Dosimetric comparison of pre-planned and or-planned prostate seed brachytherapy

PURPOSE

To compare the dosimetry of the traditional two step procedure (volume study + treatment planning several weeks later) with that of an OR-based single procedure in which these two steps follow one another immediately. Computer generated treatment plans were used in both procedures.

METHODS AND MATERIALS

Several dosimetric parameters relating to target coverage were obtained from dose volume histograms of CT-based evaluation plans developed either 1 or 3 days following seed implantation. A total of 113 patients with early stage (T1C, T2A) prostate cancer were used for this retrospective study.

RESULTS

The fraction of target (prostate) covered by the prescription dose (144 Gy), 90% of the prescription dose (115 Gy), and the dose encompassing 90% of the target in the evaluation plan were all statistically significantly improved for OR-based plans compared to pre-planned cases.

CONCLUSION

In our hands, there is a small but significant improvement in dose coverage of the prostate when the ultrasound volume study and treatment planning are combined into a single procedure.

Clinicopathologic study of forty-four histologically pure supratentorial oligodendrogliomas

Few studies in recent years have specifically focused on pure oligodendroglial neoplasms. We retrospectively reviewed the clinicopathologic features of 44 patients with supratentorial oligodendroglioma diagnosed over a 19-year period (1974 to 1993). The study group consisted of 44 patients (age range, 8 to 69 years; median, 42 years), including 31 males. Thirty-one initially resected tumors (70%) were low grade and 13 (30%) were high grade (anaplastic). Using the St Anne-Mayo criteria for astrocytic tumors, 19 tumors (43%) were grade 2, 17 (39%) were grade 3, and 8 were (18%) grade 4. Histologic features of the tumors at initial resection included prominent nucleoli (N = 18, 41%), vascular proliferation (N = 9, 20%), necrosis (N = 6, 14%), and microcystic degeneration (N = 23, 52%). Nuclear atypia was graded as mild in 22 tumors (50%), moderate in 18 (41%), and marked in four (9%). The highest mitosis counts ranged from 0 to 10 mitotic figures (MF)/10 high-power fields (HPF) (mean, 2.4). Twelve patients (27%) had four or more MF/10 HPF. Initial surgery included gross total resection in 10 patients, subtotal resection in 16 patients, and biopsy in 14 patients. Thirty-one patients received adjuvant radiotherapy and 15 received chemotherapy. MIB-1 labeling indices ranged from 0 to 42.3 (median, 1.2 [low grade tumor median, 0.5; anaplastic tumor median, 6.2]). p53 immunostaining was observed in 18 of 43 stained tumors (41%). Overall, 5- and 10-year survival rates were 71% and 63%, respectively. The entire group had a median follow-up of 5.2 years. Age greater than 45 years (P = .02), mitosis counts of > or =4 MF/10 HPF (P = .0004), and MIB-1 labeling indices <2 (P = .03) were independent predictors of survival (Kaplan-Meier analysis). MIB-1 labeling indices <2 (P = .0009) was an independent predictor of disease-free survival. Low cell density (P = .04) and low histologic grade (P = .03) show trends with regard to being associated with longer survival. In conclusion, older patients (>45 years) or patients with tumors with an increased rate of cell proliferation generally have a worse prognosis. Although tumors of high histologic grade generally have a worse survival, the correlation was not statistically significant.

Short-course intensity-modulated radiotherapy for localized prostate cancer with daily transabdominal ultrasound localization of the prostate gland

PURPOSE

To present our initial observations on the clinical feasibility of the technique of short-course intensity-modulated radiotherapy (SCIM-RT) in the treatment of localized prostate cancer coupled with daily transabdominal ultrasound localization of the prostate. The proposed regimen consists of a hypofractionated course delivering 70.0 Gy in 28 fractions.

METHODS AND MATERIALS

The treatment data of the first 51 patients treated with SCIM-RT at the Cleveland Clinic Foundation are presented in this report. The technique consisted of intensity-modulated radiotherapy using 5 static fields (anterior, 2 laterals, and 2 anterior obliques). Inverse plans were generated by the Corvus treatment-planning system. The treatment delivery was performed with a Varian Dynamic Multileaf Collimator. The target was the prostate only in patients with low-risk disease (stage T1-T2, pretreatment PSA < or =10, and biopsy Gleason < or =6). The target was the prostate and seminal vesicles in patients with high-risk disease (stage T3 or pretreatment PSA > 10 or biopsy Gleason > or =7). In the Corvus planning system, the margins for the planning target volume (PTV) were 4 mm posteriorly, 8 mm laterally, and 5 mm in all other directions. A total of 70.0 Gy (mean prostate dose approximately 75 Gy) was prescribed in all cases at 2.5 Gy per fraction to be delivered in 28 fractions over 5 1/2 weeks. Prior to treatment delivery, the patients were minimally immobilized on the treatment table, only using lasers and skin marks. The location of the prostate gland was verified daily with the BAT transabdominal ultrasound system and patient position adjustments were performed accordingly. Fifty-one patients completed therapy between October 1998 and May 1999.

