Results of a phase II trial of external beam radiation with etanidazole (SR 2508) for the treatment of locally advanced prostate cancer (RTOG Protocol 90-20).

PURPOSE: RTOG Protocol 90-20 was designed to evaluate the effect of the hypoxic cell sensitizer Etanidazole (SR-2508) on locally advanced adenocarcinoma of the prostate treated with concurrent external beam irradiation. METHODS AND MATERIALS: Patients with biopsy-proven adenocarcinoma of the prostate with locally advanced T2b, T3, and T4 tumors were eligible for this study. No patients with disease beyond the pelvis were eligible. Serum prostate specific antigen (PSA) was mandatory. All patients received definitive external beam irradiation using standard four-field whole pelvis treatment to 45-50 Gy, followed by a cone down with a minimum total dose to the prostate of 66 Gy at 1.8-2.0 Gy/fraction over 6.5-7.5 weeks. Etanidazole was delivered 1.8 g/m2 given 3 times a week to a total of 34.2 g/m2 or 19 doses. RESULTS: Thirty-nine patients were entered onto the study. Three patients refused treatment; therefore, 36 patients were eligible for further evaluation. Median follow-up was 36.9 months from treatment end. All patients had elevated initial PSA levels, and 18 patients had PSAs of > 20 ng/ml. Tumor classification was T2, 12 patients (33.3%); T3, 22 patients (61.1%); and T4, 2 patients (5.6%). Complete clinical response, defined as PSA < 4 ng/ml and complete clinical disappearance, was attained in 17.9% of (5/28 pts) with information at 90 days and 56% of patients by 12 months following treatment. Relapse-free survival was 13% at 3 years with PSA < 4 ng/ml. There were no Grade 4 or 5 toxicities, either acute (during treatment) or in follow-up. CONCLUSIONS: Results of this trial regarding PSA response and clinical disappearance of disease are similar to historical controls and do not warrant further investigation of etanidazole as was done in this trial. Drug toxicity that, in the past, has been unacceptably high with other hypoxic cell sensitizers does not appear to be a significant problem with this drug.

Evolution of the Radiation Therapy Oncology Group clinical trials for head and neck cancer.

During the past 25 years, the Radiation Therapy Oncology Group (RTOG) has played a major role in head and neck cancer clinical research. The major research themes for recent and currently active trials have been: (a) combined modality therapy, (b) altered fractionation radiotherapy, (c) hypoxic cell sensitizers, (d) organ preservation, (e) chemoprevention, and (f) clinical/laboratory correlations. For advanced operable disease, the RTOG showed improved local-regional control with postoperative radiotherapy as compared to preoperative radiotherapy for carcinoma of the supraglottic larynx and hypopharynx. This established the use of surgery followed by postoperative radiotherapy as the standard treatment in subsequent RTOG and Intergroup trials for operable disease. For advanced inoperable disease, the RTOG demonstrated the feasibility of testing altered fractionation radiotherapy in a multiinstitutional clinical trials setting. A Phase III trial comparing hyperfractionation and accelerated fractionation to conventional fractionation is now in progress. Phase I/II combined modality studies established the efficacy of concurrent high-dose cisplatin and radiotherapy in the treatment of advanced disease and provided the basis for further testing in Phase III trials for nasopharyngeal carcinoma, larynx preservation, and high-risk advanced operable disease. Analysis of the extensive RTOG Head and Neck Cancer database established the incidence of second malignancies and their adverse impact on patients whose initial tumors were cured by radiotherapy, and provided the basis for chemoprevention trials. Recursive partitioning analysis identified 6 distinct prognostically homogeneous patient groups based on pretreatment tumor or patient characteristics and/or treatment variables. Retrospective analysis identified tumor p105 antigen density as an independent prognostic indicator in patients irradiated for head and neck cancer. Future trials will continue to focus on the reduction of morbidity and mortality, and improvement of the quality of life of head and neck cancer patients through innovative radiotherapy delivery, multimodality approaches, use of chemical and biological modifiers, and other novel therapies, identification of clinical and biological prognostic indicators, and prevention or diminution of acute morbidity and late complications of the disease and its treatment.

Altered fractionation and extended-field irradiation of carcinoma of the cervix.

