Limited-field radiation therapy in the management of early-stage breast cancer

BACKGROUND

Several phase III trials have demonstrated equivalent long-term survival between breast conserving surgery plus radiation therapy and mastectomy in patients with early-stage breast cancer but have not provided information on the optimal volume of breast tissue requiring post-lumpectomy radiation therapy. Therefore, we examined the 5-year results of a single institution's experience with radiation therapy limited to the region of the tumor bed (i.e., limited-field radiation therapy) in selected patients treated with breast-conserving therapy and compared them with results of matched breast-conserving therapy patients who underwent whole-breast radiation therapy.

METHODS

A total of 199 patients with early-stage breast cancer were treated prospectively with breast-conserving therapy and limited-field radiation therapy using interstitial brachytherapy. To compare potential differences in local recurrence rates based on the volume of breast tissue irradiated, patients in the limited-field radiation therapy group were matched with 199 patients treated with whole-breast radiation therapy. Match criteria included tumor size, lymph-node status, patient age, margins of excision, estrogen receptor status, and use of adjuvant tamoxifen therapy. Local-regional control and disease-free and overall survival were analyzed using the Kaplan-Meier method, and the statistical significance of differences between treatment groups was calculated using the log-rank test. All statistical tests were two-sided.

RESULTS

Median follow-up for surviving patients was 65 months (range = 12-115 months). Five ipsilateral breast failures (i.e., recurrences) were observed in patients treated with limited-field radiation therapy. The cumulative incidence of local recurrence was 1% (95% confidence interval [CI] = 0% to 2.8%). On matched-pair analysis, the rate of local recurrence was not statistically significantly different between the patient groups (1% [95% CI = 0% to 2.4%] for the whole-breast radiation therapy patients versus 1% [95% CI = 0% to 2.8%] for the limited-field radiation therapy patients; P =.65).

CONCLUSIONS

Limited-field radiation therapy administered to the region of the tumor bed has comparable 5-year local control rates to whole-breast radiation therapy in selected patients.

Optimizing breast cancer treatment efficacy with intensity-modulated radiotherapy

PURPOSE

To present our clinical experience using intensity-modulated radiation therapy (IMRT) to improve dose uniformity and treatment efficacy in patients with early-stage breast cancer treated with breast-conserving therapy.

METHODS AND MATERIALS

A total of 281 patients with Stage 0, I, and II breast cancer treated with breast-conserving therapy received whole breast RT after lumpectomy using our static, multileaf collimator (sMLC) IMRT technique. The technical and practical aspects of implementing this technique on a large scale in the clinic were analyzed. The clinical outcome of patients treated with this technique was also reviewed.

RESULTS

The median time required for three-dimensional alignment of the tangential fields and dosimetric IMRT planning was 40 and 45 min, respectively. The median number of sMLC segments required per patient to meet the predefined dose-volume constraints was 6 (range 3-12). The median percentage of the treatment given with open fields (no sMLC segments) was 83% (range 38-96%), and the median treatment time was <10 min. The median volume of breast receiving 105% of the prescribed dose was 11% (range 0-67.6%). The median breast volume receiving 110% of the prescribed dose was 0% (range 0-39%), and the median breast volume receiving 115% of the prescribed dose was also 0%. A total of 157 patients (56%) experienced Radiation Therapy Oncology Group Grade 0 or I acute skin toxicity; 102 patients (43%) developed Grade II acute skin toxicity and only 3 (1%) experienced Grade III toxicity. The cosmetic results at 12 months (95 patients analyzable) were rated as excellent/good in 94 patients (99%). No skin telengiectasias, significant fibrosis, or persistent breast pain was noted.

CONCLUSION

The use of intensity modulation with our sMLC technique for tangential whole breast RT is an efficient method for achieving a uniform and standardized dose throughout the whole breast. Strict dose-volume constraints can be readily achieved resulting in both uniform coverage of breast tissue and a potential reduction in acute and chronic toxicities. Because the median number of sMLC segments required per patient is only 6, the treatment time is equivalent to conventional wedged-tangent treatment techniques. As a result, widespread implementation of this technology can be achieved with minimal imposition on clinic resources and time constraints.

Intensity-modulated radiotherapy results in significant decrease in clinical toxicities compared with conventional wedge-based breast radiotherapy

PURPOSE

We have previously demonstrated that intensity-modulated radiotherapy (IMRT) with a static multileaf collimator process results in a more homogenous dose distribution compared with conventional wedge-based whole breast irradiation (WBI). In the present analysis, we reviewed the acute and chronic toxicity of this IMRT approach compared with conventional wedge-based treatment.

METHODS AND MATERIALS

A total of 172 patients with Stage 0-IIB breast cancer were treated with lumpectomy followed by WBI. All patients underwent treatment planning computed tomography and received WBI (median dose, 45 Gy) followed by a boost to 61 Gy. Of the 172 patients, 93 (54%) were treated with IMRT, and the 79 patients (46%) treated with wedge-based RT in a consecutive fashion immediately before this cohort served as the control group. The median follow-up was 4.7 years.

