Arnold M. Markoe

Preliminary report of toxicity following 3D radiation therapy for prostate cancer on 3DOG/RTOG 9406

PURPOSE A prospective Phase I dose escalation study was conducted to determine the maximally-tolerated radiation dose in men treated with three-dimensional conformal radiation therapy (3D CRT) for localized prostate cancer. This is a preliminary report of toxicity encountered on the 3DOG/RTOG 9406 study. METHODS AND MATERIALS Each participating institution was required to implement data exchange with the RTOG 3D quality assurance (QA) center at Washington University in St. Louis. 3D CRT capabilities were strictly defined within the study protocol. Patients were registered according to three stratification groups: Group 1 patients had clinically organ-confined disease (T1,2) with a calculated risk of seminal vesicle invasion of < 15%. Group 2 patients had clinical T1,2 disease with risk of SV invasion > or = 15%. Group 3 (G3) patients had clinical local extension of tumor beyond the prostate capsule (T3). All patients were treated with 3D techniques with minimum doses prescribed to the planning target volume (PTV). The PTV margins were 5-10 mm around the prostate for patients in Group 1 and 5-10 mm around the prostate and SV for Group 2. After 55.8 Gy, the PTV was reduced in Group 2 patients to 5-10 mm around the prostate only. Minimum prescription dose began at 68.4 Gy (level I) and was escalated to 73.8 Gy (level II) and subsequently to 79.2 Gy (level III). This report describes the acute and late toxicity encountered in Group 1 and 2 patients treated to the first two study dose levels. Data from RTOG 7506 and 7706 allowed calculation of the expected probability of observing a > or = grade 3 late effect more than 120 days after the start of treatment. RTOG toxicity scores were used. RESULTS Between August 23, 1994 and July 2, 1997, 304 Group 1 and 2 cases were registered; 288 cases were analyzable for toxicity. Acute toxicity was low, with 53-54% of Group 1 patients having either no or grade 1 toxicity at dose levels I and II, respectively. Sixty-two percent of Group 2 patients had either none or grade 1 toxicity at either dose level. Few patients (0-3%) experienced a grade 3 acute bowel or bladder toxicity, and there were no grade 4 or 5 toxicities. Late toxicity was very low in all patient groups. The majority (81-85%) had either no or mild grade 1 late toxicity at dose level I and II, respectively. A single late grade 3 bladder toxicity in a Group 2 patient treated to dose level II was recorded. There were no grade 4 or 5 late effects in any patient. Compared to historical RTOG controls (studies 7506, 7706) at dose level I, no grade 3 or greater late effects were observed in Group 1 and Group 2 patients when 9.1 and 4.8 events were expected (p = 0.003 and p = 0.028), respectively. At dose level II, there were no grade 3 or greater toxicities in Group 1 patients and a single grade 3 toxicity in a Group 2 patient when 12.1 and 13.0 were expected (p = 0.0005 and p = 0.0003), respectively. Multivariate analysis demonstrated that the relative risk of developing acute bladder toxicity was 2.13 if the percentage of the bladder receiving > or = 65 Gy was more than 30% (p = 0.013) and 2.01 if patients received neoadjuvant hormonal therapy (p = 0.018). The relative risk of developing late bladder complications also increased as the percentage of the bladder receiving > or = 65 Gy increased (p = 0.026). Unexpectedly, there was a lower risk of late bladder complications as the mean dose to the bladder and prescription dose level increased. This probably reflects improvement in conformal techniques as the study matured. There was a 2.1 relative risk of developing a late bowel complication if the total rectal volume on the planning CT scan exceeded 100 cc (p = 0.019). CONCLUSION Tolerance to high-dose 3D CRT has been better than expected in this dose escalation trial for Stage T1,2 prostate cancer compared to low-dose RTOG historical experience. With strict quality assurance standards and review, 3D CRT can be safely studied in a co

