Single Anterior Field Research Articles

Posterior Neck Coverage in Patients Receiving Regional Nodal Irradiation for Breast Cancer

Patterns-of-failure studies suggest the posterior neck (PN) may harbor microscopic disease in patients with locally advanced breast cancer. We compared target coverage, lung dose, and toxic effects in patients treated with either an anterior oblique field (AO) or opposed oblique fields (OO) to address the superior axillary and supraclavicular nodal (SCV) regions. We identified 119 consecutively treated patients who received regional nodal irradiation, including a "third field," to address the superior axillary and supraclavicular nodal regions with a monoisocentric technique in our institution. Coverage of the axillary clinical target volume (CTV), SCV CTV and PN CTV was determined based on the delivered treatment plan. Wilcoxon rank-sum test and Fisher's exact test were used to compare coverage of the axillary, SCV, and PN CTVs, lung dosimetry, and toxic effects (graded by the Common Terminology Criteria for Adverse Events v4.0) between patients receiving an AO or OO. There were 29 patients in the AO group and 80 in the OO group. All patients in the AO group received conventionally fractionated radiation versus 61% in the OO group. Modestly hypofractionated plans were delivered to 39% of the OO group. The body mass index and anterior-posterior separation at the matchline (measured at the center of the carotid artery) were similar in both groups. The median volume (%) of the SCV CTV receiving at least 90% of the prescription dose (V90%) was 91% (85, 99) in the AO group and 93% (91, 95) in the OO group (P = 0.2). The median V90% of the PN CTV was 30% (12, 49) in the AO group and 100% (100, 100) in the OO group (P<0.001). The median V90% in the axillary levels I, II and III CTVs were 98%, 95% and 90%, respectively, in the AO group and all 100% in the OO group (P<0.001). Maximum dose and heterogeneity in the SCV CTV were similar in both groups. Including only patients who received conventionally fractionated plans, the mean lung dose (cGy) was 1216 in the AO group and 1328 in the OO group (P = 0045). The lung V5 Gy, V10 Gy and V20 Gy were similar in both groups. Ipsilateral upper extremity lymphedema (all grade 1) was 3.4% in the AO group and 2.5% in the OO group (p>0.9). Moist desquamation in the neck was 0% in the AO group and 1.2% in the OO group (p>0.9). Pneumonitis (all grade 1) was 0% in the AO group and 1.2% in the OO group (p>0.9). Compared to a single anterior field, opposed oblique fields provide superior axillary and posterior neck coverage without increasing toxicity.

Acanthocephalans from Australian elasmobranchs (Chondrichthyes) with a description of a new species in the genus Gorgorhynchus Chandler, 1934 (Rhadinorhynchidae).

Gorgorhynchus occultus n. sp. is described from Sutorectus tentaculatus (Peters) (Orectolobidae) collected off Bunbury, Western Australia in 1986. The new species differs from all other species of Gorgorhynchus Chandler, 1934 by having a suite of characters including a proboscis hook formula of 18-20 rows of 8-9 hooks, a well-developed neck, irregular circles of small spines in a single anterior field, the male reproductive system limited to the posterior quarter of the trunk and three cement glands. In a survey of 284 sharks collected between 2015 and 2018 from 10 localities in Australian waters, 11 individuals were infected with acanthocephalan cystacanths. One individual of Sphyrna mokarran (Rupell) (Sphyrnidae) was infected with Corynosoma cetaceum Johnston & Best, 1931. Serrasentis sagittifer (Linton, 1889) (Rhadinorhynchidae) was found in five individuals of S. mokarran, four individuals of Syphyrna lewini (Griffith & Smith) and one individual of Carcharhinus coatesi (Whitley) (Carcharhinidae). These infections may be accidental because it has been suggested that acanthocephalans cannot tolerate the high levels of urea used by marine and esturine elasmobranchs for osmoregulation. The two most common host species examined, S. mokarran and S. lewini had the highest intensities and prevalences of infection with S. sagittifer. Although more individuals of S. lewini were examined, S. mokarran had the higher prevalence of infection.

Unplanned irradiation of internal mammary lymph nodes in breast cancer.