Conventional radiotherapy for treatment of carcinoma of the cervix consists of five daily fractions of 1.80-2.00 Gy, 5 days/week, up to 40.00-50.00 Gy, followed by intracavitary brachytherapy to complete a paracentral dose ranging from 70 to 90 Gy and a lateral pelvic wall dose ranging from 50 to 60 Gy. This results in tumor control in the pelvis for at least 91% of patients with Stage IB disease. However, survival rates at 5-year follow-up have ranged from 49% to 69% for patients with Stage III disease and 25% to 34% for patients with Stage IVA disease. Attempts to improve clinical results for patients with more advanced stages of disease have included hypofractionated and hyperfractionated radiotherapy, accelerated fractionation, and concomitant boost. However, no improvement of tumor control or survival has been obtained. Hyperfractionated external pelvic radiation remains undefined as a method of improving results. Extended-field prophylactic irradiation of the paraaortic lymph nodes has shown significant value in a study group setting. Early diagnosis and prevention continue to be the most promising approaches in the control of carcinoma of the cervix.

Carcinoma of the cervix: patterns of care studies: review of 1978, 1983, and 1988-1989 surveys.

PURPOSE: A review of the Patterns of Care Studies Process Survey data on carcinoma of the cervix conducted on patients in 1978, 1983, and 1988-89 was carried out to identify changes or trends in the demographics, evaluation, and treatment that might have occurred over this time period. METHODS AND MATERIALS: Patterns of Care Studies conducted surveys on patients treated by radiation therapy for cervical carcinoma in 1978, 1983, and 1988-89. These surveys have compiled demographic and treatment data on a total of 993 patients. There is outcome data for the 1978 and 1983 surveys, but not for the 1988-89 survey because follow-up has not been collected yet. The demographic and treatment delivery data on all three surveys has been reviewed and analyzed and is the subject of this study. RESULTS: There was no difference in the age distribution at the time of diagnosis of the patients in these surveys. The percentage of black patients remained constant in the three surveys, 19%, 17%, and 21%, respectively. The percentage of white patients was 76%, 78%, and 67%, but that of nonwhite/nonblack patients was 3%, 4%, and 12% (p < 0.001). The distribution of patients by stage was similar in the first two surveys. In the third survey, there was a decrease in the percentage of patients with Stage IA and IB (first = 35%; second = 38%; third = 29%) with a concurrent increase in Stage IIIA and IIIB patients (first = 20%; second = 18%; third = 26%). The surveys showed a major change in the pretreatment evaluation tests used. There was a progressive decrease in the use of intravenous pyelogram (IVP) (86 to 42%), barium enema (58 to 32%), cystoscopy for patients Stage IIB and higher (64 to 52%), and lymphangiography (18 to 14%). The use of abdominal or pelvic computed tomography dramatically increased from 6 to 70% between the first and third surveys. The use of 60Co units decreased from 35 to 2% from the first to the third survey [6 to 0% for short source-surface distance (SSD) 60Co units]. Point dose calculations for the intracavitary therapy increased from 78% in the 1978 survey to 95% in the third survey. As determined by the total dose delivered to the paracentral points, more patients (75.1%) were treated according to the Patterns of Care recommended guidelines in the 1988-89 survey than in the 1983 survey (63.6%). Chemotherapy was given to 12% of the patients undergoing radiation therapy during the period of the third survey, but these data are not available for the first and second surveys. CONCLUSION: Review of the Carcinoma of the Cervix Patterns of Care studies discloses significant changes in the demographics, patient evaluation, and radiation therapy techniques during the period of the studies. The potential impact of these changes on treatment outcome cannot be determined at this time until longterm follow-up for the 1988-89 survey is available, but improvements in the processes of care should lead to improvements in outcome.

Results of an RTOG phase III trial (RTOG 85-27) comparing radiotherapy plus etanidazole with radiotherapy alone for locally advanced head and neck carcinomas.

