PREDICTORS OF BIOCHEMICAL REMISSION AND RECURRENCE AFTER SURGICAL AND RADIATION TREATMENTS OF CUSHING DISEASE: A SYSTEMATIC REVIEW AND META-ANALYSIS.

OBJECTIVE: We conducted a systematic review and meta-analysis to synthesize the evidence about predictors that may affect biochemical remission and recurrence after transsphenoidal surgery (TSS), radiosurgery (RS), and radiotherapy (RT) in Cushing disease. METHODS: We searched multiple databases through December 2014 including original controlled and uncontrolled studies that enrolled patients with Cushing disease who received TSS (first-line), RS, or RT. We extracted data independently, in duplicates. Outcomes of interest were biochemical remission and recurrence. A meta-analysis was conducted using the random-effects model to estimate event rates with 95% confidence intervals (CIs). RESULTS: First-line TSS was associated with high remission (76% [95% CI, 72 to 79%]) and low recurrence rates (10% [95% CI, 6 to 16%]). Remission after TSS was higher in patients with microadenomas or positive-adrenocorticotropic hormone tumor histology. RT was associated with a high remission rate (RS, 68% [95% CI, 61 to 77%]; RT, 66% [95% CI, 58 to 75%]) but also with a high recurrence rate (RS, 32% [95% CI, 16 to 60%]; RT, 26% [95% CI, 14 to 48%]). Remission after RS was higher at short-term follow-up (≤2 years) and with high-dose radiation, while recurrence was higher in women and with lower-dose radiation. Remission was after RT in adults who received TSS prior to RT, and with lower radiation doses. There was heterogeneity (nonstandardization) in the criteria and cutoff points used to define biochemical remission and recurrence. CONCLUSION: First-line TSS is associated with high remission and low recurrence, while RS and RT are associated with reasonable remission rates but important recurrence rates. The current evidence warrants low confidence due to the noncomparative nature of the studies, high heterogeneity, and imprecision.

Update on radiation therapy in patients with Cushing's disease.

INTRODUCTION: Radiation therapy is an important therapy for patients with Cushing's disease who are not in remission or relapse after transsphenoidal pituitary surgery and are not considered surgical candidates. The development of stereotactic radiation therapy, using gamma knife, linear accelerators or proton beam based methods, has enabled selective radiation delivery to the target while minimizing exposure of healthy tissues. In patients whose tumors are sufficiently distant from the optic apparatus, stereotactic radiation therapy can be delivered in a single session, a procedure termed radiosurgery, which significantly improves patient convenience. METHODS: Original articles on radiation therapy in Cushing's disease, published during the past 12 months (2013-2014), were identified and pertinent data extracted. RESULTS: Recent studies have reported on the outcomes of patients with Cushing's disease who received mostly stereotactic radiation therapy. While tumor control has been excellent, biochemical remission was less consistently achieved. Some studies suggested that stereotactic radiation may lead to biochemical remission faster than conventional radiation therapy. In addition, retrospective data have suggested that withdrawing medical therapy around the time stereotactic radiation therapy is administered might lead to a faster biochemical response. Regardless of the radiation therapy method, biochemical recurrences may develop and these patients are at long-term risk of developing anterior hypopituitarism and require lifelong periodic endocrine follow-up. Other, less frequent complications may include cranial neuropathies, secondary tumor formation or temporal lobe necrosis. It is plausible that complications may be less frequent after stereotactic radiation therapy, but this requires confirmation. CONCLUSIONS: Radiation therapy is an effective second line therapy in patients with Cushing's disease. Ongoing refinements in delivery of radiation therapy are anticipated to lead to improved patient outcomes, but long-term follow-up data, including adequate control groups, are needed to fully investigate this possibility.

The therapy of Cushing's disease in adults and children: an update.