To evaluate the incidental dose to the internal mammary chain (IMC) in patients treated with three-dimensional conformal radiotherapy, to estimate the predictors affecting the magnitude of IMC receiving dose and to determine the predictive role of clinical parameters on survival. Between 2009 and 2015, 348 patients undergoing RT for breast cancer were retrospectively analyzed. All patients underwent our department's routine procedure for breast cancer. The internal mammary lymph nodes were contoured according to Radiation Therapy Oncology Group (RTOG) concensus. Based on each patient's dose-volume histograms, the mean doses (D mean) to internal mammary gland were analyzed. Overall survival and disease-free survival were also evaluated. The median follow-up time was 38 (range 3-80) months. The D mean to IMC was 32.8Gy and the dose delivered to IMC showed a greater coverage in modified radical mastectomy (MRM) group compared with breast conserving surgery (34.6 vs 26.7Gy). The T-stage of tumor and the N-stage of tumor affected the incidental dose to IMC. The tumor size, the number of involved lymph nodes, the percentage of involved lymph nodes, hormonal status, advanced T-stage and advanced N-stage were the prognostic factors that affect survival. The IMC received meaningful incidental irradiation dose when treated with two opposite tangential fields and ipsilateral supraclavicular fossa with a single anterior field. The real effect of incidental dose on survival and the hypothesis about the benefit of incidental irradiation of IMC should be examined in clinical studies.

The dosimetric impact of supraclavicular nodal irradiation on the thyroid gland in patients with breast cancer

PurposeThe thyroid is not routinely considered an organ at risk in supraclavicular (SC) nodal radiation therapy (RT) for breast cancer. We compared the dosimetric impact of the following 2 RT planning techniques on the thyroid: (1) conventional single anterior field to encompass the SC nodal volume defined clinically; and (2) 3-dimensional conformal radiation therapy (3DCRT) planning to encompass the computed tomography (CT)-contoured SC nodal volume. Methods and MaterialsThe thyroid, SC nodal volumes, and organs at risk were contoured on the planning CT of 20 patients who received 50 Gy in 2-Gy daily fractions to the breast or chest wall, and SC nodes. Comparisons of dosimetric parameters between the techniques were performed: thyroid, mean and maximum dose, V5, V30, and V50 (percentage of thyroid receiving ≥5 Gy, ≥30 Gy, and ≥50 Gy, respectively); SC nodal volume, homogeneity index (HI, percentage volume receiving 95%-107% of prescribed dose); and maximum doses of spinal cord and brachial plexus. Anatomic characteristics that influenced the dose distributions were investigated. ResultsThe 3DCRT planning technique significantly increased all thyroid dosimetric measures (mean dose 17.2 Gy vs 26.7 Gy; maximum dose 48.5 Gy vs 51.9 Gy; V5 45.7% vs 64.9%; V30 33.7% vs 48%; and V50 0.6% vs 26.7%; P < .001). It improved HI for the SC nodal volumes (P < .001) but resulted in higher maximum doses to the spinal cord (6.1 Gy vs 30 Gy) and brachial plexus (43.2 Gy vs 51.4 Gy). The thyroid volume and depth of SC nodes did not influence the thyroid dose distribution. The depth of SC nodes impacted on the HI of SC nodal volumes in the conventional technique (P = .004). ConclusionsThe 3DCRT planning improved dosimetric coverage of the SC nodal volume but increased thyroid radiation doses. The potential adverse effects of incidental thyroid irradiation should be considered while improving dosimetric coverage in SC nodal irradiation for breast cancer.

The dosimetric impact of supraclavicular nodal irradiation on the thyroid in patients receiving radiotherapy for breast cancer.

198 Background: The thyroid is not routinely considered an organ at risk in supraclavicular (SC) nodal radiotherapy (RT) for breast cancer. We aim to compare the dosimetric impact of two RT planning techniques on the thyroid: (1) conventional single anterior field to encompass the SC nodal volume defined using clinical and radiological landmarks; and (2) 3-dimensional (3D)-conformal planning to encompass the SC nodal volume contoured on planning computed tomography (CT) scans. Methods: The thyroid and SC nodal volumes were contoured on the planning CT datasets of 20 patients who had RT to the breast/chest wall and SC nodes to a dose of 50 Gy in 2-Gy daily fractions. Comparison of the following dosimetric parameters between the techniques was performed: mean and maximum thyroid dose; V5, V30, and V50 (percentage of thyroid receiving ≥5, ≥30, and ≥50 Gy respectively); percentage of SC nodal volume receiving 95-107% of the prescribed dose (homogeneity index, HI); and maximum spinal cord dose. Anatomical characteristics that influenced the dose distribution were investigated. Results: The 3D-conformal planning technique significantly increased all dosimetric parameters for the thyroid (p&lt;0.001) (Table). It improved the mean HI of the SC nodal volume (16% vs. 93.2%; p&lt;0.001) but resulted in a higher spinal cord dose (mean maximum dose 6.1 Gy vs. 30 Gy). The thyroid volume and depth of SC nodes did not influence the differences in the thyroid doses between the two techniques. The depth of SC nodes was significantly associated with the difference seen in the HI of SC nodal volumes between the techniques (p=0.004). Conclusions: The 3D-conformal planning technique improved the dosimetric coverage of the SC nodal volume but increased radiation doses to the thyroid compared to the single field technique. The longer term clinical consequences of radiation to thyroid should be considered in SC nodal irradiation for patients with breast cancer. [Table: see text]

