The Radiation Therapy Oncology Group: an update of clinical research activities

This paper provides an introduction into the clinical activities of the RTOG (Radiation Therapy Oncology Group), its goals, its organization, its format for protocol development, and presents major areas of achievement. It provides an organizational chart of the group, a disease site modality cross-reference for protocols, and appendices which provide the key published results of the Group's clinical activities. This paper presents an important overview of the RTOG clinical research activities, which are designed to improve the role of radiation therapy.

Cervical stump carcinoma

Although supracervical hysterectomy is becoming a vanishingly rare procedure, there are still many women with a retained cervical stump. We have reviewed 70 patients treated at the Radiation Oncology Center, Mallinckrodt Institute of Radiology for carcinoma of the cervical stump. The average time between the hysterectomy and the diagnosis of cancer in the stump was 26.6 years. The median age at diagnosis of 63.5 years is 8.5 years older than the median age at diagnosis of patients with cancer of the cervix with an intact uterus. Patients were treated with external beam radiation and/or intracavitary implants. Sixteen patients underwent surgery as well. The 5- and 10-year overall actuarial survival for all patients was 60% and 40%, respectively. The 5- and 10-year progression-free survival for all patients was 77% and 70%, respectively. Ten-year progression-free survival by stage was: 0--100%, 1A--100%, 1B--79%, 2A--100%, 2B--66%, and 3B--39%. Poor histologic differentiation correlated with a decreased long-term progression-free survival. Black patients, and those receiving prolonged courses of external beam irradiation, had a trend toward a worse prognosis. Neither non-squamous histology nor gross appearance affected outcome. With a median follow-up time of 12.9 years, there were only three isolated local failures and four combined with distant metastases. Complications were few, with twice as many occurring in the gastrointestinal system as in the genitourinary tract. We conclude that carcinoma of the cervical stump effectively treated by radiation therapy yields results equivalent to those seen in patients with an intact uterus.

Radiation sensitivity of Copenhagen rat prostatic carcinoma (R3327-AT and R3327-MATLyLu)

The radiosensitivity of two variants of the Dunning Copenhagen rat prostatic tumor R3327 was investigated. The R3327-AT variant, which is a poorly differentiated anaplastic, fast-growing tumor, was irradiated both in vivo and in vitro. Following irradiation, monodispersed cells were plated in vitro and colonies were counted after 7 days. The survival curve of R3327-AT cells irradiated in vivo showed an initial shoulder (Dq-value 0.97 Gy), followed by two exponential parts. The D0-value for the first part of the curve (0-10 Gy) was 2.76 Gy and for the second part of the curve (greater than 10 gy) 9.05 Gy. Extrapolation of the second part of the curve to the Y-axis indicated that the proportion of more radioresistant cells was about 10%. The survival curve for R3327-AT cells irradiated in vitro also suggested the presence of a radioresistant subpopulation, although the proportion was lower (about 3%). This difference might be due to the presence of an hypoxic fraction in the tumors irradiated in vivo, but not in vitro. Tumor cells from the R3327 tumor variant metastatic to lymph nodes and lungs (R3327-MATLyLu), were irradiated in vitro. The radiation effect was evaluated by in vitro colony formation in agar and by in vivo lung colony assay. The colony formation in agar yielded a D0-value of 1.09 Gy. No radioresistant subpopulation was identified in this variant. A similar radiosensitivity was observed by the in vivo lung colony assay (D0 1.39 Gy). The mean inactivation dose calculated for R3327-AT cells (3.45 Gy) was significantly higher than for the metastatic variant (2.00 Gy).

Randomized phase III study comparing irradiation and hyperthermia with irradiation alone in superficial measurable tumors. Final report by the Radiation Therapy Oncology Group

