Axillary Apex Research Articles

A Three-Dimensional (3D) Analysis of the Conventional Supra-clavicular Field in Breast Cancer

Purpose: To assess the 3D dose coverage of the supraclavicular fossa (SCF) and axillary apex (AA) following conventional dose prescription and blocking. Materials and Methods: 16 patients with breast cancer were evaluated using CT-based planning. The SCF, AA, and brachial plexus (BP) were outlined on the planning CT. Spinal cord and humeral head blocks were drawn on the 2D digitally-reconstructed radiograph without the targets displayed. The prescription point was placed 3cm deep, lateral to the sternocleidomastoid muscle, and superior to the medial third of the clavicle. From an oblique 6MV beam plan, dose-volume histograms were generated. Results: The fraction of SCF underdosed by 5% ranged from 2–85%. 2–5% of the SCF was underdosed in five patients, 13–20% in five, 24–30% in three and 68–85% in three. The portion of AA underdosed by 10% was 0–8% in five patients, 20–32% in four, 42–62% in three and 84–100% in five. The volume of BP receiving > 90% of the prescription dose varied from 7–93%. In 6/16 patients, >50% of the BP received >90% of the dose. 2D blocking was suboptimal for the SCF in 2 patients and for the AA in 6. Better target coverage and less volume above 100% of the dose was achieved with inverse planning. Conclusions: Although 2D SCF coverage was adequate in the majority of patients, the conventional field does not optimally cover the SCF in 3D. When the intention is to treat the AA, 3D planning may be required for adequate coverage. Intensity modulation may result in better coverage of the SCF and AA while reducing dose to the BP.

Breast cancer: Post-mastectomy radiotherapy: recommended standards

The local recurrence rate after mastectomy in breast cancer patients varies significantly in reported series; in some publications from 2% to even more than 50% at 10 years. The reasons for these differences can be found in patient selection and the surgical method and technical skills of the surgeon. For example, a low recurrence percentage can be obtained by combining a good surgical procedure with the exclusion of patients for radical mastectomy by following strict inoperability criteria. For this purpose, the following criteria are often used: fixation of the tumour and/or lymph nodes to the chest wall, inflammatory breast cancer, and in some institutes a positive axillary apex biopsy. In 1949 Ralston Paterson and colleagues in Manchester started probably the first randomized clinical trial in the world investigating the potential of radiotherapy in improving local control and indirectly survival [1]. They randomized patients after mastectomy between no radiotherapy and post-mastectomy radiotherapy. For this purpose 1461 patients were entered in this trial. He and his colleagues demonstrated that radiotherapy was able to reduce significantly the amount of local recurrences thereby preventing patients dying from symptoms of uncontrolled local disease. Unfortunately long term follow up showed that the potential gain in survival was diminished by an excess of radiotherapy-related cardiovascular complications. It would be unfair to criticize the trial design according to current standards and the radiation technique used but a few remarks should be made here. For example, the randomization was based on the patient's date of birth (odd or even), so the surgeon would know beforehand in which arm the patient would be randomized. He may have therefore decided not to select patients for the trial if they had a high risk of local recurrence knowing that they would be randomized to no further treatment. Instead he may have referred these patients for radiotherapy, leading to unbalanced treatment arms. The major reason for the excess of cardiovascular deaths seen in this trial was the equipment available at that time. The patients were treated with orthovoltage equipment using a technique that delivered a high dose to a large part of the heart with higher fraction doses. A reduction of the local recurrence rate, by a factor of 0.6, by post-mastectomy radiotherapy has now been confirmed by many trials. It took until recently for it to be demonstrated that improvement in local control could result in about 10% improved survival rate [2-4]. These results became available with the publication of the long term follow up data from a few major trials started after 1975. These trials have shown a gain that can be reached by careful selection of high-risk patients for radiotherapy and through the execution of meticulous radiotherapy techniques, avoiding over dosage of radiation to the heart. The impact of improved local control on the survival rate shown by these trials suggests that distant metastases may arise from recurrent local disease, stressing the need for adequate local treatment.