Integral dose to the carotid artery in intensity modulated radiotherapy of carcinoma nasopharynx: Extended field IMRT versus split-field IMRT

To evaluate the integral dose to carotid vessels in extended field intensity modulated radiotherapy (IMRT) (including the lower neck nodes in IMRT field) and split field IMRT (using separate single anterior field to treat lower neck nodes) in cancer nasopharynx. Dosimetric data from 10 patients of carcinoma nasopharynx, undergoing IMRT, were evaluated in this prospective study. The carotid vessels were contoured from sternoclavicular joints upto the base of skull. IMRT plans were generated for all patients with extended field and split field IMRT techniques using nine coplanar beams with 6 MV photons. A dose of 70 Gy to planning target volume (PTV) 70 Gy, 59.4 Gy to PTV 59.4 Gy and 54 Gy to PTV 54 Gy was delivered in 33 fractions. The dose constraints were similar for both the techniques. The integral dose to the carotid arteries was calculated as the mean dose times the volume (mean dose Χ volume) in units of liter-gray. The mean dose to the carotid vessels in the extended field IMRT was 63.88 ± 0.97 Gy (mean dose ± SD) and it was 64.43 ± 0.73 Gy for the split field technique. The integral dose in the extended field versus split field technique was 0.29 ± 0.0207 and 0.32 ± 0.0213 liter-gray, respectively. The difference was statistically significant (P < 0.013). Extended field IMRT delivers a slightly lower integral dose to carotid arteries in treatment of cancer nasopharynx while maintaining good dose homogeneity to the PTV 54 Gy and can be preferred over split field radiotherapy.

Matching Intensity-Modulated Radiation Therapy to an Anterior Low Neck Field

When using intensity-modulated radiation therapy (IMRT) to treat head and neck cancer with the primary site above the level of the larynx, there are two basic options for the low neck lymphatics: to treat the entire neck with IMRT, or to match the IMRT plan to a conventional anterior "low neck" field. In view of the potential advantages of using a conventional low neck field, it is important to look for ways to minimize or manage the problems of matching IMRT to a conventional radiotherapy field. Treating the low neck with a single anterior field and the standard larynx block decreases the dose to the larynx and often results in a superior IMRT plan at the primary site. The purpose of this article is to review the most applicable studies and to discuss our experience with implementing a technique that involves moving the position of the superior border of the low neck field several times during a single treatment fraction.

Head and neck field matching verification using three dimensional PAGAT polymer gel dosimetry

Independent jaw collimation on modern linear accelerators allows matching of non-diverging field edges (laterals and anterior) when using head and neck treatment techniques. It is a common practice to split a head and neck cancer radiotherapy treatment volume into two separate abutting mono-isocenter fields because the treatment volume lies above and below the line of the shoulders. In a standard three field technique parallel-opposed lateral fields are used to treat the primary tumour site, upper and mid-cervical nodes and a single anterior field is used to treat the lower neck and superior mediastinal lymph nodes. If these fields are non-diverging fields, there is a possibility of creating an under dose or over dose region at the junction of the abutting fields. The purpose of this study was to evaluate the suitability of the PAGAT polymer gel dosimeter as a tool for verification of the dosimetric match of non-diverging field junctions of a mono-isocenter setup.

Technical and dosimetric considerations in IMRT treatment planning for large target volumes

