Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “local control”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 73 records · Page 4Linked to original sources

Local control of molecular fragmentation: the role of orientation.

Local control theory, where the instantaneous response of a system to an external field determines the control field, is employed for the purpose of inducing molecular fragmentation processes via infrared excitation. In particular, the effects of the orientational motion are investigated and compared with the idealized case of a frozen rotation. It is shown that the rotational degree of freedom is crucial for the applicability of the employed local control algorithm. The addition of an additional static electric field which induces a molecular preorientation offers an efficient way for the local control. In particular, with increasing static field strength, the fragmentation yield approaches unity so that the idealized rotationless case is recovered. Numerical results are presented for the NaI molecule.

Journal Article↗

Effect of delayed radiation therapy on local control in breast conservation therapy.

PURPOSE: To assess local control when radiation therapy is delayed to complete chemotherapy in breast conservation therapy. MATERIALS AND METHODS: Breast conservation therapy was performed in 310 cases in 297 patients (aged 24-85 years) with stage 0-II breast cancer. Adjuvant chemotherapy was used in 76 cases. The authors analyzed the time between diagnosis and radiation therapy and correlated these findings with local control of disease. RESULTS: The time between diagnosis and radiation therapy in the 247 cases treated without chemotherapy-related delay was 2-59 weeks (mean, 8 weeks). The interval in the 63 cases with chemotherapy-related delay was 12-63 weeks (mean, 31 weeks; P < .001). Ten of the 11 cases with an in breast relapse were in the group treated without a delay (P = .57). CONCLUSION: Delaying radiation therapy for chemotherapy does not compromise local control.

Adult↗

Does the dose fractionation schedule influence local control of adjuvant radiotherapy for early stage breast cancer?

PURPOSE: To explore the correlation between dose fractionation and local control for the adjuvant radiotherapy of early stage breast cancer. METHODS AND MATERIALS: A matched-pair analysis of early stage invasive breast cancer treated adjuvantly with two different dose fractionation schedules, 4000 cGy in 16 fractions (Cohort A) vs. 5000 cGy in 25 fractions (Cohort B) was undertaken to compare local control rates. A systematic review of the published experience in similar patient populations was conducted and the reported dose fractionation schedule was converted to a biologic effect dose (BED) based upon the linear quadratic equation. The BED was then used as a basis for comparing reported local control rates with different dose fractionation schemes. RESULTS: The 118 patient pairs were matched from Cohort A and Cohort B using known significant prognostic factors including age, histology, surgical margins, receptor status, lymphvascular space invasion, extensive intraductal disease, lymph node status, and systemic therapy. The local recurrence rate at 5 years for those treated with 4000 cGy (BED = 65 cGy4) and 5000 cGy (BED = 75 cGy4) was 12.7% and 6.8%, respectively, and this difference was not statistically significant (p = 0.09). Overall survival was 84% at 5 years for both groups. Comparison of the different dose fractionation schemes reported in the literature revealed a highly statistically significant difference between those treated with less than a BED of 75 Cy4 and those treated with a BED of 75 Gy4 or greater. CONCLUSION: Although not statistically significant, there was a trend in the matched pair analysis which suggests that 4000 cGy in 16 fractions (BED = 65 cGy4) provides inferior local control compared to 5000 cGy in 25 fractions (BED = 75 cGy4). Moreover, the literature review demonstrates that a dose control relationship may exist for local control in the adjuvant setting. A dose fractionation schedule equivalent to 5000 cGy in 25 fractions to the whole breast may represent the optimal dose fractionation schedule for local control.

Adult↗

Flow cytometric analysis of DNA ploidy, percent S-phase fraction, and total proliferative fraction as prognostic indicators of local control and survival following radiation therapy for prostate carcinoma.