Conservative surgery and radiotherapy in early stage breast cancer: a comparison between tumourectomy and quadrantectomy

Background and purpose: This study analyses and compares the results of local regional control, distant metastases and survival in two series of patients irradiated from 1986 to 1992 in our radiation oncology centre following quadrantectomy or tumourectomy for early stage breast cancer. Materials and methods: The quadrantectomy group consisted of 152 women, 109 (72%) with T1 and 43 (28%) with T2 tumours. Axillary nodes in this group were positive in 51 (33%) patients. The tumourectomy group included 123 women, 71 (58%) with T1 and 52 (42%) with T2 tumours. Positive axillary nodes were found in 56 (46%) of these patients. All quadrantectomy and tumourectomy patients received a dose of 50 Gy in 5 weeks to the whole breast, followed by a 10–16 Gy electron boost. Node positive patients in the tumourectomy group also received 50 Gy to the axillary apex and supraclavicular region. In both surgical groups, node positive premenopausal and postmenopausal patients received adjuvant CMF or tamoxifen therapy, respectively. Results: After a median follow-up of 58 months, 89% of women in the tumourectomy group and 87% in the quadrantectomy group were alive and 80 and 73%, respectively, were free of disease. Breast and nodal failures were detected in 4.9 and 0.8% of cases, respectively, in the tumourectomy group, as compared to 5.9 and 3.3% of cases, respectively, in the quadrantectomy group. Distant relapses were observed in 16 and 18% of patients in the former and latter groups, respectively. Actuarial overall and disease-free survival was similar in the two series, with 5-year rates of 90 and 72%, respectively, in the tumourectomy group, and of 91 and 78%, respectively, in the quadrantectomy group. The differences in survival are not statistically different. Conclusions: Our findings show that tumourectomy and quadrantectomy, followed by adequate radiotherapy, provide comparable results in terms of local-regional control and survival.

The prognostic significance of the axillary apex biopsy in clinically operable breast cancer.

To evaluate the prognostic significance of the axillary apex biopsy and its impact on clinical practice, a retrospective analysis was performed in 875 patients with clinically operable breast cancer who underwent this procedure from 1977 to 1985 (165 TNM stage I; 512 TNM stage II; 198 TNM stage IIIA). Apex biopsy is performed as a staging procedure. Apex biopsy positive patients are treated by radiotherapy alone, while apex biopsy negative patients are treated with breast conserving therapy or mastectomy, both including complete axillary dissection. The apex biopsy was tumour positive in 4% of TNM stage I patients; 17% of stage II patients and 40% of stage IIIA patients. Among patients with clinically node-negative disease, the apex biopsy was positive in 12%; in patients with palpable suspected lymph nodes this figure was 45%. Actuarial 8 y survival rates for patients with stage I, II and III disease and a negative apex biopsy were 83, 70 and 50%, respectively. The corresponding figures for patients with a positive apex biopsy were 60, 28 and 14%. In a multivariate analysis, a positive apex biopsy, clinical N classification and T classification were independent prognostic factors for survival (P < 0.0001). We conclude that a positive apex biopsy is rare in clinical stage I breast cancer, and that in patients with TNM stage II and III disease the procedure is an important tool to assess prognosis pre-operatively.

Primary radiotherapy of breast cancer: Treatment results in locally advanced breast cancer and in operable patients selected by positive axillary apex biopsy

To evaluate the efficacy of radiotherapy without surgery, treatment results in patients treated for locally advanced breast cancer ( n = 209) and those selected by positive axillary apex biopsy ( n = 289) in the period between 1977 and 1985 have been analysed retrospectively. Treatment consisted of primary irradiation to the breast and regional lymph nodes followed by a boost to the primary breast tumour and palpable regional disease to a mean normalised total dose (NTD) of 64.7 Gy with a range of 33.4–93 Gy (2 Gy fractions, α/β = 5 Gy). Adjuvant systemic treatment was given in 30% of the locally advanced and in 40% of the apex positive patients. Thirty percent of the apex positive patients had an excisional biopsy of the breast tumour. By multivariate analysis a prognostic index is constructed for locoregional control, overall survival and distant disease-free interval. Primary tumour size and clinical nodal status are independent prognostic factors for locoregional control. Based on the prognostic index for local control four different groups can be identified with 5 year local control rates varying from 47 to 86%. Patients treated with adjuvant chemotherapy and patients irradiated to a NTD of 60 Gy or more had significantly better local control. For overall survival primary tumour size, clinical nodal size and age are independent prognostic factors. Patients irradiated to a NTD above 60 Gy had significantly better results. Survival according to the prognostic index for survival varies between 20 and 50% at 5 years for the four groups subdivided according to the index for survival. Primary tumour size, clinical node size and age are independent prognostic factors for distant disease-free interval. Patients treated with adjuvant hormonal therapy had significantly better results. In the four groups subdivided according to the prognostic index for distant disease-free interval results vary from 17 to 30% at 5 years.