The maximum width of an intensity-modulated radiotherapy (IMRT) treatment field is usually smaller than the conventional maximum collimator opening because of design limitations inherent in some multileaf collimators (MLCs). To increase the effective field width, IMRT fluences can be split and delivered with multiple carriage positions. However, not all treatment-planning systems and MLCs support this technique, and if they do, the maximum field width in multiple carriage position delivery is still significantly less than the maximum collimator opening. For target volumes with dimensions exceeding the field size limit for multiple carriage position delivery, such as liver tumors or other malignancies in the abdominal cavity, IMRT treatment can be accomplished with multiple isocenters or with an extended treatment distance. To study dosimetric statistics of large field IMRT planning, an elliptical volume was chosen as a target within a cubic phantom centered at a depth of 7.5 cm. Multiple three-field plans (one AP and two oblique beams with 160° between them to avoid parallel opposed geometry) with constraints designed to give 100% dose to the elliptical target were developed. Plans were designed with a single anterior field with dual carriage positions, or with the anterior field split into two fields with separate isocenters 8 cm apart with the beams being forcibly matched at the isocenter or with a 1 cm, 2 cm, 3 cm, and 4 cm overlap. The oblique beams were planned with a single carriage position in all cases. All beams had a nominal energy of 6 MV. In the dual isocenter plans, jaws were manually fixed and dose constraints remained unaltered. Dosimetric statistics were studied for plans developed for treatment delivery using both dynamic leaf motion (sliding window) and multiple static segments (step and shoot) with the number of segments varying from 5 to 30. All plans were analyzed based on the dose homogeneity in the isocenter plane, 2 cm anterior and 2 cm posterior to it, along with their corresponding dose-volume histograms (DVHs). All the dual isocenter plans had slight underdosage anterior to the match point and slight overdosage posterior to it, while the dual carriage plan had a nice blending of the dose distribution without the accompanying hot or cold spots. Based on the dose statistics, it was noted that the dual isocenter plans can be clinically acceptable if they have at least a 3-cm overlap. In the case of step and shoot IMRT, the number of segments used in a dual carriage plan was found to affect the overall plan dosimetric indices. PACS number: 87.53.Tf

Technical and dosimetric considerations in IMRT treatment planning for large target volumes

The maximum width of an intensity‐modulated radiotherapy (IMRT) treatment field is usually smaller than the conventional maximum collimator opening because of design limitations inherent in some multileaf collimators (MLCs). To increase the effective field width, IMRT fluences can be split and delivered with multiple carriage positions. However, not all treatment‐planning systems and MLCs support this technique, and if they do, the maximum field width in multiple carriage position delivery is still significantly less than the maximum collimator opening. For target volumes with dimensions exceeding the field size limit for multiple carriage position delivery, such as liver tumors or other malignancies in the abdominal cavity, IMRT treatment can be accomplished with multiple isocenters or with an extended treatment distance. To study dosimetric statistics of large field IMRT planning, an elliptical volume was chosen as a target within a cubic phantom centered at a depth of 7.5 cm. Multiple three‐field plans (one AP and two oblique beams with 160° between them to avoid parallel opposed geometry) with constraints designed to give 100% dose to the elliptical target were developed. Plans were designed with a single anterior field with dual carriage positions, or with the anterior field split into two fields with separate isocenters 8 cm apart with the beams being forcibly matched at the isocenter or with a 1 cm, 2 cm, 3 cm, and 4 cm overlap. The oblique beams were planned with a single carriage position in all cases. All beams had a nominal energy of 6 MV. In the dual isocenter plans, jaws were manually fixed and dose constraints remained unaltered. Dosimetric statistics were studied for plans developed for treatment delivery using both dynamic leaf motion (sliding window) and multiple static segments (step and shoot) with the number of segments varying from 5 to 30. All plans were analyzed based on the dose homogeneity in the isocenter plane, 2 cm anterior and 2 cm posterior to it, along with their corresponding dose‐volume histograms (DVHs). All the dual isocenter plans had slight underdosage anterior to the match point and slight overdosage posterior to it, while the dual carriage plan had a nice blending of the dose distribution without the accompanying hot or cold spots. Based on the dose statistics, it was noted that the dual isocenter plans can be clinically acceptable if they have at least a 3‐cm overlap. In the case of step and shoot IMRT, the number of segments used in a dual carriage plan was found to affect the overall plan dosimetric indices.PACS number: 87.53.Tf

Regional radiotherapy to axilla and supraclavicular fossa for adjuvant breast treatment: A comparison of four techniques

