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At least 253 records · Page 14Linked to original sources
PubMed2000

Dose-response relationships for radiotherapy of brain metastases: role of intermediate-dose stereotactic radiosurgery plus whole-brain radiotherapy.

The effects of intermediate-dose radiotherapy consisting of whole-brain radiotherapy (WBRT, 10 fractions of 3 Gy) plus stereotactic radiosurgery (SRS) were studied prospectively. Twenty-five adult patients with 31 brain metastases received WBRT plus linear accelerator (LINAC)-based single dose SRS with fixed treatment parameters (10 Gy at the isocenter, target volume enclosed by the 90% isodose). Median age was 63 years, median Karnofsky performance status 80%, and median diameter of brain metastases 2.4 cm. Fifteen patients had non-small-cell lung cancer. Because of some early deaths, only 26 lesions could be evaluated for response. We observed 1 complete and 15 partial remissions. Median time to progression inside or outside the SRS volume was 4.5 months. Actuarial local control of SRS-treated lesions was 61% at 1 year. At that time, only 37% of patients were free from new lesions outside the SRS volume. Median survival and cause-specific survival were 2.3 and 4.5 months, respectively (1-year survival rate 8% and 21%). Ten patients died of progressive brain metastases, 13 from extracranial disease progression (unknown cause of death in 2 cases). Comparable to SRS studies with higher doses, the majority of brain failures occurred outside the SRS volume and more patients died of extracranial progression than of uncontrolled brain metastases. Failure to improve survival can be explained by the high percentage of patients with extracranial metastases (52%). However, the present results appear less favorable than those of previous studies of SRS with 15 Gy to 16 Gy (1-year actuarial local control rates of 66-89%). Therefore, we recommend SRS with 15 Gy to 16 Gy for patients whose favorable prognostic factors justify a boost after WBRT.

Adult↗
PubMed1997

Final results of a randomized trial comparing chemotherapy plus radiotherapy with chemotherapy plus surgery plus radiotherapy in locally advanced resectable hypopharyngeal carcinomas.

After neoadjuvant chemotherapy, a routine conservative approach followed by salvage surgery was evaluated in terms of local control and survival in cases of advanced potentially resectable hypopharyngeal carcinoma. Between 1985 and 1989, 92 patients with T3 or T4-NO,N3 operable squamous cell hypopharyngeal carcinomas received three courses of neoadjuvant chemotherapy every 2 weeks involving a combination of cisplatin, 100 mg/m2, on day 1 and fluorouracil, 1 g/m2, on days 2 to 5, followed by total laryngopharyngectomy plus postoperative radiotherapy in 47 patients (arm A) or radiotherapy alone in 45 patients (arm B). Randomization was always performed prior to chemotherapy. The response rates of tumor and node to chemotherapy were, respectively, 67% in arm A versus 79% in arm B (P > 0.05) and 54% in arm A versus 73% in arm B (P > 0.05). Grade III or IV toxicity was similar, affecting 15% of patients and 7% of cycles in arm A versus 16% of patients and 6% of cycles in arm B. After a mean follow-up of 92 months, survival was statistically better (P = 0.04) in arm A (5-year overall survival, 37%; median survival, 40 months) than in arm B (19% and 20 months) because of a better local control rate (63% versus 39%; P < 0.01). Better results were obtained for mutilant surgery in terms of local control and overall survival, regardless of response to neoadjuvant chemotherapy.

Adult↗
PubMed2001

[Carcinoma of the nasopharynx. Radiotherapy modalities and combined radiotherapy and chemotherapy: state of the art and perspectives].

Nasopharyngeal carcinoma (NPC) is a highly radiosensitive and chemosensitive. In the patient with locally advanced tumours, the results of conventional radiotherapy are unsatisfactory with significant rates of both local recurrences and distant metastases. The aim of this review is to report the innovative strategies for treatment of the nasopharyngeal carcinoma. Altered fractionation techniques can improve local control. The impact of the innovative techniques, including conformal radiation, stereotactic radiation and IMRT, on survival, must be evaluated in randomised trials. The encouraging early results obtained with concurrent (more than sequential) chemotherapy and radiotherapy must be confirmed in prospective randomized trial in endemic areas.