PURPOSE: Treatment recommendations for localized prostate cancer may be improved by the identification of tumor factors prognostic for local control and survival. In this retrospective study, flow cytometric deoxyribonucleic acid (DNA) ploidy analysis and cell cycle analysis were performed on paraffin-embedded biopsy material to determine if additional prognostic factors could be identified in patients treated with radiation therapy. METHODS AND MATERIALS: Seventy patients with T1-4NxM0 tumors were identified in whom the primary treatment had been radical radiation therapy with no prior or concurrent endocrine therapy and in whom sufficient prostatic tissue was available for flow cytometric analysis. There were 40 diploid, 26 aneuploid, and 4 multiploid cases. Aneuploid and multiploid cases were combined for analysis. Cell cycle data were obtained on all diploid and 10 aneuploid cases. RESULTS: The histologic differentiation of the tumor (well or moderate vs. poor) was an independent predictor of overall survival and disease-free survival (p = 0.05 and 0.01, respectively). Local control was worse in the poorly differentiated patients, although this was not statistically significant in a multivariate analysis (p = 0.08). Neither T-stage, deoxyribonucleic acid ploidy (diploid vs. nondiploid), percent S-phase fraction, nor total proliferative fraction (S-phase fraction + G2M) significantly predicted for any of these endpoints. Within the diploid and well or moderately differentiated subgroup (n = 25), S-phase (< 4.2 vs. > or = 4.2) was a significant predictor of local control (100% vs. 51%, p = 0.03). A comparable distinction could be made using total proliferative fraction (< 10% vs. > or = 10%) with local control rates of 100% vs. 56% (p = 0.05). Among the poorly differentiated tumors, no similarly favorable subgroup was identified. CONCLUSIONS: This retrospective and multivariate analysis identifies both histology and percent S-phase or total proliferative fraction as predictors of local control following irradiation, and confirms that histology, but not DNA ploidy, is significant for overall survival. If these previously unreported findings are confirmed by prospective studies, S-phase should be added to histology as a parameter in the evaluation of clinical trials.

Cell Division↗

Relationship between the radiologic features of esophageal cancer and the local control by radiation therapy.

In order to predict the possibility of local control of esophageal cancer by radiation therapy, the relationship between the x-ray findings before and after irradiation and the histologic radiation effect obtained from the surgically resected esophagus was analyzed in 130 cases irradiated preoperatively during the period 1971 through 1980. In the superficial or proliferative type in x-ray image before treatment, the local control was obtained in 46.5% of the cases with the dose of 40 Gy, whereas in the ulcerative or infiltrative type, in 21.8%. The barium examination performed after irradiation was more useful to evaluate the radiation effect than that before treatment. In cases with a marked radiation effect after irradiation, the frequency of local control reached 76.9%. On the other hand, the local control remained 11.9% in cases with no or poor radiation effect. The results obtained by the preoperatively irradiated cases were applied to the analysis of 119 cases irradiated radically during the period 1965 to 1980. Almost the same results were also acquired in radically irradiated cases. The degree of radiologic and histologic radiation effect on the primary tumor was closely related to the long-term survival rate of the patient.

Adult↗

The effect of delay in treatment on local control by radiotherapy.

PURPOSE: The objective of this study was to estimate the effect of delay in initiation of treatment on rates of local control by radiotherapy. METHODS AND MATERIALS: A model of the effects of delay was developed based on the following assumptions: (a) that tumor growth rate is exponential, (b) that a predetermined radiotherapy regimen will kill the same fraction of clonogenic cells in a given tumor whether it is administered early or late, and (c) that the absolute number of cells surviving in a tumor is determined by Poisson statistics. Monte Carlo simulation was used to estimate the expected rate of decrease in local control associated with delay in a population of tumors, which was heterogeneous with respect to doubling time and initial volume. The model was applied to carcinoma of the tonsillar region. RESULTS: It was shown that at some point in the evolution of every case, the probability of local control decreases sharply over a relatively short period of time. The maximum rate of decrease in the probability of local control occurs at the 37% local control level when it reaches 25.5% per tumor doubling time. When heterogeneity with respect to doubling time and stage was taken into account, it was estimated that the local control rate would decrease by approximately 10% per month in a typical series of patients with carcinoma of the tonsillar region. CONCLUSIONS: It was concluded that delay in initiation of radiotherapy may be associated with a clinically important deterioration in local control rates. We recommend that waiting times for radiotherapy should be As Short As Reasonably Achievable (ASARA).