PURPOSE: The objectives of this study were to determine the efficacy and toxicity of Etanidazole (ETA), a hypoxic cell sensitizer, when combined with conventional radiotherapy (RT) in the management of advanced head and neck carcinomas. METHODS AND MATERIALS: From March 1988 to September 1991, 521 patients who had Stage III or IV head and neck carcinomas were randomized to receive conventional RT alone (66 Gy in 33 fractions to 74 Gy in 37 fractions, 5 fractions per week) or RT+ETA (2.0 g/m2 thrice weekly for 17 doses), of whom 504 were eligible and analyzable. Treatment assignments were stratified before randomization according to the primary site (oral cavity + hypopharynx vs. supraglottic larynx + oropharynx + nasopharynx), T-stage (T1-3 vs. T4), and N-stage (N0-2 vs. N3). Pretreatment characteristics were balanced. In the RT-alone arm, 39% of patients had T3 and 34% had T4 disease, whereas in the RT+ETA arm, 42% of patients had T3 and 33% had T4 disease. Thirty-eight percent of the RT-alone patients and 37% of the RT+ETA patients had N3 disease. The median follow-up of surviving patients was 3.38 years, with a range between 0.96 and 5.63 years. RESULTS: One hundred and ninety-four of the 252 (77%) RT+ETA patients received at least 14 doses of the drug. Overall RT protocol compliance rate was 82% in the RT-alone arm and 86% in the RT+ETA arm. No Grade 3 or 4 central nervous system or peripheral neuropathy was observed in the RT+ETA arm. Eighteen percent of the patients developed Grade 1 and 5% developed Grade 2 peripheral neuropathy. Other drug related toxicities included nausea/vomiting (27%), low blood counts (15%), and allergy (9%). Most of these toxicities were Grade 1 and 2. The incidence of severe acute and late radiation effects were similar between the two arms. The 2-year actuarial local-regional control rate (LCR) was 40% for the RT-alone arm and 40% for the RT+ETA arm. Two-year actuarial survival was 41% for the RT-alone arm and 43% for the RT+ETA arm (p = 0.65). Multivariate analyses were performed to investigate the influence of covariates on treatment effects. A strong treatment interaction with N-stage was revealed: LCR (50% vs. 40% at 2 years), RT+ETA improved for patients with N0-2 disease but not for N3 patients (22% for RT+ETA and 40% for RT). Further analyses showed that RT+ETA was more advantageous in N0-1 patients, with a 2-year LCR of 55% for RT+ETA vs. 37% for RT only (p = 0.03). A similar phenomenon was observed when using survival as the end point. CONCLUSION: The results showed that adding Etanidazole to conventional RT produced no global benefit for patients who had advanced head and neck carcinomas. There was a suggested benefit for patients who had N0-1 disease, and that needs to be confirmed by another study.

Late effects of hyperfractionated radiotherapy for advanced head and neck cancer: long-term follow-up results of RTOG 83-13.

PURPOSE: The objective of this study was to examine the incidence of late effects of hyperfractionated radiotherapy for head and neck cancer as a function of the dose delivered, as well as the daily interfraction interval. In addition, we wished to examine the influence of other prognostic factors including age, gender, primary site, T- and N-stage, and overall stage on the late effects of hyperfractionated radiotherapy. METHODS AND MATERIALS: Between 1983 and 1987, 479 patients with advanced head and neck cancer were entered on a Phase ILE/II dose escalation trial of hyperfractionated radiotherapy. They were randomly assigned to receive a dose of 67.2, 72.0, 76.8, or 81.6 Gy, delivered at 1.2 Gy/fraction, twice a day (BID), 5 days/week. Of the 451 analyzable patients, 399 patients who received > or = 64.8 Gy and had a follow-up > 90 days were eligible for this study. Acute and late effects were scored with the RTOG/EORTC late radiation morbidity scoring scheme. For this analysis, patients were subclassified by the actual doses delivered and by an average daily interfraction interval of < or = 4.5 h or > 4.5 h. The incidence of late effects was estimated using a cumulative incidence approach. RESULTS: Fifty-nine patients received 67.2 +/- 2.4 Gy, 119 received 72.0 +/- 2.4 Gy, 98 received 76.8 +/- 2.4 Gy, and 123 received 81.6 +/- 2.4 Gy. The proportion of patients treated with a daily interfraction interval of > 4.5 h was 32, 50, 43, and 71%, respectively. The four treatment groups were well balanced with respect to pretreatment characteristics. The median follow-up was 1.71 years (range: 0.24-9.6) for all evaluable patients and 6.12 years for 85 alive patients. There was no significant difference in the incidence of late effects between the different dose levels. At 5 years, the cumulative incidence of late effects was 17, 14, 20, and 13% for grade 3, and 7, 3, 7, and 5% for grade 4. However, the incidence of late effects differed significantly with respect to daily interfraction interval. The cumulative incidence of grade 4 late effects increased from 6.3% at 2 years to 7.5% at 3 years to 8.0% at 4 years and 8.6% at 5 years with an interval of < or = 4.5 h, while it remained at a constant of 2.0% with an interval of > 4.5 h during the same period (p = 0.0036). Multivariate analysis showed that among the prognostic factors examined, daily interfraction interval of < or = 4.5 h was the only significant independent prognostic factor for the development of grade 3+ or grade 4 late effects (p = 0.0167 and p = 0.0013, respectively). CONCLUSION: Results of this randomized Phase ILE/II trial of hyperfractionated radiotherapy in head and neck cancer showed no apparent dose-response relationship for late effects within the range of 67.2-81.6 Gy. Daily interfraction interval was a significant independent factor for the development of late effects in a multivariate analysis.