Carcinoma↗
PubMed2002

The Brain Tumor Cooperative Group NIH Trial 87-01: a randomized comparison of surgery, external radiotherapy, and carmustine versus surgery, interstitial radiotherapy boost, external radiation therapy, and carmustine.

OBJECTIVE: The objective of the Brain Tumor Cooperative Group NIH Trial 87-01 trial was to investigate the effect of additional implanted radiation therapy in newly diagnosed patients with pathologically confirmed malignant gliomas. METHODS: The study involved a randomized comparison of surgery, external beam radiotherapy, and carmustine (BCNU) versus surgery, external beam therapy, interstitial radiotherapy boost, and BCNU in newly diagnosed malignant gliomas. (125)I was chosen as best suited for this effort because it allowed preimplantation planning and postimplantation quality assurance review. Two hundred ninety-nine patients met the eligibility criteria and were randomized into the two arms of the study between December 1987 and April 1994. Follow-up continued for an additional 3 years. Twenty-nine patients were identified as having committed protocol violations and were excluded, resulting in 270 subjects in the Valid Study Group. One hundred thirty-seven patients received external beam radiation and BCNU, and 133 underwent the (125)I implantation plus external beam radiation and BCNU therapy. RESULTS: The overall median survival for the Valid Study Group was 64.3 weeks. The median survival for patients receiving additional therapy of (125)I was 68.1 weeks, and median survival for those receiving only external beam radiation and BCNU was 58.8 weeks. The cumulative proportion surviving between the two treatment groups was not statistically significantly different (log-rank test, P = 0.101). As in other studies in the literature, age, Karnofsky score, and pathology were predictors of mortality. Additional analyses incorporating an adjustment for these prognostic variables, either in a stratified analysis or Cox proportional hazards model, did not result in statistically significant differences in the cumulative proportion of patients surviving between the two treatment groups. CONCLUSION: We conclude that there is no long-term survival advantage of increased radiation dose with (125)I seeds in newly diagnosed glioma patients.

Antineoplastic Agents, Alkylating↗
PubMedDate not supplied

Is one Gy equal to one Gy in chemo-radiotherapy or hormono-radiotherapy?

The biological effect induced in the cell by a fixed dose of radiotherapy (e.g. 1 Gy) can be increased, reduced or significantly altered when chemotherapeutic or hormonal agents interact. A different timing of the combination between chemo/hormonotherapy and radiotherapy may also influence the cascade of effects induced by the dose of 1 Gy. Furthermore, patient, tumor and treatment-related factors are individual parameters which should be carefully considered for their potential impact on the radiation dose.

Animals↗
PubMedDate not supplied

Low pre-radiotherapy prostate-specific antigen level is a significant predictor of treatment success for postoperative radiotherapy in patients with prostate cancer.

BACKGROUND: The optimal role of postoperative radiotherapy for patients with prostate cancer remains undefined. MATERIALS AND METHODS: The medical records of 70 patients (median age: 66 years), who had received radical radiotherapy (RT) between the years 1996 and 2004 after radical prostatectomy (RP), were analyzed. Fifteen patients had received immediate adjuvant RT, while the other 55 patients had received salvage therapy. Hormonal therapy had been performed in 28 patients before RT and continued in two of them concurrently with RT. A median dose of 60 Gy was delivered to the prostate bed. Pelvic node irradiation was performed in all patients. RESULTS: After a median follow-up period of 23 months, 21 patients had experienced biochemical failure. Actuarial 3- and 5-year biochemical relapse-free survival estimates were 67.4%. No patient had local failure, although distant metastases with biochemical failure were found in five patients. On univariate analysis, the following were significant for biochemical failures: seminar vesicle involvement, serum PSA level >1 ng/ml before RT, pathological pelvic node involvement, RT indication (adjuvant vs. salvage) and Gleason score. However, only the serum PSA level before RT was significant on multivariate analysis. CONCLUSION: Postoperative RT with a pre-RT PSA level <0.1 ng/ml seemed to be effective in patients with prostate cancer.

Aged↗
PubMed1991

Nasopharyngeal carcinoma: results of treatment by radiotherapy vs chemotherapy plus radiotherapy.