Algorithms↗

Preoperative chemoradiotherapy (modified Eilber protocol) provides maximum local control and minimal morbidity in patients with soft tissue sarcoma.

BACKGROUND: Local recurrence rates of 15% to 30% after treatment of soft tissue sarcoma (STS) are still common but unacceptable. Our hypothesis was that a refined neoadjuvant chemotherapy and radiation protocol (modified Eilber protocol) improves local control rates while minimizing major morbidity. METHODS: Consecutive patients with STS deep to the fascia of the extremity or trunk during 1984 to 1996 were treated with 3 days of doxorubicin (30 mg/day) and sequential radiation (300 cGy/day for 10 days). Wide excision with limb preservation was performed 4 to 8 weeks after radiation completion. Treatment complications, margins, local recurrence, and survival were prospectively documented. RESULTS: Of 75 patients, 66% had tumors >5 cm, and 71% were grade 2/3. In eight patients, negative margins were not achieved, and four of these had amputation (95% limb salvage). Three of the remaining four had local recurrence with a 5- and 7-year actuarial local control rate of 50% and 25%, respectively. In contrast, of the 67 patients with negative margins, a local control rate of 97% at 5 years and 94% at 7 years and an overall survival of 63% were achieved. Although margin (P = .001) and stage (P = .035) were correlated, these were not significant on multivariate Cox regression analysis. Risk factors for death included tumor stage (hazard ratio, 1.54; P = .001) and tumor grade (hazard ratio, 1.4; P = .02). Three patients (4%) required reoperation for tissue loss, and eight patients (10.6%) developed minor wound complications. CONCLUSIONS: This modified Eilber protocol seems to maximize local control and minimize major wound complications for extremity/truncal STS.

Adolescent↗

Local control in pelvic Ewing sarcoma: analysis from INT-0091--a report from the Children's Oncology Group.

PURPOSE: The impact of the modality used for local control of Ewing sarcoma is uncertain. We investigated the relationship between the type of local control modality, surgery, radiation (RT) or both (S + RT), and subsequent risk for local failure (LF) in patients with nonmetastatic pelvic Ewing sarcoma treated on INT-0091. PATIENTS AND METHODS: Patients < or = 30 years with Ewing sarcoma, primitive neuroectodermal tumor or primitive sarcoma of bone were randomly assigned to receive chemotherapy with doxorubicin, vincristine, cyclophosphamide, and dactinomycin, (VACA) or with these four drugs alternating with ifosfamide and etoposide (VACA-IE). The local control modality, surgery, RT or both was chosen by the treating physicians. The effect of local control modality was assessed after adjusting for the size of tumor (< 8 cm, > or = 8 cm) and chemotherapy type. RESULTS: Seventy-five patients with pelvic tumors and a median follow-up of 4.4 years (0.6 to 11.4 years) comprised the study population. Twelve underwent surgery, 44 received RT, and 19 received both. The 5-year event-free survival (EFS) and cumulative incidence of LF was 49% and 21% (16%, LF only; 5%, LF and distant failure). There was no significant difference in EFS or LF by tumor size (< 8 cm, > or = 8 cm), local control (LC) modality, or chemotherapy. However, VACA-IE seems to confer an LC benefit (11% v 30%; P = .06). CONCLUSION: There was no significant effect of local control modality (surgery, RT or S + RT) selected by the treating physicians on rates of local failure or EFS. However, VACA-IE improves LC (11%) compared with previously published results for pelvic Ewing sarcoma.

Antineoplastic Combined Chemotherapy Protocols↗

Radiotherapy and local control in rectal cancer.

