Local Field Irradiation Research Articles

Fotemustine-based therapy in combination with rituximab as a first-line induction chemotherapy followed by WBRT for newly diagnosed primary central nervous system lymphoma: a prospective phase II trial.

Objective:This study aimed to evaluate the safety, efficacy, and feasibility of the rituximab, fotemustine, pemetrexed, and dexamethasone (R-FPD) regimen followed by whole-brain radiotherapy (WBRT) for patients with primary central nervous system lymphoma (PCNSL).Methods:A prospective, single-center phase II clinical trial was conducted. Patients with PCNSL newly diagnosed at the First Affiliated Hospital of Zhengzhou University between July 2018 and July 2020 were studied. The R-FPD regimen consisted of rituximab (375 mg/m2 i.v. on D0), fotemustine (100 mg/m2 i.v. on D1), pemetrexed (600 mg/m2 i.v. on D1), and dexamethasone (40 mg i.v. on D1-5). Patients 60 years or younger who showed a complete response (CR) were treated with 23.4 Gy of WBRT after the end of chemotherapy; those older than 60 years with CR were treated with a wait-and-see approach; and those who did not show CR after the 4th cycle of chemotherapy were given salvage WBRT 30 Gy + local tumor field irradiation up to 45 Gy, regardless of age.Results:A total of 30 patients were included. After 2 cycles, the objective response rate (ORR) was 96.5% (28/29, 1 CR, 27 PR, 0 SD, and 1 PD). After 4 cycles, the ORR was 73.1% (19/26, 11 CR, 8 PR, 4 SD, and 3 PD). After WBRT, the ORR was 90.9% (10/11, 7 CR, 3 PR, and 1 SD). The grade III and IV toxicity responses were mainly leukopenia (20.0%), thrombocytopenia (23.3%), and anemia (10.0%).Conclusions:Fotemustine-based therapy in combination with rituximab chemotherapy followed by WBRT can improve outcomes, providing ORR benefits and favorable tolerability in patients newly diagnosed with PCNSL.

Local Field Radiotherapy Induced Therapy Related Myeloid Neoplasms and Bone Marrow Suppression

Introduction: Different cytotoxic agents have been implicated in development of therapy related myeloid neoplasm (t-MN). These include alkylating agents, topoisomerase II inhibitors, antimetabolites, and ionizing field radiation given to large field including active bone marrow (BM) (Swerdlow, 2016). This report highlight the impact of local field radiotherapy on BM through discussing few patients diagnosed in our center who showed profound BM hypocellularity or developed t-MN following exposure to local field radiotherapy without chemotherapy. Local field Radiotherapy as a causative agent for t-MN: A result of retrospective study performed in our center through (2012-2018), a total of 20 patients of t-MN out of 232 total AML patients (8.6%) were detected. Two patients out of 20 (10%) in our cohort had developed t-MN following exposure to local field radiotherapy. Patient (1): 50-year old Asian male diagnosed as Vocal cord tumor, received local field radiotherapy for 2 months with no chemotherapy. 15.8 months later, he presented to with two days history of gum bleeding associated with pancytopenia (WBCx10^3/µl:2.3, Hb g/dl:6.7, Platelets x10^3/µl:100). Peripheral blood smear showed infiltration with many leukaemic promyelocytes and diagnosed as Acute promyelocytic leukemia (APL). The diagnosis was confirmed by BM examination and detection of PML RARA classic rearrangement fusion indicating PML/RARA, t(15;17) in 88.5% cells. Reticulin stain shows increased reticulin fibrosis (1-2/ 3). The patient was stratified as intermediate risk and started on ATRA followed by PETHEMA protocol with complete remission. Patient (2): A 62-year old Egyptian lady with background of hepatitis C and previous stroke, diagnosed as Endometrioid Endometrial Cancer FIGO grade I. The patient received Brachytherapy 21 Gy dose to vaginal vault, in 3 fractions (7 Gy each) without complications. 22 months later, she developed progressive neutropenia and diagnosed as high grade myelodysplastic syndrome (MDS-EB-2) with complex karyotype and P53 somatic mutation, managed by palliative therapy. Discussion: Generally laryngeal cancers radiotherapy is directed to confined area and secondary cancers are more common in the area of close proximity to radiation field. Brachytherapy is a limited source of radiation placed into a cylinder and inserted within the prostate or the vagina for treatment of cancer prostate or endometrial carcinoma respectively. Compared to external radiotherapy (RT), the limited field radiotherapy (including external beam RT and brachytherapy), the doses received by BM is very low and hence the risk of secondary leukaemia is expected to be significantly lower. Although local field RT appears to be associated with a small increase in the incidence of solid cancers, only a few studies have evaluated the risk of developing myeloid malignancies after limited field radiotherapy. Numerous cases of (t-APL) have been reported in the literature mostly following TOPO isomerase II inhibitors. However, up to our knowledge no previous reports of t-MN with recurrent genetic translocations (including t-APL) following local field radiotherapy. Local field radiotherapy induced bone marrow suppression: Two male patients with previous history of cancer prostate and limited field radiotherapy. BM examination for both patients revealed profound hypocellularity (<5-5%) with suppressed trilineage hematopoiesis. Patient (3): A 66 year-old male diagnosed as cancer prostate, subjected to radical prostatectomy, followed by salvage radiotherapy. Two months later, the patient was referred for persistent cytopenia (WBC 2.9 x10^3/uL, Hemoglobin 12.8 gm/dL and platelets (92 x10^3/uL). Follow-up revealed persistent thrombocytopenia. No follow-up BM was performed. Patient (4): A 73-year old male patient with previous history of marginal zone lymphoma and cancer prostate treated by brachytherapy. He underwent BM examination for lymphoma staging. Discussion: For patients who have received adjuvant, salvage or radical RT, a significant portion of the pelvic BM receives a substantial dose of RT. To our knowledge, there are no significant published data assessing the impact of limited field radiotherapy on BM particularly radiation induced BM suppression. Larger studies are required in order to accurately assess the actual effect of local field radiotherapy on hematopoiesis and its genetic profiling. Disclosures No relevant conflicts of interest to declare.