Cushing's disease (CD) is a rare endocrine disorder resulting from excessive production of adrenocorticotrophin hormone by a pituitary adenoma. The consequent hypercortisolaemia gives rise to characteristic features of the disease and its morbidities. Treatments aim to restore normal cortisol levels, provide long-term control of the disease and the tumour, and the improvement of patient well-being. The first line of treatment remains transsphenoidal surgery with remission rates of 65-90% in CD secondary to a pituitary microadenoma. Second-line treatment includes repeat surgery, radiotherapy, medical therapy, and bilateral adrenalectomy. The success rate of radiotherapy ranges from 46% to 74% and is probably independent of the mode of delivery of the radiation, but may take several years to become effective. Medical therapy is useful in acutely unwell patients or while awaiting radiotherapy to become effective. The most often-used medical agents include metyrapone and ketoconazole, which inhibit steroidogenesis; less often, centrally-acting drugs or a glucocorticoid receptor blocker are used, but experience with them is more limited. Bilateral adrenalectomy remains an important treatment option to control unresponsive severe hypercortisolism, particularly in patients with severe CD.The management of childhood CD does not differ from adult disease, with transsphenoidal surgery as successful as in adults but radiotherapy is more rapid in onset. Regardless of the age of the patient, Cushing's disease remains a challenge to the physician and requires a multidisciplinary approach to achieve the most desirable outcome.

Temozolomide for corticotroph pituitary adenomas refractory to standard therapy.

To highlight the potential of temozolomide (TMZ) to induce rapid tumor regression in patients with aggressive corticotroph adenomas (CA) that are refractory to surgery and radiation therapy and to review use of TMZ in other pituitary tumors. We present a case of a 56-year-old male with a 3 cm CA treated with transphenoidal surgery (TSS) and conventional radiotherapy in the same year. His hypercortisolemia recurred 11 years later with rapid tumor growth (to 4.2 × 2.5 cm) and he underwent a second TSS with good resection. The tumor recurred 6 months later with ophthalmoplegia. Over 16 months he underwent an additional three surgeries (two TSS, one craniotomy) and repeated conventional radiotherapy. Ki67 staining index on surgical specimens was 5-6%. Temozolomide is an oral alkylating agent approved for glioblastoma multiforme treatment that has only recently shown promise in treating some pituitary tumors. In this patient TMZ was started at 150 mg/m²/day, titrated to 200 mg/m²/day, taken 5 days per month. The only significant side effect was moderate nausea. After 10 weeks, the tumor showed a remarkable 60% regression with objective improvement in ophthalmoplegia. Treatment of aggressive CAs represents a therapeutic challenge and in some cases surgical debulking and radiotherapy are of limited success. Few reports of CAs responsive to TMZ have been reported in the literature. To our knowledge, this case represents the most rapid robust CA shrinkage response reported to date. Further randomized clinical trials of TMZ in the treatment of aggressive pituitary adenomas are warranted.

Possible role of a radiation-induced p53 mutation in a Nelson's syndrome patient with a fatal outcome.

Nelson's syndrome (NS) is characterized by the appearance and/or progression of ACTH-secreting pituitary macroadenomas in patients who had previously undergone bilateral adrenalectomy for the treatment of Cushing's disease. Such corticotroph macroadenomas respond poorly to currently available therapeutic options which include surgery, radiotherapy and chemotherapy. P53 protein accumulation may be detected by immunohistochemistry in pituitary corticotroph adenomas and it has been suggested that it might be causally related to tumor development. Wild type P53 protein plays an important role in the cellular response to ionizing radiation and other DNA damaging agents and is mutated in many human tumors. In this study we report an adult male patient with NS who underwent both transsphenoidal and transcranial pituitary surgeries, conventional and stereotaxic radiotherapy and brachytherapy. Despite of the efforts to control tumor mass and growth, this macroadenoma displayed relentless growth and aggressive behavior. DNA extracted from the first two surgical samples, as well as DNA from peripheral blood leukocytes disclosed normal p53 sequence. DNA extracted from tumor samples obtained at surgeries performed after pituitary irradiation carried a somatic heterozygous mutation, consisting of a deletion of four cytosines between nucleotides 12,144-12,149 in exon 4 of the p53 gene. This frameshift mutation creates a stop codon in exon 4 excluding the expression of a functional protein from the defective allele. These data demonstrate a possible association between the P53 protein loss of function induced by radiotherapy and the aggressive course of the disease in this patient.