Recurrence is a stage in the natural history of rectal cancer. Preoperative radiotherapy or postoperative radiochemotherapy lower the rate of recurrence, improving local control. From 1980 to 1997, at the "Divisione di Radioterapia" of the "Università Cattolica del S. Cuore" of Rome 380 patients with rectal cancer of early clinical stage T2-3, candidates for surgery for cure, underwent radiation therapy. 119 patients underwent postoperative radiotherapy (45-50 Gy); 45 patients underwent "sandwich" radiotherapy (45 Gy:27 Gy before and 28 Gy after surgery), of whom 7 were treated with preoperative radiotherapy alone; 145 patients underwent preoperative concomitant radiochemotherapy according to 3 different protocols, radiotherapy (38 Gy) combined with mitomycin C and 5-FU; radiotherapy (50.4 Gy) combined with cisplatin and 5-FU; radiotherapy (45 Gy) combined with 5-FU and folinic acid. 71 patients were treated with preoperative radiotherapy (38 Gy) combined with IORT (10 Gy). Median follow-up was 6 years. Overall local control was 85% at 3 years, 83% at 5 years, 81% at 10 years. The rate of local control at 5 years was: 76% for postoperative radiotherapy, 83% for "sandwich" radiotherapy, 84% for preoperative radiochemotherapy and 93% for preoperative radiotherapy combined with IORT. Local control was shown to be significantly better with preoperative treatment as compared to postoperative treatment (p = 0.02). The incidence of metastases was 35% in the patients with local recurrence and 16% in those with local control. The difference in survival was highly significant in patients with local control as compared to those with local recurrence: at 5 years 87% and 32% respectively. Patients with local control showed a lower incidence of metastasis and a better survival.

Antineoplastic Combined Chemotherapy Protocols↗

Split-course accelerated hyperfractionation radiotherapy for advanced head and neck cancer: influence of split time and overall treatment time on local control.

We analyzed 52 patients with stage III and IV head and neck cancer who were given split-course accelerated hyperfractionated radiotherapy with curative intent, focusing particularly on the influence of split-time on local control. An initial complete response was achieved in 16 patients (31%), and the rate of persistent local control at 3 years was 23%. The cause specific survival rate at 3 years was 29%. Univariate analysis of local control according to the split-time duration and overall treatment time showed that shorter duration (< or = 14 days or < or = 45 days, respectively) had a significantly positive impact on local control (P < 0.05). Multivariate analysis using local control as an endpoint also demonstrated that gender (women showing a better outcome than men) and split-time (< or = 14 days was better than > 14 days) were statistically significant factors for local control. These results suggest that shortening the split-time during radiotherapy might improve local control in accelerated hyperfractionation.

Adult↗

The effect of overall treatment time on local control in patients with adenocarcinoma of the prostate treated with radiation therapy.

Studies of patients treated with radiation therapy for squamous cell carcinoma of the head and neck have demonstrated that when all other variables are constant, protraction of the overall treatment time leads to a decreased probability of local control. Few data exist on the effect of overall treatment time on local control following irradiation of tumors that are generally thought to be slowly proliferating, such as adenocarcinoma of the prostate. This analysis was undertaken to determine the time-dose relationships for local control of prostatic adenocarcinoma at the University of Florida. All patients were treated at least 5 years prior to the date of analysis. For patients with Stage A2 disease, a tumor dose of 6500 cGy in 7 to 7.5 weeks to 7000 cGy in 8 weeks resulted in local control in 17/17 patients (100%). For patients with Stage B1 disease, the local control rate was 14/16 (88%) with an overall treatment time of less than or equal to 8 weeks versus 1/3 in patients who received split-course treatment in greater than 8 weeks (p = .097). For patients with Stage B2, C1, and C2 disease who received greater than or equal to 6500 cGy, the 5-year rate of local control was lower when overall treatment time was protracted beyond 8 weeks. Results were as follows: B2 (62 patients), less than or equal to 8 weeks, 88%, versus greater than 8 weeks, 55%, p = .002; C1 (87 patients), less than or equal to 8 weeks, 88%, versus greater than 8 weeks, 73%, p = .052; Cs (33 patients), less than or equal to 8 weeks, 81%, versus greater than 8 weeks, 65%, p = .056. Stratification by tumor grade of patients with Stage B1, B2, C1, and C2 disease who received greater than or equal to 6500 cGy demonstrated significantly lower local control rates for all grade categories when the overall treatment time was protracted beyond 8 weeks. Five-year local control rates (life-table method) for overall treatment time less than or equal to 8 weeks versus greater than 8 weeks were as follows: well differentiated, 93% versus 73% (p = .003); moderately differentiated, 86% versus 69% (p = .017); and poorly differentiated, 75% versus 59% (p = .046). These data suggest that tumor repopulation during excessively protracted treatment may be a clinically significant factor in patients with adenocarcinoma of the prostate.