RESULTS

The dose was prescribed to an isodose line ranging from 82.0% to 90.0% (mean: 87.2%). The range of the individual prostate mean doses was 73.5 to 78.5 Gy (average: 75.3 Gy). The range of the maximum doses was 77.4 to 84.5 Gy (average: 80.2 Gy). The range of the minimum doses was 64.3 to 69.2 Gy (average: 67.5 Gy). The average time for the prostate position verification and alignment of the prostate using the BAT system was 5 minutes. The entire localization/alignment process was performed by the radiation therapists. The daily alignment images were automatically saved and reviewed by the radiation oncologist, a process similar to port film checks. The total treatment (beam-on) time was around 6 minutes using the 5 static intensity-modulated fields. The mean and standard deviation (SD) of bladder volumes irradiated to 50, 60, and 70 Gy were as follows: 24 +/- 11 cc, 16 +/- 8 cc, and 8 +/- 6 cc. The mean and SD of rectal volumes irradiated to 50, 60, and 70 Gy were as follows: 22 +/- 11 cc, 15 +/- 8 cc, and 7 +/- 5 cc. The RTOG acute bladder toxicity scores were as follows: 0 in 3 (6%), 1 in 38 (74%), and 2 in 10 (20%). The RTOG acute rectal toxicity scores for SCIM-RT cases were as follows: 0 in 10 (20%), 1 in 33 (65%), and 2 in 8 (16%). No Grade 3 or 4 acute toxicities were observed.

CONCLUSION

The delivery of our proposed hypofractionated-schedule SCIM-RT in combination with daily target localization/alignment with the BAT transabdominal ultrasound system is clinically feasible. It is an alternative method of dose escalation in the treatment of localized prostate cancer. The proposed schedule would significantly increase convenience to patients due to the decrease in overall treatment time. Preliminary acute toxicity results are extremely encouraging. Long-term follow-up is needed to assess late complications and treatment efficacy.

Higher than standard radiation doses (> or =72 Gy) with or without androgen deprivation in the treatment of localized prostate cancer

PURPOSE

To study the effect on biochemical relapse-free survival (bRFS) and clinical disease-free survival of radiation doses delivered to the prostate and periprostatic tissues for localized prostate cancer.

METHODS AND MATERIALS

A total of 1041 consecutive localized prostate cancer cases treated with external beam radiotherapy (RT) at our institution between 7/86 and 2/99 were reviewed. All cases had available pretreatment parameters including pretreatment prostate-specific antigen (iPSA), biopsy Gleason score (bGS), and clinical T stage. The median age was 69 years. Twenty-three percent of cases (n = 238) were African-American. The distribution by clinical T stage was as follows: T1 in 365 cases (35%), T2 in 562 cases (54%), and T3 in 114 cases (11%). The median iPSA level was 10.1 ng/ml (range: 0.4-692.9). The distribution by biopsy Gleason score (bGS) was as follows: < or =6 in 580 cases (56%) and > or =7 in 461 cases (44%). Androgen deprivation (AD) in the adjuvant or neoadjuvant setting was given in 303 cases (29%). The mean RT dose was 71.9 Gy (range: 57.6-78.0 Gy). The median RT dose was 70.2 Gy, with 458 cases (44%) receiving at least 72.0 Gy. The average dose in patients receiving <72 Gy was 68.3 Gy (median 68.4) versus 76.5 Gy (median 78.0) for patients receiving > or =72 Gy. The mean follow-up was 38 months (median 33 months). The number of follow-up prostate-specific antigen (PSA) levels available was 5998.

RESULTS

The 5- and 8-year bRFS rates were 61% (95% CI 55-65%) and 58% (95% CI 51-65%), respectively. The 5-year bRFS rates for patients receiving radiation doses > or =72 Gy versus <72 Gy were 87% (95% CI 82-92%) and 55% (95% CI 49-60%), respectively. The 8-year bRFS rates for patients receiving radiation doses > or =72 Gy versus <72 Gy were 87% (95% CI 82-92%) and 51% (95% CI 44-58%), respectively (p < 0.001). A multivariate analysis of factors affecting bRFS was performed using the following parameters: age (continuous variable), race, T-stage (T1-T2 vs. T3), iPSA (continuous variable), bGS (< or =6 vs. > or =7), use of AD (yes vs. no), radiation technique (conformal versus standard), and radiation dose (continuous variable). T-stage (p < 0.001), iPSA (p < 0.001), bGS (p < 0.001), and RT dose (p < 0.001) were independent predictors of outcome. Age (p = 0.74), race (p = 0.96), radiation technique (p = 0.15), and use of AD (p = 0.31) were not. We observed 11% clinical failures (local, distant, or both) at 5 years and 15% at 8 years for the entire cohort. There was a statistically significant improvement with higher radiation doses (p = 0.032). The 5-year clinical relapse rates for patients receiving > or =72 Gy versus <72 Gy were 5% and 12%, respectively. The 8-year clinical relapse rates for patients receiving radiation doses > or =72 Gy versus <72 Gy were 5% and 17%, respectively (p = 0.026).