Optic neuropathy following radiotherapy for Cushing's disease: case report and literature review.

Radiation-induced optic neuropathy is a rare adverse effect of radiotherapy applied for the treatment of pituitary adenomas. We report a patient with a recurrent adrenocorticotrophin secreting pituitary adenoma who received external beam irradiation after failing surgical and medical therapy. Sixteen months after radiotherapy, the patient was presented with declining visual acuity, and radiation-induced optic neuropathy was diagnosed. Despite treatment with glucocorticoids and hyperbaric oxygen, her vision did not improve. The pathophysiology, prevention and treatment of radiation-induced optic neuropathy, including the efficacy of hyperbaric oxygen therapy are reviewed.

Radiosurgical Management of Patients With Persistent or Recurrent Cushing Disease After Prior Transsphenoidal Surgery: A Management Algorithm Based on a 25-Year Experience.

BACKGROUND: Patients with persistent or recurrent Cushing disease (CD) after prior transsphenoidal surgery require further treatment to reduce the disease's metabolic consequences. OBJECTIVE: To assess patient outcomes after stereotactic radiosurgery (SRS) for persistent or recurrent CD from adrenocorticotropin hormone (ACTH)-secreting pituitary adenomas and propose a management algorithm. METHODS: Retrospective review of 38 patients without prior radiation treatment having SRS for ACTH-secreting pituitary adenomas from 1990 to 2015. Favorable outcome was defined as biochemical remission and tumor growth control. Patients were evaluated separately if they underwent bilateral adrenalectomy (Adx). RESULTS: Twenty patients (53%) were treated with Adx and SRS (median margin dose, 25 Gy) and 18 patients (47%) received SRS alone (median margin dose, 22.5 Gy). Median follow-up after SRS was 76 mo. Of patients undergoing Adx, 18/20 (90%) had a favorable outcome. Two patients (10%) had tumor growth requiring additional treatment. A favorable outcome was achieved in 13/18 patients (72%) having SRS alone (median, 14 mo; interquartile range, 8-23). Five patients (28%) required additional treatment due to persistent hypercortisolemia (n = 4) or hypercortisolemia and tumor growth (n = 1). Favorable outcomes were more frequent in the Adx and SRS group at 1 yr (100% vs 33%; P < .001) and 3 yr (100% vs 62%; P < .01), but no different at 5 yr (88% vs 77%; P = .63). CONCLUSION: SRS was effective for patients with persistent or recurrent CD. Patients with mild to moderate CD can be safely managed with SRS alone; patients with severe CD should be considered for Adx with either concurrent SRS or SRS performed at a later date if tumor growth occurs.

Endocrine Remission After Pituitary Stereotactic Radiosurgery: Differences in Rates of Response for Matched Cohorts of Cushing Disease and Acromegaly Patients.

PURPOSE: To compare and describe the time to endocrine remission and new hypopituitarism among patients with growth hormone (GH) and adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas after radiosurgery, controlling for several known prognostic factors. METHODS AND MATERIALS: An institutional review board-approved, institutional retrospective analysis of patients with GH- and ACTH-secreting pituitary adenomas was performed, with matching for patient sex, age at radiosurgery, interval between the last resection and radiosurgery, use of previous radiation therapy, whole sella treatment, suprasellar extension, cavernous sinus invasion, and margin dose. Endocrine remission was defined as a normal serum insulin-like growth factor-1 (GH secreting) or a normal 24-hour urine-free cortisol (ACTH secreting) level without suppressive medications. Endocrine remission and the incidence of new hypopituitarism after single-fraction radiosurgery were recorded and compared between the 2 groups. RESULTS: The data from 242 patients were evaluated, 121 with GH-secreting tumors and 121 with ACTH-secreting tumors. Of the 242 patients, 75% had cavernous sinus invasion and 10% had suprasellar extension at radiosurgery. The median radiosurgical marginal dose was 25 Gy to the 50% isodose line between each group. After multivariable adjustment, the factors associated with an increased time to endocrine remission included patient age (hazard ratio [HR] 1.016; P = .023), cavernous sinus invasion (HR 1.793; P = .004), and the presence of acromegaly (HR 2.912; P < .001). The incidence of new hypopituitarism developing after stereotactic radiosurgery was 29% and did not appreciably differ by adenoma subtype (P = .180). CONCLUSIONS: After radiosurgery, patients with ACTH-secreting tumors achieved endocrine remission sooner than did those with GH-secreting tumors. These results provide insight into the relative tumor biology and disease course after radiosurgery that will serve to further improve clinical outcomes and patient treatment in the future.