A total of 307 patients with superficial measurable tumors were registered on a Radiation Therapy Oncology Group (RTOG) protocol involving fractionated radiation therapy, either alone or followed immediately by hyperthermia (42.5 degrees C, 45-60 min). Overall complete response (CR) was observed in 30% of the lesions treated with radiotherapy (RT) and 32% of those receiving RT and heat. Response was found to be significantly related to both maximum tumor diameter (less than 3 or greater than or equal to 3 cm) and site/histology (breast/adenocarcinoma, head and neck/squamous, or other site/histologies). In tumors less than 3 cm in diameter in the breast, trunk, and extremities, a better CR rate was noted with irradiation and heat (62 and 67%) than with irradiation alone (40 and 0%). However, in the head and neck there was only minimal difference in CR with irradiation alone or combined with hyperthermia (50 vs 38%). In lesions less than 3 cm treated with irradiation and heat, there was improved local control. In lesions greater than 3 cm, there was no difference in local control between the two treatment arms. The higher response rate in patients with smaller lesions (less than 3 cm) may be explained by the fact that these tumors are easier to heat. Problems in correlating tumor response with quality of heating include less than optimal heating in larger lesions and the limited ability of current thermometry to map the temperature distribution in a tumor. Acute and late toxicities in both treatment arms were comparable, except for an overall 30% incidence of thermal blisters in the heated tumors.

Reduction in radiation exposure to nursing personnel with the use of remote afterloading brachytherapy devices

The radiation exposure to nursing personnel from patients with brachytherapy implants on a large brachytherapy service were reviewed. Exposure to nurses, as determined by TLD monitors, indicates a 7-fold reduction in exposure after the implementation of the use of remote afterloading devices. Quarterly TLD monitor data for six quarters prior to the use of remote afterloading devices demonstrate an average projected annual dose equivalent to the nurses of 152 and 154 mrem (1.5 mSv). After the implementation of the remote afterloading devices, the quarterly TLD monitor data indicate an average dose equivalent per nurse of 23 and 19 mrem (0.2 mSv). This is an 87% reduction in exposure to nurses with the use of these devices (p less than 0.01).

N2 (clinical) non-small cell carcinoma of the lung: prospective trials of radiation therapy with total doses 60 Gy by the Radiation Therapy Oncology Group

Clinical Stage III (N2) non-small cell carcinoma of the lung encompasses a large group of patients, frequently treated with radiation therapy alone, who are now considered to have borderline-resectable tumors. Pilot studies are proceeding which use combinations of resection, radiation therapy, and chemotherapy. To place trials of combination therapy in perspective with contemporary results of radiation therapy alone, recently completed trials of the RTOG were analyzed specifically for clinical Stages T1-3N2. A prospective randomized trial of hyperfractionated radiation therapy (HFX), conducted from 1983 through 1987, compared total doses of 60.0, 64.8, and 69.6 Gy using 1.2 Gy bid with greater than or equal to 4 hr interval. After acute and late effects were considered tolerable, 74.4 Gy and 79.2 Gy arms supplanted the two lowest dose arms. Survival was compared among the five total dose arms, and with 60 Gy in 30 fractions in 6 weeks (standard fractionation-STD) from earlier RTOG studies. Of 516 HFX patients analyzed, 296 (57.3%) with Performance Status (PS) 70-100 and less than 5% weight loss (favorable) had a significantly (p = .001) better survival than those with PS 50-69 or weight loss greater than 5%. Patients with RTOG Stage III (361, 70.0%) experienced better survival (p = .027) than RTOG Stage IV M0. The 69.6 Gy total dose arm was significantly (p = .031) better in favorable RTOG Stage III patients than all other total dose arms: the 1-year survival rate was 58% and the 3-year rate was 20%. The 69.6 Gy HFX results were significantly (p = .002) better than results with STD fractionation in comparable patients from earlier RTOG trials (1-year survival = 30%, 3-year survival = 7%). A prospective, randomized Phase III comparison of STD with 60 Gy versus HFX with 69.6 Gy is underway. These results provide benchmarks for studies of surgical resection combined with chemotherapy and/or radiation therapy until results of prospective comparisons with concurrent controls are available.

Phase I/II study, combination of radiotherapy and hyperthermia in patients with deep-seated malignant tumors: report of a pilot study by the Radiation Therapy Oncology Group

