Toxicity Of Three-dimensional Conformal Radiotherapy Research Articles

Three-Dimensional Conformal Radiotherapy for Hepatocellular Carcinoma in Patients Unfit for Resection, Ablation, or Chemotherapy: A Retrospective Study

Purpose. The purpose is to evaluate the feasibility, efficacy, and the toxicity of three-dimensional conformal radiotherapy (3DCRT) in patients with advanced hepatocelluar carcinoma (HCC) and inferior vena cava tumor thrombosis (IVCTT). Methods. Between 2007 and 2012, in a retrospective way, 9 patients (median age 69 years) with advanced HCC and IVCTT unfit for surgery, radiofrequency ablation, embolization, or chemotherapy were treated with three-dimensional conformal radiotherapy (3DCRT). The radiotherapy volume included both primary tumor and IVTT. The radiotherapy schedule was 50–52 Gy in 2 Gy fractions. Overall survival (OS), response to radiotherapy, visual analogue scale (VAS), and toxicity were assessed. Results. All patients demonstrated a response rate up to 60%. During radiotherapy, 3 patients experienced grade 1 nausea/vomit toxicity. All patients demonstrated an elevation of the liver enzymes (3 patients with grade 1 and 6 patients with grade 2). The mean VAS-score was decreased from 6.11 to 3.11, while the median overall survival was 24 months. Conclusion. 3DCRT achieves a very high local control rate and is suitable for patients with HCC and IVTT, while the documented radiation induced toxicity is moderate. It can be recommended for palliation in patients unable to undergo curative therapies.

Prone Hypofractionated Whole-Breast Radiotherapy Without a Boost to the Tumor Bed: Comparable Toxicity of IMRT Versus a 3D Conformal Technique

We report a comparison of the dosimetry and toxicity of three-dimensional conformal radiotherapy (3D-CRT) vs. intensity-modulated radiotherapy (IMRT) among patients treated in the prone position with the same fractionation and target of the hypofractionation arm of the Canadian/Whelan trial. An institutional review board-approved protocol identified a consecutive series of early-stage breast cancer patients treated according to the Canadian hypofractionation regimen but in the prone position. Patients underwent IMRT treatment planning and treatment if the insurance carrier approved reimbursement for IMRT; in case of refusal, a 3D-CRT plan was used. A comparison of the dosimetric and toxicity outcomes during the acute, subacute, and long-term follow-up of the two treatment groups is reported. We included 97 consecutive patients with 100 treatment plans in this study (3 patients with bilateral breast cancer); 40 patients were treated with 3D-CRT and 57 with IMRT. IMRT significantly reduced the maximum dose (Dmax median, 109.96% for 3D-CRT vs. 107.28% for IMRT; p < 0.0001, Wilcoxon test) and improved median dose homogeneity (median, 1.15 for 3D-CRT vs. 1.05 for IMRT; p < 0.0001, Wilcoxon test) when compared with 3D-CRT. Acute toxicity consisted primarily of Grade 1 to 2 dermatitis and occurred in 92% of patients. Grade 2 dermatitis occurred in 13% of patients in the 3D-CRT group and 2% in the IMRT group. IMRT moderately decreased rates of acute pruritus (p = 0.03, chi-square test) and Grade 2 to 3 subacute hyperpigmentation (p = 0.01, Fisher exact test). With a minimum of 6 months' follow-up, the treatment was similarly well tolerated in either group, including among women with large breast volumes. Hypofractionated breast radiotherapy is well tolerated when treating patients in the prone position, even among those with large breast volumes. Breast IMRT significantly improves dosimetry but yields only a modest but confirmed benefit in terms of toxicities. If a concurrent boost to the tumor bed is not required, a conformal 3D-CRT approach can adequately deliver prone whole-breast hypofractionation radiotherapy.

Predictors of Long Term Toxicity of Three-dimensional Conformal Radiotherapy for Accelerated Partial Breast Irradiation

Multiple institutions have published data on toxicities observed with accelerated partial breast irradiation (APBI) using 3-dimensional conformal radiotherapy (3D-CRT) and reported different factors to be significantly correlated with the incidence of toxicity. We sought predictors of toxicity for patients treated with APBI using 3D-CRT among a larger cohort of patients with greater long-term follow-up than those previously studied.

Toxicity of Three-Dimensional Conformal Radiotherapy for Accelerated Partial Breast Irradiation