Radiotherapy and radiosurgery for Cushing's disease.

Patients with residual or recurrent Cushing's disease receive external beam radiotherapy (RT) with the aim of achieving long-term tumour control and normalization of elevated hormone levels. Treatment is given either as conventional radiotherapy using conformal techniques or as stereotactic radiotherapy, which is either used as fractionated treatment (SCRT) or as single fraction radiosurgery (SRS). We describe the technical aspects of treatment and report a systematic review of the published literature on the efficacy and toxicity of conventional RT, SCRT and SRS. There are no studies directly comparing the different radiation techniques and the reported results are inevitably of selected patients by investigators with interest in the treatment tested. Nevertheless the review of the published literature suggests better hormone and tumour control rates after fractionated irradiation compared to single fraction radiosurgery. Hypopituitarism represents the most commonly reported late complication of radiotherapy seen after all treatments. Although the incidence of other late effects is low, the risk of radiation injury to normal neural structures is higher with single fraction compared to fractionated treatment. Stereotactic techniques offer more localized irradiation compared with conventional radiotherapy, however longer follow-up is necessary to confirm the potential reduction of long-term radiation toxicity of fractionated SCRT compared to conventional RT. On the basis of the available literature, fractionated conventional and stereotactic radiotherapy offer effective treatment for Cushing's disease not controlled with surgery alone. The lower efficacy and higher toxicity of single fraction treatment suggest that SRS is not the appropriate therapy for the majority of patients with Cushing's disease.

Temozolomide treatment can improve overall survival in aggressive pituitary tumors and pituitary carcinomas.

OBJECTIVES: Only few retrospective studies have reported an efficacy rate of temozolomide (TMZ) in pituitary tumors (PT), all around 50%. However, the long-term survival of treated patients is rarely evaluated. We therefore aimed to describe the use of TMZ on PT in clinical practice and evaluate the long-term survival. DESIGN: Multicenter retrospective study by members of the French Society of Endocrinology. METHODS: Forty-three patients (14 women) treated with TMZ between 2006 and 2016 were included. Most tumors were corticotroph (n = 23) or lactotroph (n = 13), and 14 were carcinomas. Clinical/pathological characteristics of PT, as well as data from treatment evaluation and from the last follow-up were recorded. A partial response was considered as a decrease in the maximal tumor diameter by more than 30% and/or in the hormonal rate by more than 50% at the end of treatment. RESULTS: The median treatment duration was 6.5 cycles (range 2-24), using a standard regimen for most and combined radiotherapy for six. Twenty-two patients (51.2%) were considered as responders. Silent tumor at diagnosis was associated with a poor response. The median follow-up after the end of treatment was 16 months (0-72). Overall survival was significantly higher among responders (P = 0.002); however, ten patients relapsed 5 months (0-57) after the end of TMZ treatment, five in whom TMZ was reinitiated without success. DISCUSSION: Patients in our series showed a 51.2% response rate to TMZ, with an improved survival among responders despite frequent relapses. Our study highlights the high variability and lack of standardization of treatment protocols.

Long-term Outcome After Fractionated Radiotherapy for Pituitary Adenoma: The Curse of the Secretory Tumor.