This is a report of a Phase I/II study activated in March 1984 and completed in October 1988 by the Radiation Therapy Oncology Group on the feasibility/toxicity of hyperthermia in patients with deep-seated malignant tumors. The main objective of this study was to evaluate the morbidity of regional hyperthermia (systemic and regional, acute and late effects); a secondary objective was to evaluate tumor response to combined irradiation and regional hyperthermia. A total of 54 patients with locally advanced abdominal or pelvic malignancy were accrued to this study; 42% were male and 58% female. Seventy-five of the patients had pelvic tumors and 25% abdominal tumors. Acute toxicities included grade 4 in three patients (1 cutaneous, 1 infection and 1 chemical peritonitis) one grade 3 (skin), and 12 grade 2 toxicities (6 skin and 6 gastrointestinal). With regard to late toxicities, grade 4 was noted in one patient (skin), grade 3 (GI) in one, and grade 2 (skin, peripheral neuropathy) in six patients. The prescribed course of hyperthermia was completed in 17 (32%) of patients. In 36 patients (68%) the course of hyperthermia was terminated, primarily because of patient discomfort. Tumor response was assessed by physical examination or radiological studies. Of 44 patients evaluable for response, there were 17 (39%) complete responses and 6 (14%) partial responders. Significant technical problems in heat delivery and thermometry remain.

Preliminary report on 10 patients treated with radiotherapy after radical prostatectomy for isolated elevation of serum PSA levels

Since 1987, 10 patients have been treated with irradiation to a limited pelvic volume for elevation of serum prostate-specific antigen (PSA) level above expected post-radical prostatectomy levels without clinical or radiological evidence of either metastatic or locoregional disease. The patients were treated 3 to 43 months after radical prostatectomy, using bilateral 120 degrees arcs to deliver 6000 cGy to the prostatic bed. The pathologic findings of the initial surgical specimens for all patients were reviewed. Eight patients had pathologic Stage C disease, and five patients had one or more positive margins. All patients had negative staging lymphadenectomies. After irradiation, eight patients had decreases in PSA levels indicative of response of isolated local disease. Through preliminary, these results suggest that post-prostatectomy PSA levels are useful for detecting subclinical local recurrence or persistence in the prostatic bed, as well as monitoring these patients' response to therapy. The value of this elective treatment remains to be documented.

Phase II Radiation Therapy Oncology Group study of hormonal cytoreduction with flutamide and Zoladex in locally advanced carcinoma of the prostate treated with definitive radiotherapy

In patients with locally advanced (bulky) carcinoma of the prostate, definitive radiotherapy is associated with a high rate of local recurrence. The Radiation Therapy Oncology Group (RTOG) has conducted several studies evaluating hormonal cytoreduction (used as an induction regimen) as a means of improving the local control rate. RTOG 85-19 tested an induction regimen consisting of a depot LH-RH agonist (Zoladex) and an antiandrogen (flutamide). Eligible patients were those with bulky primary lesions (stage B2 and C) with disease confined to the pelvis. Zoladex was administered every 29 days via a subcutaneous injection. Flutamide was given by mouth in a dose of 250 mg t.i.d. Administration of the drugs was initiated 2 months prior to start of radiotherapy and was terminated at completion of the radiotherapy course. Radiotherapy consisted of 180-200 rad/day, 4,400-4,500 rad to the regional lymphatics, and 6,500-7,000 rad to the prostate. The primary aim of the study was to evaluate the effectiveness and toxicity of the combined (hormonal cytoreduction plus definitive radiotherapy) regimen. Thirty-one patients were accessioned; 30 are analyzable. The drug-related toxicity appears acceptable. It included appearance of diarrhea before initiation of radiotherapy in two patients, nausea during the 2nd week of drug administration in two patients, and skin rash in three patients. These phenomena appear to be related to flutamide. Hot flashes were recorded in 17 patients. With a minimum follow-up of 2 years, clearance of the primary lesions (by clinical examination) was documented in 28 of 30 patients. During the 1st year, two of 30 patients died (of unrelated causes) with residual palpable tumors. The observed toxicity appears acceptable and the response rate encouraging. A phase III study comparing the tested regimen against radiotherapy alone appears warranted.

Cervical metastases from unknown primaries: radiotherapeutic management and appearance of subsequent primaries