Phase II trial of hormonal cytoreduction with megestrol and diethylstilbestrol in conjunction with radiotherapy for carcinoma of the prostate: outcome results of RTOG 83-07.

PURPOSE: RTOG 83-07 is a Phase II randomized protocol designed to compare the efficacy and toxicity of Megestrol vs. Diethylstilbestrol (DES) used as cytoreductive agents prior to and during radiotherapy. The end points of this study include tumor clearance rate, effect on serum testosterone, loco-regional control, disease-free interval, and survival. METHODS AND MATERIALS: Eligible patients were those with histologically confirmed locally advanced adenocarcinoma, clinical Stage B2 (T2B) and C (T3) without regional lymph node involvement, or with lymph node involvement limited to the pelvis. Patients were stratified by clinical stage, histological grade, and nodal status, and were randomized to receive either Megestrol 40 mg three times per day by mouth, or Diethylstilbestrol 1 mg three times per day by mouth. The drugs were started 2 months prior to initiation of radiotherapy and were continued throughout the radiotherapy course. Radiotherapy consisted of 44-46 Gy, 1.8-2 Gy per day to the regional lymphatics, followed by a boost to the prostate consisting of 20-25 Gy, 1.8-2 Gy per day, to a total of 65-70 Gy. Serum testosterone levels were recorded throughout the treatment course. Tumor response was assessed clinically and radiographically (CT scan). From March 1983 through June 1986 a total of 203 patients were accessioned to the study; 198 were analyzable. RESULTS: Correlation of the incidence of drug-related toxicity and treatment arm assignment revealed a significantly higher incidence of complications in the Diethylstilbestrol (DES) arm. The most prominent were the differences in the incidence of gynecomastia (55% vs. 7%) and fluid retention (21% vs. 6%). The incidence of thromboembolic phenomena was comparable (8% vs. 5% in the Megestrol arm). Patients on the DES arm demonstrated a significantly greater median decrease in testosterone level. Correlation of the treatment arm assignment and the rate of tumor regression and the incidence of complete response revealed no significant difference between the arms. At 7 years, 16% of patients on the Megace arm and 21% of patients on the DES arm manifested evidence of local failure. CONCLUSIONS: The results of the study indicate comparable efficacy (using tumor clearance as an end point) of DES and Megestrol. Although DES appears more effective in suppressing testosterone, it is also associated with a higher incidence of drug-related toxicity.

The role of radiation therapy in the multidisciplinary management of recurrent and metastatic breast cancer.

Carcinoma of the breast is a disease that is associated with 10-year recurrence rates of 25% in operable patients with no spread to the axillary nodes and 75% in patients in whom the tumor has extended to the axillary nodes. Locoregional recurrence rates of close to 50% have been reported in patients with Stage III disease. Adjuvant prophylactic postoperative irradiation can reduce locoregional recurrences to less than 10%. When locoregional recurrence occurs after mastectomy, therapeutic irradiation is required. It can achieve tumor control in at least 50% of cases. The best conditions exist when a surgical procedure can achieve gross removal of the recurrent tumor before irradiation and when the fields of irradiation encompass the chest wall and pertinent lymph node areas. The required dose of radiation is lower after excision of the tumor, and the chances of local tumor control are higher. The dose of radiation must be 4500-5000 cGy (fractions of 180-200 cGy) to the subclinical disease and a boost of 1000-1500 cGy added to the known tumor areas. Distant metastatic manifestations must be dealt with for palliative purposes, except in the case of isolated supraclavicular metastasis, where radical irradiation can achieve cure. The need exists for a definition of the role of systemic therapy for locoregional recurrence, and for the development of the optimal integration of systemic chemotherapy and local radiotherapy in patients with locoregional or distant breast cancer recurrences.