The Prognostic Significance of Surgical Staging for Carcinoma of the Endometrium

This study is based on a retrospective review of 156 patients with endometrial carcinoma from 1978 through 1984 who underwent primary surgical evaluation. All cases were retrospectively restaged using the newly adopted FIGO surgical staging. The preoperative FIGO clinical stage distribution for this study was as follows: 121 (77.6%) Stage I, 22 (14.1%) Stage II, 5 (3.2%) Stage III, 2 (1.3%) Stage IV, and 6 (3.8%) unstaged patients. Most patients had TAH-BSO with a collection of peritoneal washings and retroperitoneal lymph node sampling. Surgical staging revealed 122 (78.2%) Stage I, 9 (5.8%) Stage II, 12 (7.7%) Stage III, and 13 (8.3%) Stage IV patients. Surgery upstaged 12.4% of clinical Stage I. In clinical stage II, 59.0% were downstaged while 27.3% were upstaged. For clinical Stage III, 60.6% were upstaged, but no downstaging occurred. No change in stage occurred for clinical Stage IV patients. Ninety-seven surgically staged patients received no adjuvant therapy. The remaining 59 patients had adjunctive treatment which consisted of radiotherapy (59.3%), hormonal therapy (25.4%), chemotherapy (5.1%), or combined modality treatment (10.2%). All patients were followed until death or a minimum of 5 years (60-139 months; median, 82 months) with the exception of 13 patients who were lost to follow-up (2-58 months; median, 34 months). Five-year survival by clinical staging was as follows: 86.2% for Stage I, 85.9% for Stage II, and 0% for Stage III and IV. Five-year survival by surgical staging was 90.6% for Stage I, 85.7% for Stage II, 58.3% for Stage III, and 0% for Stage IV. The 13 patients who were lost to follow-up were censored in all survival analyses at the time of last contact. Stepwise regression analysis using a parametric proportional hazards model identified surgical stage as the most significant prognostic factor (P = 0.02). Univariate analysis showed that patients with surgical Stage IC had significantly worse prognosis (75.0%, 5 years) than those in surgical Stage IA (93.8% 5 YS) or IB (95.4% 5 years). In summary, this study demonstrates that surgical staging as recommended by FIGO is indicated to accurately determine the initial extent of disease in endometrial carcinoma. In addition, surgical staging is the strongest predictor of survival. Deep myometrial invasion appears to be a significant independent prognostic factor within surgical Stage I. The role of adjunctive radiotherapy in Stage I disease awaits the results from an ongoing multi-institutional, prospectively randomized trial.

Interim report of toxicity from 3D conformal radiation therapy (3D-CRT) for prostate cancer on 3DOG/RTOG 9406, level III (79.2 Gy).

PURPOSE A prospective Phase I dose escalation study was conducted to determine the maximally tolerated radiation dose in men treated with three-dimensional conformal radiotherapy (3D-CRT) for localized prostate cancer. This is a preliminary report of toxicity at Level III (79.2 Gy) on 3D Oncology Group/Radiation Therapy Oncology Group (RTOG) 9406. METHODS AND MATERIALS Between November 26, 1996 and October 1, 1998, 173 patients with clinically organ-confined prostate cancer (T1 and T2) were accrued to a Level III dose of 79.2 Gy. One hundred sixty-nine patients were available for analysis of toxicity. Patients were registered to two groups according to the risk of seminal vesicle invasion (SVI) on the basis of presenting PSA and Gleason score. Group 1 patients had a calculated risk of SVI <15%, and Group 2 patients had a risk of SVI > or = 15%. For Group 1 patients, the planning target volume (PTV) margins were 5-10 mm around the prostate only. For Group 2 patients, the same margins were applied to the prostate and seminal vesicles (PTV(1)) for the initial 55.8 Gy; then treatment volume was reduced to the prostate only (PTV(2)). To reduce the rectal dose on dose Level III, the minimum PTV dose was limited to 73.8 Gy, whereas the minimum gross target volume dose was 79.2 Gy, both in 44 fractions. The incidence of > or = 3 Grade late effects was compared to that in a similar group of patients treated on RTOG 7506 and 7706 studies. RESULTS Acute tolerance to 79.2 Gy was excellent with no patients experiencing > or = Grade 3 acute toxicity. The acute toxicity rate was comparable to that reported for previous lower dose levels. With the median follow-up of 3.3 years (range: 0.4-4.4 years), a total of 4 patients (2.4%) experienced Grade 3 late toxicity, three cases of which were related to the bladder, and one related to the rectum. There were no Grade 4 or 5 late complications noted during the period of observation. These results are also comparable to those reported at dose Levels I and II. The expected incidence of > or = 3 Grade 3 late toxicity was calculated using historical data from two previous RTOG prostate cancer trials, 7506 and 7706. The calculated risk accounted for the difference in follow-up duration between patients in this study and the historical experience. The observed rate of > or = Grade 3 late effects for Group 1 (two cases) is significantly lower (p = 0.0002) than the 17.6 cases that would have been expected from the historical control. The observed rate for Group 2 (two cases) was also significantly lower (p = 0.0037) than the 12.1 cases expected. CONCLUSION Based on excellent tolerance of 3D-CRT for stages T1 and T2 prostate cancer, further biological dose escalation has been pursued to Levels IV and V, 74 Gy and 78 Gy, respectively, at 2 Gy per day, in an attempt to reduce the total treatment duration. This trial has closed. A Phase III comparative RTOG trial is being developed to determine whether high-dose 3D-CRT improves efficacy.

