxygen partial pressures of muscle tissue were measured and served as a normal tissue control. Statistical analyses were applied to determine whether tumor oxygen levels were different between the two tumor histologies, whether sequential measurements in the same tumor were reproducible, and whether tumor oxygenation correlated with tumor volume. RESULTS: The average median pO2 of the well-differentiated (n = 15) and the anaplastic (n = 15) tumors was 6.0 mmHg (SE +/- 1.3) and 2.2 mmHg (SE +/- 0.3), respectively. The average median pO2 of normal rat muscle (n = 15) was 23.6 mmHg (SE +/- 2.0). These values represent highly significant differences in oxygen concentration between the two tumors and rat muscle. The differences in average mean pO2 values were also highly significant. Repeat measurements in the same tumors on different days gave average median values of 4.7 and 2.2 mmHg in the R3327-H (n = 15) and R3327-AT (n = 15) tumors, respectively. For these repeat measurements, median pO2 values decreased in 15 and increased in 15 tumors, and were not significantly different from the first measurements. The average differences observed in median pO2 were 37% (SE +/- 7) and 58% (SE +/- 10) for the R3327-H and R3327-AT tumors, respectively. No significant correlation was observed between pO2 levels and the tumor volumes investigated in this study. CONCLUSIONS: The median pO2 values of the anaplastic Dunning tumors were significantly lower than those of the well-differentiated tumors (p < 0.001). Oxygen levels in both tumors were significantly lower than those measured in normal rat muscle (p < 0.00005). Repeat measurements of median pO2 in the same tumors were not significantly different for either tumor model (p > 0.5). The changes observed in pO2 distributions within individual tumors from day to day may indicate true dynamics of its oxygenation status and/or the limits of electrode measurements, by sampling along only two insertion sites. The electrode measurements of pO2 in these tumor models are reproducible and confirm previously detected oxygenation differences between the anaplastic and well-differentiated tumors.

Management of retroperitoneal sarcomas: does dose escalation impact on locoregional control?

PURPOSE: Only 50% of patients with retroperitoneal sarcomas undergo complete resection and of these, 47% develop local tumor recurrence. To determine whether irradiation with dose escalation improves locoregional control, we reviewed the experience with adjuvant radiotherapy in the treatment of retroperitoneal sarcomas at the Fox Chase Cancer Center and the Hospital of the University of Pennsylvania. METHODS AND MATERIALS: Twenty-one patients with retroperitoneal sarcomas were treated with curative intent with surgical resection and radiation therapy at Fox Chase Cancer Center or the Hospital of the University of Pennsylvania between May 1965 and July 1992. Follow-up ranged from 14-340 months. Nineteen patients were treated postoperatively and 2 preoperatively. Radiation doses were between 36.0 Gy and 90.0 Gy (median 54.0 Gy). RESULTS: The 2-year rates of local control and survival were 72% and 69%, respectively. Tumor size, stage, grade, and histology did not influence local control. Two of eight patients (25%) who received a total dose of > 55.2 Gy experienced local failure compared to 5 of 13 (38%) who received < or = 55.2 Gy. One patient experienced a small bowel obstruction that required surgical intervention. There were no other severe complications. CONCLUSION: Postoperative treatment with radiotherapy using a dose > 55.0 Gy is recommended for patients with retroperitoneal sarcomas following surgical resection due to the significant likelihood of local recurrence. Innovative adjuvant radiation techniques to escalate doses to greater than 55.0 Gy including intraoperative radiation therapy, brachytherapy, or use of small bowel exclusion devices to reduce small bowel toxicity should be considered for retroperitoneal sarcomas.

Management of extremity soft tissue sarcomas with limb-sparing surgery and postoperative irradiation: do total dose, overall treatment time, and the surgery-radiotherapy interval impact on local control?