Purpose The three techniques commonly used to treat the axilla and supraclavicular nodes in adjuvant radiotherapy all have significant disadvantages, including underdosing the deeper nodes, excessively irradiating normal tissues, or producing undesirable hot spots. We assessed whether an anterior field with posterior boost field to the axilla with customized compensation of the anterior beam (APcomp–PAboost) would minimize these drawbacks. Methods and materials The axillary and supraclavicular nodal volumes, planning target volume (PTV), irradiated volume, and brachial plexus were contoured for 10 patients. The plans for each technique—single anterior field (AP); anterior to posterior parallel pair (AP–PA); anterior field with posterior boost (AP–PAboost); and APcomp–PAboost—were then generated for each patient using CadPlan and compared. Results The AP plan gave poor PTV coverage in 60% of cases. The AP–PA provided good PTV coverage and minimal hot spots, but resulted in consistent unnecessary RT to the medial posterior neck. The skin and tissue of the medial posterior neck and chest wall (i.e., the tissue overlying the posterior half of the ribs and posterior to the latissimus dorsi muscle, which forms the posterior wall of the axilla) was incidentally included in the radiation fields of the AP–PA and the exit of the AP beam. No nodal tissue is present in this region, and, therefore, this tissue was unnecessarily irradiated to higher doses with the AP–PA technique. The AP–PAboost provided adequate PTV coverage and a limited dose to the medial posterior neck, but produced hot spots in excess of 120% in 90% of cases. The APcomp–PAboost provided good PTV coverage, a limited dose to the medial posterior neck, and hot spots to <120% in all cases. Conclusion In most cases, the APcomp–PAboost technique offered the best compromise, but the AP–PA technique may be preferred if a less intense hot spot is sought.

A systematic study of techniques for elective cervical nodal irradiation with anterior or opposed anterior and posterior beams

Purpose: To assess target coverage and dose homogeneity using conventional radiotherapy (RT) and intensity-modulated RT (IMRT) with anterior and posterior beams for elective irradiation of the cervical lymph nodes in patients with head and neck cancer.Materials and methods: A planning study was performed in six patients who had undergone radical RT for head and neck cancer. RT plans to irradiate the cervical lymph nodes using a single anterior field, or opposed anterior and posterior fields, with 6 or 10 MV photons were compared. Plans using IMRT for missing-tissue compensation were also studied. An algorithm was developed to guide clinicians to the most appropriate treatment technique depending on the nodal groups to be irradiated.Results: With 6 MV single field (SF) irradiation significant under-dose (minimum dose <70% of prescription dose) was seen in nodal groups II and V, due to their posterior position. With SF 10 MV the mean dose to level II was higher (p<0.001) and dose homogeneity to levels Ib and II was improved. Using opposed fields (OF), minimum doses to the nodes in levels II and V were improved. OF using 10 MV showed significant advantage over 6 MV with reduction of maximum doses to levels II, III and V. SF 10 MV IMRT improved maximum doses to levels Ib and II compared to SF 6 MV IMRT. OF IMRT gave the best dose distributions with optimal mean dose and dose homogeneity. Beam energy made no difference with OF IMRT.Conclusions: The optimal technique for elective cervical node irradiation depends on the lymph node levels within the PTV. If irradiation of the level II or V nodes is required, then the OF IMRT technique with either 6 or 10 MV gives the best dose distributions. In the absence of IMRT, then OF conventional techniques are best. If the aim is to irradiate levels III and IV or level IV only, then 6 MV SF non-IMRT is the simplest technique.

Conjunctival Lymphoma: Retrospective Analysis of the Treatment Result and Complications with Radiation Therapy.

In order to evaluate the response to radiation therapy and to analyze the patterns of failure, survival and complications, we performed a retrospective analysis of patients with conjunctival lymphoma. From November 1991 to March 1999, 11 patients were diagnosed as conjunctival lymphoma at Asan Medical Center. Five patients had bilateral involvements, and a total of 16 eyes received radiation therapy. Using 6 to 9 MeV electrons or 4 MV photon beams, all patients were treated with a single anterior field to total doses ranging from 30 Gy to 45 Gy delivered in 10 to 25 fractions. The median follow up period was 57 Months. All patients achieved a complete response with radiation therapy. Two of 16 eyes that were treated (12.5%) developed local recurrence after radiation therapy, however they were salvaged with 30 Gy of reirradiation. The five-year local control was 88.9%. One out of 11 patients (9.9%) developed lung metastasis and received chest irradiation. At the last follow up, one had died of pneumonia and 10 patients were alive without disease evidence. The five-year overall survival rate was 77.8% and 5-year disease free survival was 77.8%. Cataract and dry eye occurred in one patient (9.9%) respectively. Radiation therapy is a very effective and safe treatment modality for conjunctival lymphoma. The local control rate of radiotherapy was excellent and complications were acceptable. Radiation therapy is also an effective treatment modality for recurrent conjunctival lymphoma. It generally requires more than three months to achieve complete response following radiation therapy, thus we recommend evaluating the response to radiation therapy at three months after completion of treatment.