OBJECTIVES: To determine the influence of secretory status on long-term outcome after fractionated radiotherapy (RT) for gross residual pituitary adenoma. MATERIALS AND METHODS: This is a retrospective study of 116 consecutively treated patients who met the following inclusion criteria: tissue diagnosis of pituitary adenoma, visible tumor at the time of RT, treatment with fractionated RT, and imaging follow-up of ≥2 years. Hypersecretion of growth hormone, adrenocorticotrophic hormone, prolactin, or thyroid-stimulating hormone was documented in 30 patients (26%). The RT dose in most (78%) patients was 45 Gy at 1.8 Gy per fraction. The major outcome endpoint is clinical and biochemical control, meaning no growth on follow-up scans and normalization of hypersecretion, if present before RT. RESULTS: Long-term tumor control was outstanding for nonsecretory tumors: 96% at 10 years. There was a major drop in the control rate of secretory tumors: 10-year clinical and biochemical control was 62% (P<0.0001 vs. 96%). Multivariate analysis confirmed secretory status as the only independent prognostic factor (variables analyzed were sex, age, tumor size, RT dose, and secretory status). CONCLUSIONS: Secretory pituitary adenomas have a worse prognosis than nonsecretory tumors after 45 to 50 Gy of conventionally fractionated RT. As a result of this finding, our plan is to increase the intensity of RT in secretory tumors, but our data did not evaluate this approach. The treatment guidelines that we currently use in pituitary adenoma are as follows. Radiosurgery (20 to 30 Gy) is our first-choice treatment of a secretory tumor that cannot be completely resected. When treating gross residual pituitary adenoma with fractionated RT, we use the following dose schedules: Nonsecretory: 45 Gy at 1.8 Gy/fraction, once-daily fractionation. Secretory: 54 Gy at 1.8 Gy/fraction once daily or 55.2 Gy at 1.2 Gy/fraction with twice-daily treatment.

An ACTH-secreting pituitary adenoma within the sphenoid sinus.

A 68-year-old woman developed Cushingoid features three months prior to admission. She was found to have a markedly elevated plasma ACTH-cortisol level. Magnetic resonance imaging (MRI) revealed a mass in the left sphenoidal sinus, which had become enlarged to a point where it could not be removed by transsphenoidal surgery. We decided to proceed with radiation therapy to shrink the tumor. However, it was ineffective. Despite a reduction in serum cortisol levels using metyrapone, she died of septic shock. We describe a rare case of an ACTH-secreting pituitary adenoma within the sphenoid sinus.

Radiation therapy and stereotactic radiosurgery for the treatment of Cushing's disease: an evidence-based review.

PURPOSE OF REVIEW: The indications, efficacy, and safety of radiation therapy and stereotactic radiosurgery for Cushing's disease are evaluated.We queried PubMed using the terms, 'Cushing's disease', 'radiotherapy', and 'radiosurgery', then evaluated each study for the number of patients, method of radiation delivery, type of radiation therapy or radiosurgical device used, treatment parameters (e.g. maximal dose, tumor margin dose), length of follow-up, tumor-control rate, complications, rate of hormone normalization, newly onset loss of pituitary function, and method used to assess endocrine remission. RECENT FINDINGS: A total of 39 peer-reviewed studies with 731 patients were included. The reported rates of tumor-volume control following radiotherapy and radiosurgery vary considerably from 66-100%. Additionally, the reported rates of endocrine remission vary substantially from 17-100%. The incidence of serious complications following radiosurgery is quite low. Although post-treatment hypopituitarism and disease recurrence were uncommon, they did occur, and this underscores the necessity for long-term follow-up in these patients. SUMMARY: Radiosurgery and, in the modern era, less commonly, radiation therapy, offer both well tolerated and reasonably effective treatment for recurrent or residual Cushing's adenomas.

Long-term follow-up results of postoperative radiation therapy for Cushing's disease.