Twice-daily fractionation of external irradiation with brachytherapy in bulky carcinoma of the cervix. Phase I/II study of the Radiation Therapy Oncology Group 88-05.

BACKGROUND: Hyperfractionated radiation therapy (HFX), which may permit higher total doses of radiation therapy without increased toxic effects to normal tissues, has been used with pelvic tumors, but its combination with brachytherapy has not been well studied. METHODS: A prospective Phase I/II trial was designed to study HFX with brachytherapy in patients with bulky Stage IB and IIA, IIB, III, and IVA carcinomas of the cervix. HFX doses of 1.2 Gy were administered to the whole pelvis twice daily at 4-6 hour intervals, 5 days per week; the total dose to the whole pelvis was 24-48 Gy. External pelvic irradiation was followed by one or two intracavitary applications to deliver the total minimum dose of 85 Gy at point A and 65 Gy to the lateral pelvic nodes. RESULTS: Eighty-one patients were enrolled in this protocol; 14% had Stage IB, 43% stage II, 38% stage III, and 4% stage IVA carcinomas. Seventy-one patients were evaluable for HFX and brachytherapy; 38 patients received one intracavitary application, and 33 received two applications. Four patients had Grade 3 acute reactions. The cumulative rates of Grade 3-4 late toxicities were 1.9% at 1 year, and 6.3% at 2 and 3 years. Of 80 patients evaluated for response, 80% had complete disappearance of disease. Comparisons with historical rates of late toxicity with standard fractionation (STD) revealed similar results in spite of higher total doses with HFX. Comparisons between historical STD and HFX also revealed equivalent rates of pelvic tumor control, Grade 3-4 toxicity, and survival at 3 years. CONCLUSIONS: Results suggest that combined with brachytherapy, HFX at total parametrial doses 10% above those used with STD was tolerated and at least as effective as STD. Further study with higher doses and extended fields is indicated. Comparisons of long term (5-plus years) survival and late-effects rates with STD versus HFX are planned.

"Compensated" split-course versus continuous radiation therapy of carcinoma of the tonsillar fossa. Final results of a prospective randomized clinical trial of the Radiation Therapy Oncology Group.

The Radiation Therapy Oncology Group conducted a prospective comparison of a compensated split course radiotherapy technique (300 cGy x 10, 3 weeks rest, 300 cGy x 10), versus continuous radiotherapy (200-220 cGy up to 6000-6600 cGy), in 137 evaluable patients. The complete response (CR) was 57% in 63 patients, treated with the split-technique vs 61% in 74 patients submitted to continuous course radiotherapy. The completion of therapy as planned was better in the split-technique, but acute and late tissue reactions were the same. Locoregional control of tumor at 5 years was 25% for split and 28% for continuous therapy. At 7 years this was 25% and 24%, respectively. Absolute survival in the split-course patients tended to be lower than in the continuous group, but when the sample of patients was enlarged by the addition of cases from similar trials of nasopharynx and base of tongue lesions, the survival difference was eliminated. On the basis of the results of this study we conclude that the stated compensated split-course technique gives equal clinical results as conventional continuous therapy, with the advantage of requiring fewer radiation fractions, and less burden on the patient and therapy facilities.

Radiation therapy of cervical cancer. New developments.

BACKGROUND: Invasive carcinoma of the cervix will be diagnosed in 13,500 women in the USA in 1992, of which a significant number will require radiation therapy. METHODS: Based on available information one can define optimal workup and staging, optimal radiation therapy, and the possibilities of interaction of radiation with surgery and chemotherapy in these cases. RESULTS: The pelvic tumor control rates achieved with radiation therapy can reach close to 100% in subclinical tumor (Stage IA), range from 91-98% in Stage IB, but can be as low as 25-34% in Stage IVA. Survival is affected by the presence of metastatic tumor deposits outside the pelvis, which when present in the inguinal or para-aortic nodal regions can be controlled with irradiation. The 5-year survival can be as high as 92% for carcinoma of the cervix Stage I and as low as 28% in Stage III. CONCLUSIONS: Radiation therapy can control the tumor in the pelvis in approximately 90% of patients with Stage I carcinoma of the cervix, but in only approximately 25% in patients with Stage IV disease. To increase tumor control, research is being conducted combining irradiation with chemotherapy, radiation sensitizers, hyperthermia, and new modalities such as neutron irradiation. Prophylactic para-aortic node irradiation is justified in some stages of the disease.