Local field radiotherapy without elective nodal irradiation for postoperative loco-regional recurrence of esophageal cancer.

Radiotherapy is an effective treatment for the postoperative loco-regional recurrence of esophageal cancer; however, the optimal treatment field remains controversial. This study aims to evaluate the outcome of local field radiotherapy without elective nodal irradiation for postoperative loco-regional recurrence of esophageal cancer. We retrospectively investigated 35 patients treated for a postoperative loco-regional recurrence of esophageal cancer with local field radiotherapy between December 2008 and March 2016. The median irradiation dose was 60 Gy (range: 50-67.5 Gy). Thirty-one (88.6%) patients received concurrent chemotherapy. The median follow-up period was 18 months (range: 5-94 months). The 2-year overall survival was 55.7%, with a median survival time of 29.9 months. In the univariate analysis, the maximal diameter ≤20 mm (P = 0.0383), solitary lesion (P = 0.0352), and the complete remission after treatment (P = 0.00411) had a significantly better prognosis. A total of 27 of 35 patients (77.1%) had progressive disease (loco-regional failure [n = 9], distant metastasis [n = 7], and both loco-regional failure and distant metastasis [n = 11]). No patients had Grade 3 or greater mucositis. Local field radiotherapy is a considerable treatment option for postoperative loco-regional recurrence of esophageal cancer.

Comparison between local and extended field radiotherapy, including regional nodes radiotherapy, in combination with concurrent chemotherapy for T1bN0M0 esophageal cancer.