Between 1964 and 1986, 72 patients who presented with squamous or undifferentiated metastatic carcinoma to neck nodes, where the primary tumor could not be found by standard clinical procedures, were treated at the Mallinckrodt Institute of Radiology. These cases were managed in the following manner: biopsy and radiotherapy in 46 out of 72 patients, radiotherapy (RT) and a planned neck dissection in 14 out of 72, and neck dissection after failure to achieve a complete response (CR) with RT in 12 out of 72. Minimum follow-up was 2 years. The initial CR rates for stages N1, N2a, N2b, N3a, and N3b were 83%, 93%, 61%, 50%, and 33%, respectively. The long-term neck tumor control for the same stages was 83%, 71%, 67%, 44%, and 50%, respectively. One patient had soft tissue necrosis and two had carotid artery ruptures, one of which left no symptomatic sequelae. Twenty-one out of 72 patients developed subsequent primary tumor. Only one of these patients survived. This incidence was not affected significantly by prophylactic treatment of the mucosal areas except in patients with bilateral neck nodes, undifferentiated or poorly differentiated histologies, and/or posterior cervical node involvement. A multivariate analysis showed that prognosticators of an improved disease-free survival were: a complete clearance of tumor by the end of radiotherapy (p less than 0.0009) and no appearance of a subsequent primary tumor (p = 0.035). The only factor that correlated with an increased loco-regional control was having a complete response by the end of radiotherapy (p less than 0.00009). The recommended management and possible ways of preventing the appearance of subsequent primaries will be discussed.

Chemotherapy for advanced thymoma. Preliminary results of an intergroup study

OBJECTIVE

To determine the efficacy of combination therapy with cisplatin, doxorubicin, and cyclophosphamide alone or with radiotherapy for patients with extensive and those with limited unresectable thymoma.

DESIGN

Nonrandomized, prospective phase I-II trial.

SETTING

A Cooperative Oncology Group trial involving tertiary medical centers.

PATIENTS

Twenty of twenty-two patients with measurable, extensive or limited, unresectable thymoma were evaluable for response.

INTERVENTION

Patients were given cisplatin, 50 mg/m2 body surface area, doxorubicin, 50 mg/m2, and cyclophosphamide, 500 mg/m2, on day 1, with cycles repeated every 21 days until progression or until the maximally tolerated total doxorubicin dosage (for example, 450 mg/m2) was reached. Intravenous hydration with normal saline was administered during treatment courses. For responding patients with limited disease, 4500 cGy was administered to primary tumors after the second cycle of chemotherapy and before the initiation of the third cycle.

MEASUREMENTS AND MAIN RESULTS

Three complete and eleven partial remissions were seen in 20 evaluable patients, for a total response rate of 70% (95% CI, 46% to 88%). The median duration of remission was 13 months with three patients remaining continuously disease free for over 2 years. The median survival time of all eligible patients was 59 months (CI, 22 months to infinity). Four patients developed infections, including listerial and aseptic meningitides, mucocutaneous candidiasis, and cryptococcal pneumonia, that were indicative of a defect in cell-mediated immunity.

CONCLUSIONS

Combination therapy with cisplatin, doxorubicin, and cyclophosphamide frequently produces objective remissions in patients with advanced thymoma. Further experience with this treatment regimen is warranted to clarify potential prognostic factors in patients with unresectable thymoma.

Isolated local-regional recurrence of breast cancer following mastectomy: radiotherapeutic management

Two hundred twenty-four patients with their first, isolated local-regional recurrence of breast cancer were irradiated with curative intent. Patients who had previous chest wall or regional lymphatic irradiation were not included in the study. With a median follow-up of 46 months (range 24 to 241 months), the 5- and 10-year survival for the entire group were 43% and 26%, respectively. Overall, 57% of the patients were projected to be loco-regionally controlled at 5 years. The 5-year local-regional tumor control was best for patients with isolated chest wall recurrences (63%), intermediate for nodal recurrences (45%), and poor for concomitant chest wall and nodal recurrences (27%). In patients with solitary chest wall recurrences, large field radiotherapy encompassing the entire chest wall resulted in a 5- and 10-year freedom from chest wall re-recurrence of 75% and 63% in contrast to 36% and 18% with small field irradiation (p = 0.0001). For the group with recurrences completely excised, tumor control was adequate at all doses ranging from 4500 to 7000 cGy. For the recurrences less than 3 cm, 100% were controlled at doses greater than or equal to 6000 cGy versus 76% at lower doses. No dose response could be demonstrated for the larger lesions. The supraclavicular failure rate was 16% without elective radiotherapy versus 6% with elective radiotherapy (p = 0.0489). Prophylactic irradiation of the uninvolved chest wall decreased the subsequent re-recurrence rate (17% versus 27%), but the difference is not statistically significant (p = .32). The incidence of chest wall re-recurrence was 12% with doses greater than or equal to 5000 cGy compared to 27% with no elective radiotherapy, but again was not statistically significant (p = .20). Axillary and internal mammary failures were infrequent, regardless of prophylactic treatment. Although the majority of patients with local and/or regional recurrence of breast cancer will eventually develop distant metastases and succumb to their disease, a significant percentage will live 5 years. Therefore, aggressive radiotherapy should be used to provide optimal local-regional control.(ABSTRACT TRUNCATED AT 400 WORDS)