Adenocarcinoma↗

[Importance of local control of cancer after conservative therapy].

The role of local control in the cure of solid tumors remains a matter of crucial importance particularly for the cases of conservative therapy. Arguments that higher local control rates would result in more cured patients is a subject of controversies for some tumors as breast cancer. For tumors with different natural history, the authors outlined the crucial role of local control to improve cure rate thank to surgery and radiotherapy.

Combined Modality Therapy↗

Muscle-invasive bladder cancer treated with external beam radiation: influence of total dose, overall treatment time, and treatment interruption on local control.

PURPOSE: To evaluate and eventually quantify a possible influence of tumor proliferation during the external radiation course on local control in muscle invasive bladder cancer. METHODS AND MATERIALS: The influence of total dose, overall treatment time, and treatment interruption has retrospectively been analyzed in a series of 379 patients with nonmetastasized, muscle-invasive transitional cell carcinoma of the urinary bladder. All patients received external beam radiotherapy at the Netherlands Cancer Institute between 1977 and 1990. Total dose varied between 50 and 75 Gy with a mean of 60.5 Gy and a median of 60.4 Gy. Overall treatment time varied between 20 and 270 days with a mean of 49 days and a median of 41 days. Number of fractions varied between 17 and 36 with a mean of 27 and a median of 26. Two hundred and fourty-four patients had a continuous radiation course, whereas 135 had an intended split course or an unintended treatment interruption. Median follow-up was 22 months for all patients and 82 months for the 30 patients still alive at last follow-up. A stepwise procedure using proportional hazard regression has been used to identify prognostic treatment factors with respect to local recurrence as sole first recurrence. RESULTS: One hundred and thirty-six patients experienced a local recurrence and 120 of these occurred before regional or distant metastases. The actuarial local control rate was 40.3% at 5 years and 32.3% at 10 years. In a multivariate analysis total dose showed a significant association with local control (p = 0.0039), however in a markedly nonlinear way. In fact only those patients treated with a dose below 57.5 Gy had a significant higher bladder relapse rate, whereas no difference in relapse rate was found among patients treated with doses above 57.5 Gy. This remained the case even after adjustment for overall treatment time and all significant tumor and patient characteristics. The Normalized Tumor Dose (NTD) (alpha/beta = 10) and NTD (alpha/beta = 15) were not significantly related to local control (p = 0.96 and p = 0.053, respectively). Only weak evidence was found for an association between local control and overall treatment time (p = 0.067). No difference in bladder relapse rate was found among patients treated with a continuous course and patients who had treatment interruptions (p = 0.099). Neither the length of the interruption, nor the actual number of treatment days has a significant influence on local control (p = 0.04 and p = 0.09, respectively). CONCLUSION: In contrast to two earlier, but smaller reports, in this study no significant effect of treatment prolongation on outcome after radiotherapy could be demonstrated and thus no support was found for an important role for tumor proliferation as the cause of treatment failure in muscle-invasive bladder cancer. Results of large-sized phase III trials will have to be awaited to show any benefit from reduction of the overall treatment time and to quantify the potential effect of tumor proliferation.

Aged↗

Effect of overall treatment time on local control in radical radiotherapy for squamous cell carcinoma of esophagus.