To determine the efficacy of neoadjuvant chemotherapy over radiotherapy alone in locally advanced nasopharyngeal carcinoma, a prospective non-randomized study was performed from 1 January 1982 to 31 December 1985 at Ramathibodi Hospital, Thailand. There were 69 new cases who completed treatment and were followed up at least once. Thirty-three cases were treated by radical radiotherapy (RT) alone and 36 cases by chemotherapy (CT) + RT. CT were by the combination of cis-diamminedichloroplatinum II and 5 fluorouracil. Of 32 cases, 2 courses of CT were given before RT and 1 after. The other 4 received 3 courses prior to RT. For both groups, RT technique and dosage were similar. Follow-up time of both groups ranged from 6-104 months (mean 50.3, median 50) and 8-100 months (mean 52.2, median 54.5), and total failures were 18/33 and 13/36, respectively, with no statistical difference (p greater than 0.05). Estimated actual survival and disease free survival from Kaplan-Meier curves at 3 years were about 75 per cent vs 75 per cent and 65 per cent vs 65 per cent, respectively, with no statistical differences (Log-Rank test). Therefore, we concluded that induction chemotherapy had some benefit but no statistical significance over RT alone. However, the role of maintenance chemotherapy is now being studied.

Adolescent↗
PubMed1983

[Curative radiotherapy in stage C prostatic carcinoma. Experiences with radiotherapy-endocrine treatment].

In a prospective study 209 patients with prostatic cancer stage C who were seen between 1968-1974 received endocrine treatment and radiotherapy (6000 r) of the prostate without inclusion of regional lymph nodes. The patients were seen every 6 months up to 8 years. 247 transrectal biopsies and 7 transurethral resections of the prostate were performed. The analysis of the biopsies revealed that the combined endocrine and radiotherapy is followed by tumor neutralisation of about 70% in highly differentiated prostatic cancers and less effective in lower differentiated tumors. 80% of biopsies from tumors responding to therapy still show tumor cells. The 5-year-survival corresponded with tumor regression and tumor size. However a prognosis on the basis of these findings is not possible for the individual case.

Adenocarcinoma↗
PubMed1996

Extrapolated response dose as a potential tool in radiotherapy and chemo-radiotherapy of head and neck cancers.

An analysis of head and neck cancer patients treated by radiotherapy (RT) alone (114 patients) and by chemo-radiotherapy (RT + CT) (115 patients) was carried out; the doses varied from 40-77 Gy and 35-71 Gy in RT and RT + CT groups respectively. The chemotherapy (CT) (induction/concurrent) drugs used were 5-FU, cisplatin, methotrexate either single or in combination. Extrapolated response dose values were evaluated with alpha/beta values of 10, 2.5 and 6 Gy for acute, late complications and tumour response, respectively. Dose enhancement factor (DEF) and Therapeutic gain factor (TGF) values were evaluated on the basis of ERD for patients receiving 5-FU RTCT (72 patients). ERD vs late complication rate and response rate curves were drawn for RT, RT + CT (< 7 cycles), RT + CT (> 6 cycles) and RT + CT (cumulative). DEF values for response rate were 0.95, 0.95 and 0.82 for the three RT + CT groups respectively. Similarly DEF values for late complication rate were evaluated as 0.87, 0.93 and 0.88. TGF values for RT + CT were 1.09, 1.02 and 0.93. TGF values indicated lack of significant influence of CT on clinical outcome. The correlation of ERD with late complication, response and status at last follow up (NED) was statistically significant for both groups (P < 0.01). ERD did not correlated with acute complication in RT group (P > 0.01). From the present analysis, in RT + CT treatments of head and neck cancers, an ERD value of 69 Gy is suggested as the limit for an acceptable 5% late complication rate.

Combined Modality Therapy↗
PubMed2004

[Comparison of intensity-modulated postoperative radiotherapy with conventional postoperative conformal radiotherapy for retroperitoneal sarcoma].