Carcinoma of the prostate stage B and C: lack of influence of duration of radiotherapy on tumor control and treatment morbidity

Between 1966 and 1985, 542 of 585 patients with histologically confirmed carcinoma of the prostate, Stages B and C, were treated with definitive radiation therapy to a minimum of 6300 cGy. There were 191 Stage B patients and 351 Stage C patients. The median tumor dose for Stage B patients was 6957 cGy and for Stage C patients 7020 cGy. Daily fractions of 180 to 200 cGy were given 4 or 5 times per week with occasional rest periods of several days, usually because of side effects of radiation therapy. The minimum follow-up time was 3 years; maximum follow-up was 16.0 years, and the median was 4.8 years. In this analysis, within each stage, patients were divided into four groups based on the number of treatment days: less than or equal to 56 days (8 weeks), 57 to 63 days (9 weeks), 64 to 70 days (10 weeks), and greater than 70 days. The distribution of Stage B and Stage C patients by histologic grade and duration of therapy is fairly even within each group. The influence of duration of radiotherapy on actuarial survival, progression-free survival, pelvic control, and incidence of complications was analyzed, and no statistical difference among the four groups of patients was found. The scatterplots of pelvic failure by radiation dose and duration of radiotherapy for both Stage B and C prostate carcinoma patients did not show a correlation between failure rate and duration of radiotherapy. Tumor histologic grade did not influence the incidence of pelvic failure. In summary, within the dose range used in this analysis the overall length of radiation treatment time did not seem to affect the clinical outcome of patients with Stage B and C prostate carcinoma.

External irradiation of epithelial skin cancer

A total of 339 consecutively treated, biopsy proven squamous and basal cell carcinomas of the skin treated from January 1966 to December 1986 were retrospectively analyzed to determine the patterns of local recurrence. There were 242 basal cell carcinomas, 92 squamous cell carcinomas, and 5 variants of squamous cell carcinoma in various locations. Radiotherapy was the initial treatment modality in 212 patients and 127 were treated after failing initial surgical excision. Lymph nodes were involved in 1/242 patients (.4%) with basal cell carcinoma, 14/92 patients (15%) with initially treated squamous cell carcinoma, and 20/51 (39%) with recurrent squamous cell lesions. Distant metastasis was found in one patient. Superficial X rays were given to 187 patients, electrons to 57 patients, megavoltage photons to 15, and a combination of modalities to the remainder. Overall local tumor control was achieved in 292 of 339 patients (86%), 220 of 242 (91%) with basal cell and 73 of 97 (75%) with squamous cell carcinoma. Tumor control was closely related to the size of the primary lesion. For lesions less than 1 cm tumor control was 97% (86/89) for basal cell and 91% (21/23) for squamous cell carcinoma. For 1 to 5 cm, tumor control was 87% (116/133) for basal cell and 76% (39/51) for squamous cell carcinoma and for lesions greater than 5 cm, the tumor control was 87% (13 of 15) and 56% (9/16), respectively. Tumor control was related to the modality used to treat the patient in spite of stratification of primary lesion size. For superficial X rays, tumor control was 98% (81/83) for lesions less than 1 cm, 93% (94/101) for lesions 1-5 cm and 100% (5/5) for lesions greater than 5 cm. For electrons tumor control was 88% (14/16), 72% (23/32), and 78% (7/9), respectively. For mixed beams tumor control was 90% (9/10), 76% (32/42), and 64% (9/14), respectively, and for 60Co-4 MV X rays, tumor control was 100% (3/3), 67% (6/9), and 33% (1/3), respectively. Cosmesis and complications were analyzed in 261 patients. An excellent or good cosmetic result was found in 92% (239/261) of the patients. There were 8 of 261 patients (3.1%) with fair and 19 of 261 (7.3%) with poor cosmesis. Cosmesis had an inverse relation to the primary lesion size with 97 of 99 patients (98%) with tumors 1 cm or less, 123 of 140 patients (88%) with lesions 1 to 5 cm and 13 of 16 patients (82%) with larger tumors having excellent or good cosmetic results. Cosmesis is also related to treatment modality.(ABSTRACT TRUNCATED AT 400 WORDS)