142 Background: Extended field (EF) radiotherapy including regional nodes, has been adopted for the treatment of esophageal squamous cell carcinoma (ESCC), but it sometimes causes severe radiation-related adverse events. The purpose of this study is to compare local-field (LF) to EF radiotherapy administered as chemoradiotherapy (CRT) in early esophageal cancer. Methods: Selection criteria included histologically proven T1bN0M0 ESCC, performance status (PS) 0-1, adequate organ function and no other active malignancy. Data on patients who received CRT concurrently with 5-FU and cisplatin between Jan. 2000 and Dec. 2012 in our hospital were evaluated. All patients received radiotherapy at a dose of 60Gy without a planned break. The clinical target volume (CTV) of LF included gross tumor volume (GTV) plus 3-cm superior and inferior margins, and that of EF included GTV plus regional lymph nodes. Overall survivals (OS) were estimated with the Kaplan-Meier method and compared with the log-rank test. The Cox regression model was used for multivariate analysis. Adverse events were graded according to the CTCAE v.4.0. Results: The characteristics of the EF group (n = 120) and LF group (n = 79) are: Median age, 68.0 years and 65.0 years; male/female, 106/14 and 67/12; PS 0/1, 93/27 and 63/18; median tumor length, 40.6mm and 35.4mm, respectively. The complete response rates were 90.0% and 98.7%, respectively. The median follow-up periods were 103 months and 69 months, respectively. The 5-year overall and cause-specific survival rates were 74.5% and 90.6%, 89.5% and 91.8%, respectively. According to a multivariate analysis, EF was a significant negative prognostic factor for OS (hazard ratio = 2.88, p = 0.002) but not for cause-specific survival. Cardiopulmonary toxicities of grade 3 or greater were observed more frequently in the EF group (p = 0.035), with statistical significance. Treatment-related death occurred at 6.7% and 1.3%, respectively, in the two groups. Conclusions: It is suggested that radiation with LF may be better than EF in combination with concurrent chemotherapy in early esophageal cancer (T1bN0M0).

Primary intracranial germ cell tumours: Experience of a single South-East Asian institution

Primary intracranial germ cell tumours (ICGCT) are a rare group of brain tumours arising predominantly in the paediatric and pre-adult population, accounting for up to 9.5% of paediatric brain tumours in East Asia. The National Cancer Centre Singapore (NCCS) is a tertiary referral centre for patients from all over South-East Asia. Our study aims to describe the characteristics of ICGCT patients in South-East Asia. Data on all patients with ICGCT who were seen at the Therapeutic Radiology Department of NCCS from 2000 to 2013 were collected retrospectively. Patient demographics, disease characteristics and treatment outcomes were analysed. Characteristics and survival of our patients were similar to other centres. Pure germinomas demonstrated 5year overall survival (OS) and disease-free survival (DFS) rates of 89.2% (95% confidence interval [CI] 60.2–97.5) and 85.2% (95%CI 60.8–95.0) respectively. Secreting germinomas, non-germinomatous germ cell tumours and mixed germ cell tumours were evaluated together and demonstrated 5year OS of 70.6% (95%CI 41.0–87.3) and DFS of 61.4% (95%CI 31.9–81.3). Patients ⩽12years had marginally better 5year OS than their older counterparts (81.0% [95%CI 49.5–93.9] versus 77.9% [95%CI 47.3–92.0], respectively). Patients who underwent extended field radiotherapy had longer OS and DFS than those who received local field irradiation. Treatment outcomes of our ICGCT patients are comparable with those in other Asian and Western centres. Extended field radiotherapy is a pivotal component of ICGCT treatment. Adding chemotherapy confers no extra survival benefit in treating germinomas. Treatment of mixed germ cell tumours and non-germinomatous germ cell tumours involves a multidisciplinary approach that varies for each histological subtype.

Field theory model of brain extracellular matrix

The perineural net (PNN) is responsible for synaptic stabilization of adult brain. It plays an important role in brain signal processing and non-synaptic signal transfer as well [ 1]. Since it is composed of largely negatively charged chains of disaccharides, it can be easily affected by strong external electromagnetic field irradiated by high-energy particles passing brain tissues. One of the effects of such exposure is a cognitive impairment. Since outside of the Bragg peak area local electromagnetic field irradiation strong enough to affect on the PNN's dynamics, it is very important to understand PNN's behavior in locally strong electromagnetic fields. The presented work is devoted to PNN modeling in field theory framework. As a toy model of PNN, we consider fractal lattice with Ising and XY model applied. More precise study requires application of the quantum electrodynamics on the lattice. We study how local excitations can change phase state of the overall lattice and its finite clusters. For this propose, the partition function of the Ising model is calculated using Monte Carlo simulation [ 2]. The two-dimensional Serpinsky Carpet lattice is applied to approximate structure of the brain extracellular matrix. Order parameter is calculated for different levels of the self-similarity of the Serpinsky Carpet. It is shown that starting from the level = 3, the lattice with fractal structure has irreversible phase transition: phase state after restoration differs from the initial one. In Fig. 1, the calculation of the correlation length change due to the energy dissipation after a local impact is shown. The column shows correlation strength (from 0 to 1), the right axis shows the cluster size ratio to the whole lattice size in percentage. The initial lattice was totally correlated (100% of the lattice has correlation strength that equals 1). The left side of the picture corresponds the locally excited lattice with no correlation, the right side of the picture corresponds the lattice after the relaxation to the equilibrium state due to the energy dissipation. It can be clearly seen that the lattice is not correlated after the relaxation. Fig. 1.Correlation length change due to the energy dissipation.ConclusionsLocal impact changes the correlation length of the fractal lattice: after the restoration, the correlation length becomes short, thus signal processing on the lattice changes significantly. Thus, it can be considered as a good model to study of the extracellular matrix change due to local excitations of strong electromagnetic field.

