Parenchymal pineal tumors: a clinicopathological study of 76 cases

PURPOSE

The aim of this study was to identify factors that could lead to optimization of the management of pineal parenchymal tumors (PPT) which remains equivocal and controversial.

METHODS AND MATERIALS

In order to determine factors that influence PPT prognosis, a series of 76 consecutive patients from 12 European centers with histologically proven tumors was retrospectively reviewed. The clinical records and material for histologic review were available in all cases. Follow-up was achieved in 90% of cases.

RESULTS

According to WHO classification, there were 19 pineocytomas, 28 intermediate and mixed PPT, and 29 pineoblastomas. According to a four-grade institutional classification, there were 11 Grade 1, 27 Grade 2, 20 Grade 3, and 18 Grade 4. Surgical resection was attempted in 44 patients, whereas 30 had biopsy only. In one case, diagnosis was made at autopsy and in another on spinal deposits. Forty-four patients were irradiated following surgery, 15 patients received chemotherapy. Forty-one patients were alive (median follow-up: 85 months); 9 patients died perioperatively; 26 patients relapsed. Univariate analysis showed a good outcome correlated with age above 20 years, tumor diameter less than 25 mm, and low-grade histology. Multivariate analysis confirmed histology and tumor volume to be significant independent prognostic factors. The extent of surgery and radiotherapy had no clear influence on survival.

CONCLUSIONS

This review highlights the prognostic features of PPT and may help to determine treatment strategies based on radiologic and pathologic characteristics.

[Implementation of receiver operating characteristics for the quantitative evaluation of stereotactic radiotherapy treatment plans]

The definition of criteria and of a methodology dedicated to the quantitative evaluation of conformal stereotactic treatment plans is presented. We implemented the 'Receiver Operating Characteristics' (ROC) analysis, already used in medical imaging, for the quantitative evaluation of irradiation treatment plans. This implementation is based on data provided by dose-volume histograms (DVH). Three techniques, each one using a different dosimetric criterion, were defined for the choice of a reference isodose for a given treatment plan. We used this ROC analysis for the selection of the most conformal treatment plan and its reference isodose among the treatment plans proposed for one patient. This study revealed the interest of ROC analysis based on dose-volume histograms for the quantitative evaluation of treatment plans.

Study of ill-conditioning of Linac stereotactic irradiation subspaces using singular values decomposition analysis

A Linac stereotactic irradiation space is characterized by different angular separations of beams because of the geometry of the stereotactic irradiation. The regions of the stereotactic space characterized by low angular separations are one of the causes of ill-conditioning of the stereotactic irradiation inverse problem. The singular value decomposition (SVD) is a powerful mathematical analysis that permits the measurement of the ill-conditioning of the stereotactic irradiation problem. This study examines the ill-conditioning of the stereotactic irradiation space, provoked by the different angular separations of beams, using the SVD analysis. We subdivided the maximum irradiation space (MIS: (AA)AP x (AA)RL = 180 degrees x 180 degrees) into irradiation subspaces (ISSs), each characterized by its own angular separation. We studied the influence of ISSs on the SVD analysis and the evolution of the reconstruction quality of well defined three-dimensional dose matrices in each configuration. The more the ISS is characterized by low angular separation the more the condition number and the reconstruction inaccuracy are increased. Based on the above results we created two reduced irradiation spaces (RIS: (AA)AP x (AA)RL = 180 degrees x 140 degrees and (AA)AP x (AA)RL = 180 degrees x 120 degrees) and compared the reconstruction quality of the RISs with respect to the MIS. The more an irradiation space is free of low angular separations the more the irradiation space contains useful singular components.

Small intestine protection from radiation by means of a removable adapted prosthesis

BACKGROUND

A prosthesis has been designed to protect intestinal loops from radiation when postsurgical radiotherapy is necessary in cancer treatment. It is a silicone balloon that allows the small bowel to be pushed back away from the radiation field, and it is easily removed at the conclusion of radiotherapy.

METHODS

The device was used in 22 patients: 5 retroperitoneal tumors and 17 pelvic cancers. After surgical resection of the tumor, the device is placed either in the retroperitoneal area or in the pelvic cavity. A polyglactine 910 mesh is placed between the spacer and the bowel to prevent incarceration of the loops. The prosthesis can be filled or emptied between each radiation course and finally removed by means of a short incision under local or locoregional anesthesia.