Juvenile nasopharyngeal angiofibroma: efficacy of radiation therapy

From 1962 to 1984, 13 patients with juvenile nasopharyngeal angiofibroma (JNA) were treated with megavoltage radiation therapy. Follow-up ranged from 40 to 255 months (median, 136 months). Two patients received radiation therapy as the initial treatment; the other 11 patients had undergone unsuccessful previous surgical treatment (median, three resections). Gross tumor was evident at the start of radiation therapy in seven patients, and orbital, sphenoid sinus, or intracranial extension was noted in eight of 13 (62%). Doses ranged from 3,600 to 5,200 cGy (median, 4,800 cGy in daily fractions of 180-200 cGy). Tumor was controlled in 11 patients (85%) after irradiation. Two patients were treated with embolization for residual mass; both remained asymptomatic and without evidence of tumor 134 and 83 months after embolization, respectively. With the exception of xerostomia and caries, no significant chronic morbidity was seen. This review and other studies demonstrate that megavoltage radiation therapy is an effective and appropriate treatment for advanced and recurrent JNA; its routine use for early tumors remains controversial.

Thoracic radiotherapy does not prolong survival in patients with locally advanced, unresectable non-small cell lung cancer

STUDY OBJECTIVE

To compare the survival of patients with locally advanced non-small cell lung cancer treated with single-agent vindesine, thoracic radiotherapy, or both treatment modalities.

DESIGN

Randomized, prospective, phase III trial.

SETTING

Multi-institutional, university-based national cooperative oncology group.

PATIENTS

The study included 319 patients with locally advanced, unresectable non-small cell lung cancer who had no evidence of extrathoracic metastases. All patients were ambulatory and had measurable disease. Some patients could not have surgery because of coexisting medical conditions.

INTERVENTION

Patients were randomly assigned to receive vindesine, 3 mg/m2 body surface area weekly; standard thoracic radiotherapy, 60 Gy over 6 weeks; or both vindesine and thoracic radiotherapy. Vindesine was administered for 6 weeks and then every other week to patients who had no disease progression. Patients who developed progressive disease while receiving vindesine or radiotherapy alone were crossed over to radiotherapy or vindesine, respectively. Response assessment took place at week 6.

RESULTS

The overall response rate was superior in the radiotherapy arms (radiotherapy alone, 30%; radiotherapy plus vindesine, 34%; vindesine alone, 10%; P = 0.001). However, with a minimum follow-up of 42 months, no improvement in survival has been seen with radiotherapy. The median survival was 8.6 months for patients receiving radiotherapy alone, 9.4 months for those receiving radiotherapy plus vindesine, and 10.1 months for those receiving vindesine (P = 0.58). Radiotherapy also failed to improve long-term survival. The 5-year survivals were 3%, 3%, and 1%, respectively (P = 0.56).

CONCLUSION

Patients with non-small cell lung cancer who have inoperable, nonmetastatic disease gain no clinically meaningful survival advantage with immediate thoracic irradiation, even when modern megavoltage radiation therapy techniques and equipment are used.

Design of an afterloading vaginal applicator (MIRALVA)

A vaginal applicator was designed and constructed that incorporates two ovoid sources and a central tandem which can be utilized to treat the entire vagina (alone or in combination with the uterine cervix). The average surface dose rate around the 2 cm ovoids is 120 cGy/hr and in the 2.5 cm diameter vaginal cylinder about 100 cGy/hr with usual loading of 20 mg Ra eq 137-Cs sources in the ovoids and 10-15 mg Ra eq 137-Cs sources in the cylinder. The applicator has vaginal apex caps and additional cylinder sleeves that allow for increased dimensions. The tandem in the uterus can be utilized when clinically indicated using standard loadings, depending on the depth of the uterus (20-10-10 or 20-10 mg Ra eq). When the tandem and vaginal cylinder are utilized the strength of the sources in the ovoids should be 15 mg Ra eq. The vaginal cylinder or uterine tandem never carry an active source at the level of the ovoids. Thermoluminescent dosimetry measurements throughout the surface of the applicator showed close agreement with the computer dose calculations (within +/- 2%). The acronym MIRALVA describes the device (Mallinckrodt Institute of Radiology Afterloading Vaginal Applicator).