First-line management of diffuse large B cell lymphoma

Short course chemotherapy combined with local field radiotherapy (IFRT) is an important treatment for limited-stage (Ⅰ -Ⅱ)diffuse large B cell lymphoma patients,but the value of radiotherapy has been disputed.Some patients may be cured by combined chemotherapy which contains anthracycline,but there are some patients still facing death.Therefore,researchers try to improve survival of patients further by increasing the density or intensity of the chemotherapy dose,but attempt to reduce the dose or the use of low toxicity drugs for elderly patients.In addition,researches such as radioimmunotherapy and biological targeted therapy have made certain progress. Key words: Lymphoma, large B-cell, diffuse; Radiotherapy; Drug therapy

Efficacy and the prognostic factors of postoperative radiotherapy in malignant gliomas

Objective To explore the clinical effects and prognostic factors of postoperative radiotherapy for malignant gliomas. Methods From June 1998 to October 2007, seventy-eight cases of malignant gliomas patients were treated with radiotherapy after surgery, including -28 cases received whole brain radiotherapy, 34 cases local field irradiation and 16 cases three-dimensional conformal radiotherapy. Thirty-one cases received chemotherapy which included semustine, semustine plus teniposide and temozolomide. Kaplan-Meier survival analysis and COX regression analysis were used to analyze the prognostic factors. Results The median survival time and 1-, 3-, 5-year survival rate were 16 months, 65.4 %, 32.8 % and 17.9 % for all patients, respectively; 24 months, 72.7 %, 41.5 % and 22.8% for grade 1 patients; 11 months, 47.8 %, 10.9 % and 5.4 % for grade IV patients. Univariate analysis showed the age, Karnofsky, pathologic grade, surgical approach and the time from surgery to radiotherapy were significantly correlated with the survival time (P <0.05). Karnofsky (P =0.000), pathologic grade (P =0.004) and age (P =0.011) were independent prognostic factors in the multivariate analysis. Conclusion Prognosis of the patients with Karnofsky ≥70, age < 50 years and grade Ⅲ is better in malignant gliomas. Postoperative radiotherapy combined with chemotherapy may prolong the survival time. Key words: Brain; Glioma; Radiotherapy; Prognosis

Pattern of skeletal metastases from breast cancer in an Asian population

Objectives:: To evaluate the pattern of skeletal metastases from breast carcinoma in an Asian population. To study the radiological pattern and distribution of bone metastases from breast cancer .Background: Breast cancer is a disease that is prevalent world wide and frequently metastasis to the bones . Bone metastasis is associated with increase morbidity and poor quality of life in breast cancer patients. Prompt identification and treatment is the best way of improving the patients’ quality of life. Skeletal x-rays and bones scan of relevant bones should be part of staging investigations and metastatic survey in breast cancer.Methods: This study was prospective, non-randomized, and single institution based. A total of 30 consecutive patients having bone pains with radiological evidence of bone metastases were included. Questionnaire was designed for the collection of patients’ data for evaluation, which was then entered on database and analyzed on the Statistical Package for Social Sciences (SPSS). Patient were staged using TNM Classification.Results: The radiological pattern was Osteolytic in (28) 93.3% and mixed pattern (osteolytic & osteoblastic) in (2)6.7%. The commonest site of bone metastases was Lumbar spine (51.5%) followed by the Thoracic spine (21.6%). There was involvement of multiple, non-contiguous skeletal bones in(7)23.3% of the patients. Majority of the patients were stage III (56.6%) at first presentation. At presentation (6) 20% had painful bone metastases and 16.7% developed painful bone metastases within 12 months, 30.0% from 12 to 24 months, and 33.3% after 24 months of diagnosing breast cancer. 20.0% of patients had painful bone metastases for < 3 months prior to local field irradiation (LFI); 46.7% had pain for 4 – 6 months; 6.7% had pain for 7 – 9 months; 10.0% had pain for 10 – 12 months; and 16.7% had pain for more than 12 months prior to treatment with LFI.Conclusion: The predominant x-ray finding in bone metastases from breast cancer was osteolytic and the Lumbar spine was the commonest site of involvement . Involvement of Multiple bones in 25% of the patients suggest widespread search in a staging protocol.