RESULTS

The tolerance of the small intestine to radiation therapy has been satisfactory in each case, with a mean follow-up of 24.5 months (range 10 to 73). No modification of biological parameters was observed during the pelvic radiation therapy at 30, 45, and 65 Gy.

CONCLUSION

This device should appears to efficient for prevention of bowel injury during postsurgical radiation in successful treatment of abdominal, pelvic, or retroperitoneal tumors when indicated.

Gallbladder cancer: role of radiation therapy

BACKGROUND/AIMS

Gallbladder carcinoma is characterized by late diagnosis, ineffective treatment and poor prognosis. These tumors were usually considered to be radioresistant. So far, the role of radiotherapy has not been adequately evaluated. The aim of this report is to assess the value of radiotherapy in carcinoma of the gallbladder.

METHODOLOGY

We reviewed all publications concerning the role of radiation therapy in gallbladder carcinoma. External radiation therapy, intra-operative radiation therapy, and brachytherapy were evaluated in two groups in which the prognosis is quite different; a group operated on, with apparent complete resection of the tumor, and a palliative surgery group.

RESULTS

It appears that gallbladder carcinomas are not as radioresistant as was formerly thought. Local control of the tumor and reduction of tumor size was reported in several publications. Collected data showed a slight improvement of survival after adjuvant or palliative radiotherapy, especially in the advanced stage of gallbladder carcinomas. It appears preferable to give a "boost" (15 Gy) to the gross lesion or residual lesion at operation (intra-operative irradiation or brachytherapy), and deliver an additional 45-50 Gy post-operatively.

CONCLUSIONS

The results published encourage further trials in well defined populations. Radiotherapy seems to be a safe procedure, morbidity is minimal, and a slight effect on survival is observed after curative or palliative surgical procedures.

A computerized dosimetric database for conformal stereotactic irradiations

An innovative computerized dosimetric database (DDB) is proposed to enable the analysis of the stereotactic radiosurgical dose distributions; it contains relationships between the irradiation parameters and the dose-volume data. Dose-volume data provide guidance to the physicist-physician team by facilitating the initialization of the irradiation parameters and the treatment planning. The presented DDB contains dose-volume data such as the 70% isodose widths and the 70%-30% isodose penumbra along the right-left, anterior-posterior, and superior-inferior directions as a function of the irradiation parameters defined by the user. In order to demonstrate the usefulness of the DDB, the effects of the collimator diameter, the number of arcs, and their length on the shape of the prescription isodose surface are shown and are related to practical considerations for the treatment plan. However, the presented DDB is one example that can be generated by the DDB system. The planner can define as many different DDBs as he/she wishes, which can then be used for different investigations. This type of DDB enables us to investigate the irradiation technique used, to compare different irradiation techniques, to inspect the feasibility of planning different lesion types, or to define some dosimetric rules. The DDB provides useful interactive guidelines for the treatment planning process and replaces the voluminous dosimetric atlas. It has now been in clinical use for a year in a conformal procedure which automatically proposes collimator diameters, arc positions, and lengths allowing rapid conformal planning.

Radiosurgery of cerebral arteriovenous malformations: is an early angiogram needed?

BACKGROUND AND PURPOSE

Radiosurgical treatment of arteriovenous malformations (AVMs) has slow and progressive vasoocclusive effects. We sought to determine if early posttherapeutic angiography provides relevant information for the management of radiosurgically treated AVMs.

METHODS

Between 1990 and 1993, the progress of 138 of 197 cerebral AVMs treated by linear accelerator (Linac) was regularly followed by angiographic study. On each posttherapeutic angiogram ("early," 6-18-month follow-up; "intermediate," 19-29-month-follow-up; and "late," > 30-month follow-up), the degree of reduction across the greatest diameter of the nidus and hemodynamic modifications were analyzed. Each cerebral AVM was qualitatively classified into one of the following categories after early angiographic study: 0%-reduced, 25%-reduced, 50%-reduced, 75%-reduced, and 100%-reduced or "complete obliteration." Vasoocclusive progress for each category was then studied over time.