RESULTS

A significant reduction in acute Grade 2 or worse dermatitis, edema, and hyperpigmentation was seen with IMRT compared with wedges. A trend was found toward reduced acute Grade 3 or greater dermatitis (6% vs. 1%, p = 0.09) in favor of IMRT. Chronic Grade 2 or worse breast edema was significantly reduced with IMRT compared with conventional wedges. No difference was found in cosmesis scores between the two groups. In patients with larger breasts (> or =1,600 cm(3), n = 64), IMRT resulted in reduced acute (Grade 2 or greater) breast edema (0% vs. 36%, p <0.001) and hyperpigmentation (3% vs. 41%, p = 0.001) and chronic (Grade 2 or greater) long-term edema (3% vs. 30%, p = 0.007).

CONCLUSION

The use of IMRT in the treatment of the whole breast results in a significant decrease in acute dermatitis, edema, and hyperpigmentation and a reduction in the development of chronic breast edema compared with conventional wedge-based RT.

Ongoing clinical experience utilizing 3D conformal external beam radiotherapy to deliver partial-breast irradiation in patients with early-stage breast cancer treated with breast-conserving therapy

PURPOSE

We present our ongoing clinical experience utilizing 3D conformal radiation therapy (3D-CRT) to deliver partial-breast irradiation (PBI) in patients with early-stage breast cancer treated with breast-conserving therapy.

MATERIALS AND METHODS

Thirty-one patients referred for postoperative radiation therapy after lumpectomy were treated with PBI using our previously reported 3D-CRT technique. Ninety-four percent of patients had surgical clips outlining the lumpectomy cavity (mean: 6 clips). The clinical target volume (CTV) consisted of the lumpectomy cavity plus a 10-mm margin in 9 patients and 15-mm margin in 22 (median: 15 mm). The planning target volume consisted of the CTV plus a 10-mm margin for breathing motion and treatment setup uncertainties. The prescribed dose (PD) was 34 or 38.5 Gy (6 patients and 25 patients, respectively) in 10 fractions b.i.d. separated by 6 h and delivered in 5 consecutive days. Patients were treated in the supine position with 3-5 beams (mean: 4) designed to irradiate the CTV with <10% inhomogeneity and a comparable or lower dose to the heart, lung, and contralateral breast compared with standard whole-breast tangents. The median follow-up duration is 10 months (range: 1-30 months). Four patients have been followed >2 years, 6 >1.5 years, and 5 >1 year. The remaining 16 patients have been followed <12 months.

RESULTS

No skin changes greater than Grade 1 erythema were noted during treatment. At the initial 4-8-week follow-up visit, 19 patients (61%) experienced Grade 1 toxicity and 3 patients (10%) Grade 2 toxicity. No Grade 3 toxicities were observed. The remaining 9 patients (29%) had no observable radiation effects. Cosmetic results were rated as good/excellent in all evaluable patients at 6 months (n = 3), 12 months (n = 5), 18 months (n = 6), and in the 4 evaluable patients at >2 years after treatment. The mean coverage of the CTV by the 100% isodose line (IDL) was 98% (range: 54-100%, median: 100%) and by the 95% IDL, 100% (range: 99-100%). The mean coverage of the planning target volume by the 95% IDL was 100% (range: 97-100%). The mean percentage of the breast receiving 100% of the PD was 23% (range: 14-39%). The mean percentage of the breast receiving 50% of the PD was 47% (range: 34-60%).

CONCLUSIONS

Utilizing 3D-CRT to deliver PBI is technically feasible, and acute toxicity to date has been minimal. Additional follow-up will be needed to assess the long-term effects of these larger fraction sizes on normal-tissue sequelae and the impact of this fractionation schedule on treatment efficacy.

Dose escalation improves cancer-related events at 10 years for intermediate- and high-risk prostate cancer patients treated with hypofractionated high-dose-rate boost and external beam radiotherapy

PURPOSE

To evaluate the 10-year outcomes of intermediate- and high-risk prostate cancer patients treated with a prospective dose escalation hypofractionated trial of pelvic external beam radiation therapy (P-EBRT) with a high-dose-rate (HDR) brachytherapy boost.

METHODS AND MATERIALS

From 1992 to 2007, 472 patients were treated with a HDR boost at William Beaumont Hospital. They had at least one of the following: a prostate-specific antigen (PSA) level of >10 ng/ml, a Gleason score of ≥7, or clinical stage ≥T2b. Patients received 46-Gy P-EBRT and an HDR boost. The HDR dose fractionation was divided into two dose levels. The prostate biologically equivalent dose (BED) low-dose-level group received <268 Gy, and the high-dose group received >268 Gy . Phoenix biochemical failure (BF) definition was used.

RESULTS

Median follow-up was 8.2 years (range, 0.4-17 years). The 10-year biochemical failure rate of 43.1% vs. 18.9%, (p < 0.001), the clinical failure rate of 23.4% vs. 7.7%, (p < 0.001), and the distant metastasis of 12.4% vs. 5.7%, (p = 0.028) were all significantly better for the high-dose level group. On Cox multivariate analysis, higher BED levels (p = 0.017; hazard ratio [HR] = 0.586), pretreatment PSA assays (p < 0.001, HR = 1.022), and Gleason scores (p = 0.004) were significant variables for reduced biochemical failure. Higher dose levels (p, 0.002; HR, 0.397) and Gleason scores (p < 0.001) were significant for clinical failure. Grade 3 genitourinary complications were 2% and 3%, respectively, and grade 3 gastrointestinal complication was <0.5%.