Fractionated Wide-Field Radiation Therapy Followed by Fractionated Local-Field Irradiation for Treating Widespread Painful Bone Metastasis

Wide-field radiation therapy (WFRT) is an effective treatment for widespread bone metastasis. We evaluated local-field irradiation (LFI) after fractionated WFRT (f-WFRT) for treating the patients with multiple painful bone lesions. From 1998 to 2007, 32 patients with multiple bone metastases were treated with fractionated LFI (f-LFI) after f-WFRT. All patients initially received 15 Gy in 5 fractions to a wide field, followed by LFI (9-15 Gy in 3 Gy fractions). Response was assessed by evaluating the degree of pain relief using a visual analog scale before radiotherapy, after f-WFRT, and after f-LFI. Fractionated LFI following f-WFRT yielded an overall relief rate of 93.8% and a complete relief rate of 43.8%. The rate of the appearance of new disease was 6.3% for the patients with complete relief, 20.5% for the patients with a partial relief, and 50% for the patients with no relief. Fractionated LFI after f-WFRT is a well-tolerated and effective treatment for multiple metastatic bone disease.

Long-Term Follow-Up of Dose-Adapted and Reduced-Field Radiotherapy With or Without Chemotherapy for Central Nervous System Germinoma

To update our institutional experience with neoadjuvant chemotherapy and minimized radiotherapy vs. radiation monotherapy for intracranial germinoma. We retrospectively reviewed records of 59 patients with diagnosis of primary intracranial germinoma between 1977 and 2007. Treatment was irradiation alone or neoadjuvant platinum-based chemotherapy and local irradiation (initial tumor plus margin) for patients with localized complete response and reduced-dose craniospinal irradiation for others. For the chemoradiotherapy group (n = 28), median follow-up was 7 years. No patient died. The freedom from progression (FFP) rate was 88% at 5 years and 80% at 10 years. In 4 patients, disease recurred 1.1 to 6.8 years after diagnosis. All were young male patients who received 30.6 Gy to local fields after complete response to chemotherapy. The FFP rate was 88% for local irradiation vs. 100% for more extensive fields (p = .06). For the radiotherapy-alone group (n = 31), median follow-up was 15 years. Overall and disease-free survival rates were 93% and 93% at 5 years and 90% and 87% at 15 years. In 5 patients, disease recurred 1.1 to 4.9 years after diagnosis. Most patients in this group were young men 18 to 23 years of age with suprasellar primary disease treated with about 50 Gy to local fields. The FFP rate was 44% for local irradiation vs. 100% for more extensive fields (p < .01). The addition of neoadjuvant chemotherapy to local-field radiotherapy reduced central nervous system cancer recurrence when high-risk patients were excluded by thorough pretreatment staging. There was trend toward improved central nervous system tumor control when larger fields (whole brain, whole ventricle, or craniospinal axis) were used.

Long term outcomes in patients with intracranial germinomas: a single institution experience of irradiation with or without chemotherapy