RESULTS

Three (10%) of the 30 0-25%-reduced, eight (38%) of 21 50%-reduced, and 27 (84%) of 32 75%-reduced cerebral AVMs showed complete obliteration after further follow-up. The three 0-25%-reduced AVMS that went on to complete obliteration underwent very early angiography (6-7 months). Fifty-five cerebral AVMs showed complete obliteration on early angiograms (40%). In this group, more follow-up, when performed, confirmed complete obliteration in all cases (n = 17).

CONCLUSION

An early angiogram is needed to predict the effectiveness of radiosurgery. Important AVM changes seen on early angiograms are highly correlated with treatment success. Moreover, no or minor changes seen on early angiograms are highly predictive of radiosurgical failure. For these patients, further treatment should be discussed promptly.

Local recurrences and distant metastases after breast-conserving surgery and radiation therapy for early breast cancer

PURPOSE

To identify predicting factors for local failure and increased risk of distant metastases by statistical analysis of the data after breast-conserving treatment for early breast cancer.

METHODS AND MATERIALS

Between January 1976 and December 1993, 528 patients with nonmetastatic T1 (tumors < or = 1 cm [n = 197], >1 cm [n = 220]) or T2 (tumors < or = 3 cm [n = 111]) carcinoma of the breast underwent wide excision (n = 435) or quadrantectomy (n = 93) with axillary dissection (negative nodal status [n-]: 396; 1-3 involved nodes: 100; >3 involved nodes: 32). Radiotherapy consisted of 45 Gy to the entire breast via tangential fields. Patients with positive axillary lymph nodes received 45 Gy to the axillary and supraclavicular area. Patients with positive axillary nodes and/or inner or central tumor locations received 50 Gy to the internal mammary lymph node area. A boost dose was delivered to the primary site by iridium 192 Implant in 298 patients (mean total dose: 15.2+/-0.07 Gy, range: 15-25 Gy) or by electrons in 225 patients (mean total dose: 14.8+/-0.09 Gy, range: 5-20 Gy). The mean age was 52.5+/-0.5 years (range: 26-86 years) and 267 patient were postmenopausal. Histologic types were as follows: 463 infiltrating ductal carcinomas, 39 infiltrating lobular carcinomas, and 26 other histotypes. Grade distribution according to the Scarff, Bloom, and Richardson (SBR) classification was as follows: 149 grade 1, 271 grade 2, 73 grade 3, and 35 nonclassified. The mean tumor size was 1.6+/-0.3 cm (range: 0.3-3 cm). The intraductal component of the primary tumor was extensive (EIC = IC > or = 25%) in 39 patients. Tumors were microscopically bifocal in 33 cases. Margins were assessed in the majority of cases by inking of the resection margins and were classified as positive in 13 cases, close (< or = 2 mm) in 21, negative (>2 mm tumor-free margin) in 417, and indeterminate in 77. Peritumoral vascular invasion was observed in 40 patients. Tamoxifen was administered for at least 2 years in 176 patients. At least six cycles of adjuvant systemic chemotherapy were administered in 116 patients. The mean follow-up period from the beginning of the treatment was 84.5+/-1.7 months.

RESULTS

First events included 44 isolated local recurrences, 8 isolated axillary node recurrences, 44 isolated distant metastases, 1 local recurrence with synchronous axillary node recurrence, 7 local recurrences with synchronous metastases, and 2 local recurrences with synchronous axillary node recurrences and distant metastases. Of 39 pathologically evaluable local recurrences, 33 were classified as true local recurrences and 6 as ipsilateral new primary carcinomas. Seventy patients died (47 of breast carcinoma, 4 of other neoplastic diseases, 10 of other diseases and 9 of unknown causes). The 5- and 10-year rates were, respectively: specific survival 93% and 86%, disease-free survival 85% and 75%, distant metastasis 8.5% and 14%, and local recurrence 7% and 14%. Mean intervals from the beginning of treatment for local recurrence or distant metastases were, respectively, 60+/-6 months (median: 47 months, range: 6-217 months) and 49.5+/-5.4 months (median: 33 months, range: 6-217 months). After local recurrence, salvage mastectomy was performed in 46 patients (85%) and systemic hormonal therapy and/or chemotherapy was administered to 43 patients. The 5-year specific survival rate after treatment for local recurrence was 78+/-8.2%. Multivariate analysis (multivariate generalization of the proportional hazards model) showed that the probability of local control was decreased by the following four independent factors: young age (< or = 40 yr vs. >40 yr; relative risk [RR]: 3.15, 95% confidence interval [CI]: 1.7-5.8, p = 0.0002), premenopausal status (pre vs. post; RR: 2.9, 95% CI: 1.4-6, p = 0.0048), bifocality (uni- vs. bifocal; RR: 2.7, 95% CI: 2.6-2.8,p = 0.018), and extensive intraductal component (IC <25% vs. IC > or = 25%; RR: 2.6, 95% CI: 13-5.2, p = 0