Tumor control in long-term survivors following superficial hyperthermia

Sixty tumors with a minimum of 1-year follow-up were treated with radiation and superficial microwave hyperthermia (915 MHz). The overall local control rate was 50% (30/60). The most important factor in outcome was appropriateness of the hyperthermia applicator. Tumors covered by at least the 25% iso-SAR contour achieved 65% local control versus 21% local control with less than 25% SAR coverage (p less than 0.01). Several measures of adequate minimum monitored tumor temperature and duration were considered. The measure best correlated with outcome was best single session time at or above 43 degrees C (t43). If each monitored tumor catheter achieved t43 greater than or equal to 30 minutes in at least one session, then tumor control was significantly (p less than 0.01) improved (63% with Min t43 greater than or equal to 30 versus 25% with Min t43 less than 30). Although there was considerable overlap between tumors with SAR greater than or equal to 25% and those achieving Min t43 greater than or equal to 30, a statistically significant (p = 0.02) difference could be demonstrated between the group meeting both the SAR and the minimum tumor time/duration standards as opposed to those meeting only one standard. The actuarial local progression-free survival for tumors most likely to have had adequate hyperthermia (defined as SAR greater than or equal to 25% and Min t43 greater than or equal to 30) and all other tumors did not begin to separate significantly until 8 to 12 months after treatment. Implications for future randomized studies are discussed.

Phase I/II study of definitive radiotherapy and chemotherapy (cisplatin and 5-fluorouracil) for advanced or recurrent gynecologic malignancies. Preliminary report

Twenty-three patients with advanced gynecologic malignancy were treated with definitive irradiation and synchronous sensitizing chemotherapy (CT) consisting of cisplatin (CDDP), 50 mg/m2 i.v. rapid infusion, and a 5-day continuous infusion of 5-fluorouracil (5-FU), 750 mg/m2/day. A total of three cycles were administered every 3-4 weeks. Fifteen patients had primary cervical epidermoid carcinoma (three bulky stage IIB, one stage IIIA, ten stage IIIB, one stage IV), four had pelvic recurrences of carcinoma of the cervix, two had endometrial adenocarcinomas (stage IV), and two had vulvar epidermoid carcinoma (one stage III and one stage IV). Radiotherapy (RT) for implantable tumors consisted of 2,000 cGy whole pelvis, 3,000-4,000 cGy split field, and two intracavitary or interstitial insertions, resulting in a total dose of 7,500-8,000 cGy to point A. Three courses of CT were delivered simultaneously with irradiation of the central bulk of tumor: during the first week of whole pelvis RT and with each of the two brachytherapy procedures. Nonimplantable tumors were treated with protracted external beam RT (5,500 cGy tumor dose) and three courses of CT during weeks 1, 4, and 7 of RT. Twenty-one of 23 patients completed RT and 18 of 23 patients completed CT as planned, but half had delays in either RT or CT. Grade 2 or 3 late sequelae consisted of leg edema (one patient), proctosigmoiditis (one patient), bowel obstruction (one patient), vesicovaginal fistula (one patient), and pulmonary embolus (two--one fatal). The incidence of grade 2 and 3 sequelae were 18 and 22%, respectively. With 1-3 years of follow-up evaluation, 12 of 23 (52%) patients are free of disease, and 9 of 22 evaluable patients (41%) have had failure within the pelvis. We conclude that high-dose definitive RT can be delivered with synchronous CDDP and 5-FU at the doses given, with acceptable toxicity. Further study is required to evaluate the impact of radiosensitization on tumor control and late morbidity of therapy. Optimization of irradiation and drug doses as well as the best schedules that may enhance the interaction of these two modalities should be further investigated.

