Craniopharyngioma: the role of radiation therapy

A systematic review of the results of surgery and radiotherapy on tumor control for pediatric craniopharyngioma

OBJECTIVE

Craniopharyngiomas are rare tumors with bimodal incidence in the pediatric and adult age groups. Treatment strategies range from aggressive resection to planned limited resection combined with adjuvant therapies. Currently there is no consensus for standard of care for pediatric craniopharyngioma.

MATERIALS AND METHODS

We performed a systematic review of the published literature on pediatric craniopharyngioma. Patients were grouped based on extent of resection into gross total resection (GTR), subtotal resection (STR), and biopsy procedures. These groups were compared with respect to tumor control. Chi square was used to compare rates of recurrence. Kaplan-Meier was used to generate progression-free survival (PFS) estimates. Cox proportional hazard modeling was used to evaluate risk of progression. Each extent of resection group was also subdivided based on adjuvant therapy and compared.

RESULTS

A total of 109 studies described extent of resection resulting in a cohort of 531 patients. Recurrence data were available for 377 patients. There was no difference in 1- or 5-year PFS between the groups who underwent GTR and STR combined with radiation (XRT; log-rank; p = 0.76; 1-year PFS 89 vs 84%; 5-year PFS 77 vs 73%, respectively). One-year PFS was 84% for STR+XRT compared to 76% for STR alone while 5-year PFS was 73% for STR+XRT compared to 43% for STR alone (log-rank; p = 0.003).

CONCLUSION

Although there are limitations of a systematic review of retrospective data, our results suggest that STR+XRT of pediatric craniopharyngioma is associated with similar rates of tumor control as GTR.

Treatment-related morbidity and the management of pediatric craniopharyngioma: a systematic review

OBJECT

Craniopharyngiomas are benign tumors but their close anatomical relationship with critical neurological, endocrine, and vascular structures makes gross-total resection (GTR) with minimal morbidity difficult to achieve. Currently, there is controversy regarding the extent, timing, and modality of treatment for pediatric craniopharyngioma.

METHODS

The authors performed a systematic review of the published literature on pediatric craniopharyngioma to determine patterns of clinical practice and the reported outcomes of standard treatment strategies. This yielded 109 studies, which contained data describing extent of resection for a total of 531 patients. Differences in outcome were examined based upon extent of resection and choice of radiation treatment.

RESULTS

Gross-total resection was associated with increased rates of new endocrine dysfunction (OR 5.4, p < 0.001), panhypopituitarism (OR 7.8, p = 0.006), and new neurological deficits (OR 9.9, p = 0.03) compared with biopsy procedures. Subtotal resection (STR) was not associated with an increased rate of new neurological deficits. Gross-total was associated with increased rates of diabetes insipidus (OR 7.7, p = 0.05) compared with the combination of STR and radiotherapy (RT). The addition of RT to STR was associated with increased rates of panhypopituitarism (OR 9.9, p = 0.01) but otherwise similar rates of morbidities.

CONCLUSIONS

Although subject to the limitations of a literature review, this report suggests that GTR is associated with increased rates of endocrinopathies compared with STR + RT, and this should be considered when planning goals of surgery.

Endocrinologic, neurologic, and visual morbidity after treatment for craniopharyngioma

Craniopharyngiomas are locally aggressive tumors which typically are focused in the sellar and suprasellar region near a number of critical neural and vascular structures mediating endocrinologic, behavioral, and visual functions. The present study aims to summarize and compare the published literature regarding morbidity resulting from treatment of craniopharyngioma. We performed a comprehensive search of the published English language literature to identify studies publishing outcome data of patients undergoing surgery for craniopharyngioma. Comparisons of the rates of endocrine, vascular, neurological, and visual complications were performed using Pearson's chi-squared test, and covariates of interest were fitted into a multivariate logistic regression model. In our data set, 540 patients underwent surgical resection of their tumor. 138 patients received biopsy alone followed by some form of radiotherapy. Mean overall follow-up for all patients in these studies was 54 ± 1.8 months. The overall rate of new endocrinopathy for all patients undergoing surgical resection of their mass was 37% (95% CI = 33-41). Patients receiving GTR had over 2.5 times the rate of developing at least one endocrinopathy compared to patients receiving STR alone or STR + XRT (52 vs. 19 vs. 20%, χ(2) P < 0.00001). On multivariate analysis, GTR conferred a significant increase in the risk of endocrinopathy compared to STR + XRT (OR = 3.45, 95% CI = 2.05-5.81, P < 0.00001), after controlling for study size and the presence of significant hypothalamic involvement. There was a statistical trend towards worse visual outcomes in patients receiving XRT after STR compared to GTR or STR alone (GTR = 3.5% vs. STR 2.1% vs. STR + XRT 6.4%, P = 0.11). Given the difficulty in obtaining class 1 data regarding the treatment of this tumor, this study can serve as an estimate of expected outcomes for these patients, and guide decision making until these data are available.