External postoperative radiation therapy for retroperitoneal sarcoma is an example of treatment using large fields for complex shaped volumes of irradiation. Prescribed dose is limited by tolerance of adjacent organs at risk (OAR). From a recent case treated by conventional conformal radiotherapy (3D-CRT), we evaluate the benefit of five theoretical IMRT plans. Criteria used are calculated from DVH related to delineated PTV and OAR. IMRT should permit to enhance the prescribed dose without increasing dose in the OAR (especially residual kidney, spinal cord and small bowel). This theoretical study show the feasibility of a dose escalation from a treatment dose of 45 Gy delivered by 3D-CRT up to a planning dose of 54 Gy calculated by IMRT with: for the PTV: an improvement of the dose homogeneity about 5% (range 2-6%) and moreover the coverage factor (CF) about 13% (range 9-16%); for the OAR: an improvement of the protection factor (PF) about 20% (range 11-24%); and thus an improved conformity index (CI = CF x PF) about 25% (range 15-32%).

Feasibility Studies↗
PubMed2005

Intensity-modulated radiotherapy planning from limited anatomical information: is Sim-CT sufficient for planning women with breast cancer receiving intensity-modulated radiotherapy?

AIMS: To investigate intensity-modulated radiotherapy (IMRT) plans for women with carcinoma of the breast, using a small number of Sim-CT slices, thus avoiding changing the patient's position and potential problems with CT capacity. MATERIALS AND METHODS: Ten CT scans of women with breast cancer were obtained for use in the study. IMRT plans based on an open tangent pair and additional top-up segment fields were created using the full CT scan, and represented the gold standard treatment plan for comparison purposes. Five-slice CT simulator scans were artificially created by omitting intermediate slices from the full CT scans. Additionally, the intermediate CT slices were recreated via interpolation of the five slices using a standard interpolation algorithm. IMRT plans were created in the same way as for the full CT scans. To allow a suitable plan comparison to be made, the beam segments and monitor units were transferred to the full CT scans, and the dose distribution calculated. RESULTS: The interpolated five-slice plans showed no significant difference in the volume of tissue receiving dose outside the range 95-105%, compared with the IMRT plans created using the full CT data set (1.3 +/- 2.2%, P = 0.092). In contrast, the discrete slice CT simulator plans increased by 6.3 +/- 5.4%, P = 0.0054, showing a statistically significant difference in the dose distribution produced and a clinically inferior plan. CONCLUSIONS: Plans created using five discrete slice CT scans were inferior to full CT-derived IMRT treatment plans, and are therefore not acceptable for IMRT. However, interpolating five CT simulator slices provides adequate anatomical information to produce comparable IMRT plans to those created by full CT scans of the patient. This allows the introduction of IMRT for this patient group without the need to change treatment position to accommodate CT scanning.

Anatomy, Cross-Sectional↗
PubMed2006

Comparison of inverse-planned three-dimensional conformal radiotherapy and intensity-modulated radiotherapy for non-small-cell lung cancer.

PURPOSE: Lungs are the major dose-limiting organ during radiotherapy (RT) for non-small-cell lung cancer owing to the development of pneumonitis. This study compared intensity-modulated RT (IMRT) with three-dimensional conformal RT (3D-CRT) in reducing the dose to the lungs. METHODS: Ten patients with localized non-small-cell lung cancer underwent computed tomography (CT). The planning target volume (PTV) was defined and the organs at risk were outlined. An inverse-planning program, AutoPlan, was used to design the beam angle-optimized six-field noncoplanar 3D-CRT plans. Each 3D-CRT plan was compared with a series of five IMRT plans per patient. The IMRT plans were created using a commercial algorithm and consisted of a series of three, five, seven, and nine equidistant coplanar field arrangements and one six-field noncoplanar plan. The planning objectives were to minimize the lung dose while maintaining the dose to the PTV. The percentage of lung volume receiving >20 Gy (V20) and the percentage of the PTV covered by the 90% isodose (PTV90) were the primary endpoints. The PTV90/V20 ratio was used as the parameter accounting for both the reduction in lung volume treated and the PTV coverage. RESULTS: All IMRT plans, except for the three-field coplanar plans, improved the PTV90/V20 ratio significantly compared with the optimized 3D-CRT plan. Nine coplanar IMRT beams were significantly better than five or seven coplanar IMRT beams, with an improved PTV90/V20 ratio. CONCLUSION: The results of our study have shown that IMRT can reduce the dose to the lungs compared with 3D-CRT by improving the conformity of the plan.