PURPOSE: To analyze the effect of overall treatment time on local control in radical radiotherapy for squamous cell carcinoma of esophagus. METHODS AND MATERIALS: Three hundred and fifty-three patients with inoperable esophageal cancer (tumor length < or = 10 cm in all cases) treated during 1963-1988 by radical radiotherapy alone either as continuous or split-course therapy. The overall treatment time varied from 35 to 55 days and the total dosage from 50 to 71 Gy in the continuous therapy group (n = 138), and in the split-course group (n = 215) with a planned 3-week rest interval in the middle of the treatment from 56 to 70 days and from 55 to 70 Gy, respectively. The logit method of the linear-quadratic formula for local control at 1 year was used to examine the effect of treatment time on local control. All patients were pooled to obtain a wide range of overall treatment times. RESULTS: The 1-, 2-, and 5-year actuarial survival rates according to the T-stage in the continuous therapy group from the first day of the radiotherapy were: 57%, 32%, and 10% for the T1 tumors and 23%, 8%, and 5% for the T2 tumors. The corresponding figures for the split-course group were: 50%, 19%, and 4% for the T1 tumors and 17%, 6%, and 3% for the T2 tumors. The 1-year local control rate was 56% for the T1 tumors and 15% for the T2 tumors in the continuous therapy group and 48% for the T1 tumors and 10% for the T2 tumors in the split-course group. The results of the logit method did not fit well with the T1 tumors. For the T2 tumors, they showed Dprolif to be about 0.24 Gy/day for local control at 1 year. As a consequence, protraction of overall time by 1 week should be compensated by increasing the total dose by 1.8 Gy for 1 year local control. CONCLUSIONS: More attention should be focused on repopulation. Shortening of overall treatment time might be beneficial for the treatment of squamous cell carcinoma of esophagus.

Adult↗

Influence of postsurgical residual tumor volume on local control in radiotherapy for maxillary sinus cancer.

BACKGROUND: The aim was to study the influence of postsurgical gross residual tumor volume on local control of maxillary sinus cancer treated with radiotherapy combined with debulking surgery. METHODS: Forty-three patients who underwent combined surgery and radiotherapy (50-72 Gy, median 60 Gy) for squamous cell carcinoma of the maxillary sinus were reviewed. Gross residual tumor volume (GRTV) after surgery was measured on computed tomograms obtained during the radiotherapy planning. Patients were classified according to GRTV as follows: group AA, GRTV = 0 (microscopic residual, n = 2); group A, GRTV < 10 cm3 (n = 24); group B, 10-40 cm3 (n = 9); and group C, > or = 40 cm3 (n = 8). The relationship between local control and GRTV was analyzed using univariate and multivariate analysis. RESULTS: The 2-year local control rate for all patients was 62%. The differences in local control rates between groups AA, A and B were not significant (P > 0.05), but the rate was significantly lower in group C than in the other groups (69% at 2 years vs 31% at 1 year, P < 0.001). Multivariate analysis showed that GRTV (P = 0.002) and histological differentiation (poorly differentiated histology was favorable, P = 0.035) were independent prognostic factors and that intra-arterial chemotherapy and administered total dose were not. Local control in groups A and B significantly depended on the total dose of radiotherapy, with 2-year control rates of patients receiving 50 Gy (n = 6) and > or = 60 Gy (n = 27) of 17% vs 79%, respectively (P < 0.001). CONCLUSIONS: Our data suggest that adequate, not complete, debulking associated with a total radiotherapy dose of > or = 60 Gy can provide satisfactory local control for patients with squamous cell carcinoma of the maxillary sinus.

Carcinoma, Squamous Cell↗

The impact of the sequence of radiation and chemotherapy on local control after breast-conserving surgery.