CONCLUSIONS

This prospective trial using P-EBRT with HDR boost and hypofractionated dose escalation demonstrates a strong dose-response relationship for intermediate- and high-risk prostate cancer patients. The improvement at 10 years for locoregional control with higher radiation doses (BED, > 268 Gy) has significantly decreased biochemical and clinical failures as well as distant metastasis.

Treatment of prostate cancer with radiotherapy: should the entire seminal vesicles be included in the clinical target volume?

PURPOSE

When treating high-risk prostate cancer with radiation therapy, inclusion of the seminal vesicles (SVs) within the clinical target volume (CTV) can dramatically increase the volume of radiated normal tissues and hinder dose escalation. Because cancer may involve only the proximal portion of the frequently lengthy SVs, we performed a complete pathology review of prostatectomy specimens to determine the appropriate length of SV to include within the CTV when SV treatment is indicated.

METHODS AND MATERIALS

A detailed pathologic analysis was performed for 344 radical prostatectomy specimens (1987-2000). All slides from each case were reviewed by a single pathologist (N.S.G.). Factors recorded for each case included length of each SV (cm), length of cancer involvement in each SV (cm) measured from the prostate-SV junction, and percentage of SV length involved.

RESULTS

Fifty-one patients (15%) demonstrated SV involvement in 81 SVs (21 unilateral, 30 bilateral SV involvement). The median SV length was 3.5 cm (range: 0.7-8.5 cm). Factors associated with SV involvement included the pretreatment PSA level, biopsy Gleason score, and clinical T classification. The commonly used risk group stratification was very effective at predicting SV positivity. Only 1% of low-risk patients (PSA <10 ng/mL, Gleason <or=6, and clinical stage <or=T2a) demonstrated SV involvement vs. 27% of high-risk patients. Patients with only one high-risk feature still demonstrated a 15% risk of SV involvement, whereas 58% of patients with all three high-risk features had positive SVs. The median length of SV involvement was 1.0 cm (90th percentile: 2.0 cm, range: 0.2-3.8 cm). A median of 25% of each SV was involved with adenocarcinoma (90th percentile: 54%, range: 4%-75%). For the 81 positive SVs, no factor was associated with a greater length or percentage of SV involvement. In the entire population, 7% had SV involvement beyond 1.0 cm. There was an approximate 1% risk of SV involvement beyond 2.0 cm or 60% of the SV. In addition, this risk was less than 4% for all subgroups, including high-risk patients.

CONCLUSIONS

A portion of the SV should be included in the CTV only for higher-risk patients (PSA >or=10 ng/mL, biopsy Gleason >or=7, or clinical T stage >or=T2b). When treating the SV for prostate cancer, only the proximal 2.0-2.5 cm (approximately 60%) of the SV should be included within the CTV.

Comparison of acute and late toxicities for three modern high-dose radiation treatment techniques for localized prostate cancer

PURPOSE

We compared acute and late genitourinary (GU) and gastrointestinal (GI) toxicities in prostate cancer patients treated with three different high-dose radiation techniques.

METHODS AND MATERIALS

A total of 1,903 patients with localized prostate cancer were treated with definitive RT at William Beaumont Hospital from 1992 to 2006: 22% with brachytherapy alone (BT), 55% with image-guided external beam (EB-IGRT), and 23% external beam with high-dose-rate brachytherapy boost (EBRT+HDR). Median dose with BT was 120 Gy for LDR and 38 Gy for HDR (9.5 Gy × 4). Median dose with EB-IGRT was 75.6 Gy (PTV) to prostate with or without seminal vesicles. For EBRT+HDR, the pelvis was treated to 46 Gy with an additional 19 Gy (9.5 Gy × 2) delivered via HDR. GI and GU toxicity was evaluated utilizing the NCI-CTC criteria (v.3.0). Median follow-up was 4.8 years.

RESULTS

The incidences of any acute ≥ Grade 2 GI or GU toxicities were 35%, 49%, and 55% for BT, EB-IGRT, and EBRT+HDR (p < 0.001). Any late GU toxicities ≥ Grade 2 were present in 22%, 21%, and 28% for BT, EB-IGRT, and EBRT+HDR (p = 0.01), respectively. Patients receiving EBRT+HDR had a higher incidence of urethral stricture and retention, whereas dysuria was most common in patients receiving BT. Any Grade ≥ 2 late GI toxicities were 2%, 20%, and 9% for BT, EB-IGRT, and EBRT+HDR (p < 0.001). Differences were most pronounced for rectal bleeding, with 3-year rates of 0.9%, 20%, and 6% (p < 0.001) for BT, EB-IGRT, and EBRT+HDR respectively.

CONCLUSIONS

Each of the three modern high-dose radiation techniques for localized prostate cancer offers a different toxicity profile. These data can help patients and physicians to make informed decisions regarding radiotherapy for prostate andenocarcinoma.

Confirmation of a low α/β ratio for prostate cancer treated by external beam radiation therapy alone using a post-treatment repeated-measures model for PSA dynamics

PURPOSE

To estimate the α/β ratio of prostate cancer treated with external beam radiation only by use of a model of long-term prostate-specific antigen (PSA) dynamics.

METHODS AND MATERIALS

Repeated measures of PSA from 5,093 patients from 6 institutions treated for localized prostate cancer by external beam radiation therapy (EBRT) without planned androgen deprivation were analyzed. A biphasic linear mixed model described the post-treatment evolution of PSA, rather than a conventional model of time to biochemical recurrence. The model was adjusted for standard prognostic factors (T stage, initial PSA level, and Gleason score) and cohort-specific effects. The radiation dose fractionation effect was estimated from the long-term rate of rise of PSA level.