Complete remission can be achieved soon after irradiation in patients with intracranial germinoma. This study aimed to analyze the follow-up outcome of intracranial germinoma patients. About 39 intracranial germinoma patients (29 males and 10 females; average age, 15 years; range, 7-27 years) treated at Kyoto University Hospital from 1978 to 2004 were included in the study group. Six patients had multifocal disease at initial diagnosis, and 10 had human chorionic gonadotropin (HCG)-producing tumors. Thirteen patients were treated with craniospinal axis irradiation, 6 with whole-brain irradiation, 17 with whole-ventricle irradiation, and 3 with local field irradiation. Since 1997, 15 patients were treated with reduced-dose whole-ventricle irradiation (median, 23.4 Gy; range, 20.4-27 Gy) followed by a local boost (median, 40.8 Gy; range, 36-54 Gy) combined with chemotherapy. The median follow-up was 94 months (18 months to 25 years). The 5- and 10-year overall survival (OS) rates of the entire group were 97 and 90%, respectively. The 5- and 10-year progression-free survival (PFS) rates of the entire group were 91 and 87%, respectively. The 8-year OS and PFS in 15 patients treated by whole-ventricle irradiation combined with chemotherapy were 100% and 92%, respectively. Four patients had recurrences within a median period of 59.5 months (51-85 months). All relapses occurred outside the radiation fields. Tumor site, tumor size, HCG production, multifocal disease and radiation dose to the primary site or whole ventricle did not significantly affect PFS. All initial recurrences of intracranial germinoma occurred at the distant site out of the radiation field. Our data suggested that reduced doses to the whole ventricle, combined with chemotherapy, should be sufficiently effective in patients with intracranial germinoma.

198: Treatment of Localized Intracranial Germinoma Using Chemotherapy Followed by Whole Ventricular Radiotherapy With a Simultaneous Integrated Boost

Localized intracranial germinoma (LIG) is highly curable using a radiation dose of 45 Gy. Although highly effective, this treatment is likely to produce permanent neurocognitive sequelae. Chemotherapy alone and chemotherapy with local field irradiation regimens have resulted in unacceptable relapse and/or morbidity rates. A combined radiation and chemotherapy regimen was instituted at CHLA in May 2004 with the goal of producing a relapse-free survival rate of >90% with reduced acute and chronic adverse effects.

Lack of benefit of spinal irradiation in the primary treatment of intracranial germinoma

The current study assessed the contribution of spinal irradiation to the treatment outcome of patients with intracranial germinoma. Clinical data from 180 patients with intracranial germinoma, who were treated with radiotherapy and/or chemotherapy from 1980 to 2001, were collected from 6 institutions. The patients' median age was 16 years (range, 1-47 yrs), and the male-to-female ratio was 133:47. Pathologic verification was obtained in 88 patients. A solitary tumor was seen in 129 patients, and multifocal or disseminated tumors were detected in 51 patients. The median tumor size was 2.5 cm (range, 0.6-7.0 cm). Local field and/or whole brain irradiation was performed in 114 patients, and craniospinal irradiation was performed in 66 patients. Fifty-five patients were treated with chemotherapy. The median follow-up time was 89 months (range, 3-297 mos). Eight-year overall and event-free survival rates were 91% and 89%, respectively. The 8-year recurrence rates at the primary site, intracranial space, and the spinal space were 1%, 6%, and 6%, respectively. Cox regression analysis showed that spinal irradiation (hazard ratio, 1.050; 95% confidence interval [CI], 0.355-3.170) did not contribute to a favorable event-free survival. Spinal irradiation did not contribute to favorable event-free survival in patients with intracranial germinoma.

Dosimetry and radiobiologic model comparison of IMRT and 3D conformal radiotherapy in treatment of carcinoma of the prostate