Interruptions adversely affect local control and survival with hyperfractionated radiation therapy of carcinomas of the upper respiratory and digestive tracts. New evidence for accelerated proliferation from Radiation Therapy Oncology Group Protocol 8313.

Hyperfractionated radiation therapy (HFX) attempts to overcome tumor proliferation during treatment by permitting higher total doses in the same overall time as standard fractionation. Whereas interruptions, including splits, reduce local control with standard fractionation in carcinoma of the upper respiratory and digestive tracts, HFX might compensate for interruptions. Patients were randomized to receive total doses of 6720, 7200, 7680, and 8160 cGy, using 120 cGy twice daily, 5 days per week. Those analyzed received +/- 4% of assigned total dose and lived 90 days or more. Treatment was completed within 5 days of the time specified for each treatment arm in 233 patients; 48, 80, and 131 patients had delays 14, 10, and 5 days or more, respectively. Locoregional control and survival were significantly (P less than or equal to 0.03) reduced with delays of 5 days or more when corrected for prognostic factors. Late effects of radiation therapy were not affected by interruptions. These data support the hypothesis that proliferation (possibly accelerated) of tumor clonogens during treatment influences the outcome.

Logistics in designing clinical trials for etanidazole (SR 2508): an RTOG experience.

In a Phase II study of etanidazole (SR 2508), the dose of 17 x 2 g/m2 (total drug dose: 34 g/m2) was tested in 33 patients and the toxicity was deemed acceptable. A Phase III trial is now in progress comparing conventional radiotherapy with conventional radiotherapy plus etandizole (2 g/m2 i.v. 30 to 60 min before radiotherapy each Monday, Wednesday, and Friday to 34 g/m2 in 17 doses) in patients with unresectable head and neck carcinomas. A recent analysis showed only 14.7% grade 1 and 3.9% Grade 2 peripheral neuropathy. In the initial study design, 133 evaluable patients per treatment arm could achieve an 80% level of power of detecting a 15% difference in local-regional control rates between the radiotherapy arm (25% local-regional control at 2 years) and the radiotherapy plus etanidazole arm (assuming a 40% rate). Allowing for 20 ineligible cases in each arm, a total number of 306 was required. An interim analysis showed that 27% of the patients assigned to radiotherapy plus etanidazole are receiving less than 14 doses of the drug. It is assumed that less than 14 drug doses will not produce any therapeutic gain, therefore, a true 40% local-regional control rate in the radiotherapy plus etanidazole arm will be observed as a 36% rate when analyzed by assigned treatment. Using this information, the study was modified to have an 80% level of power in detecting a difference between a 25% local-regional control rate in the radiotherapy group and a 36% rate in the radiotherapy plus etanidazole group. Allowing for a 10% patient ineligibility rate, 518 patients are required. With 12 patients entered per month, it is estimated that patient accrual to this study will continue through October 1991.

The effect of local-regional control on distant metastatic dissemination in carcinoma of the head and neck: results of an analysis from the RTOG head and neck database.

A retrospective analysis of the effect of local control on the development of distant metastases was performed in 2648 patients with carcinoma of the head and neck selected from the RTOG database. The 5-year time-adjusted incidence of distant metastases was 21% for patients who were in local-regional control at 6 months after the start of treatment, compared to 38% for local-regional failure patients (p less than 0.001). The incidence of distant metastases detected between the interval of 6 months to 2.5 years after treatment was significantly increased in patients with tumors of the oral cavity, oropharynx, supraglottic larynx, and glottis who developed local-regional failure within this time period, compared to those who remained locally controlled (19% distant metastases for local-regional failure vs 7% for local-regional control (p less than 0.001)). In contrast, there as no difference in the incidence of distant metastases in patients with carcinoma of the nasopharynx or hypopharynx regardless of the local-regional disease status. A Cox proportional hazards regression analysis demonstrated that local-regional control was the most significant variable affecting the development of distant metastases, followed by tumor site, N-stage, and T-stage. For all tumor sites, except for the hypopharynx and nasopharynx, improvements in local-regional control are likely to improve survival. Tumors of the hypopharynx and nasopharynx have a higher probability of micro-metastatic dissemination at the time of initial diagnosis, and until effective methods to treat disseminated disease are developed, the effect of local control on survival will not be readily discerned.