Pre-flowering Growth and Development of the Inflorescences of Maize

The growth and development of the main stem and the two uppermost axillary apices of maize were studied during the period from emergence until flowering. Plants were grown in the field under varying levels of applied nitrogen fertilizer at two times of sowing. The effects of daylength were isolated from those of temperature by making comparisons of growth and development on a thermal time basis. The growth and development of the terminal (male) apex and the two uppermost axillary (female) apices followed the same patterns, with apex volumes increasing curvilinearly with increase in number of leaf or husk primordia. The f?Gf?(relative growth rate of volume) of the terminal apex was, however, only approximately one-tenth of the axillary apices. There was no difference in growth and development between the first and second axillary apices before flowering: other factors, such as accumulation of dry weight, rather than primordia production, must be responsible for an axillary apex's potential to bear grain. Applied N, and to a lesser extent short days, increased the rates of growth and development of all the apices. For example, applied N increased the RGR (volume) of the apical domes, and the rate of production of spikelet primordia, by about 25%. All axillary apices and treatments showed a single relationship between number of spikelets and surface area of the ear: a favourable environment (e.g. high N) simply accelerated the progression of spikelet production and area expansion along this single path. We conclude that this path is probably determined genetically and that N and time of sowing influence potential yield of maize through effects on the surface area of the ear but not on the density of spikelets formed.

Adjuvant chemo- and hormonal therapy in locally advanced breast cancer: a randomized clinical study

Between 1977 and 1980, 118 breast cancer patients with locally advanced disease, T 3B–4, any N, M 0 or T 1−3, tumor positive axillary apex biopsy, were randomized to one of three arms: I: radiotherapy (RT) to the breast and adjacent lymph node areas; II: RT followed by 12 cycles of cyclophosphamide, methotrexate, 5 fluorouracil (CMF) and tamoxifen during the chemotherapy period; III: 2 cycles of adriamycin and vincristine (AV), alternated with 2 cycles of CMF, then RT, followed by another 4 cycles of AV, alternated with 4 CMF; tamoxifen during the entire treatment period. The median follow-up period was 5 1 2 years. The adjuvant chemo- and hormonal therapy did not improve the overall survival; the 5-year survival was 37% for all three treatment arms. There was no statistically significant difference in RFS between the three modalities, nor when arm I was compared to arm II and III together, p = 0.11. Local recurrence (LR) was observed in 24 of the 86 patients (28%) who had reached complete remission (CR). LR was not statistically different over the three treatment arms. In 18 of the 24 patients with LR, distant metastases appeared within a few months from the local recurrence. In arm III, the CR rate after 4 cycles AV plus CMF and RT hardly changed after another 8 cycles of chemotherapy. The menopausal status did not influence the treatment results. Dose reduction in more than 4 cycles of chemotherapy was accompanied by better results, p = 0.04. In conclusion: adjuvant chemo- and hormonal therapy did not improve RFS and overall survival. These findings do not support the routine use of adjuvant chemo- and endocrine therapy for inoperable breast cancer.

Bud development in mountain hemlock (Tsuga mertensiana). II. Cone-bud differentiation and predormancy development

Seed cones of Tsuga mertensiana (Bong) Carr. occur terminally on distal lateral branches and form from the differentiation of a terminal, previously vegetative apex, into a seed-cone apex. Pollen cones commonly occur on lateral branches and form from the differentiation of an undetermined axillary apex about 6 weeks after axillary bud initiation. Pollen cones also occasionally occur terminally. All cone buds began differentiation in late July after bud-scale initiation was complete and at about the end of lateral shoot elongation. Seed-cone buds initiated bracts and ovuliferous scales, but not ovules, before they became dormant at the end of October. Pollen-cone buds initiated all microsporophylls by early September. Microsporangia containing microspore mother cells differentiated before pollen-cone buds became dormant in mid-October. The time of cone-bud differentiation is related to vegetative bud and shoot development. The time and method of cone-bud differentiation is discussed in relation to T. heterophylla and other conifers having similar bud development.