A custom three-dimensional electron bolus technique for optimization of postmastectomy irradiation

Purpose: Postmastectomy irradiation (PMI) is a technically complex treatment requiring consideration of the primary tumor location, possible risk of internal mammary node involvement, varying chest wall thicknesses secondary to surgical defects or body habitus, and risk of damaging normal underlying structures. In this report, we describe the application of a customized three-dimensional (3D) electron bolus technique for delivering PMI.Methods and Materials: A customized electron bolus was designed using a 3D planning system. Computed tomography (CT) images of each patient were obtained in treatment position and the volume to be treated was identified. The distal surface of the wax bolus matched the skin surface, and the proximal surface was designed to conform to the 90% isodose surface to the distal surface of the planning target volume (PTV). Dose was calculated with a pencil-beam algorithm correcting for patient heterogeneity. The bolus was then fabricated from modeling wax using a computer-controlled milling device. To aid in quality assurance, CT images with the bolus in place were generated and the dose distribution was computed using these images.Results: This technique optimized the dose distribution while minimizing irradiation of normal tissues. The use of a single anterior field eliminated field junction sites. Two patients who benefited from this option are described: one with altered chest wall geometry (congenital pectus excavatum), and one with recurrent disease in the medial chest wall and internal mammary chain (IMC) area.Conclusion: The use of custom 3D electron bolus for PMI is an effective method for optimizing dose delivery. The radiation dose distribution is highly conformal, dose heterogeneity is reduced compared to standard techniques in certain suboptimal settings, and excellent immediate outcome is obtained.

Curative radiation therapy for primary orbital lymphoma

Purpose: To review our institutional experience with primary orbital lymphoma and determine prognostic factors for survival, local control and distant metastases. In addition, we also analyzed the risk factors for complications in the radiotherapeutic management of this tumor. Materials and Methods: Tumor registry records of 91 patients (pts) with orbital lymphoma from 1973 to 1998 treated at one institution were reviewed. Pts were excluded from the study if they had pseudolymphoma, intraocular lymphoma, metastases to the orbit, palliative radiation therapy or follow-up of less than 6 months. A total of 47 pts with primary orbital lymphoma were treated for cure with radiation therapy. There were 18 males and 29 females with a median age of 69 years (range, 32 to 89 years). Four pts had bilateral involvement. Tumor was located in the eyelid and extraocular muscles in 58%, lacrimal gland 21% and conjunctiva in 21%. Histology was low grade in 68%, intermediate in 30% and high grade in 2%. All pts were stage IAE. Median dose for low grade tumors was 3000 cGy with a range of 2000 – 4020 cGy, while the median dose for intermediate and high grade tumors was 4140 cGy with a range of 3000 – 5100 cGy. Fraction size was 200 cGy in 32 pts, 180 cGy in 14 pts and 170 cGy in 1 patient. Beam energy was 4 MV photons in 62%, 6 MV in 13%, 1.25 MV in 8% and orthovoltage in 2%. Electrons were used in 9% of pts. A single anterior field was employed in 32% pts; the remaining pts were treated with a two field technique that included an anterior and an oblique field or two oblique fields. Pts with bilateral involvement were treated with two lateral fields. Lens sparing technique was used in 34% of pts. None of the pts received chemotherapy for initial management of the tumor. Median follow-up time was 55 months (range 6 to 232 months). Log rank analysis was performed to determine the factors which influenced overall survival and distant metastases. Multivariate logistic regression analysis was employed to determine risk factors for cataract formation and corneal injury. Lens and corneal complications were graded according to objective portion of the SOMA scale of the Late Effects of Normal Tissue (LENT) Scoring System. Results: Local control was 100% in the 51 orbits treated. The overall survival at 5 years was 73.6%. Tumor grade and location within the orbit had no prognostic significance for overall survival or distant metastases. Seven pts developed distant metastases. Sites of metastases included mediastinum, abdomen, extremity and CNS. Cataracts were LENT grade 1 in 8 and grade 2 / 3 in 4 pts. Corneal toxicity was LENT grade 1 in 17 and grade 3 in 1 patient. All pts who had corrective surgery had grade 2 or 3 complications. On multivariate analysis, only male gender predicted for increased risk of cataract formation. Age, radiation dose, fraction size, steroid use and lens sparing technique did not affect the rate of complications. None of the pts who had a lens block had a grade 2 or 3 complication or required surgical correction. Conclusion: Radiation therapy alone is a highly effective modality in the curative management of primary non-Hodgkin’s lymphoma of the orbit. Excellent local control is achievable with radiation doses of 3000 cGy in low-grade and 4000 cGy in intermediate/high grade tumors using conventional fractionation. Although the use of lens sparing technique did not influence cataractogenesis, we continue to recommend lens blocks whenever possible because our experience indicates a higher grade of toxicity and corrective surgery in pts treated without lens sparing technique.