[Locoregional recurrence of adenocarcinomas of the rectum treated with irradiation combined with or without excision surgery]

PURPOSE

Retrospective study to analyze the results of external beam radiation treatment with or without surgery for loco-regional recurrence of adenocarcinoma of the rectum following previous surgery without pre- or post-operative radiotherapy.

PATIENTS AND METHODS

Between March 1973 and November 1991, 211 patients with loco-regional recurrence of rectum cancer were treated with external beam radiation treatment. Radical surgery was the only initial treatment modality. Surgical resection of local recurrence was done in 36 patients and only 17 patients could undergo complete resection. Forty-seven patients underwent radiotherapy (RT) combined with surgery and 164 received external beam radiation treatment alone to a mean total dose of 46 Gy.

RESULTS

Among the 151 patients whose recurrence was revealed by pain, 64 (42%) were considered to have a complete symptomatic response after loco-regional treatment with radiosurgery or RT alone. The mean duration of response was 12 months. The 3-year overall survival rate was 16%. Five prognostic factors decreased the overall survival rate in multivariate analysis: high age, sex (male), concomitant distant metastasis, no tumor resection, and low total radiation dose with external beam radiation treatment alone. The 3-year overall survival rate for patients with completely resected recurrences was 39%.

CONCLUSION

External beam RT treatment can only be considered a palliative symptomatic treatment. New techniques of early detection of local recurrence and new combined modalities approaches (radiation sensitizers or intra-operative radiotherapy) with surgical resection in some favorable cases should be studied.

Parenchymal changes after radiosurgery of cerebral arteriovenous malformations. Preliminary report of a proposed classification

Radiosurgery of cerebral arteriovenous malformations (cAVM) can induce parenchymal changes seen on MRI. The purpose of this study was to classify these changes and to correlate them to clinical outcome and obliteration of the cAVM. 142 patients with cAVM underwent radiosurgery with a linear accelerator between 1994 and 1995. 60 clinical records, MR images, and postradiation angiograms were reviewed. Signal abnormalities and contrast enhancements were correlated with clinical deterioration and size decrease of the AVM. The Spearman nonparametric test was used for statistical correlation. MR findings allowed to differentiate between four grades: grade 1 = no parenchymal changes; grade 2 = hypersignal on T2-weighted sequences, grade 3 = grade 2 + contrast enhancement on T1-weighted sequences; grade 4 = grade 3 + central hyposignal (necrosis-like) + peripheral hyposignal surrounding the AVM on T1-weighted sequences. Grade 4 was significantly related (p < 0.001) to clinical deterioration (deficit, seizures, increased intracranial pressure). All grade 4 patients, and only them, had clinical symptoms. Most of these symptoms regressed with corticoid treatment. Grade 4 was also related to the proportion of obliteration of the cAVM at 1 year after radiotherapy: mean proportion of obliteration was 12.5% for grade 2, 25% for grade 3 and 82.2% for grade 4 (p < 0.01). The size of T2-weighted MR images was related to clinical symptom appearance (p < 0.001). Finally, contrast enhancement was not predictive of the occurrence of the clinical symptoms. This proposed classification allows one to differentiate between the various MR images, and seems to predict clinical complications and response to radiotherapy of the cAVM.

Single-fraction stereotactic radiotherapy: a dose-response analysis of arteriovenous malformation obliteration

PURPOSE

Stereotactic radiotherapy delivered in a high-dose single fraction is an effective technique to obliterate intracranial arteriovenous malformations (AVM). To attempt to analyze the relationships between dose, volume, and obliteration rates, we studied a group of patients treated using single-isocenter treatment plans.