RESULTS

Adjusted for other factors, total dose of EBRT and sum of squared doses per fraction were associated with long-term rate of change of PSA level (p = 0.0017 and p = 0.0003, respectively), an increase of each being associated with a lower rate of rise. The α/β ratio was estimated at 1.55 Gy (95% confidence band, 0.46-4.52 Gy). This estimate was robust to adjustment of the linear mixed model.

CONCLUSIONS

By analysis of a large EBRT-only cohort along with a method that uses all the repeated measures of PSA after the end of treatment, a low and precise α/β was estimated. These data support the use of hypofractionation at fractional doses up to 2.8 Gy but cannot presently be assumed to accurately represent higher doses per fraction.

Computed Tomography Guided Management of Interfractional Patient Variation

Interfractional patient variation occurs regularly and considerably during the radiotherapy course. Consequently, a generic but large planning target margin has to be applied when patient treatment plan design based on a single pre-treatment computed tomography scan is used to guide multifraction radiation treatment, which creates a major limiting factor for radiotherapy improvement. Planning target margins can be significantly reduced using multiple (or 4-dimensional) image feedback management in the routine treatment process. The most effective method in multiple-image feedback management of radiotherapy is the adaptive control methodology. The adaptive radiotherapy technique aims to customize each patient's treatment plan to patient-specific variation by evaluating and characterizing the systematic and random variations through image feedback and including them in adaptive planning. Adaptive radiotherapy will become a new treatment standard, in which a predesigned adaptive treatment strategy, including the schedules of imaging and replanning, will eventually replace the predesigned treatment plan in the routine clinical practice.

Four-year efficacy, cosmesis, and toxicity using three-dimensional conformal external beam radiation therapy to deliver accelerated partial breast irradiation

PURPOSE

This prospective study examines the use of three-dimensional conformal external beam radiation therapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI). Four-year data on efficacy, cosmesis, and toxicity are presented.

METHODS

Patients with Stage O, I, or II breast cancer with lesions </=3 cm, negative margins, and negative nodes were eligible. The 3D-CRT delivered was 38.5 Gy in 3.85 Gy/fraction. Ipsilateral breast, ipsilateral nodal, contralateral breast, and distant failure (IBF, INF, CBF, DF) were estimated using the cumulative incidence method. Disease-free, overall, and cancer-specific survival (DFS, OS, CSS) were recorded. The National Cancer Institute Common Terminology Criteria for Adverse Events (version 3) toxicity scale was used to grade acute and late toxicities.

RESULTS

Ninety-four patients are evaluable for efficacy. Median patient age was 62 years with the following characteristics: 68% tumor size <1 cm, 72% invasive ductal histology, 77% estrogen receptor (ER) (+), 88% postmenopausal; 88% no chemotherapy and 44% with no hormone therapy. Median follow-up was 4.2 years (range, 1.3-8.3). Four-year estimates of efficacy were IBF: 1.1% (one local recurrence); INF: 0%; CBF: 1.1%; DF: 3.9%; DFS: 95%; OS: 97%; and CSS: 99%. Four (4%) Grade 3 toxicities (one transient breast pain and three fibrosis) were observed. Cosmesis was rated good/excellent in 89% of patients at 4 years.

CONCLUSIONS

Four-year efficacy, cosmesis, and toxicity using 3D-CRT to deliver APBI appear comparable to other experiences with similar follow-up. However, additional patients, further follow-up, and mature Phase III data are needed to evaluate thoroughly the extent of application, limitations, and complete value of this particular form of APBI.

Conformal high dose rate brachytherapy improves biochemical control and cause specific survival in patients with prostate cancer and poor prognostic factors

PURPOSE

To improve outcome for patients with prostate cancer with poor prognostic factors higher than conventional radiation doses are required. To achieve this outcome a brachytherapy boost was given. We report the results of the first high dose rate dose-escalation brachytherapy trial.

MATERIALS AND METHODS

Between 1991 and 2000, 207 patients were prospectively enrolled in a dose escalation trial including pelvic radiotherapy and conformal high dose rate prostate brachytherapy boost. The dose was increased from 5.5 to 11.5 Gy. per implant. Patient eligibility for the study included pretreatment prostate specific antigen 10 or greater, Gleason 7 or greater or clinical stage T2b or higher. No patient received hormonal therapy. The American Society for Therapeutic Radiology and Oncology consensus panel definition of biochemical failure was applied.

RESULTS

Median patient age was 69 years. Mean followup was 4.7 years (range 0.6 to 10.4). The 5-year actuarial biochemical control rate was 74%. The 5-year biochemical control was 85% for 1 poor prognostic factor, 75% for 2 and 50% for all 3 (p = 0.001). On Cox regression multivariate analysis lower brachytherapy dose, and higher Gleason and nadir value were associated with biochemical failure. The 5-year actuarial overall survival was 92%, cause specific survival 98% and disease-free survival 68%. The 5-year actuarial rates of complications were 8% and 0% for grades 3 and 4 genitourinary, and 0.5% and 0.5% for grades 3 and 4 gastrointestinal, respectively. The 5-year actuarial impotence rate was 51%.