Impact of surgical staging in evaluating the radiotherapeutic outcome in RTOG phase III study for A2 and B prostate carcinoma

Radiation Therapy Oncology Group (RTOG) protocol 7706 was a randomized Phase III study designed to test the value of elective (prophylactic) pelvic irradiation in addition to prostatic irradiation in patients with carcinoma of the prostate with no clinical evidence of tumor extension through the capsule. Eligible patients were those who had clinical Stage T1bNOMO (A2) or T2NOMO (B), who did not have curative surgery, and who had no evidence of lymph node metastases. Assessment of the regional lymphatics was mandatory but, at the discretion of the investigator, lymphangiography (LAG) or staging lymphadenectomy (SL) could be used. A total of 445 eligible and analyzable patients were entered in the study between 1978 and 1983 when the study was closed. The median follow-up was 7 years; minimum follow-up was 5 years. There were no significant differences in survival or local control whether treatment was administered to the prostate or to the prostate and pelvic lymph nodes. The nodal status for 117 (26%) patients was assessed by staging lymphadenectomy (SL) whereas for 328 (74%) patients it was assessed by lymphangiography (LAG). Pretreatment characteristics felt to have impact on survival were evaluated and found to be free of serious imbalance between the staging lymphadenectomy and lymphangiography groups. Compared to the lymphangiography group, the staging lymphadenectomy group showed better overall survival (87% to 76% at 5 years, p = .02), better disease-free survival (76% to 63% at 5 years, p = .008) and better metastases-free survival (88% to 82% at 5 years, p = .04). There was no difference between the groups in local control. The lymphangiography evaluation of pelvic nodes was clearly inferior for demonstration of the absence of pelvic node metastasis as reflected by reduced survival and increased metastasis.

Management of sequelae of chest irradiation

High-dosage irradiation is an important component in the treatment of patients with lung cancer. While most patients tolerate therapy well, certain changes can be expected in their bodies. The authors review these effects and offer suggestions for their management.

Physical predictors of adequate hyperthermia with the annular phased array

One hundred and fifty-two hyperthermia sessions in 36 consecutive patients treated with the BSD 1000 annular phased array system (APAS) are reviewed with regard to physical predictors of quality of hyperthermia. Although central tumour temperatures exceeding 42 degrees C were momentarily obtained in 62% of the sessions, it frequently proved difficult to maintain the patient at temperature for prolonged periods of time. The time to reach target temperature was negatively associated with quality of hyperthermia. Thus, of 25 sessions which required over 25 min to attain a temperature of 42 degrees C, only one was adequate (defined as central tumour temperature greater than or equal to 42 degrees C maintained for at least 30 min) as opposed to 28/69 adequate sessions when 42 degrees C was reached in less than 25 min. Physical parameters measured in the first 3 min of the session found to be associated with adequate hyperthermia include an initial rate of temperature rise at the tumour site exceeding 0.4 degrees C/min achieved with a net forward power less than 1500 W. Only three of 57 sessions not meeting these criteria were adequate. Treatment policy recommendations and recommendations for future research are made.

Outcome of recurrent cervical carcinoma following definitive irradiation

This report is a retrospective analysis of 376 patients with recurrent cervical carcinoma, following definitive radiation therapy to 1054 patients with stage IB-IVA carcinoma of the uterine cervix treated at the Radiation Oncology Center, Mallinckrodt Institute of Radiology, from January 1959 through December 1982. The sites of failure after treatment by stage at initial diagnosis were classified as pelvic only (P), pelvic plus distant metastasis (P + DM), or distant metastasis only (DM). The sites of first failure were for stage IB, P = 0.8%, P + DM = 7.4%, DM = 7.9%; for stage IIA, P = 1.7%, P + DM = 14.7%, DM = 17.2%; for stage IIB, P = 10.4%, P + DM = 11.0%, DM = 14.9%; for stage III, P = 15.4%, P + DM = 23.9%, DM = 18.9%; and for stage IV, P = 16.7%, P + DM = 61.1%, DM = 16.7%. The actuarial probability of pelvic failure at 5 years from initial therapy was 8% for stage IB, 16% for stage IIA, 21% for stage IIB, 42% for stage III, and 100% for stage IV. The incidence of distant metastasis at 5 years was 14, 32, 28, 47, and 100% for stages IB, IIA, IIB, III, and IV, respectively. The therapy after failure was surgery, irradiation, irradiation plus surgery, or chemotherapy. There appeared to be no major difference in survival after recurrence by type of treatment or initial stage. The overall survival at 5 years for all untreated patients was 1%. The median survival was evaluated as a function of time to failure after initial treatment. Patients who developed disease more than 36 months after initial treatment had a median survival of 22.5 months. The median survival was 12.1, 7.6, 9.4, and 9.1 months for those failing less than 6, 6-12, 13-24, and 25-36 months after initial treatment. Severe treatment complications occurred in 3.6% (5/140).