PURPOSE: To evaluate potential prognostic factors in the treatment of extremity soft tissue sarcomas that may influence local control, distant metastases, and overall survival. METHODS AND MATERIALS: Sixty-seven patients with extremity soft tissue sarcomas were treated with curative intent by limb-sparing surgery and postoperative radiation therapy at the Fox Chase Cancer Center or the Hospital of the University of Pennsylvania, between October 1970 and March 1991. Follow-up ranged from 4-218 months. The median external beam dose was 60.4 Gy. In 13 patients, interstitial brachytherapy was used as a component of treatment. RESULTS: The 5-year local control rate for all patients was 87%. The 5-year local control rate for patients who received < or = 62.5 Gy was 78% compared to 95% for patients who received > 62.5 Gy had larger tumors (p = 0.008) and a higher percentage of Grade 3 tumors and positive margins than patients who received < or = 62.5 Gy. The 5-year local control rate for patients with negative or close margins was 100% vs. 56% in patients with positive margins (p = 0.002). Cox proportional hazards regression analysis was performed using the following variables as covariates: tumor dose, overall treatment time, interval from surgery to initiation of radiation therapy, margin status, grade, and tumor size. Total dose (p = 0.04) and margin status (p = 0.02) were found to significantly influence local control. Only tumor size significantly influenced distant metastasis (p = 0.01) or survival (p = 0.03). CONCLUSION: Postoperative radiation therapy doses > 62.5 Gy were noted to significantly improve local control in patients with extremity soft tissue sarcomas. This is the first analysis in the literature to demonstrate the independent influence of total dose on local control of extremity soft tissue sarcomas treated with adjuvant postoperative irradiation.

Volumetric analysis of small bowel displacement from radiation portals with the use of a pelvic tissue expander.

PURPOSE: Many techniques and devices have been used in an attempt to minimize gastrointestinal morbidity of pelvic irradiation. The value of a temporary intrapelvic tissue expander to displace small bowel from pelvic radiotherapy fields was analyzed by comparing volumetric treatment parameters of patients with and without such a device. METHODS AND MATERIALS: Between 1983 and 1991, 77 patients with a diagnosis of endometrial (n = 35), colorectal (n = 41), or anal carcinoma (n = 1) received adjuvant postoperative radiotherapy after undergoing treatment planning simulation with the use of small bowel oral contrast medium. Fourteen of these patients underwent surgical placement of a temporary intrapelvic tissue expander prior to radiotherapy, and 63 patients did not. Small bowel volume within the treatment portals was measured for both initial pelvic and conedown fields for all cases, and compared between the two patient groups. RESULTS: The volume of small bowel within the initial pelvic fields receiving full dose irradiation was significantly less among patients with a tissue expander. For patients with a tissue expander, mean volume receiving full dose irradiation was 25 cm3 (median 0 cm3, range 0-297 cm3), whereas the corresponding volume was 239 cm3 (median 181 cm3, range 0-943 cm3) without a tissue expander (p < .0001). A similar reduction of irradiated small bowel volume was noted in the conedown fields with the use of a tissue expander (p = .07). Volumes receiving less than full dose irradiation were also less within the initial pelvic (p = .0001) and conedown (p = .002) fields with a tissue expander. Multivariate analysis of patient and treatment-related parameters showed the use of a tissue expander to be the only factor correlated with decreased small bowel volume within the treatment field (p = .003). Morbidity related to placement and removal of the tissue expander was acceptable. Acute radiation-related morbidity was significantly less in patients irradiated with a tissue expander in place (p < .001). CONCLUSIONS: Placement of an intrapelvic tissue expander was correlated with decreased small bowel volume within the radiotherapy treatment field. Diminished radiation-induced acute gastrointestinal morbidity was noted with use of a tissue expander.

The justification for a surgical staging system in endometrial carcinoma.

Three hundred and one patients with endometrial carcinoma who were surgically staged and treated postoperatively with irradiation at the Fox Chase Cancer Center or the Hospital of the University of Pennsylvania were retrospectively substaged by the 1988 FIGO staging system. For pathological stage I endometrial carcinoma, FIGO substage (IA/IB vs. IC) in addition to depth by thirds (< or = 2/3 vs. > 2/3), grade (1 or 2 vs. 3), age (< or = 60 vs. > 60), and type of postoperative irradiation (vaginal alone vs. external +/- vaginal) were predictive for 5-year cause-specific survival in univariate analysis. For all pathological stages, excluding IIIB and IV endometrial carcinoma, FIGO stage (I or II vs. III) in addition to depth by thirds (< or = 2/3 vs. > 2/3), grade (1 or 2 vs. 3), age (< or = 60 vs. > 60), and type of postoperative irradiation (vaginal alone vs. external +/- vaginal) were predictive for 5-year cause-specific survival in univariate analysis. Clinical stage (I vs. II or III) was not a significant predictor of outcome in univariate analysis. Multivariate analysis of the above factors revealed FIGO stage in addition to grade, age and depth by thirds to be independent predictors of outcome. In conclusion, the FIGO surgical staging system better predicts outcome compared with the prior clinical staging system, although the FIGO substaging needs refinement. Grade, age, and depth by thirds are equally important prognostic factors in addition to FIGO stage and can add to the predictive value of the current FIGO staging system.