Craniopharyngioma: a comparison of tumor control with various treatment strategies

OBJECT

Craniopharyngiomas have a propensity to recur after resection, potentially causing death through their aggressive local behavior in their critical site of origin. Recent data suggest that subtotal resection (STR) followed by adjuvant radiotherapy (XRT) may be an appealing substitute for gross-total resection (GTR), providing similar rates of tumor control without the morbidity associated with aggressive resection. Here, the authors summarize the published literature regarding rates of tumor control with various treatment modalities for craniopharyngiomas.

METHODS

The authors performed a comprehensive search of the English language literature to identify studies publishing outcome data on patients undergoing surgery for craniopharyngioma. Rates of progression-free survival (PFS) and overall survival (OS) were determined through Kaplan-Meier analysis.

RESULTS

There were 442 patients who underwent tumor resection. Among these patients, GTR was achieved in 256 cases (58%), STR in 101 cases (23%), and STR+XRT in 85 cases (19%). The 2- and 5-year PFS rates for the GTR group versus the STR+XRT group were 88 versus 91%, and 67 versus 69%, respectively. The 5- and 10-year OS rates for the GTR group versus the STR+XRT group were 98 versus 99%, and 98 versus 95%, respectively. There was no significant difference in PFS (log-rank test) or OS with GTR (log-rank test).

CONCLUSIONS

Given the relative rarity of craniopharyngioma, this study provides estimates of outcome for a variety of treatment combinations, as not all treatments are an option for all patients with these tumors.

Radiation therapy for pediatric craniopharyngioma

Object

The treatment of craniopharyngioma is highly controversial. Continued advances in limited surgery and radiation therapy have maintained excellent local disease control while minimizing treatment-related sequelae. Further analyses of outcomes are necessary to characterize the long-term effects of radiation therapy.

Methods

An extensive literature review was performed for all studies including radiation therapy, with or without surgery, for pediatric craniopharyngioma.

Results

The authors identified 32 papers describing radiation therapy for treatment of pediatric craniopharyngioma, with disease control ranging from 44 to 100%. Modern studies report at least 90% disease control with 5-year follow-up. Fifteen studies reported outcomes, demonstrating that more than two-thirds of patients treated with surgery and radiation therapy have favorable outcomes, and this rate is more than 85% in the modern era.

Conclusions

Conservative surgery and radiation therapy results in long-term disease control in pediatric patients with craniopharyngioma that is comparable to results obtained with radical surgery alone. However, children with craniopharyngioma remain vulnerable to late treatment failures and side effects from radiation therapy, including endocrinopathies, vasculopathies, and secondary tumors, which may be detrimental to the quality of life. Long-term follow-up beyond 5–10 years is necessary to assess tumor control relative to functional outcomes.

Atypical magnetic resonance imaging findings of craniopharyngioma

Three cases of craniopharyngiomas with atypical MRI findings are reported. The first patient had a nasopharyngeal craniopharyngioma. Its unusual location made diagnosis difficult. The second patient had a massive craniopharyngioma with extensive cystic expansion, involving the anterior, middle and posterior cranial fossae, and extending into the foramen magnum. The tumour of the third patient involved the suprasellar region with a large extension into the third ventricle, and demonstrated a predominantly high signal intensity on all T1-weighted, proton-weighted and T2-weighted images. These patients further stressed the complexity of MRI findings in craniopharyngiomas.