Introduction Intensity-modulated radiotherapy (IMRT) has introduced novel dosimetry that often features increased dose heterogeneity to target and normal structures. This raises questions of the biologic effects of IMRT compared to conventional treatment. We compared dosimetry and radiobiologic model predictions of tumor control probability (TCP) and normal tissue complication probability (NTCP) for prostate cancer patients planned for IMRT as opposed to standardized three-dimensional conformal radiotherapy (3DCRT). Methods and materials Segmented multileaf collimator IMRT treatment plans for 32 prostate cancer patients were compared to 3DCRT plans for the same patients. Twenty-two received local-field irradiation (LFI), and 10 received extended-field irradiation (EFI) that included pelvic lymph nodes. For LFI, IMRT was planned for delivery of 2 Gy minimum dose to the prostate (≥99% volume coverage) for 35 fractions. The 3DCRT plans, characterized by more homogenous dose to the target, were designed according to a different protocol to deliver 2 Gy to the center of the prostate for 37 fractions. Mean total dose from 35 fractions of IMRT was equal to mean total dose from 37 fractions of 3DCRT. For EFI, both IMRT and 3DCRT were planned for 2 Gy per fraction to a total dose of 50 Gy to prostate and pelvic lymph nodes, followed by 2 Gy per fraction to 20 Gy to the prostate alone. Treatment dose for EFI-IMRT was defined as minimum dose to the target, whereas for EFI-3DCRT, it was defined as dose to the center of the prostate. TCP was calculated for the prostate in the linear-quadratic model for two choices of α/β. NTCP was calculated with the Lyman model for organs at risk, using Kutcher-Burman dose–volume histogram reduction with Emami parameters. Results and conclusions Dose to the prostate, expressed as mean ± standard deviation, was 74.7 ± 1.1 Gy for IMRT vs. 74.6 ± 0.3 Gy for 3D for the LFI plans, and 74.8 ± 0.6 Gy for IMRT vs. 71.5 ± 0.6 Gy for 3D for the EFI plans. For the studied protocols, TCP was greater for IMRT than for 3D across the full range of target sensitivity, for both localized- and extended-field irradiation. For LFI, this was due to the smaller number of fractions (35 vs. 37) used for IMRT, and for EFI, this was due to the greater mean dose for IMRT, compared to 3D. For all organs, mean NTCP tended to be lower for IMRT than for 3D, although NTCP values were very small for both 3D and IMRT. Differences were statistically significant for rectum (LFI and EFI), bladder (EFI), and bowel (EFI). For both LFI and EFI, the calculated NTCPs qualitatively agreed with early published clinical data comparing genitourinary and gastrointestinal complications of IMRT and 3D. Present calculations support the hypothesis that accurately delivered IMRT for prostate cancer can limit dose to normal tissue by reducing treatment margins relative to conventional 3D planning, to allow a reduction in complication rate spanning several sensitive structures while maintaining or increasing tumor control probability.

Craniospinal radiation in the treatment of biopsy-proven intracranial germinomas: twenty-five years' experience in a single center

Purpose The optimal treatment for intracranial germinomas remains controversial. We report on our 25-year experience using craniospinal irradiation (CSI) for this disease. Methods and materials Between September 1976 and May 2001, 39 patients with biopsy-proven intracranial germinomas seen at the Children's Hospital of Philadelphia/Hospital of the University of Pennsylvania received CSI. Thirteen of 36 patients (36%) had evidence of spinal dissemination. Median doses to the whole brain, primary site, and spine were 36 Gy (range, 18–44.2 Gy), 50.4 Gy (range, 44–55.8 Gy), and 30.6 Gy (range, 18–40 Gy), respectively. Results With a median follow-up of 7.1 years (range: 1.5–20.2 years), there have been no documented relapses. This includes 5 patients without spinal dissemination who received 18–19.8 Gy to the craniospinal axis; for these patients, the median length of follow-up was 5.5 years (range, 1.3–6.8 years). One patient, who had no evidence of disease 12.9 years after CSI, died of unknown causes 4 months later. Conclusions Our treatment of intracranial germinomas with CSI has yielded outstanding results with no known relapses during a long follow-up period. These results must be considered when evaluating other approaches, such as chemotherapy only or local field irradiation.

Strontium-89 chloride versus palliative local field radiotherapy in patients with hormonal escaped prostate cancer: A phase III study of the European organisation for research and treatment of cancer

Strontium-89 chloride versus palliative local field radiotherapy in patients with hormonal escaped prostate cancer: A phase III study of the European organisation for research and treatment of cancer

Radiotherapy of Hodgkin's disease in early pregnancy: embryo dose measurements.

Limited information exists on the possibility of pregnant women undergoing radiotherapy for Hodgkin's disease in early pregnancy. The purpose of this study was to measure embryo dose resulting from treatment of supra-diaphragmatic Hodgkin's disease at the first trimester of gestation. A humanoid phantom was used to simulate pregnancy at the first trimester of gestation. Embryo dose, was measured using three different field sizes that may be applied for local field irradiation in each of the regions of neck, axilla, neck-mediastinum and for mantle treatment. A shielding device consisting of 5 cm of lead was used to reduce the embryo dose. Dose measurements were carried out using thermoluminescent dosimeters. Phantom exposures were made with a 6 MV photon beam. Local field irradiation in the regions of neck or axilla always resulted in embryo doses below 10 cGy. For local field irradiation in the region of neck-mediastinum and for mantle treatment, the radiation dose to a shielded embryo was 2.8-18.6 and 4.2-24.5 cGy depending upon the distance from the field isocenter and the field size used, respectively. The corresponding dose for an unshielded embryo exceeded 10 cGy. All the above embryo doses were obtained for a tumor dose of 40 Gy. Local field irradiation in the regions of neck or axilla may be safely performed even without uterus shielding. For local field irradiation in the region of neck-mediastinum and for mantle radiotherapy, the extent of the irradiated area, the distance separating the embryo from the field isocenter and the tumor dose are the factors, determining whether the radiation dose to a shielded embryo may possibly be reduced below 10 cGy.