Carcinoma, Non-Small-Cell Lung↗
PubMed2007

Intensity-modulated or conformal radiotherapy improves the quality of life of patients with nasopharyngeal carcinoma: comparisons of four radiotherapy techniques.

BACKGROUND: It was reported previously that the dosimetric superiority of conformal radiotherapy (RT), either 3-dimensional conformal RT (3D-CRT) or intensity-modulated RT (IMRT), over conventional 2D-RT translated into clinical benefits for patients with nasopharyngeal carcinoma (NPC). In this study, the authors compared quality-of-life (QOL) outcomes of NPC survivors who received treatment with 1 of 4 different RT techniques at a single institute during different periods. METHODS: The authors analyzed QOL data of from 237 patients with NPC who were cancer free for 2 or 3 years when their QOL was assessed. The study population included 152 patients who received conventional RT (2D-RT, 61 patients; 2D-RT plus 3D-CRT boost, 91 patients) and 85 patients who received conformal RT (3D-CRT, 33 patients; IMRT, 52 patients). The European Organization for the Research and Treatment of Cancer (EORTC) Core QOL questionnaire and the EORTC Head and Neck QOL questionnaire were completed. RESULTS: Compared with patients who received with conventional RT, patients who received conformal RT had both statistically (P < .05) and clinically (a difference in mean scores >or=10 points) significant improvements in the scales of global QOL, pain, appetite loss, senses, speech, social eating, teeth, opening mouth, xerostomia, sticky saliva, and feeling ill. No significant difference was observed in any of the scales that compared 2D-RT with 2D-RT plus 3D-CRT boost or that compared 3D-CRT with IMRT. Survivors who received conformal RT had a 2.01-fold higher probability (odds ratio [OR], 2.01; 95% confidence interval [95% CI], 1.19-3.68) of reporting good global QOL and a 2.70-fold lower probability (OR, 0.37; 95% CI, 0.20-0.66) of reporting a high level of xerostomia than survivors who received conventional RT. CONCLUSIONS: Conformal RT substantially improved head and neck-related symptoms and broad aspects of QOL for survivors of NPC.

Adult↗
PubMed2004

Target dose conformity in 3-dimensional conformal radiotherapy and intensity modulated radiotherapy.

BACKGROUND AND PURPOSE: Dose conformity to the planning target volume is an important criterion in radiotherapy treatment planning, for which the conformity index is a useful assessment tool. The purpose of this study is to compare the differences in CI for the treatment planning of four cancers including the nasopharynx, oesophagus, lung and prostate. PATIENTS AND METHODS: Seventy patients with cancers of nasopharynx (30), oesophagus (15), lung (15) and prostate (10) were recruited. Each of these patients was planned with three sets of treatment plans using the FOCUS treatment planning system: the forward and inverse 3DCRT plans and the IMRT plan. The CI was generated for each treatment plan. The mean CI from each cancer patient group was calculated and compared with the other three cancer groups. The mean value of CI was also compared among the three planning methods. RESULTS: The oesophageal and lung cancers demonstrated relatively higher overall mean CI values (0.64 and 0.62, respectively), whereas that of the nasopharynx and prostate were lower (0.54 and 0.50, respectively). With regards to the planning method groups, the IMRT plans produced the highest overall mean CI (0.62), while those for the forward and inverse 3DCRT were similar (0.57 and 0.55, respectively). CONCLUSION: For the four selected cancers, oesophageal and lung cancers were easier to conform than the nasopharyngeal and prostate cancers. The IMRT plans were more effective in achieving better dose conformity than that of the 3DCRT.

Cohort Studies↗
PubMed2003

Intensity-modulated radiotherapy as a means of reducing dose to bone marrow in gynecologic patients receiving whole pelvic radiotherapy.