CONCLUSION

Patients receiving radiation doses exceeding 72 Gy had significantly better bRFS and clinical disease-free survival rates. Although results need to be confirmed with longer follow-up, these preliminary results are extremely encouraging. If these results are confirmed by other institutions and by longer follow-up, RT doses exceeding 72 Gy should be considered as standard of care.

Local control and overall survival in atypical meningioma: a retrospective study

PURPOSE

To evaluate local control and overall survival after primary surgery for patients with atypical meningiomas.

METHODS AND MATERIALS

From the Department of Pathology database, we identified 491 cases of meningioma treated at the Cleveland Clinic Foundation from 1979 through 1995. Thirty-three were diagnosed with atypical meningioma. Eleven of the excluded patients had incomplete records, were lost to follow-up, or received treatment elsewhere. Of the 22 evaluable patients, 15 underwent gross total resection (GTR), 4 had a subtotal resection (STR), and 3 had a resection of unknown extent. Eight patients received radiation therapy (2 after initial resection and 6 after at least one recurrence). The median radiation dose was 5,400 cGy (range 3,500-5,940). The median age at presentation was 55.5 years, the male:female ratio was 14:8, and 19/22 patients had a Karnofsky performance score (KPS) > or =80. The independent variables analyzed for overall survival and local control were gender, KPS (> or =80 vs. < 80), extent of surgery (GTR vs. STR or unknown extent of surgery), and postoperative radiation therapy.

RESULTS

Median survival was 10.6 years, with a median follow-up of 5.5 years (range 1.5-14.8). Eight of the 22 patients had local recurrence, including 2/15 with GTR, 3/4 with STR, and all 3 patients who underwent resection of unknown extent. At 10 years, patients with GTR had a higher local control rate than those who had either a STR or a resection of unknown extent (87% vs. 17%; p = 0.02). The 5- and 10-year overall survival rates for the entire group were 91% and 76%, respectively. Patients who had GTR had 5- and 10-year overall survival of 87% and 87%, respectively. Patients with STR or resection of unknown extent had 5- and 10-year overall survival rates of 100% and 75%, respectively.

CONCLUSION

In patients with atypical meningiomas, gross total resection is associated with a lower recurrence rate than in subtotal resection.

Importance of high radiation doses (72 Gy or greater) in the treatment of stage T1-T3 adenocarcinoma of the prostate

OBJECTIVES

To analyze the effect of total radiation dose on the outcome of patients treated with external beam radiotherapy for early-stage prostate cancer.

METHODS

The records of a total of 738 patients with localized prostate cancer treated with external beam radiotherapy (RT) and no androgen deprivation at our institution between July 1986 and February 1999 were reviewed. Two risk groups were defined: favorable (Stage T1-T2, pretreatment prostate-specific antigen [PSA] level 10.0 ng/mL or less, and biopsy Gleason score 6 or less) and unfavorable (Stage T3 lesion or pretreatment PSA level greater than 10.0 ng/mL or biopsy Gleason score 7 or greater). The median RT dose was 70.0 Gy (range 57.6 to 78.0), with 192 patients (26%) receiving at least 72.0 Gy. The mean follow-up was 45 months.

RESULTS

The 5-year biochemical relapse-free survival (bRFS) rate was 58%. The 5-year bRFS rate for patients who received radiation doses of 72 Gy or greater versus less than 72 Gy was 85% and 54%, respectively (P <0.001). On multivariate analysis of factors affecting bRFS rates, the number of follow-up PSA levels (P <0.001), tumor stage (P <0.001), pretreatment PSA (P <0.001), biopsy Gleason score (P <0.00 1), and RT dose (P = 0.001) were the only independent predictors of outcome. For favorable tumors, the 5-year bRFS rate for patients who received radiation doses of 72 Gy or greater versus less than 72 Gy was 98% and 81 %, respectively (P = 0.023). For unfavorable tumors, the 5-year bRFS rate for patients who received radiation doses of 72 Gy or greater versus less than 72 Gy was 75% and 41 %, respectively (P = 0.001).