ASTRO plenary: interfraction interval is a major determinant of late effects, with hyperfractionated radiation therapy of carcinomas of upper respiratory and digestive tracts: results from Radiation Therapy Oncology Group protocol 8313.

A prospective, randomized, multi-institutional, Phase I(LE)/II trial of HFX was conducted by the RTOG between 1983 and 1987. Patients with histologically proven, inoperable squamous cell carcinoma of the upper respiratory and digestive tracts stratified by site, nodal status, and performance status, were assigned to one of three arms, were assigned to one of three arms, 67.2 Gy, 72.0 Gy, or 76.8 Gy. Fractions of 1.2 Gy were given twice daily, 5 days per week: intervals of 4 to 8 hours were permitted between fractions. After acceptable rates of acute normal tissue effects were found, the randomization was changed to evaluate a new higher total dose, 81.6 Gy. Of 479 patients entered, 447 were analyzed, 63 on 67.2 Gy, 129 on 72.0 Gy, 117 on 76.8 Gy, and 138 on 81.6 Gy. The treatment arms were well balanced with respect to pretreatment characteristics. Acute reactions consisted almost entirely of pseudomembranous inflammation. "Severe" (Grade 3) acute reactions were reported in 33% to 41% and grade 4 reactions were found in 0 to 3% of patients, with no differences in frequencies among the four arms. Toxicities that developed or persisted beyond 90 days after the first treatment (408 patients evaluable greater than 90 days) did not differ among arms: grade 3+ reactions occurred in 10% to 14%, and grade 4+ effects (necroses) were reported in 5% at 67.2 Gy, 3% at 72.0 Gy, 7% at 76.8 Gy, and 2% at 81.6 Gy. Grade 3+ acute reactions occurred in 40% of patients when the interfraction interval was less than or equal to 4.5 hours versus 31% with greater than 4.5 hours (p = .03). Interfraction intervals less than or equal to 4.5 hours were associated with higher frequencies of grade 4+ late effects in all four arms, 8% of 197 patients with less than or equal to 4.5 hours versus 1% of 211 patients with greater than 4.5 hours. Estimates of late toxicity at 1, 2, and 3 years were 5.5%, 9.8%, and 15.4% with intervals less than or equal to 4.5 hours, versus 1.7% at all three periods for greater than 4.5 hours (p = .006). Local-regional control at 2 years was 25% for the assigned dose of 67.2 Gy compared to 43% to 45% for the three higher doses (p = .01), but a similar comparison for survival showed no significant difference (p = .35). There was no evidence for an effect of interfraction interval on either local-regional control (p = .38) or survival (p = .28).(ABSTRACT TRUNCATED AT 400 WORDS)

Elapsed treatment days--a critical item for radiotherapy quality control review in head and neck trials: RTOG report.

For all randomized trials since 1978, the Radiation Therapy Oncology Group has required the study chairman for radiation therapy to review the treatment given to each patient. The chairman scores the compliance of the treatment borders, total dose, fraction, and total elapsed time relative to the protocol prescription at the primary site, regional nodes, and any critical structure. The individual parameters are then considered together to derive an "overall" treatment score. For two RTOG head and neck studies in patients with moderately and very advanced carcinomas, the "overall" treatment was classified as unacceptable if the treatment at primary was scored unacceptable with respect to dose, fractionation, and field borders. However, prolonged elapsed treatment was not included. Analysis of these studies with 426 evaluable patients was performed to assess the relationship of unacceptable "overall" treatment compliance with outcome. Patients with prolonged treatment elapsed days (14 days beyond the protocol prescription) exhibited significantly poorer loco-regional control (13% vs. 27% at 3 years with p = .007) and absolute survival (13% vs. 26% at 3 years with p = .01). As a result, the criteria for unacceptable "overall" treatment were revised to include prolonged elapsed treatment days. Further multivariate analyses showed the revised criteria identified patients with significantly poorer loco-regional control and absolute survival even after adjusting for other prognostic factors.