METHODS AND MATERIALS

From May 1986 to December 1989, 100 consecutive patients with angiographically proven AVM had stereotactic radiotherapy delivered as a high-dose single fraction using a single-isocenter technique. Distribution according to Spetzler-Martin grade was as follows: 79 grade 1-3, three grade 4, 0 grade 5, and 18 grade 6. The target volume was spheroid in 74 cases, ellipsoid in 11, and large and irregular in 15. The targeted volume of the nidus was estimated using two-dimensional stereotactic angiographic data and, calculated as an ovoid-shaped lesion, was 1900 +/- 230 mm3 (median 968 mm3; range 62-11, 250 mm3). The mean minimum target dose (Dmin) was 19 +/- 0.6 Gy (median 20 Gy; range: 3-31.5). The mean volume within the isodose which corresponded to the minimum target dose was 2500 +/- 300 mm3 (median 1200 mm3; range 75-14 900 mm3). The mean maximum dose (Dmax) was 34.5 +/- 0.5 Gy (median 35 Gy; range 15-45). The mean angiographic follow-up was 42 +/- 2.3 months (median 37.5; range 7-117).

RESULTS

The absolute obliteration rate was 51%. The 5-year actuarial obliteration rate was 62.5 +/- 7%. After univariate analysis, AVM obliteration was influenced by previous surgery (p = 0.0007), Dmin by steps of 5 Gy (p = 0.005), targeted volume of the nidus (< or = 968 mm3 vs. >968 mm3; p = 0.015), and grade according to Spetzler-Martin (grade 1-3 vs. grade 4-6; p = 0.011). After multivariate analysis, the independent factors influencing AVM obliteration were the Dmin [relative risk (RR) 1.9; 95% confidence interval (CI) 1.4-2.5; p < 0.0001] and grade distribution according to Spetzler-Martin (RR 1.4; 95% CI 1.1-1.7; p = 0.010). Delayed complications were observed in eight patients. The 5-year actuarial rate of delayed complications was 7.4%.

CONCLUSION

After stereotactic radiotherapy delivered in a single high dose using a single-isocenter technique, the success rate for complete obliteration is independently correlated to Dmin but does not seem to be influenced by Dmax and the targeted volume of the nidus.

Failure in radiosurgery treatment of cerebral arteriovenous malformations

OBJECTIVE

The aim of this study was to retrospectively analyze the reasons for the failure of radiosurgical treatment of cerebral arteriovenous malformations (AVMs).

METHODS

Seventeen cases of noncured AVMs were reviewed 3 years after radiosurgical treatment. Follow-up ranged from 33 to 54 months (mean, 44.3 mo). Lesion dimensions varied from 9 to 55 mm (mean, 29.2 mm). The lesions were located in critical or near-critical brain regions. Angiography was performed under Talairach's stereotactic conditions. Two large AVMs bled 36 and 39 months after receiving irradiation, respectively. These two AVMs had been incompletely irradiated.

RESULTS

Retrospectively, in four cases (23.5%) we observed errors in determining AVM target shape and size because of inaccurate definition of the nidus and/or because of stereoangiographic incompleteness (absence of external carotid artery injections). In five large and/or irregularly shaped AVMs (29.4%), a strategy of partial volume irradiation had been used. In one patient (5.8%), we observed the recanalization of previously embolized AVMs. In another case (5.8%), the target had been partially missed. The AVMs in one case (5.8%) had been treated with an ineffective peripheral dose. In one (5.8%), the failure occurred because of the lesion angio-architecture. In four cases (23.5%), no evident reasons for failure were determined.

CONCLUSION

The results of this study suggest the necessity of complete irradiation of the nidus. The strategy of partial volume irradiation might be avoided, even if it necessitates lowering the doses to treat large AVMs. Accuracy in the target determination is required, and complete stereoangiography is necessary.

Use of a general inverse technique for the conformational stereotactic treatment of complex intracranial lesions

PURPOSE

The stereotactic irradiation of intracranial lesions constitutes an excellent example of conformational therapy whose purpose is to adapt the dose envelope to the target volume with great precision and at the same time to deliver as low a dose as possible to the healthy tissues. We propose the mathematical analysis of the singular values decomposition (SVD) as an inverse planning process to find the optimal minibeam weightings that permit the calculation of the most conformational dose distribution.