Influence of an oligodendroglial component on the survival of patients with anaplastic astrocytomas: A report of radiation therapy oncology group 83-02

PURPOSE Seven percent of patients with high grade gliomas enrolled in RTOG 83-02 had mixed astrocytoma/oligodenroglial elements on central pathology review. It has often been assumed that the most aggressive histologic component of a tumor determines biologic behavior; however in this trial, the survival of patients who had mixed glioblastomas/oligodenrogliomas was significantly longer than that of patients with pure glioblastomas (GBM). We therefore evaluated the effect of an oligodendroglial component on the survival of patients who had anaplastic astrocytomas (AAF) treated in the same trial. METHODS AND MATERIALS One hundred nine patients who had AAF and 24 patients with mixed AAF/oligodendrogliomas (AAF/OL) were enrolled in a Phase I/II trial of randomized dose-escalation hyperfractioned radiotherapy plus BCNU. AAF/OL patients were older and more likely to have had more aggressive surgery than AAF patients. Other pretreatment characteristics were balanced between groups, as was assigned treatment. RESULTS The median survival time for AAF was 3.0 years versus 7.3 years for AAF/OL (p = 0.019). In a multivariate analysis, adjusting for extent of surgical resection and age, an oligodendroglial component was an independent prognostic factor for survival. CONCLUSION The results support the concept that AAFs with an oligodendroglial component have a better prognosis than pure AAF tumors, similar to the effect seen among patients with glioblastoma multiforme tumors. This better survival outcome should be taken into consideration in the design and stratification of future trials. Additionally, in contrast to patients with GBMs, patients who have AAF/OL have the potential for prolonged survival; therefore, late sequelae of treatment (both radiation and chemotherapy) must be weighed more heavily in the benefits to risks analysis.

Recurrence of Posterior Uveal Melanoma after 60Co Episcleral Plaque Therapy

The authors analyzed the clinical and follow-up data on 277 selected patients with primary choroidal or ciliochoroidal melanoma who were treated with 60Co plaque radiotherapy between 1976 and 1982. Local recurrence of the irradiated melanoma developed in 39 (14%) patients during the follow-up interval. The 5-year tumor recurrence rate (Kaplan-Meier) was estimated to be 12%. Multivariate prognostic factor analysis (Cox proportional hazards modeling) identified the largest linear tumor dimension and proximity of the posterior margin of the tumor to the optic nerve head as predictors of recurrence. The 5-year survival rate of patients whose tumors recurred (58%) was significantly (log-rank test P = 0.0023) worse than that of patients whose tumor remained clinically controlled (82%).

Long-term toxicity following 3D conformal radiation therapy for prostate cancer from the RTOG 9406 phase I/II dose escalation study.