CONCLUSIONS

For patients with poor prognostic factors external beam radiation therapy with conformal high dose rate brachytherapy boost improved biochemical control, resulting in a high cause specific survival rate with low toxicity. Another important advantage is that the patient is not radioactive after the high dose rate implant.

Does local recurrence affect the rate of distant metastases and survival in patients with early-stage breast carcinoma treated with breast-conserving therapy?

BACKGROUND

The purpose of the current analysis was to evaluate the impact of local recurrence (LR) on the development of distant metastases (DM), overall survival (OS), and cause specific survival (CSS) in patients with early-stage breast carcinoma who underwent conservative surgery (CS) and received postoperative radiotherapy (RT).

METHODS

Between 1980 and 1995, 1169 patients underwent CS and received RT. All patients were followed for > 1 year and had < or = 4 lymph nodes involved with disease. The median duration of follow-up was 7.7 years. A Cox proportional hazards model was performed to evaluate the effect of LR on the development of DM and CSS. A matched-pair analysis that controlled for multiple prognostic factors also was performed comparing the outcomes of patients with and without LR.

RESULTS

The LR rate was 11% at 12 years. For the entire population, LR led to poorer OS and CSS rates at 12 years compared with local control (LC) (71% vs. 81% [P = 0.001] and 69% vs. 88% [P < 0.001], respectively). In a Cox multiple regression model, LR was a significant predictor of disease specific mortality. The hazard ratio (HR) associated with LR was 2.69 for mortality and 2.67 for DM (P < 0.001 and P < 0.001, respectively). The median time from surgery to the development of DM was 3.8 years for patients without LR compared with 4.7 years for patients with LR. Patients who developed LR also had two peaks in the rate of DM (at 2.5 years and at 6.5 years) compared to only one peak (at 1.5 years) for patients who did not develop LR. The impact of LR on DM still was evident in patients with small tumors (< or = 2.0 cm; P < 0.001), negative lymph nodes (P = 0.004), or both (P < 0.001). Recurrent disease that developed outside of the surgical bed region had no negative effect on survival. In the matched-pair analysis (controlling for age, tumor size, grade, number of positive lymph nodes, and estrogen receptor status), LR remained the most significant predictor of mortality (HR: mortality, 5.86; DM, 6.43).

CONCLUSIONS

The current results suggest that LR may be responsible for an increase in DM and disease specific mortality in patients who undergo CS and receive RT. This suggestion is reinforced by the distinct difference seen in the time distribution of DM after LR developed and by the fact that recurrent disease that originated outside of the surgical bed did not affect OS. These data reinforce the necessity to insure optimal LC in patients who are treated with breast-conserving therapy.

Surgical considerations in the treatment of early stage breast cancer with accelerated partial breast irradiation (APBI) in breast conserving therapy via intersitial brachytherapy

OBJECTIVE

To examine early and late toxicities, evaluate cosmetic results, and determine the need for reoperation or additional diagnostic procedures in patients treated with accelerated partial breast irradiation (APBI) delivered by way of an interstitial implant in breast-conserving therapy.

METHODS

A total of 199 patients with stage I or II breast cancer were managed with lumpectomy followed by radiation restricted to the tumor bed using an interstitial implant (APBI). Retrospective analyses were performed for early and late toxicities (infection, fat necrosis, breast pain, edema, erythema, fibrosis, pigmentation changes, and telangiectasias), need for reoperation or additional diagnostic procedures, cosmetic results, and local control. Patient selection criteria by the surgeon for referral to RT for APBI included age, tumor size, histology, nodal status, margin status, and absence of extensive intraductal component. Treatment was delivered with either a low-dose or high-dose rate implant. Median follow-up was 5.7 years, and 54% of the patients were followed-up for >7 years.

RESULTS

Infections developed in 22 of 199 (11%) patients: 7% early (</=1 month after implant removal) and 4% late (>1 month after implant removal). Five of the 22 patients (2% of all patients) required operative intervention for the infection, either incision and drainage or debridement. There was a statistically significant difference between infection rates with open (8.5%) versus closed (2.5%) cavity placement of the interstitial needles (P = 0.005). There was no statistically significant difference between low-dose rate (inpatient) and high-dose rate (outpatient) treatment (P = 0.207). Forty-five patients (23%) had an additional diagnostic procedure to evaluate a suspicious or uncertain finding on physical examination or mammogram. Fibrosis and fat necrosis were found in 26 of the 45 patients. The incidence of fat necrosis increased with time. More patients were found to have fat necrosis after 5 years. One patient had fat necrosis diagnosed at <6 months; 8 patients (4% of total) at >/=6 months to <2 years; 10 patients (5% of total) at >/=2 years to <5 years; and 22 patients (11% of total) at >/=5 years. The majority of fat necrosis was detected on mammogram (80%) and was asymptomatic (78%). Cosmesis and toxicities were assessed at 3 defined time points: </=6 months, 2 years, and >/=5 years of follow-up. Using Harvard criteria, good to excellent cosmetic results were observed in >90% of patients. Breast pain, edema, and erythema diminished with time. Of the 199 cases, there were only 5 ipsilateral breast failures, yielding a 5-year actuarial local recurrence rate of 1.2%. Of these 5 failures, 2 were true recurrences/marginal misses, yielding a 5-year actuarial true recurrence/marginal miss rate of 0.5%. The 5-year actuarial cause-specific survival rate was 99% for APBI patients.