METHODS

For the radiosurgical treatment of complex lesions, we realize a division of the lesion into several elliptic volumes using the "Associated Target Methodology." This division allows the definition of an irradiation configuration: the number of isocenters, the position of the isocenters, and the diameter of each collimator. For this defined irradiation configuration, we use SVD to find the optimal minibeam weightings. This analysis enables us to understand better the ill-conditioning of the multi-isocentric irradiation and the influence of irradiation parameters on the process of reconstruction minibeam weightings.

RESULTS

In this paper, the SVD analysis and the reconstruction technique have been evaluated for the first time on practical cases. We present, as an example, a complex lesion compartmentalized into 3 subvolumes according to our Associated Target Methodology. This analysis allows us to study the ill-conditioning of the example and proposes a large number of solutions from among which we have to choose the most conformational physical solution. This choice is based on the dose-volume histograms.

CONCLUSION

We use the SVD procedure as a computer-aided planning system and obtain good solutions, i.e., healthy tissue protection and lesion coverage similar to or better than an experimented planner solution.

[The point of view of the radiotherapist]

During the last decade, stereotactic radiotherapy has widely improved in France. Thus one should study the present situation and its future trend. QUANTITATIVE NEED: Considering single dose radiotherapy, there are about 900 to 1,000 cases treated per year. However, the trend towards more fractionated treatment will disturb this temporary equilibrium; thus more machine time will be necessary. QUALITATIVE NEED: Stereotactic radiotherapy is practiced by multi-disciplinary teams including physicians, physicists and scientific specialists. Radiotherapists and physicist are responsible for treatment planning and evaluation as well as for clinical and methodological research. Accordingly, they should possess computers, treatment planning systems, etc. Such teams are necessary to carry out complex irradiations. GENERAL EVOLUTION: Fractionation of irradiation nowadays seems mandatory for most intracranial tumors except metastases and small regular arteriovenous malformations. Heterogeneity of lesion dose is related to the geometry and the physics of convergent fixed or mobile beams. It can be improved and the healthy tissue irradiation can be diminished using the multi-isocentric planning for complex lesion or with micro multi leaf collimators. MODALITIES OF STEREOTACTIC RADIOTHERAPY ACCORDING TO LESION TYPE: For neurinomas of the acoustic nerve, fractionated stereotactic radiotherapy yields few of the complications published after single dose stereotactic radiotherapy. The same can be said for meningiomas although some series reported very few complications after single dose stereotactic radiotherapy. Solitary metastases without systemic evolution, not situated on the mid-line, are favorable candidates for palliative single dose stereotactic radiotherapy. The conjunction with total brain irradiation seems to be useful. Small arteriovenous malformations will be treated with single dose stereotactic radiotherapy, whereas voluminous and/or geometrically complex nidus could benefit from protons or photon beams modulated by micro multi leaf collimators and a few fractions. EXTRA-CRANIAL STEREOTACTIC RADIOTHERAPY: Single dose stereotactic radiotherapy and fractionated stereotactic radiotherapy will be used as boost in various situations such as massif facial and in all sorts of tumors in the body specially when lesions are close to critical organs.

Cerebral arteriovenous malformations: the value of radiologic parameters in predicting response to radiosurgery

PURPOSE

To define the morphological patterns of cerebral arteriovenous malformations (AVMs) that influence their response to radiosurgery at 2 years.

METHODS

We retrospectively reviewed the yearly MR and angiographic follow-up studies in 102 patients who had radiosurgical treatment for cerebral AVMs between 1990 and 1992. Parameters studied were maximum length and volume of the nidus, position relative to the midline, anatomic structures involved, sectional anatomic location (depth within the brain tissue), angioarchitecture, and Spetzler and Martin grading. Statistical analysis determined their influence on treatment results at 2 years.

RESULTS

Parameters that correlated with obliteration at 2 years were maximum length less than 25 mm, small volume, sectional location deep within brain tissue, and plexiform angioarchitecture. Ventricular and paraventricular locations correlated with nonobliteration at 2 years.