Axillary Recurrence Following Conservative Surgery and Radiotherapy in Early Breast Cancer

At the institute, since the late 1980s, there has been a uniform treatment protocol for the management of the regional lymph nodes in patients referred for radiotherapy following breast-conserving surgery. An analysis of 2277 consecutive patients referred for radiotherapy between 1989 and 1992, with particular reference to regional lymph node management, has been undertaken. Axillary surgery alone was used in 517 patients (23%); 1191 (52%) patients had no axillary surgery but had radiotherapy to the axilla, and infraclavicular and supraclavicular fossae by a single anterior field, delivering 40 Gy in 15 daily fractions over 3 weeks; and 474 patients (21%) had axillary surgery followed by radiotherapy. Ninety-five patients (4%) underwent no axillary treatment. There was a total of 155 axillary recurrences with a median follow-up of 5.9 years, giving an actuarial nodal control rate of 94% at 5 years (95% confidence interval (CI) 93.1–95.1). The overall survival at 5 years was 86% (95% CI 84.6–87.5). There was a trend towards improved axillary control with surgery alone compared with radiotherapy alone (4.5% versus 5.9% actuarial axillary failure rate at 5 years). An extremely low incidence of brachial plexus neuropathy secondary to radiotherapy was reported. The multidisciplinary treatment protocol used gave a high rate of regional node control, with minimal recorded morbidity.

Radiation therapy for stage I primary orbital non-Hodgkin's lymphomas.

The orbit is an uncommon primary site for non-Hodgkin's lymphomas (NHL), and it accounts for less than 1% of all sites of primary presentations. We report the experience of the Department of Radiation Oncology at Ankara University Faculty of Medicine with radiation therapy in treatment of patients with stage I primary orbital NHL. From February 1978 through August 1993, 14 patients with stage I primary orbital NHL were treated with radiation therapy. According to the Working Formulation classification, 8 patients had low-grade and 6 had intermediate-grade lymphomas. The most commonly used radiation therapy technique was a single anterior field with a Cobalt-60 unit, delivering 40 Gy in 2 Gy daily fractions. Two patients with intermediate-grade lymphomas received the CHOP regimen following radiation therapy. Follow-up ranged from 0.8 to 18.3 years (median, 10.3 years). Local control was achieved in all patients. Two patients with low-grade lymphomas relapsed locally and were successfully salvaged with radiation therapy. Three patients with intermediate-grade lymphomas failed systemically. Salvage therapy consisted of combination chemotherapy for 2 of them but was unsuccessful. Overall survival probabilities at 2, 5 and 10 years were 78.6%, 61.1% and 52.4%, respectively, for the entire group of 14 patients. Overall, cause-specific and disease-free survival probabilities were higher for patients with low-grade lymphomas than for those with intermediate-grade lymphomas (P = 0.03, P = 0.03 and P = 0.06, respectively). Cataracts were observed in 9 and lacrimal disorders in 4 patients. The study suggests that among stage I primary orbital NHL, low-grade lymphomas could be treated with radiation therapy alone, whereas combination chemotherapy could accompany radiation therapy for intermediate-grade lymphomas.

Surgical maxillary buccal segment advancement as an alternative to orthodontic treatment

The thyroid is not routinely considered an organ at risk in supraclavicular (SC) nodal radiation therapy (RT) for breast cancer. We compared the dosimetric impact of the following 2 RT planning techniques on the thyroid: (1) conventional single anterior field to encompass the SC nodal volume defined clinically; and (2) 3-dimensional conformal radiation therapy (3DCRT) planning to encompass the computed tomography (CT)-contoured SC nodal volume.The thyroid, SC nodal volumes, and organs at risk were contoured on the planning CT of 20 patients who received 50 Gy in 2-Gy daily fractions to the breast or chest wall, and SC nodes. Comparisons of dosimetric parameters between the techniques were performed: thyroid, mean and maximum dose, V5, V30, and V50 (percentage of thyroid receiving ≥ 5 Gy, ≥ 30 Gy, and ≥ 50 Gy, respectively); SC nodal volume, homogeneity index (HI, percentage volume receiving 95%-107% of prescribed dose); and maximum doses of spinal cord and brachial plexus. Anatomic characteristics that influenced the dose distributions were investigated.The 3DCRT planning technique significantly increased all thyroid dosimetric measures (mean dose 17.2 Gy vs 26.7 Gy; maximum dose 48.5 Gy vs 51.9 Gy; V5 45.7% vs 64.9%; V30 33.7% vs 48%; and V50 0.6% vs 26.7%; P < .001). It improved HI for the SC nodal volumes (P < .001) but resulted in higher maximum doses to the spinal cord (6.1 Gy vs 30 Gy) and brachial plexus (43.2 Gy vs 51.4 Gy). The thyroid volume and depth of SC nodes did not influence the thyroid dose distribution. The depth of SC nodes impacted on the HI of SC nodal volumes in the conventional technique (P = .004).The 3DCRT planning improved dosimetric coverage of the SC nodal volume but increased thyroid radiation doses. The potential adverse effects of incidental thyroid irradiation should be considered while improving dosimetric coverage in SC nodal irradiation for breast cancer.