PURPOSE To update the incidence of late toxicity of RTOG 9406, a three-dimensional conformal radiation therapy (3DCRT) dose escalation trial for prostate cancer. METHODS AND MATERIALS A total of 1,084 men were registered to this Phase I/II trial of 3DCRT (eligible patients, 1,055). The dose for level I was 68.4 Gy; 73.8 Gy for level II; 79.2 Gy for level III; 74 Gy for level IV; and 78 Gy for level V. Patients in levels I to III received 1.8 Gy/fraction, and those in levels IV to V received 2.0 Gy/fraction. Disease group I patients were treated at the prostate only, group 2 patients were treated at the prostate and at the seminal vesicles with a prostate boost, and group 3 patients were treated at the prostate and seminal vesicles. The median follow-up period for surviving patients was 6.1 y (level V) to 12.1 y (level I). RESULTS The incidence rates of RTOG grade 3 or less gastrointestinal or genitourinary toxicity were 3%, 4%, 6%, 7%, and 9% in group 1 and 6%, 2%, 6%, 9%, and 12% in group 2 at dose levels of I, II, III, IV, and V, respectively. In group 1, level V patients had a higher probability of grade 2 late or greater gastrointestinal or genitourinary toxicity than those in levels I, II, and III (hazard ratio [HR] = 1.93, p = 0.0101; HR = 2.29, p = 0.0007; HR = 2.52, p = 0.0002, respectively). In group 2, dose level V patients had a higher probability of grade 2 or greater late gastrointestinal or genitourinary toxicity than those in dose levels II, III, and IV (HR = 2.61, p = 0.0002; HR = 2.22, p = 0.0051; HR = 1.60, p = 0.0276, respectively). CONCLUSIONS Tolerance to high-dose 3DCRT remains excellent. There is significantly more grade 2 or greater toxicity with a dose of 78 Gy at 2 Gy/fraction than with 68.4 Gy to 79.2 Gy at 1.8 Gy/fraction and with 74 Gy at 2 Gy/fraction.

Intraoperative Echographic Localization Of Iodine 125 Episcleral Radioactive Plaques For Posterior Uveal Melanoma

Purpose Plaque radiotherapy has been reported to have a higher relapse rate than charged-particle radiotherapy for posteriorly located uveal melanomas, which also are more technically difficult to localize accurately. The authors used intraoperative echography in patients with posterior uveal melanoma to determine the rate of inaccurate localization of iodine 125 (125I) episcleral plaques using standard localization techniques. Methods The authors reviewed the records of 29 consecutive patients with medium-sized posterior uveal melanomas who underwent 125I episcleral plaque radiotherapy with intraoperative echographic verification of plaque placement. Results After careful plaque placement using standard localization techniques, 4 of 29 plaques (14%) did not cover at least one tumor margin. All four of these plaques were associated with posterior tumors with at least one margin posterior to the temporal arcades. Two (7%) additional juxtapapillary plaques were displaced away from the sclera by the optic nerve. In all six cases, it was possible to immediately reposition the plaque to achieve coverage of all tumor margins. Conclusions Placement of 125I episcleral radioactive plaques for posteriorly located uveal melanomas using standard localization techniques occasionally results in suboptimal plaque positioning. Intraoperative echography can identify plaques that are localized poorly and allows immediate adjustment to achieve optimal plaque positioning.

Preliminary evaluation of low-grade toxicity with conformal radiation therapy for prostate cancer on RTOG 9406 dose levels I and II.

PURPOSE To evaluate the rates of low-grade late effects in patients treated for prostate cancer on Radiation Therapy Oncology Group (RTOG) 9406. MATERIALS AND METHODS Between August 1994 and September 1999, 424 patients were entered on this dose escalation trial of three-dimensional conformal radiation therapy (3D-CRT) for localized adenocarcinoma of the prostate at doses of 68.4 Gy (level I) and 73.8 Gy (level II). We have previously reported Grade 3 or greater late toxicity of patients treated on the first two dose levels of this trial. This analysis examines the distribution of all late toxicities in these patients. All radiation prescriptions were a minimum dose to a planning target volume (PTV). Patients were stratified according to clinical stage and risk of seminal vesicle invasion (SVI) based upon Gleason score and presenting prostate-specific antigen. Group 1 includes patients with T1,2 disease with SVI risk < 15%, and Group 2 includes patients with T1,2 disease with SVI risk > 15%. Group 3 patients had T3 disease. Average months at risk after completion of therapy ranged from 21.4 to 40.1 months for patients treated at dose level I and 10.0 to 34.2 months for patients at dose level II. The frequency of all grades of late effects was compared with a similar group of patients treated in RTOG studies 7506 and 7706 with adjustments made for the interval from completion of therapy. The RTOG toxicity scoring scales for late effects were used for grading. RESULTS The rate of Grade 3 or greater late toxicity continues to be low compared with RTOG historical controls. No Grade 4 or 5 late sequelae were reported in any of the 393 evaluable patients during the period of observation. The frequency of patients free of any complications was lower in RTOG 9406 than in historical controls. In the 73 Group 1 patients treated on dose level 1, there were 24 patients without sequelae compared with an expected rate of 39.7 (p = 0.013), and in 80 Group 3 patients at dose level II there were 24 patients without sequelae when 56.2 were expected (p < 0.0001). Other groups treated at these dose levels demonstrated a nonsignificant reduction in the rate of patients free of any side effects. These data suggest that the reduction in high-grade morbidity may be related to a shift of complications to lower grades. CONCLUSIONS Morbidity of 3D-CRT in the treatment of prostate cancer is low. It is important to continue to closely examine late effects in patients treated in RTOG 9406. The primary objective of dose escalation without an increase rate of >/= Grade 3 sequelae has been achieved. However, the reduction in Grade 3 complications may have resulted in a higher incidence of Grade 1 or 2 late effects. Because Grade 2 late effects may have a significant impact on a patients quality of life, it is important to reduce these complications as much as possible. Clinical trials should use quality-of-life measures to determine that trade-offs between severity and rates of toxicity are acceptable to patients.