CONCLUSION

This study highlights the role of two new morphological parameters in predicting the efficiency of radiosurgery in the treatment of cerebral AVMs: depth within the parenchyma and angioarchitecture. It also emphasizes the usefulness of sectional imaging in the work-up before radiosurgery.

Primary chemotherapy and preoperative irradiation for patients with stage II larger than 3 cm or locally advanced non-inflammatory breast cancer

BACKGROUND AND PURPOSE

To evaluate possibility of breast-conserving therapy and outcome for patients with locally advanced non-inflammatory breast cancer (LABC) and stage II >3 cm in diameter after primary chemotherapy (CT) followed by external preoperative irradiation (RT).

MATERIALS AND METHODS

Between 1982 and 1990, 147 patients were treated by four courses of induction CT (doxorubicin, vincristine, cyclophosphamide, 5-fluorouracil) followed by preoperative RT (45 Gy to the breast and nodal areas) and a fifth course of CT. Three different loco-regional approaches were proposed depending on tumour characteristics and tumour response. After completion of local therapy, all patients received a sixth course of CT and a maintenance adjuvant CT regimen without anthracycline.

RESULTS

Mastectomy and axillary dissection were performed in 52 patients, and conservative treatment in 95 patients (48 achieved complete remission and received additional radiation boost to initial tumour bed; 47 had a residual mass < or =3 cm in diameter and were treated by wide excision and axillary dissection followed by a boost to the excision site. Ten-year actuarial loco-regional failure rate was 20% after RT alone, 23% after wide excision and RT and 6% after mastectomy (P = 0.85). After multivariate analysis, possibility of breast-conserving therapy was related to initial tumour size. Ten-year overall survival rate was 66%; it was not influenced by local treatment (conservative vs. non-conservative local treatment, P = 0.89). However, local failure significantly decreased overall survival (P < 0.0001). After multivariate analysis, tumour response after induction CT and clinical stage had a significant impact on survival.

CONCLUSIONS

The present data indicate that induction CT followed by preoperative RT may permit the selection of some patients with LABC or stage II >3 cm for conservative treatment. The impact of this treatment modality on long term survival remains to be established.

Angioarchitecture associated with haemorrhage in cerebral arteriovenous malformations: a prognostic statistical model

The overall haemorrhagic risk of a cerebral arteriovenous malformation (cAVM) is 2-4% per year. However, the individual risk of haemorrhage has never been determined. This study was undertaken to assess the haemorrhage risk of an individual cAVM. Neuroangiographic findings of 160 cAVM were analysed retrospectively, looking at 30 angiographic features. A statistical model was established by logistic regression to evaluate the risk of an individual cAVM. We statistically correlated 15 parameters with the haemorrhage risk. The statistical model includes five independent parameters. Four are unfavourable: exclusively deep drainage, venous stenoses, venous reflux and the radio of afferent to efferent systems; one is favourable: venous recruitment. This model quantifies the individual risk of haemorrhage. When this model is applied to the population studied, the error rate is 5%. This model can contribute to therapeutic strategy, and to a better understanding of the natural history of cAVM.

Treatment of brain arteriovenous malformations by embolization and radiosurgery

Embolization was used to reduce the size of brain arteriovenous malformations (AVMs) prior to radiosurgical treatment in 125 patients who were poor surgical candidates or had refused surgery. Of these patients, 81% had suffered hemorrhage, and 22.4% had undergone treatment at another institution. According to the Spetzler-Martin scale, the AVMs were Grade II in 9.6%, Grade III in 31.2%, Grade IV in 30.4%, and Grades V to VI in 28.8% of the cases. Most embolizations were performed using cyanoacrylate delivered by flow-guided microcatheters. Radiosurgery was performed using a linear accelerator in 62 patients treated by the authors, and 34 patients were treated at other institutions using various methods. Embolization produced total occlusion in 11.2% of AVMs and reduced 76% of AVMs enough to allow radiosurgery. Radiosurgery produced total occlusion in 65% of the partially embolized AVMs (79% when the residual nidus was < 2 cm in diameter). Embolizations resulted in a mortality rate of 1.6% and a morbidity rate of 12.8%. No complications were associated with radiosurgery. The hemorrhage rate for partially embolized AVMs was 3% per year. No patient with a completely occluded AVM experienced rehemorrhage. Angiographic follow-up review of AVMs embolized with cyanoacrylate demonstrated a 11.8% revascularization rate, occurring within 1 year. It is concluded that after partial embolization with cyanoacrylate, the risk of hemorrhage from the residual nidus is comparable to the natural history of AVMs and that the residual nidus can be irradiated with results almost as good as for a native AVM of the same size.