CONCLUSIONS

Patients receiving radiation doses of 72 Gy or higher had a significantly better outcome. The improvement was seen in all subgroups of patients. If these results are confirmed, radiation doses exceeding 72 Gy should be considered the standard of care. Inc.

Outcome in elderly patients undergoing definitive surgery and radiation therapy for supratentorial glioblastoma multiforme at a tertiary care institution

PURPOSE

To determine the efficacy of definitive surgery and radiation in patients aged 70 years and older with supratentorial glioblastoma multiforme.

METHODS AND MATERIALS

We selected elderly patients (> or = 70 years) who had primary treatment for glioblastoma multiforme at our tertiary care institution from 1977 through 1996. The study group (n = 102) included 58 patients treated with definitive radiation, 19 treated with palliative radiation, and 25 who received no radiation. To compare our results with published findings, we grouped our patients according to the applicable prognostic categories developed by the Radiation Therapy Oncology Group (RTOG): RTOG group IV (n = 6), V (n = 70), and VI (n = 26). Patients were retrospectively assigned to prognostic group IV, V, or VI based on age, performance status, extent of surgery, mental status, neurologic function, and radiation dose. Treatment included surgical resection and radiation (n = 49), biopsy alone (n = 25), and biopsy followed by radiation (n = 28). Patients were also stratified according to whether they were optimally treated (gross total or subtotal resection with postoperative definitive radiation) or suboptimally treated (biopsy, biopsy + radiation, surgery alone, or surgery + palliative radiation). Patients were considered to have a favorable prognosis (n = 39) if they were optimally treated and had a Karnofsky Performance Status (KPS) score of at least 70.

RESULTS

The median survival for patients according to RTOG groups IV, V, and VI was 9.2, 6.6, and 3.1 months, respectively (log-rank, p < 0.0004). The median overall survival was 5.3 months. The definitive radiation group (n = 58) had a median survival of 7.3 months compared to 4.5 months in the palliative radiation group (n = 19) and 1.2 months in the biopsy-alone group (p < 0.0001). Optimally treated patients had a median survival of 7.4 months compared to 2.4 months in those suboptimally treated (p < 0.0001). The favorable prognosis group had an 8.4-month median survival compared to 2.4 months in the unfavorable group (p < 0.0001). On multivariate analysis, the KPS, RTOG group, favorable/unfavorable prognosis, and optimal treatment/suboptimal treatment were significant predictors of survival.

CONCLUSION

Elderly patients with good performance status (> or = 70 KPS) when treated aggressively with maximal resection and definitive radiation had longer survival than those treated with palliative radiation and biopsy. Aggressive treatment in such patients should be considered.

Long-term outcomes of therapeutic pelvic lymphadenectomy for stage I endometrial adenocarcinoma

OBJECTIVE

The treatment of patients with stage I endometrial adenocarcinoma is often shorter and less expensive if total abdominal hysterectomy (TAH), bilateral salpingo-oophorectomy (BSO), and therapeutic lymphadenectomy are used rather than TAH, BSO, pelvic lymph node sampling, and pelvic external beam radiation. We studied whether the survival and morbidity of patients treated with therapeutic lymphadenectomy are equal to or better than with these alternative treatments.

METHODS

We reviewed the medical records of patients with stage I endometrial adenocarcinoma who were enrolled in the MetroHealth Medical Center tumor registry between 1970 and 1993 after undergoing full pelvic lymph node dissection, in addition to total abdominal hysterectomy, bilateral salpingo-oophorectomy, and vaginal brachytherapy. The mean number of resected nodes was 33 (median, 31; interquartile range, 19). Patients were followed for 1. 6-20 years (median, 8 years; interquartile range, 5.8 years). Morbidity and survival rates were compared to published series using similar treatment strategies and to those from studies using pelvic external beam radiation and pelvic lymph node sampling rather than lymphadenectomy.

RESULTS

Of 192 patients with pathologic stage I (FIGO 1988) endometrial adenocarcinoma, 178 patients had full pelvic lymph node dissection; 159 patients were evaluable. The 15-year overall survival was 98%; 10- and 15- year disease-free survivals were 96 and 94%, respectively. Overall morbidity was 18% (29/159), and moderate-to-severe morbidity was 13% (21/159). Recurrences were seen in 4.4% (7/159) of patients. Grade and myometrial invasion were not significant predictors of disease-free survival after full pelvic lymph node dissection (grade, P = 0.42; stage, P = 0.67). The results compare favorably with those of similar studies and with studies of pelvic external beam radiation.

CONCLUSIONS

Primary surgical management with total abdominal hysterectomy, bilateral salpingo-oophorectomy, therapeutic pelvic lymphadenectomy, and vaginal brachytherapy is a viable and possibly preferable option for patients with stage I endometrial adenocarcinoma.