Posperative radiation therapy for carcinoma of the breast: Improved results with elective irradiation of the chest wall

A review was conducted of all patients with primary cancer of the breast treated by the Radiation Therapy Department of Mount Sinai Medical Center from 1966–1978. The initial surgical procedure was radical mastectomy or modified radical mastectomy for 926 patients. The mean follow-up for this group was 6.42 years, the range was 1–13 years. All postoperative therapy was given with megavoltage equipment. Treatment was directed to either the peripheral lymphatics (internal mammary chain, supraclavicular and axillary apex) or to the peripheral lymphatics fossa and chest wall. The decision to include the chest wall within the treatment volume was based upon the extent of disease at the primary site and the degree of involvement of the axilla. Curves were generated to compare, by stage, control of disease for both postoperative radiotherapy techniques. The expected enhancement of local (regional) control was seen for patients with more advanced disease who received chest wall irradiation. Differences favoring the more comprehensively irradiated group were also seen in disease-free and overall survival for all three stages of disease, with statistically significant benefit in survival analysis for patients with Stage II and III disease. (Stage II-peripheral lymphatic group: 5 years = 54%; 10 years = 36%. Peripheral lymphatic plus chest wall group: 5 years = 71%; 10 years = 49 %.Stage III-peripheral lymphatic group: 5 years = 32%; 10 years = 15%. Peripheral lymphatic plus chest wall group: 5 years = 51 %; 10 years = 38%.) These results imply that microscopic residual disease within the soft tissues of the chest wall can metastasize without necessarily manifesting as regionally recurrent disease. Postoperative irradiation of the chest wall imparts additional survival advantage to a significant percentage of patients treated by radical surgery. Criteria for the inclusion of the chest wall within postoperative radiotherapy fields should be broadened.

Etude cinétique de quelques événements lies à une levée de dominance apicale par décapitation ou ablation de l'axe principal à différents niveaux chez la Tomate, Lycopersicum esculentum

In intact tomato plants, axillary buds are completely inhibited by the main apex. A release from apical dominance is obtained by decapitation or excision of the main axis at different levels. These excisions lead to a wave of mitotic reactivation along the main stem which progresses in the basipetal way and is followed by an activation of axillary bud in the acropetal direction, from the base to the axillary bud apex. After release from apical dominance, axillary buds don't react equally. There is a basipetal gradient of their capacity of outgrowth. In the younger subapical axillary buds, mitotic reactivation is the first step observed (after 3 h); the cellular elongation occurs after 3–6 h, and foliar organogenesis begins only after 24 h. The basal axillary buds are reactivated much later. Adult leaves don't play any role on their axiliaries: the total defoliation of the plant does not lead to the outgrowth of all the axillary or cotyledonary buds.

DEVELOPMENT AND PHYLLOTAXIS OF THE VEGETATIVE AXILLARY BUD OF MICHELIA FUSCATA

Tucker, Shirley C. (Northwestern U., Evanston, III.) Development and phyllotaxis of the vegetative axillary bud of Michelia fuscata. Amer. Jour. Bot. 50(7): 661–668. Illus. 1963.—The vegetative axillary buds of Michelia fuscala are dorsiventrally symmetrical with 2 ranks of alternately produced leaves. The direction of the ontogenetic spiral in each of these buds is related both to the symmetry of the supporting branch and to the position of the bud along the branch. On a radially symmetrical branch, all the axillary buds are alike—all clockwise, for example. But in a dorsiventrally organized branch the symmetry alternates from clockwise in 1 axillary bud to counterclockwise in the next bud along the axis. Leaf initiation and ontogeny of the axillary apical meristem conform with those of the terminal vegetative bud. The axillary bud arises as a shell zone in the second leaf axil from the terminal meristem. During this process the axillary apex develops a zonate appearance. The acropetally developing procambial supply of the axillary bud consists wholly of leaf traces. At the nodal level the bud traces diverge from the same gap as the median bundle trace of the subtending leaf. Only the basal 1–2 axillary buds which form immediately after the flowers elongate each year, while the majority remains dormant with 3 leaves or fewer.