Craniopharyngioma--a long-term results following limited surgery and radiotherapy

Between 1950 and 1986 173 patients with craniopharyngioma were treated at the Royal Marsden Hospital with external beam radiotherapy either alone or following surgery. Four patients had complete tumour excision, 21 subtotal and 78 partial resection, 14 had biopsy alone, 34 aspiration alone and 22 had no surgery directed at tumour eradication. Seventy-seven (45%) were children (aged < 16 years). The 10 and 20 year progression-free survival (PFS) rates were 83% and 79%. There were no independent prognostic factors for PFS. The 10 and 20 year survival rates were 77% and 66% at a median follow-up of 12 years. After adjustment for mortality in the normal population, age and technique of radiotherapy (which corresponded with era of treatment) were significant independent prognostic factors for survival. The risk of death (corrected for mortality from natural causes and controlling for radiotherapy technique) for age groups 16-39 and > or = 40 was 0.58 and 0.40 respectively, relative to a risk of 1.0 for the age group < 16 years. Survival and PFS were not influenced by the extent of surgical excision. Visual field defect improved after radiotherapy in 36% of patients (38/106) and visual acuity in 30% (27/91). No patient developed radiation optic neuropathy. We conclude that limited surgery and radiotherapy achieve excellent long-term tumour control and survival with low morbidity.

Surgery and radiation therapy in the management of craniopharyngiomas

Twenty-nine patients with histologically confirmed craniopharyngioma were treated from 1960 to 1978, inclusive. Twelve patients were below the age of 15 years, the remaining were adults. Seventy-five percent (9/12) of the patients below the age of 15 showed increased intracranial pressure at presentation and 58% (7/12) showed visual disturbances. In the adult group, 47% (8/17) presented with increased intracranial pressure and 88% (15/17) with visual disturbances. Hormonal, mental and behavior changes were almost equally distributed in both age groups. All patients underwent craniotomy, with subtotal resection of the tumor. Three adults died of postoperative complications (10%), of whom two died of pulmonary emboli and one of cerebral hemorrhage. Of the remaining 26 patients, 13 received immediate postoperative radiotherapy to a total dose of 50.0 to 56.0 Gy, in a target volume including the sellar and parasellar region during an overall treatment period of five to six weeks. All patients were evaluable with a minimum follow-up of four years since they finished their treatment or until death. The five-year recurrence-rate in the group that did not receive postoperative radiation therapy was 45% (5/11 patients) and the five-year rate of death of disease in this group was 27% (3/11 patients). For the group that received immediate postoperative radiation therapy the five-year recurrence-rate was 11% (1/9 patients) and no death of disease was observed in this group. This difference between the two groups was not significant. The corresponding 10-year rates were 71% (5/7 patients) for recurrence and 57% (4/7 patients) for death of disease in the group without, and in the group with immediate postoperative radiation therapy the rate was 25% (2/8 patients) for recurrence and 0 for death of disease. This difference turns out to be significant. Critical analysis of the morbidity in patients surviving after treatment showed no adverse effect on the visual or endocrine status of the group that received postoperative irradiation. It is concluded that in the management of patients with craniopharyngiomas, postoperative irradiation after subtotal resection improves the prognosis of the patient and does not add to visual or endocrine morbidity.

Long-term follow-up of children with craniopharyngioma

Management of craniopharyngiomas is still controversial. 28 children with this tumor were studied. GH deficiency was present in 22 patients following surgery, 10 of these GH-lacking patients had normal or accelerated growth (usually associated with rapid weight gain) postoperatively. Somatomedin levels were normal in three of six normally growing patients. After craniotomy their basal and TRH-stimulated prolactin levels were in the normal range, but their insulin secretion was markedly increased. Postoperatively there was a significant correlation between peak insulin levels following arginine infusion and growth velocity in all patients. Complete tumor removal could be performed in 28% of our patients. Altogether 36% of all patients had at least one tumor recurrence. Recent literature with the addition of our series showed tumor recurrence in 22% of patients with "total" tumor excision and in 72% of patients with partial tumor removal. Radiotherapy seems to be capable of destroying craniopharyngioma tissue. The recurrence rate was only 26% in patients with subtotal excision plus radiotherapy. Unless radical tumor removal can be attempted with safety, subtotal tumor removal plus radiotherapy appears to be the treatment of choice for craniopharyngioma.