Treatment outcome and dose-response relationship in infants younger than 1 year treated for retinoblastoma with primary irradiation

Thirty-three infants ( < 1 year at diagnosis) were treated for retinoblastoma with primary irradiation at St. Jude Children's Research Hospital (SJCRH) between 1963 and June 1992. Staging of the 44 treated eyes was as follows: Reese-Ellsworth (R-E) Groups I (n = 20), Group II (n = 9), Group III (n = 6), Group IV (n = 2), Group V (n = 7). Irradiation was delivered using either a single anterior field (31 eyes) or lens-sparing techniques (13 eyes). Total doses ranged from 21-45 Gy (median = 36 Gy) in fractions of 150-180 cGy (n = 34) or > 180 cGy (n = 10). One child died of metastatic disease at 42 months. Three patients have developed second malignant neoplasms; two have succumbed at 88 and 125 months post-RB diagnosis; the remaining patients are alive at 6-259 months postdiagnosis (median follow-up = 127 months). Local control with irradiation alone and supplemented cryotherapy given within 2 months (n = 2) was maintained in 29 eyes, with no statistical difference seen for total doses < or = 36 Gy (21/8 eyes) vs. > 36 Gy (8/16). Of 15 eyes that required salvage therapy, tumor control has been maintained in 13. Enucleation was required for four patients, two with recurrent retinoblastoma and one with a phthisical eye. Cataract formation was documented in 23 eyes (87.5%) treated with lens-sparing techniques developed cataract. At last follow-up, 23 of 30 patients tested (77%) had visual acuity of 20/100 or better. This experience confirms early observations in that doses > or = 36 Gy do not appear to improve local control with irradiation alone in infants ( < 365 days) with retinoblastoma.

Treatment outcome and dose‐response relationship in infants younger than 1 year treated for retinoblastoma with primary irradiation

Thirty-three infants (<1 year at diagnosis) were treated for retinoblastoma with primary irradiation at St. Jude Children's Research Hospital (SJCRH) between 1963 and June 1992. Staging of the 44 treated eyes was as follows: Reese-Ellsworth (R-E) Groups I (n = 20), Group II (n = 9), Group III (n = 6), Group IV (n = 2), Group V (n = 7). Irradiation was delivered using either a single anterior field (31 eyes) or lens-sparing techniques (13 eyes). Total doses ranged from 21–45 Gy (median = 36 Gy) in fractions of 150–180 cGy (n = 34) or >180 cGy (n = 10). One child died of metastatic disease at 42 months. Three patients have developed second malignant neoplasms; two have succumbed at 88 and 125 months post-RB diagnosis; the remaining patients are alive at 6–259 months postdiagnosis (median follow-up = 127 months). Local control with irradiation alone and supplemented cryotherapy given within 2 months (n = 2) was maintained in 29 eyes, with no statistical difference seen for total doses ≤36 Gy (21/28 eyes) vs. >36 Gy (8/16). Of 15 eyes that required salvage therapy, tumor control has been maintained in 13. Enucleation was required for four patients, two with recurrent retinoblastoma and one with a massive retinal hemorrhage, one with a phthisical eye. Cataract formation was documented in 23 eyes (87.5%) treated with anterior field. Three patient treated with lens-sparing techniques developed cataract. At last follow-up, 23 of 30 patients tested (77%) had visual acuity of 20/100 or better. This experience confirms early observations in that doses ≥36 Gy do not appear to improve local control with irradiation alone in infants (<365 days) with retinoblastoma. © 1996 Wiley-Liss, Inc.