PURPOSE: To evaluate intensity-modulated whole pelvis radiotherapy (IM-WPRT) (with bone marrow [BM] as a planning constraint) as a means to reduce the volume of pelvic BM irradiated. METHODS AND MATERIALS: Ten women with cervical or endometrial cancer previously treated using IM-WPRT were selected for this analysis. Using the treatment planning CT scan, the clinical target volume was defined to encompass the gross tumor, parametrial tissues, uterus (if present), and regional lymph nodes. The clinical target volume was expanded by a 1-cm margin to form the planning target volume (PTV). The bladder, rectum, small bowel, and pelvic BM were delineated in each patient. Three plans were created for each patient: a standard four-field WPRT plan, an IM-WPRT treatment plan designed to conform the dose to the PTV while minimizing dose to the normal tissues (excluding BM), and a BM-sparing (BMS) IM-WPRT plan that included the BM as an additional treatment planning constraint. Dose-volume histograms for the PTV, small bowel, and BM were compared for each patient. RESULTS: For each of the 10 patients, BMS IM-WPRT treatment plans demonstrated a significant reduction of the volume of BM receiving >40% (18 Gy) of the prescription dose (45 Gy) compared with both IM-WPRT and four-field treatment. On average, BMS IM-WPRT resulted in only 60% of the BM volume irradiated to >50% of the dose compared with 87.4% (p <0.001) of the BM volume in a four-field plan and 75.7% (p < 0.003) of the volume in an IM-WPRT plan. Furthermore, the BMS IM-WPRT plans resulted in significant sparing of all other normal tissues that was comparable to the original IM-WPRT. In all 10 cases, the BMS IM-WPRT treatment plan did not result in any significant differences in the PTV and small bowel dose-volume histograms compared with the IM-WPRT treatment plans. CONCLUSION: BMS IM-WPRT significantly reduces the volume of pelvic BM irradiated compared with conventional WPRT. In addition, BMS IM-WPRT did not compromise the improvements previously seen in IM-WPRT treatment plans that did not consider BM. Clinical studies are necessary to assess the significance of BMS IM-WPRT in reducing hematologic toxicity.

Bone Marrow Diseases↗
PubMed2002

Intensity-modulated radiotherapy of sacral chordoma--a case report and a comparison with stereotactic conformal radiotherapy.

In a case of partially resected sacral chordoma, the planning target volume (PTV) received 60 Gy and the gross target volume (GTV) 72 Gy using inversely planned, intensity-modulated, radiation therapy (IMRT). IMRT was compared with 3D-conformal radiotherapy (CRT). With IMRT, it was found that dose distribution is more homogeneous within the PTV outside the GTV and allows simultaneous dose escalation within the GTV. The volume of bowel receiving a dose higher than 40 Gy was reduced from 400 cc with CRT to 220 cc with IMRT. If particle therapy is not available, IMRT seems to be a promising alternative in the treatment of sacral chordomas.

Aged↗
PubMed1999

Postoperative radiotherapy of paranasal sinus tumours: a challenge for intensity modulated radiotherapy.

BACKGROUND AND PURPOSE: Intensity modulated radiotherapy (IMRT) is used in our department for treatment of paranasal sinuses. We describe the methodology that was developed together with the clinical implementation, illustrated by a case report. MATERIAL AND METHODS: Patient history, treatment and short follow-up are described. An IMRT, obtained by superposition of static beam segments was implemented. Electronic portal images, compared to digitally reconstructed radiographs (DRR) were used to evaluate and adjust patient positioning. RESULTS, DISCUSSION AND CONCLUSION: IMRT is an appropriate and feasible treatment technique for head and neck cancer in anatomical regions that are difficult to treat. A high tumour dose can be combined with a good sparing of the surrounding organs at risk (OAR's).

Adenocarcinoma↗
PubMed1990

[Beam radiotherapy of malignant tumors using computer-assisted radiotherapy programs].

The authors give a brief description a ROKUS-M + Altai-MT system, its software ASPECT-1, stages of radiotherapy design and implementation of optimized programs. They gave examples of optimum computerized design of irradiation in tumors of the nasopharynx, breast, female genitals, esophagus, lungs, bladder, and rectum. The paper is illustrated with charts of isodoses and distributions corresponding to optimized programs of irradiation.

Breast Neoplasms↗