OBJECTIVES: Radiotherapy is currently used in patients with residual or recurrent pituitary adenomas after surgery. However, there is little information of long-term outcome of patients with Cushing's disease following radiotherapy. We assessed the long-term efficacy and toxicity of conventional radiotherapy in the control of Cushing's disease after unsuccessful transsphenoidal surgery. PATIENTS AND METHODS: Forty patients with Cushing's disease were treated with conventional external beam radiotherapy at our Institution between 1988 and 2002. The median age was 38. All patients received radiotherapy following unsuccessful surgery or at tumour recurrence to a dose of 45-50 Gy in 25-28 fractions. The persistence of active disease after surgery was diagnosed by the increased high plasma cortisol levels, high 24 h urinary cortisol levels and absence of cortisol suppression after administration of dexamethasone. RESULTS: The 5 and 10 year local tumour control was 93% and the 5 and 10 year survival was 97 and 95%. Normalization of plasma cortisol was seen in 28% of patients at 1 year, 73% at 3 years, 78% at 5 years and 84% at 10 years. The average timing to remission was 24 months. The most common side effect was hypopituitarism that increased progressively during the follow-up, being present in 62% and in 76% of patients at 5 and 10 years after RT. There were no other serious complications as radiation induced optic neuropathy or second tumours. CONCLUSION: Radiotherapy is effective in the long-term tumour- and hormone hypersecretion control of ACTH-secreting pituitary adenomas, however with a high prevalence of hypopituitarism. At the moment, it remains an important treatment option after failure of surgery.

Radiotherapy and radiosurgery for Cushing's disease

Patients with residual or recurrent Cushing's disease receive external beam radiotherapy (RT) with the aim of achieving long-term tumour control and normalization of elevated hormone levels. Treatment is given either as conventional radiotherapy using conformal techniques or as stereotactic radiotherapy, which is either used as fractionated treatment (SCRT) or as single fraction radiosurgery (SRS). We describe the technical aspects of treatment and report a systematic review of the published literature on the efficacy and toxicity of conventional RT, SCRT and SRS. There are no studies directly comparing the different radiation techniques and the reported results are inevitably of selected patients by investigators with interest in the treatment tested. Nevertheless the review of the published literature suggests better hormone and tumour control rates after fractionated irradiation compared to single fraction radiosurgery. Hypopituitarism represents the most commonly reported late complication of radiotherapy seen after all treatments. Although the incidence of other late effects is low, the risk of radiation injury to normal neural structures is higher with single fraction compared to fractionated treatment. Stereotactic techniques offer more localized irradiation compared with conventional radiotherapy, however longer follow-up is necessary to confirm the potential reduction of long-term radiation toxicity of fractionated SCRT compared to conventional RT. On the basis of the available literature, fractionated conventional and stereotactic radiotherapy offer effective treatment for Cushing's disease not controlled with surgery alone. The lower efficacy and higher toxicity of single fraction treatment suggest that SRS is not the appropriate therapy for the majority of patients with Cushing's disease.

Pacientes com doença de Cushing residual ou recorrente recebem radioterapia externa em feixe (RT) com o objetivo de alcançar um controle tumoral prolongado e a normalização dos níveis hormonais elevados. O tratamento é realizado tanto com RT convencional, usando técnicas conformacionais, ou com RT estereotáxica, que é usada tanto como tratamento fracionado (RTF) ou como radiocirurgia em procedimento único (RCU). Descreveremos os aspectos técnicos do tratamento e mostraremos uma revisão sistemática da literatura sobre a eficácia e toxicidade da RT convencional, da RTF e da RCU. Não existem estudos comparando diretamente as diferentes técnicas de radiação, e os resultados reportados são inevitavelmente os de pacientes selecionados pelos investigadores com interesse no tratamento testado. De qualquer maneira, a revisão dos dados publicados sugere que há melhores taxas de controle hormonal e tumoral após RTF em comparação com RCU. O hipopituitarismo representa a complicação tardia mais comumente relatada da RT, vista após todos os tipos de tratamento. Embora a incidência de outros efeitos tardios seja baixa, o risco de a radiação comprometer estruturas neurais normais é mais elevado com RCU do que com RTF. Técnicas estereotáxicas oferecem irradiação mais localizada se comparadas com a RT convencional, embora um acompanhamento prolongado seja necessário para confirmar a possível redução da toxicidade continuada da radiação na RTF em comparação com a RT convencional. Com base na literatura disponível, a RT fracionada convencional e a estereotáxica oferecem tratamento efetivo para a doença de Cushing não controlada isoladamente pela cirurgia. A baixa eficácia e alta toxicidade do tratamento em dose única sugere que a RCU não seja a terapia mais apropriada para a maioria dos pacientes com doença de Cushing.