CONCLUSIONS

In selected patients with early-stage breast cancer, APBI with targeted interstitial brachytherapy offers 5-year results comparable with conventional breast-conserving therapy employing whole-breast radiation therapy. Minimal long-term toxicities were noted, most of which demonstrated continued resolution over time. Acceptable acute (7%) and delayed (4%) infection rates were observed. Fat necrosis was identified with increasing frequency with time, but the majority was asymptomatic. Cosmetic results are good to excellent (>90%). Continued follow-up by the surgeon will be required to determine the long-term efficacy of this alternative treatment approach.

Interim cosmetic results and toxicity using 3D conformal external beam radiotherapy to deliver accelerated partial breast irradiation in patients with early-stage breast cancer treated with breast-conserving therapy

PURPOSE

We present our ongoing clinical experience utilizing three-dimensional (3D)-conformal radiation therapy (3D-CRT) to deliver accelerated partial breast irradiation (APBI) in patients with early-stage breast cancer treated with breast-conserving therapy.

METHODS AND MATERIALS

Ninety-one consecutive patients were treated with APBI using our previously reported 3D-CRT technique. The clinical target volume consisted of the lumpectomy cavity plus a 10- to 15 -mm margin. The prescribed dose was 34 or 38.5 Gy in 10 fractions given over 5 consecutive days. The median follow-up was 24 months. Twelve patients have been followed for > or =4 years, 20 for > or =3.5 years, 29 for >3.0 years, 33 for > or =2.5 years, and 46 for > or =2.0 years.

RESULTS

No local recurrences developed. Cosmetic results were rated as good/excellent in 100% of evaluable patients at > or = 6 months (n = 47), 93% at 1 year (n = 43), 91% at 2 years (n = 21), and in 90% at > or =3 years (n = 10). Erythema, hyperpigmentation, breast edema, breast pain, telangiectasias, fibrosis, and fat necrosis were evaluated at 6, 24, and 36 months after treatment. All factors stabilized by 3 years posttreatment with grade I or II rates of 0%, 0%, 0%, 0%, 9%, 18%, and 9%, respectively. Only 2 patients (3%) developed grade III toxicity (breast pain), which resolved with time.

CONCLUSIONS

Delivery of APBI with 3D-CRT resulted in minimal chronic (> or =6 months) toxicity to date with good/excellent cosmetic results. Additional follow-up is needed to assess the long-term efficacy of this form of APBI.

Changes in the respiratory pattern during radiotherapy for cancer in the lung

BACKGROUND AND PURPOSE

To quantify changes in patients' diaphragm motion pattern over the course of radiotherapy and to evaluate the implications of these changes for 4D radiotherapy.

PATIENTS AND METHODS

From January 2004 to October 2004, 10 patients with lung malignancies treated at our department underwent weekly respiratory motion verification during the course of external beam radiation. An onboard kilovoltage imaging system was used to acquire fluoroscopy weekly for patients with lung neoplasms. The diaphragm position as a function of time was extracted automatically from the fluoroscopy and used to calculate the daily mean and daily SD of motion. The diaphragm position was related to both a bony reference point and machine isocenter. Changes in the daily mean and daily SD in relation to the reference (first day) daily mean and reference daily SD were measured.

RESULTS

The mean change in the daily mean was 0.32 mm+/-6.11 mm in relation to the bony reference point and 0.38 mm+/-6.28 mm in relation to isocenter. The mean change in the daily SD was 0.91 mm+/-1.81 mm. The mean systematic change in the daily mean was 4.97 mm, and the mean random change in the daily mean was 3.61 mm.

CONCLUSIONS

Daily verification of 4D radiotherapy techniques to assess the necessity of online set-up correction may be required due to the large change in the mean diaphragm position observed for these patients. However, the variation of the daily SD was small for most patients. Adaptive adjustment of the margin may be necessary for those patients with larger variation of the daily SD.

Real-time individual predictions of prostate cancer recurrence using joint models

Patients who were previously treated for prostate cancer with radiation therapy are monitored at regular intervals using a laboratory test called Prostate Specific Antigen (PSA). If the value of the PSA test starts to rise, this is an indication that the prostate cancer is more likely to recur, and the patient may wish to initiate new treatments. Such patients could be helped in making medical decisions by an accurate estimate of the probability of recurrence of the cancer in the next few years. In this article, we describe the methodology for giving the probability of recurrence for a new patient, as implemented on a web-based calculator. The methods use a joint longitudinal survival model. The model is developed on a training dataset of 2386 patients and tested on a dataset of 846 patients. Bayesian estimation methods are used with one Markov chain Monte Carlo (MCMC) algorithm developed for estimation of the parameters from the training dataset and a second quick MCMC developed for prediction of the risk of recurrence that uses the longitudinal PSA measures from a new patient.

Long-term efficacy and patterns of failure after accelerated partial breast irradiation: a molecular assay-based clonality evaluation

PURPOSE

To determine the long-term efficacy and cosmetic results of accelerated partial breast irradiation (APBI) by reviewing our institution's experience.

METHODS AND MATERIALS

A total of 199 patients with early-stage breast cancer were treated prospectively with adjuvant APBI after lumpectomy using interstitial brachytherapy. All patients had negative margins, 82% had Stage I disease, median tumor size was 1.1 cm, and 12% had positive lymph nodes. The median follow-up for surviving patients was 8.6 years. Fifty-three patients (27%) have been followed for >or=10 years.