To assess the incidence and severity of late normal tissue toxicity using three-dimensional conformal radiotherapy to deliver accelerated partial breast irradiation. A total of 60 patients were treated with three-dimensional conformal radiotherapy for accelerated partial breast irradiation. Treatment planning and delivery were in strict accordance with the technique and specified dose-volume constraints of the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 protocol. Late toxicity was evaluated according to the Radiation Therapy Oncology Group grading schema. The cosmetic outcome was scored using the Harvard criteria. Univariate logistic regression analysis was performed to evaluate the correlation of dosimetric variables with outcome. At a median follow-up of 15 months, moderate-to-severe late toxicity developed in 10% of patients. The most pronounced late toxicity was subcutaneous fibrosis: 25% Grade 2-4 and 8.3% Grade 3-4. The modified planning tumor volume/whole breast volume ratio, ratio of the volume of breast tissue receiving 5%, 20%, 50%, and 80% of the prescription dose to the whole breast volume, and maximal dose within the breast correlated with the development of fibrosis (p = .10, p = .03, p = .04, p = .06, p = .09, and p = .046, respectively). The overall cosmetic outcome was good to excellent in 81.7%, fair in 11.7%, and poor in 6.7%. The presence of subcutaneous fibrosis, modified planning tumor volume/whole breast volume ratio, ratio of the volume of breast tissue receiving 5% and 20% of the prescription dose to the whole breast volume, and pathologic specimen volume correlated with the risk of a fair/poor cosmetic outcome (p < .001, p = .02, p = .05, p = .04, p = .01, respectively). The three-dimensional conformal radiotherapy technique for accelerated partial breast irradiation as specified in the National Surgical Adjuvant Breast and Bowel Project B-39/Radiation Therapy Oncology Group 0413 protocol resulted in a remarkably high rate of moderate-to-severe late normal tissue effects, despite the relatively brief follow-up period. The toxic events correlated clearly with several dose-volume parameters.

The effects of three-dimensional conformal radiotherapy combined with whole brain irradiation on brain metastases

Objective To observe the recently therapeutic effects and toxicity of three-dimensional conformal radiotherapy combined with whole brain irradiation for patients with brain metastasis.

Long-term results of three-dimensional conformal adjuvant and salvage radiotherapy after radical prostatectomy

Objectives To evaluate the efficacy and toxicity of three-dimensional conformal radiotherapy (3D-CRT) in the adjuvant and salvage setting after radical prostatectomy (RP). Methods From 1986 to 1997, 38 patients received adjuvant 3D-CRT, with a median time from RP to 3D-CRT of 2.8 months, and 57 patients were treated with salvage RT for a rising prostate-specific antigen with a median time to 3D-CRT of 27.7 months. The median radiation dose was 64.8 Gy. The median follow-up from completion of RT was 7.0 years (range 1.0 to 14.2). Results Overall, the 8-year actuarial rate of biochemical disease-free survival was 40% in all patients. The 8-year biochemical disease-free survival rate was 45% (standard error [SE] 8%) and 30% (SE 7%) for the adjuvant and salvage group, respectively, from RT completion. When measured from the date of RP, the 5 and 8-year biochemical disease-free survival rate for salvage radiotherapy was 58% and 37%, respectively. The corresponding results for adjuvant RT were similar at 53% and 45%. On multivariate analysis, the Gleason score was the only prognostic factor predictive of prostate-specific antigen failure in the salvage group. No prognostic factor was significant in the adjuvant group. The prevalence of major complications after 3D-CRT was low using physician-reported data. Conclusions Long-term biochemical control can be achieved in both adjuvant and salvage settings. For patients receiving salvage RT, a Gleason score greater than 7 was predictive of prostate-specific antigen failure. Prospective trials are needed to improve further on these results.

Acute toxicity of three-dimensional conformal radiotherapy in prostate cancer patients eligible for implant monotherapy

Purpose: To assess the acute toxicity of three-dimensional conformal radiotherapy (3D-CRT) in prostate cancer patients eligible for implant monotherapy. Methods and Materials: Between December 1991 and June 1998, 198 prostate cancer patients were treated with 3D-CRT at the University of California Davis Medical Center. Fifty-two of these patients had a prostate-specific antigen (PSA) level ≤ 10.0 ng/ml, Gleason score ≤ 6, and a 1997 AJCC clinical stage T1bN0–T2bN0. Eleven (21%) patients received radiotherapy to the prostate and seminal vesicles; the remaining patients were treated to the prostate only. The 3D-CRT treatment planning guidelines in Radiation Therapy Oncology Group (RTOG) 9406 were followed after 1994 (similar treatment planning was used before the protocol became available). Typically, 4 oblique and 2 lateral fields were treated. All patients were seen at least weekly while under treatment, 1 month postirradiation and then every 3 months. Total radiation doses ranged from 66.0–79.2 Gy, with a median dose of 73.8 Gy in 41 fractions over 8 weeks. Acute toxicity is described according to the RTOG acute toxicity scoring system. Results: Overall, 3D-CRT was well-tolerated: 29% of patients experienced RTOG Grade 1 and 27% experienced Grade 2 acute lower gastrointestinal (GI) toxicity. Forty percent and 33% of patients experienced Grade 1 and 2 acute genitourinary (GU) toxicity, respectively. As expected, more acute morbidity, especially GI, was observed with a larger clinical target volume (prostate and seminal vesicles versus prostate only; p = 0.05). Neoadjuvant hormonal therapy did not increase the incidence or severity of radiation-induced side effects. No acute toxicity ≥ Grade 3, e.g., hourly nocturia, gross hematuria, diarrhea requiring parenteral support, narcotics for pain control, or catheterization for acute urinary retention, was observed. Conclusion: Although relatively high doses of radiation are delivered to prostate cancers with 3D-CRT compared with conventional radiotherapy, 3D-CRT is surprisingly well-tolerated. No patients in the cohort eligible for implant monotherapy experienced acute toxicity ≥ Grade 3.