Intracranial ependymomas: an analysis of prognostic factors and patterns of failure.

From 1965 to 1997, 49 patients were diagnosed and treated for intracranial ependymoma at one institution. Tumor location was infratentorial in two thirds, and pathology was low grade in 38 patients (78%). Gross total resection of the primary tumor was achieved in 21 (43%). Thirty-six patients received adjuvant radiotherapy; the entire neuraxis was treated in 14, whole brain in 10, and local field only in 12. Median follow-up was 9.6 years (range, 2-33 years). The 5-, 10-, and 15-year overall survival rates were 71.4%, 63.5%, and 63.5% for craniospinal radiotherapy, 60.0%, 60.0%, and 40.0% for whole brain radiotherapy, and 80.8%, 64.6%, and 64.6% for local field radiotherapy (p = 0.88). The 5-, 10-, and 15-year local control rates were 60.3%, 54.4%, and 48.9%. The prognostic factors for a better local control rate were gross total resection (p = 0.021) and low grade histology (p = 0.031). Seventeen of 43 (39.5%) M0 patients did not respond to treatment; all had local failure and 4 also had a spinal relapse. Spinal relapse developed in 3 of 31 (10%) M0 patients who did not receive spinal radiotherapy, whereas 1 of 12 (8%) who had spinal radiotherapy did not respond to treatment in the spine. The results of this study indicate that local radiotherapy is sufficient for M0 patients with intracranial ependymoma.

The local field in infratentorial ependymoma: does the entire posterior fossa need to be treated?

Introduction: In the past decade, there have been multiple reports indicating that the predominant problem in the curative treatment of intracranial ependymoma is local failure. As a result, many have recommended local field radiotherapy. For infratentorial ependymoma, there is controversy regarding what constitutes the local field. Some radiation oncologists advocate coverage of the entire posterior fossa, whereas others recommend radiotherapy to the tumor bed and a safety margin. Methods and Materials: From 1984 to 1998, 28 patients with posterior fossa ependymoma were diagnosed at our institution. There were 18 males and 10 females with a median age of 12 years (range, 2–81 years). Four patients (14%) had high-grade ependymoma and 3 (11%) had M+ disease at initial diagnosis. Gross total resection was achieved in 17 (61%) and postoperative radiotherapy (RT) was given to 22 (77%). Radiotherapy fields were craniospinal in 10, whole brain in 1, posterior fossa in 2, and tumor bed with a 2-cm. margin in 9. Median dose to the primary site was 54 Gy (range, 45–55 Gy). All 4 patients with high-grade ependymoma received craniospinal RT. Six patients did not receive RT after surgery. Magnetic resonance imaging (MRI) or computed tomography (CT) scans of the brain at initial diagnosis were compared to MRI or CT scans of patients at relapse to determine if the local relapse was in the tumor bed or nontumor bed posterior fossa. Median follow-up was 127 months (range, 14–188 months). Results: Six patients have relapsed. For the 11 patients who had craniospinal or whole brain radiotherapy (RT), 3 recurred (tumor bed 1, spine 1, nontumor bed posterior fossa + spine 1). Both patients who failed in the spine had high-grade tumors. Neither of the 2 treated with posterior fossa fields relapsed. For the 9 patients who had tumor bed RT alone and the 6 who did not receive RT, there were 3 relapses; all were in the tumor bed. There were no relapses in the nontumor bed posterior fossa. Conclusion: For nondisseminated, low-grade infratentorial ependymoma, the radiotherapy volume does not need to include the entire posterior fossa. This information can be used to minimize late effects of RT in the era of three-dimensional (conformal) radiotherapy. No conclusion can be reached regarding the appropriate local field for high-grade infratentorial ependymoma because of the small number of patients.