Cataractogenesis after total body irradiation

PURPOSE

To evaluate the prognostic factors and the ophthalmologic follow-up on cataract formation following total body irradiation (TBI) prior to bone marrow transplantation (BMT).

METHODS AND MATERIALS

Between 1980 and 1992, 494 patients were referred to our department for TBI prior to BMT. The mean age was 32 +/- 11 (median: 32, range: 2-63) years and the male to female ratio was 1.6 (304:190). The majority of patients were treated for acute leukemia (lymphoblastic, n = 177, 36%; or nonlymphoblastic , n = 139, 28%); 80 (16%) for chronic myeloid leukemia, 60 (12%) for non-Hodgkin's lymphoma, 23 (5%) for multiple myeloma, and 15 (3%) for other malignancies. Two hundred and fifty-four (51%) patients were grafted in the first complete remission (CR), 118 (24%) in second CR. Allogenic BMT was performed in 210 (43%) patients, and autologous BMT in 284 (57%). Methotrexate combined to steroids (n = 47, 22%) or to cyclosporine (n = 163, 78%) was administered for graft-versus-host disease (GvHD) prophylaxis. In 188 patients (38%), heparin was used in the prevention of veno-occlusive disease (VOD) of the liver. Furthermore, steroid administration was registered in 223 (45%). The conditioning chemotherapy consisted of cyclophosphamide (Cy) alone in 332 (67%) patients. Total-body irradiation was administered either in single dose (STBI; 10 Gy in 1 day, n = 291) or in six fractions (FTBI; 12 Gy over 3 consecutive days, n = 203) before BMT. The mean instantaneous dose rate was 0.0574 +/- 0.0289 Gy/min (0.024-0.1783). It was < 0.048 Gy/min in 157 patients (LOW group), > or = 0.048 Gy/min and <0.09 Gy/min in 301 patients (MEDIUM group), and > or = 0.09 Gy/min in 36 patients (HIGH group).

RESULTS

When considering all patients, 42 (8.5%) patients developed cataracts after 13 to 72 months (median: 42 months) with a 5-year estimated cataract incidence (ECI) of 23%. Thirty-three (11.3%) out of 291 patients in the STBI group, and 9 (4.4%) out of 203 patients in the FTBI group developed cataracts with 5-year estimated incidences of 34 and 11%, respectively (p = 0.0004). Seven (19.4%) out of 36 patients in the HIGH group, 33 (10.9%) out of 301 in the MEDIUM group, and 2 (1.2%) out of 157 in the LOW group developed cataracts with respective 5-year cataract incidences of 54%, 30%, and 3.5% (HIGH vs. MEDIUM, p = 0.07; MEDIUM vs. LOW, p = 0.0001; HIGH vs. LOW, p < 0.0001). On the other hand, patients who received heparin as prophylactic treatment against VOD of the liver had less cataracts than those who did not receive (5-year ECI of 16% vs. 28%, respectively; p = 0.01). There was no statistically significant difference in terms of 5-year ECI according to age, sex, administration of steroids, GvHD prophylaxis, type of BMT, or previous cranial radiotherapy in children. Multivariate analysis revealed that the instantaneous dose rate (p = 0.001), and the administration of heparin against VOD (p = 0.05) were the two independent factors influencing the cataract incidence, while age, fractionation, and use of steroids were not. Among the 42 patients who developed cataracts, 38 had bilateral extracapsular cataract extraction and intraocular lens implantation, and only 4 (10%) developed secondary cataracts in a median follow-up period of 39 months.

CONCLUSION

Among the abovementioned TBI parameters, high instantaneous dose rate seems to be the main risk factor of cataract formation, and the administration of heparin appears to have a protective role in cataractogenesis. On the other hand, ionizing radiation seems to have a protective effect on posterior capsule opacification following extracapsular cataract extraction and intraocular lens implantation.