RESULTS

Six ipsilateral breast tumor recurrences (IBTRs) were observed, for a 5-year and 10-year actuarial rate of 1.6% and 3.8%, respectively. A total of three regional nodal failures were observed, for a 10-year actuarial rate of 1.6%. Five contralateral breast cancers developed, for a 5- and 10-year actuarial rate of 2.2% and 5.2%, respectively. The type of IBTR (clonally related vs. clonally distinct) was analyzed using a polymerase chain reaction-based loss of heterozygosity assay. Eighty-three percent of IBTRs (n = 5) were classified as clonally related. Multiple clinical, pathologic, and treatment-related factors were analyzed for an association with the development of an IBTR, regional nodal failure, or contralateral breast cancer. On multivariate analysis, no variable was associated with any of these events. Cosmetic results were rated as excellent/good in 99% of patients.

CONCLUSIONS

Long-term results with APBI using interstitial brachytherapy continue to demonstrate excellent long-term local and regional control rates and cosmetic results. According to a polymerase chain reaction-based loss of heterozygosity assay, 83% of recurrences were classified as clonally related.

Factors associated with local recurrence and cause-specific survival in patients with ductal carcinoma in situ of the breast treated with breast-conserving therapy or mastectomy

PURPOSE

We reviewed our institution's experience treating patients with ductal carcinoma in situ (DCIS) of the breast to determine risk factors for ipsilateral breast tumor recurrence (IBTR) and cause-specific survival (CSS) after breast-conserving therapy (BCT) or mastectomy.

MATERIALS AND METHODS

Between 1981 and 1999, 410 cases of DCIS (405 patients) were treated at our institution; 367 were managed with breast-conserving surgery (54 with lumpectomy alone and 313 with adjuvant radiation therapy (RT) [median dose, 45 Gy]). Of these 313 patients, 298 received also a supplemental boost of RT to the lumpectomy cavity (median dose, 16 Gy). Forty-three patients underwent mastectomy; 2 (5%) received adjuvant RT to the chest wall. A true recurrence/marginal miss (TR/MM) IBTR was defined as failure within or adjacent to the tumor bed in patients undergoing BCT. Median follow-up for all patients was 7 years (mean: 6.1 years).

RESULTS

Thirty patients (8.2%) experienced an IBTR after BCT (25 [8%] after RT, 5 [9.3%] after no RT), and 2 patients (4.7%) developed a chest wall recurrence after mastectomy. Of the 32 local failures, 20 (63%) were invasive (18/30 [60%] after BCT and 2/2 [100%] after mastectomy), and 37% were DCIS alone. Twenty-four (80%) of the IBTRs were classified as TR/MM. The 10-year freedom from local failure, CSS, and overall survival after BCT or mastectomy were 89% vs. 90% (p = 0.4), 98% vs. 100% (p = 0.7), and 89% vs. 100% (p = 0.3), respectively. Factors associated with IBTR on Cox multivariate analysis were younger age (p = 0.02, hazard ratio [HR] 1.06 per year), electron boost energy < or = 9 MeV (p = 0.03, HR 1.41), final margins < or = 2 mm (p = 0.007; HR, 3.65), and no breast radiation (p = 0.002, HR 5.56). On Cox univariate analysis for BCT patients, IBTR, TR/MM failures, and predominant nuclear Grade 3 were associated with an increased risk of distant metastases and a reduced CSS.

CONCLUSIONS

After treatment for DCIS, 10-year rates of local control, CSS, and overall survival were similar after mastectomy and BCT. Young age (<45 years), close/positive margins (< or = 2 mm), no breast radiation, and lower electron boost energies (< or = 9 MeV) were associated with IBTR. Local failure and predominant nuclear Grade 3 were found to have a small (4%-12%) but statistically significantly negative impact on the rates of distant metastasis and CSS. These results suggest that optimizing local therapy (surgery and radiation) is crucial to improve local control and CSS in patients treated with DCIS.

An interinstitutional and interspecialty comparison of treatment outcome data for patients with prostate carcinoma based on predefined prognostic categories and minimum follow-up

BACKGROUND

The optimal management of patients with clinically localized prostate carcinoma remains undefined due in part to the absence of well-designed, prospective, randomized trials. The current study was conducted to compare and contrast outcomes with different forms of therapy for patients with prostate carcinoma who were treated at several institutions using predefined prognostic categories.

METHODS

A retrospective study of 6877 men with prostate carcinoma who were treated between 1989 and 1998 at 7 different institutions with 6 different types of therapy was conducted. Five-year actuarial rates of prostate specific antigen (PSA) failure were calculated based on predefined prognostic categories, which included combinations of pretreatment PSA level, tumor stage, and Gleason score. In addition, outcome was calculated using consistent biochemical failure definitions and a minimum, median length of follow-up.

RESULTS

Substantial differences in outcome were observed for the same type of treatment and at the same institution, depending on the number of prognostic variables used to define treatment groups. However, estimates of 5-year PSA outcomes after all forms of therapy for low-risk and intermediate-risk patient groups were remarkably similar (regardless of the type of treatment) when all three pretreatment variables were used to define prognostic categories. For patients in high-risk groups, the 5-year PSA outcomes were suboptimal, regardless of the treatment technique used.