PURPOSE: We conducted this study to evaluate the effects of delaying primary radiation after adjuvant chemotherapy on local control following breast-conserving surgery compared with radiation delivered immediately following surgery. PATIENTS AND METHODS: This retrospective, nonrandomized study evaluated local control in 471 patients treated with breast-conserving surgery and radiation from 1980 through 1990. Three patient subsets were studied, identified by the sequence of radiation and adjuvant therapy if given. The three subgroups were: surgery, radiation, no chemohormonal therapy (332 patients; RT only); surgery, all chemotherapy, radiation (53 patients; chemo first); and surgery, chemotherapy, radiation, chemotherapy (86 patients; sandwich). Median follow-up times ranged from 53 months in the chemo first group to 77 months in the RT only group. RESULTS: All three groups had similar local control rates at 3 and 5 years. At 36 months, the actuarial local control rate achieved by the RT only group was 98% (confidence interval: 95%-99%); by the chemo first group, 94% (CI: 82%-98%); and the sandwich group, 96% (CI: 89%-99%). At 60 months, the local control rate for the RT only group was 96% (CI: 93%-98%), the chemo first group, 86% (CI: 70%-94%) and the sandwich group 95% (CI: 87%-98%). CONCLUSIONS: This report demonstrates no significant difference in the local recurrence rate following breast-conserving surgery and radiation therapy, whether radiation immediately followed the surgery or whether it was delayed by the administration of postsurgical adjuvant chemotherapy. These data differ from other reports, and suggest that this question remains open, requiring further follow-up that focuses not only on local control as an endpoint, but disease-free and overall survival as well.

Antineoplastic Combined Chemotherapy Protocols↗

Local control of operable breast cancer after radiotherapy alone.

221 patients with operable breast carcinoma stage Tis, T1, T2, T3, N0N1 were treated with radiotherapy alone without tumorectomy. The mean follow-up time was 15.5 years (range 5-22). The annual risk for local recurrence was 3% during the first 5 years and 1% during the following 10 years, resulting in an actuarial local control rate of 75.4% after 15 years. The risk for local recurrence was assessed in multivariate analysis and was significantly related to the size of the tumour measured on mammography (P = 0.0002), the radiation dose administered (P = 0.0018), the length of the split-course intervals being longer than 75 days (P = 0.001) and age (P = 0.019). Dose was related to response over a wide range as a function of tumour volume. All 18 patients with minimal tumour load (T0 and Paget's disease) treated with doses above 55 Gy in 6 weeks achieved local control. 5-year local control rates ranged from 40 to 100% for T1 carcinomas treated with 45-110 Gy, and from 0 to 95.3% for T2 carcinomas at the same dose. For T3 carcinomas local control varied between 50 and 83% at 60-110 Gy. The risk for local failure increased by 8% per cm tumour diameter. With exclusive radiotherapy, the doses needed to provide local control rates similar to those obtained after tumorectomy and irradiation are 10 Gy higher for T1 (95% 5 year control) and 35 Gy higher for T2 (90% 5 year control).

Adult↗

Histological and immunohistochemical prediction for local control of cervical squamous cell carcinoma treated with radiotherapy alone.

Predictability of local control following radiotherapy was evaluated with morphological methods such as histology and immunohistochemistry for 36 cervical squamous cell carcinomas. All these patients showed viable cancer cell predominance on the specimens excised with drill biopsy after radiation therapy. These specimens were stained with routine haematoxylin and eosin staining as well as with antibodies against epithelial membrane antigen (EMA), carcinoembryonic antigen, and S-100 protein. Five histological features, the number of the cancer nests per 22.5mm2 section, stromal reaction, space formation in the cancer nests, foamy cell or foreign body giant cell (FBG) clusters, and epithelial membrane antigen reactivity on the specimens excised after radiation therapy, were significantly related to the local control probability. Namel, less than 20 cancer nests, granulomatous stroma, presence of the space formation, absence of the foamy cell or foreign body giant cell clusters, and epithelial membrane antigen negativity were favorable for local control of the cervical cancer with radiation therapy. These data suggested that radiation sensitivity of cancer and stromal reaction for drainage of the degenerated cancer debris were important for local control of the tumors.

Adult↗