Reasons for Enucleation after Plaque Radiotherapy for Posterior Uveal Melanoma:Clinical Findings

A review of 1019 patients with posterior uveal melanomas who were treated with episcleral plaque radiotherapy showed that 59 (6%) required enucleation of the affected eye. Seventeen of the enucleations were done within 1 year, 30 within 2 years, and 55 within 5 years. The enucleated eyes had been treated with a cobalt-60 plaque in 39 cases, a ruthenium-106 plaque in 13 cases, an iodine-125 plaque in four cases, and an iridium-192 plaque in three cases. The primary reasons for enucleation included tumor regrowth in 30 cases (51%), neovascular glaucoma in 18 (31%), patient request in five (8%), scleral melting in four (7%), painful bullous keratopathy in one (2%), and hemolytic glaucoma in one (2%). The time interval from plaque treatment to eventual enucleation averaged 29 months. Tumor regrowth requiring enucleation was detected clinically an average of 28 months after treatment. In these cases the average radiation dose to the tumor apex was 7700 cGy and to the tumor base 36,000 cGy. Uncontrollable neovascular glaucoma occurred an average of 38 months after plaque radiotherapy and, most commonly, after cobalt-60 plaques were used. Eyes with plaque-induced scleral melting eventually required enucleation after an average of 10 months. In all cases of scleral melting, the tumor was ciliochoroidal.

Intraoperative echographic localization of iodine-125 episcleral plaque for brachytherapy of choroidal melanoma.

PURPOSE To report intraoperative echographic localization of iodine-125 episcleral plaque for brachytherapy of choroidal melanoma. METHODS In a retrospective study, 117 eyes with medium-sized choroidal melanoma in 117 patients not participating in the Collaborative Ocular Melanoma Study underwent iodine-125 episcleral plaque radiotherapy with intraoperative echographic verification of plaque placement between January 1992 and December 1998 at the Bascom Palmer Eye Institute. RESULTS After initial plaque placement using standard localization techniques, intraoperative echography demonstrated satisfactory tumor-plaque apposition in 76% of eyes (89 of 117). In the 28 eyes (28 of 117, 24%) that required repositioning of the plaque, the extent of misplacement was less than 1 mm in 10 eyes, 1.1 to 3.0 mm in six eyes, and greater than 3 mm in eight eyes. Two eyes had tilting of the plaque, and in two additional eyes, although the plaque covered all tumor margins, the centration was considered suboptimal. Repositioning was necessary in 1 eye with an anteriorly located tumor (1 of 13, 7.7%) and in 20 eyes with peripapillary or posterior pole tumors (20 of 67, 26.3%). Anteriorly located tumors required plaque repositioning significantly less frequently than did posteriorly located tumors (P = .041). Misalignment involved one tumor margin in 23 eyes and two margins in five eyes. The most commonly misaligned margins were the lateral (35%) and posterior margins (26%). In no case was an anterior marginal misalignment documented. At a mean follow-up of 37 months, no tumor-related death or metastatic disease was noted. Two of the 117 patients (1.7%) had local tumor recurrence and underwent enucleation. CONCLUSIONS Intraoperative echography is an effective adjunct for localization and confirmation of tumor-plaque relationship. This technique facilitates the identification and correction of suboptimal plaque placement at the time of surgery, potentially minimizing treatment failures.