CONCLUSIONS

The current data suggest that interinstitutional and interspecialty comparisons of treatment outcome for patients with prostate carcinoma are possible but that results must be based on all major prognostic variables to be meaningful. Analyzed in this fashion, 5-year PSA results were similar for patients in low-risk and intermediate-risk groups, regardless of the form of therapy. Findings from prospective, randomized trials using survival (cause specific and overall) as the end point for judging treatment efficacy and longer follow-up will be needed to validate these findings and to identify the most appropriate management option for patients with all stages of disease.

The emerging role of brachytherapy in the management of patients with breast cancer

Brachytherapy remains an important treatment option in the overall management of patients with breast cancer. In patients treated with breast conserving therapy (BCT), prospective randomized trials have established the advantage of a boost in most patients. Interstitial brachytherapy has consistently been shown to provide an important option to boost patients, and in certain clinical settings it may provide a more appropriate means of dose delivery. The concept of delivering partial breast irradiation with accelerated treatment schedules has now provided brachytherapy a new and exciting role in the management of patients treated with BCT. There are now data available from several phase I/II studies suggesting that brachytherapy alone can be used safely and reproducibly in this setting in order to reduce the time, inconvenience, and toxicity associated with traditional radiation therapy. Although preliminary results with brachytherapy alone are encouraging, proper patient selection and optimal dosimetric guidelines must be employed in order to achieve success when used in this setting.

LIMITATIONS IN THE USE OF SERUM PROSTATE SPECIFIC ANTIGEN LEVELS TO MONITOR PATIENTS AFTER TREATMENT FOR PROSTATE CANCER

PURPOSE

We reviewed the literature to help clarify the benefits and/or hazards associated with monitoring serum prostate specific antigen (PSA) after treatment with surgery or radiation therapy (RT) for nonmetastatic prostate cancer.

MATERIALS AND METHODS

A search was performed for 1990 to 2004 using the MEDLINE database, CancerLit database and reference lists of relevant studies to obtain articles addressing the use of serum PSA to follow patients after treatment for prostate cancer. Studies were reviewed to determine 1) if serial PSA monitoring provides an early and accurate surrogate assessment of cancer cure or treatment failure, 2) if any pattern in the PSA profile after treatment provides conclusive evidence of early local vs systemic failure, 3) the magnitude of the lead time to clinical failure that serial PSA monitoring may provide and 4) if the early identification of biochemical failure (BF) with earlier intervention improves outcome.

RESULTS

Although a lower PSA nadir after treatment with RT has been associated with cancer cure, 5% to 25% of patients ultimately have failure (beyond 5 years) even with the most optimal biochemical response. The most appropriate BF definitions to use after treatment for prostate cancer with RT remains controversial due to substantial differences in their accuracy, sensitivity, specificity and positive predictive value for clinical outcome. No pattern of PSA kinetics after treatment has conclusively been associated with a specific recurrence site. Biochemical failure definitions in patients treated with RT appear to provide a 6 to 18 month lead time to clinical failure but there are only limited published data to suggest that early intervention of any type (androgen deprivation, RT, surgery, etc) impacts survival.

CONCLUSIONS

The overall benefit of monitoring serum PSA after treatment for prostate cancer remains controversial. Considering the potential dangers associated with incorrectly assuming the efficacy of new forms of treatment, the toxicity of administering salvage therapies of uncertain efficacy after BF has been identified and the anxiety associated with tracking posttreatment serum PSA, additional studies must be done to determine the appropriate use of this marker in properly treating patients after therapy.

Intraductal carcinoma of the breast: pathologic features associated with local recurrence in patients treated with breast-conserving therapy

Local excision and radiation therapy is a standard treatment option for duct carcinoma in situ (DCIS) of the breast. There is no consensus regarding the significant histologic features associated with recurrence. The authors studied a large group of patients with mammographically detected DCIS treated with breast-conserving therapy to explore DCIS volume relationships, DCIS features, specimen characteristics, and the effect of patient age at diagnosis. Thirteen patients (10%) developed a recurrent carcinoma in the ipsilateral breast, resulting in 5- and 10-year actuarial recurrence rates of 8.9% and 10.3%, respectively. Local recurrences were identified as a true recurrence/marginal miss (TR/MM) in nine patients, and elsewhere in the breast in four patients. The notable features associated with TR/MM recurrences on univariate analysis included patient age less than 45 years old, six or more slides with DCIS, no microscopic calcifications within DCIS ducts, and five or more DCIS ducts or terminal duct lobular units (TDLUs) with cancerization of lobules (COL) within 0.42 cm of the final surgical margin. DCIS tumor size, nuclear grade, amount of central necrosis, and margin status were not associated with outcome. Multivariate analysis found that the absence of microcalcifications within DCIS ducts, patient age, number of slides with DCIS or TDLUs with COL, and the number of DCIS ducts or TDLUs with COL within 0.42 cm of the final margin were related significantly to TR/MM recurrence. Patients with a total of six or more slides with DCIS, or who have 11 or more DCIS ducts or TDLUs with COL near the final margin are at increased risk of having a substantial volume of residual DCIS in the adjacent unexcised breast. These results suggest that the volume of DCIS in the specimen, and the volume of DCIS near the margin are associated with local recurrence. These features can be used to identify those patients with a higher chance of local recurrence.